Mast Issues & Renovation

[ebb]

Alodine (chromic acid, a carcinogen) is the 'bad sister' conversion coating. It is the wash treatment of choice. Some details in the posts above here.
All the reading I've done shows everybody uses it in conjunction with the phosphoric acid etch.
We may be having a problem here with the word PRIMER.

The two WASH & RINSE treatments are not primers in the sense of a coating - altho the chromate wash leaves a film behind. That film is supposedly THE corrosion protector. But its main claim is that it bonds to aluminum and paints bond to it. And bonding is corrosion protection.
It so far looks like epoxy paint primers with chromate used over the corrosion treatment are extra insurance in the eyes of the guy who's using it. There might be no need for them.
Can a chromated epoxy primer be used as a corrosion blocker on acid washed (Alumiprep 33) aluminum? Without using the 'traditional' conversion (Alodine) coat? www.aircraftfinishing.com Stewart makes only waterborne primers and paint. They have a one part non-catalysed non chromated epoxy primer that one guy anyway on vansairforce.net forums says can do just that. Go on bare scuffed aluminum............ayeduno.

If we sand with nothing coarser than 80grit on the mast, and nothing coarser than 180grit for any subsequent sanding before the first chromate conversion coat, it has been said we are more likely to make a technical transition from prep to coating stage. Coarser grit sanding "imbeds impurities" that will come back later to screw up paint integrity. Sanding a more uniform surface without deep scratches allows the film more uniform coating.
The insurance of including chromated epoxy primers is for some painters unavoidable because of aggresive or not sure sanding prep. Or on the mast I'm in charge of, a surface of 1000s of unknown tips and crannies.

A 45 year old mast has porosity issues that thin guage furniture or hotrod aluminum sheet (that is going to be painted) doesn't have.
litlgull's mast has countless visible scars with corrosion in them. Time,neglect, and sodium chloride have left an aluminumscape of unseen pin holes and mini fissures everywhere on its surface. Can't sand away old age.

Ben, I cannot find provenace for not including the Alodine film treatment. I don't want to use it.
The first epoxy primer always seems to be a corrosion blocker.
To be a useful as a corrosion proof coating, the epoxy primer has to be water thin so that it migrates/penetrates into the smallest imperfections on the mast surface.

SherwinWilliams supplies paint to the USNavy. They also have a specific epoxy chromated primer that is meant to go over a chromated conversion film. BUT

On the SW website we can find out what was used to renovate the USS Yorktown, now a "coastal Landmark". SW's schedule for renovating the coatings on the WWII aircraft carrier consisted removing most of the old and then a prime coat of organic zinc at 3.5 to 5 mils. An intermediate coat of Macropoxy 646 at 5 to 10 mils. A topcfoat of High Solids Polyurethane at 3 to 4 mils. They used "automotive-type body filler" (bondo) and caulk where ever there were rust streaks! Intended life of 'system' is 20 to 25 years. Painting a gigantic tourist/historical attraction isn't like mast preservation for sure. But no conversion coatings were used!!
The normal "coatings specs for an aircraft carrier really is as thick as a phone book."
The system was designed to coat rusty steel, galvanized iron and aluminum.

There is available from AirCraftSpruce a plain zinc primer. Don't know about "organic."

Glisando Triton 381. TimLackey used Alumiprep 33 and Alodine 1201.
He left the mast's top and bottom cast aluminum fittings in place.
And also did not remove the sail track.
He went Awlgrip and used the 30-Y-94 "yellow anti-corrosive primer" on top of the conversion film. It is a two-part strontium chromated epoxy in a soup of solvents. Awlgrip LPU requires an epoxy base.
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Simple Green scrubbing of litlgull's mast revealed

crevis corrosion in every (104) mast-track screw holes. Seriously, almost every hole has starlike crevises emanating from the hole. Every screw that came out did so with a little bit of white powder.
In the dozen or so holes below the track in the flat where a short piece of aluminum track was attached with fine thread s.s. screws there was nearly no corrosion or white. DFO's did some mangling here that caused corrosion.

My advice is to bite the bullet and remove EVERYTHING from your mast when renovating. Even if you are not going to paint it!
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I thought SimpleGreen was an environmental product.
Seems many people do. On my now almost empty qt spray bottle it says, "non-toxic and biodegradable."
When trying to find the msds the maker won't reveal ingredients in the formula 'to protect it from piracy'.
The Environmental Working Group, a consumer watchdog takes exception to that. It evidently didn't take industrial espionage for EWG to get an analysis of the cleaner that found 2-butoxyethenol, a carcinogen,
and 66 OTHER CHEMICALS IN SIMPLEGREEN including formaldehyde. Listed on their website.
What's in your detergent?

[Ariel 109]

No matter what every finisher has to deal with them porosity issues. You might look into learning about flowable glazing putty to fill up some of your deep pits.

http://3mcollision.com/3m-flowable-f...aze-05824.html

Don't discount hot rod painters Ebb! They are the serous metal finishing talent. I've not met many who paint boats for a living with much passion for their work.

[ebb]

Hey Ben, don't take any of this as disrespectful.
My desk is stacked with downloads, Vansairforce.net forums most prevalent.
I make copies so I can sit on the couch and take notes, rather than at the monitor.
Latest one here is a three pager on what the guys think of PreKote.
Guys building airplanes and hotrodders like the rest of us are interested in less toxic materials - therefore PreKote as an alternative to Alodine.
From his description of its application to his RV7 one guy makes it sound like a description of an application of Alumiprep. But for me peeking in, it's all guys who know what they are talking about talking with each other. I'm really unable to extract info that really works for my general yet very specific interest. There's never a single track to a reasoned conclusion. PreKote seems to be softer and more difficult to apply.

An RV7 isn't a Winnebago.

But here's one for you, Ben, quote:
(dated 9-15-2010) from dedgemon, (titled) scuff, clean, epoxy
" I've painted two RV's now and have talked to countless other builders about this. The traditional method of etch, alodine, prime does work, but it is NOT necessary. Modern automotive (such as PPG DP) epoxy primers are designed for adhesion on scuffed aluminum.
I've been happy with the following. Use soapy water and scuff with a gray (or red) scotchbrite pad to a totally satin finish. Then clean and DRY thoroughly with compressed air. I use rubbing alcohol and lots of paper towels to produce a totally clean surface. Then shoot the epoxy and whatever topcoats you want.
Another friend of mine did this exact thing on his '6 about 12 years ago. Still looks great with no adhesion issues. "

Well OK, mon, no toxics at all, except for the epoxies and the urethane.

Then the next guy comes along and says:
"....try baby bath - no salt, no wax. Then, when dry, or if you don't need to wash - scuff the whole surface with red Scotchbrite - please get the real stuff, not the cheapo brand. 3M products just do it correctly. Then go over the whole aeroplane with Alumiprep from Spruce - a mild acid brightner - you really see the surface clean up.
Swill off with water, let dry in the sun, then spray on 2 part etch prime, build prime and sand, shoot colour, stand back, admire!"

This is followed by a newbie (R4LIFER) about to build a '4 uncertain from reading the posts whether he should prime at all. And how much weight all the primer and paints will add to his airplane....
"please be as complete with your answers as you have time for. THANKS!!!"

And that is the problem - because we are faced with unsubstantiated opinions and no continuity.
The PreKote thread just peters away into other subjects, and very little is revealed. If something peaks your interest it usually is one man's opinion, who writes with a little more authority than usual.
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Ben, thanks for the blueline, haven't seen that product before.
It is a polyester based 2-part fairing compound. Assume it is a squeezable 'traditional' bondo, which is a neat idea. I don't think of polyesters as glue.
This 'glazing compound' would have to go on scuffed/sanded bare metal which might be OK, but my own limited/peculiar/misinformed experience tells me not to use it like that. This whole wash&chromate business is to get aluminum to accept foreign stuff - which it really doesn't want!

In the old mast's case using the polyester material on bare sanded/etched I'd describe as "imbedding" the surface of the aluminum. But will the compound bond to it?
If the glazing is used on treated aluminum (acid etched and conversion coated) I'd guess there would be even less tooth for the polyester to stick to altho Alodine's other job is as a next coat adhesion enhancer. So maybe that would be the time to use this glazing compound.
But if applied after etching before alodine, I would be uncertain about the alodine treatment which 'traditionally' is applied to bare aluminum.
A series of unknowns, not good for the immune system or stress level. Is there any literature that specifically addresses the Alodine issue?
Or is all info anecdotal: 'my friend painted his RV'007 with only epoxy 12 years ago and it looks just fine today.'

The next usual layering on of materials would mean I could go smooth after the first thin epoxy primer, WHATEVER THAT EPOXY COATING IS I HAVEN'T A CLUE YET? Concensus has the first primer as a strontium chromated epoxy. But there is obviously movement afoot to remove chromates from the process.
But I don't think it can be just ignored. YET.

I'd go next with my familiar SherwinWilliams ProLine sandable epoxy primer that I've used all over the boat inside and out.
- then next on to the fairing/smoothing of the whole spar.
In the past I've made a kind of alternate slurry fairing compound by mixing West System 407 dust into the ProLine primer and using that for fairing. (But a normal batch of 407 mixed with top-of-the-line (TAP) laminating epoxy would be just as good because its consistancy can also be thin or thick as you like it.) Worked for me and the paint still set up like epoxy. Was even more sandable.
Then a final ProLineprimer coat. Then topcoat.
Cheeeeze! sounds..... heavy!!!
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It is my unscientific opinion that any epoxy PRIMER ( solvent or waterborne / poisoned ones like chromated primers) can be overcoated with any type of enamel topcoat, solvent or waterborne, epoxy or urethane.

[ebb]

UPDATE
Convinced self that the age & deteriorated condition of the Ariel mast required Alumiprep33 and Alodine1201.
There is anecdotal history of these two nasta sista's being used to reclaim metal spars - so at least experiences can be compared.
CommanderPete did his own mast and had some disappointment.......not sure how it chemically resolved.
Set in 95degree California mid-July afternoon shade. About 60/70 relative humidity
- at the end of the day

Alodine1201 produced NO GOLD SHEEN.

WHY?
Track holes, major repairs worked & filled, scars & depressions filled with aluminumpaste.
Orbital sanding overall with new Bosch resin-bonded 120 aluminum oxide disks - significant visible scratches with significant black pock spots remaining - surface feels completely smooth. Vibrating caused only two of the 100 old, but recently LabMetal filled, track holes to fall out!
BIG hole repairs holding steady.

Began ballet with eco dish dertergent, warm water and determined scrubbing with new maroon Scotchbrite. Hose rinse. Sanding scratches reduced.
Water used is UV treated well water without flouride added. Minerals and dead bacteria included. Not deionized as some purists insist!

1-to-2 dilution of acid etch (suggested in Process Bulletin for significant corrosion) applied with macaroon pads and scrubbed in three sections - making sure no drying occured. Immediate lightening action on metal with first application. Difficulty blending surface with subsequent dousing and abrading with pad. Process Bulletin says start at bottom work up. No bottom on horizontal mast! Visible streaking.
Pail water significantly blackened with process scouring. Half way along mixed up a second batch. Ultimately used most of the Alumiprep quart.
Thoro rinse. BUT did not scotchbrite the rinse as I should have. 100 readings of instructions made no mention, if I wanted an excuse!
Water breakfree observed. Damned if I didn't check the pH of the rinse runoff (as suggested on a vansairforce forum). But the ole spar never went dry!

One more overall hose rinse. Technical Process Bulletins for Alodine1201 & Alumiprep33 do not specifically say that after the final rinse the aluminum should be dry or wet. When used as dipping sauce Alodine is diluted with water. Wasn't concerned whether the spar was damp or hardly drip dry when I began. Full strength Alodine with a new 2 dollar 4" bristle brush.
[If Alodine has a shelf-life, I had it for a year unopened in it's original plastic shipping wrap.*]
The stuff went on nicely yellow with an immediate visual surface reaction that the second app in the same place could not amalgamate, the initial reaction photographed permanently. Extra Alodine was brushed on to keep the work from drying. After 3 or 4 minutes undisturbed each section was rinsed. Both chemicals have a max wet dwell time of 5 minutes, then must be rinsed.
A final hosing washed OFF 99 and 44/100% of the gold color. GONE. SAYONARA.

If the process was diligent, why didn't the blonde show up? I mean I really worked for this date.
On one vansairforce.net forum at 6061-T6 SaltSpray Failures, Alodine 600 (I know this is not specific, but methodology is revealing) - the poster's frustration was that his pro shop was using technically perfect processing - and getting failures with no trace as to 'why?'
One suggestion was that the first removal of oxide (mine was pretty vigorous!) was "too deep"
into the base metal. But the poster had no explanation of why that was a why!

Too clean? If we keep to the 5 minute drill, imco A338's mast cannot be too clean. It can, perhaps, be 45yrs too old, have too many pits and crannies,
too much embedded sodium chloride crystal, too many years of ingrained polutants. Vansairforce guys use brand new panels.
Awlgrip prep instructions for Alodine 1201 cautions against drying and continues:
"repeat procedure until proper color and breakfree rinse is obtained." [Have to remember we're brushing this stuff on already break free prep.]
Now that the conversion coat is there and now dry, there definitely is something there that seems smooth and glossy.
I won't add any more poison. And after drying, another coat means sanding prep befor rechromate. Too old for this prep-de-prep BS.

Hope ALUTHANE comes up to its hype! Gonna roll the mast tonight as soon as it drops below 100.
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*WHAT REALLY HAPPENED?
Checked in with many sites looking for an answer. An exchange on vansairforce confirmed and convinces me that while Alumiprep will work
no matter how long you've kept it around, Alodine has a definite shelf life of '720' days from the factory. My quart may have been old when I got it! Exposure to sun and heat alters it. My deadly was kept in a dark cupboard. If it's that sensative it should be sold in a dark container.
Still, there is on my part an OBSERVED reaction on the Alumiprep etched metal when the Alodine is first brushed on. OK, there WAS A REACTION - a conversion - an absolution - of some indetermined sort & consequence - I'll always wonder where the yellow went.
It is a GOOD sign that litlgull didn't fully accept that crap in her wings......I'm relieved for litlgull
.....but disgusted with my choice to go with that really twisted sister, Alodine.

What remains in the bottle, even toothless as a washed-up crack victim, we can assume is just as lethal as it ever was. Applied half the bottle. Will dilute remains and evaporate in a pan. When there's a concrete job on my job site here, what's left goes into the mix.
[but......but ebb, what..... what happened to the..... rinse water.....?]

[ebb]

If the refurbishment process is important to us, we might have chewed over whether it was a good idea to ignore the apparent conversion failure - or go back and reapply fresh Alodine. Have gone ahead & rolled 4 coats, so far, of Aluthane, as the final finish for the mast. Let me introduce you...
QUART CAN sat for at least a year undisturbed. Upon opening, the aluminum powder/flakes mixed in immediately. How many times has a pigmented paint been packed with solids that never get fully mixed into the liquid? No problem, no turdums on the stir-stick or in the corners of the can!

MSDS tells us Aluthane comp is 20-25% aluminum. 2-3% Xylene. 25-30% aromatic petroleum distillate (naptha). 50-55% polyisocyanate based on MDI (MDI = diphenylMethane DIsocyanate)
MDI is the code to look for to ID the best (a matter of opinion) in hi-end complex chem ambient Moisture Cure Urethanes. You've used it for bowling alleys, gym floors, and applied it to wood floors in your house with a sheep's wool applicator. It's clear, quick drying, UV + chemical + impact + abrasion + salt + gasoline resistant. It's applied independant of weather, temperature. humidity, dew point. It's elastic, quick drying, and cross links with atmospheric moisture. Water resistant but not immersion proof. Don't believe this aluminum filled urethane (or any other urethane imco) can be used as an underwater barrier coat. Xylene, Xylol is the solvent. It eats my orange 'first responder' nitryl gloves.

Aluthane goes on very very thin. 4 coats so far and at any edge it's as sharp as it began. On the smooth mast it's a flat light aluminum gray. I've been sanding between coats: beginning with 180, now 220 using an Hitatchi quarter sander. More than a single pass with the sander removes what you just rolled on. Have gone thru to bare metal in some places trying to smooth first coat mistakes.

All the anti-corrosion protection eggs are in one basket. Everything depends on this MDI MCU(moisture cure urethane) coating to bond to the mast better than epoxy primer. Failed witch's brew could invite a later big adhesion problem...but... conversion film specifically makes it possible for epoxy chromate & sanding primers to stick to aluminum for expensive LPU spray jobs..... so maybe halfast conversion film won't get in the way of super bond aluminum-urethane! A more integrative coating shouldn't create the absolute corrosive anode/cathode horror effect where epoxy-LPU gets breached on the mast. SOME vansairforcers go immediately to urethane after etch without using Alodine conversion. (Ben's posts above here.)

Aluthane, imco, being an aluminum filled coating, ought to be more tolerated by the ancient mast than talc/titanium-dioxide filled epoxy primers. Repairs to dings and scratches won't need the toxic two-sista extra step REPREP that is required to renew the LPU bond. In other words you have to reapply the conversion coat to repaint LPU on a scratch. Hey! Gotcha!
Henkel has a very expensive ding fixer 'pen' (probably with an abrupt shelf-life due to Alodine) that imco isn't realistic. In fact: stupid!

Aromatic solvents in Aluthane are carcinogenic equal oportunists like the hexavalent chromates in Alodine - there's nothing less toxic by keeping Aluthane on hand. As a coating, however, it has a 1000 uses aboard a boat. The half-sized paint-tray happens to be embossed with a tri-arrow recycled PETE....Polyethylene. Authane BONDED to the plastic!... since it also bonds to itself, the tray will become an old buddy!

Started first coat only with a standard short nap 4" roller, tipping with a foam brush. Awkward on convex mast. Left mini ridges when set. The paint being so thin means that mini ridges are really significant. Light sanding (altho I believe scouring/toothing is unnecessary when recoating Aluthane) goes toward getting an absolutely smooth final finish. The way we do varnish. This stuff goes on dense, but thinner than varnish. Thinking about clear satin coat finish (System3 WRLPU?) Aluthane can also be used as a primer for epoxies, enamels, LPU, even latex! [So says the literature - but being a urethane I would test first.]
In 100 degrees it set up too quick - shudda thinned it with a tot of xylene, even tho they say you don't have to. Found a 100% better applicator in a Whizz 4" 'premium foam' wire roller #54060 (made in Germany) $2-$2.50 per. NO RIDGES, NO PIECES PULLING OFF, NO LAPS.... S m o o o t h e.

Another attribute imco is that when rolling the spar Aluthane does not flow into the screw and bolt holes. Stays where it is rolled.

Here's another plus imco that really shows Aluthane's versatility.
By mixing (WestSystem) 407 into the coating you've got yourself a right-now filler for those holes that fell out out when you began sanding. Also those fills you thought were smooth but after coating show up like small pox craters.
407 is a propriatary composition of red phenolic micro-spheres, expanded mineral perlite, vaporized quartz sand (Cabosil). Readily availble ingredients - but aye haven't come up with a suitable mix of my own. In this case makes a silver colored hard tack that, if you've chamfered the hole, seems to stick pretty good. Maybe better than LabMetal. Using the coating also for impromptu paste repairs, rather than going with another system (epoxy) makes it a snap and imco adds bonding insurance. You might lightly wet the inside edges of the hole befor knifing in the filler.
A reasonably thick test wad of mix sets up just like 407 does in 2part epoxy paint - and of course 407 in 2part laminating epoxy. A nice surprise!
407 mixes easy to whatever paste consistency you're familiar with. Thinner mix is better for sticking. The mix holds shape when loose. 407 is very thirsty stuff. Use 1/4oz & 1/2oz amounts of Aluthane when mixing paste for touch-up - sets quick.
When sanding the naked mast, remember the sail track flat is slightly CONCAVE. Whoops! You risked removing whatever protection you had on those edges when you block sanded. A piece of 220 held around a short piece of pvc tube gives control when sanding that flat - IT'S NOT FLAT.
Those corners on the flat get hidden under the sailtrack - so you won't get to touch them up after the track is back on.

Mixing 407 filler into Aluthane is a cute trick that makes using this stuff even cuter. ALL experimental. Results unknown. Aluthane is a real treat.
emailed Paul Oman (with the paste feedback) at www.epoxyproducts.com* - who sells quarts of Aluthane for $32+UPS. Haven't finished the can yet. Probably 6 to 10 coatings with the Whizz roller? (but I began trying it out on other stuff!)
[*This site is difficult for most to navigate. When you get there, you're faced with an egg crate page. 'Marine Navigation Bar', go >right to:
and cursor 'Marine Online Catalog', scroll to Section One, scroll to Important Links, find ALUTHANE (in blue).
You can also get in thru google. But then what?...you just might find Hansel & Gretel still wandering around in there! good luck.]
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Have continued to seven coats with light 220 sanding between (single sheet in quarters for the whole mast). No appreciable buildup of coating, but each successive coat evens the surface making the mast look newer and newer, if that's the word.
Aluthane paint itself has been problematic to use. Been squirting inert gas (argon/CO2) into used can befor closing - with mixed success. It may be that the pressurized gas just gets blown right back out. But skin forms by next day & breaks like thin ice into bits if you try to lift it out, contaminating the remaing paint, so it has to be strained. And this has to be done quick like a fox.
Strain into new empty qt cans thru FINE MESH cones. Been using those fit-all yellow plastic pour spouts in an attempt to keep the Aluthane OUT OF THE MOAT that the lid seals into. The lid will SEAL & BOND making it nearly impossible to reopen the can - I've @%&*^%#$#@!!! done it, and used offset pliers completely destroying the top of the can. Empty or almost empty used cans can be reused because remaining Aluthane sets up hard.
Complicates the kit - and the cleanup ritual. The only solvent that will cut thru half set Aluthane is xylene, which destroys ALL disposable gloves. Double up on nitryl and try not to soak them. Get them off your hands immediately. ALL DISPOSABLE GLOVES ARE PERMEABLE.
Get Aluthane off your skin IMMEDIATELY or you'll be decorated for the next three weeks.
Ordered 'disposable' 5-layer laminated gloves - yet to arrive. $30 butyl (least permeable synthetic rubber) gloves get the fingers sticking together by the solvent, so you know something is not right there either!

[ebb]

ALL DISPOSABLE GLOVES ARE PERMEABLE.
It is a game to ID a single all-purpose glove we could count on to guard hands from the whole gaggle of boat yard liquids & solvents.
Ketones degrade nitrile, pvc, viton.
Alcohols degrade pva (pva is also degraded by water ! ! )
Aromatic solvents degrade neoprene, pvc, latex and butyl.

So what to grab? There are a couple brands of chemical resistant 'disposable' gloves that say they can be used with all the usual hazardous suspects. 280 hazardous chems (list exists.)
BUT take this as opinion only - you should do your own research check - can't vouch for what the corporate world foists on us po' sailors.


North 4H SilverShield - quite thin at 2.7mil. 5-layer PE/EVAL/PE (polyethylene and ethylene vinyl alcohol) laminated FILM. Gloves are not dip molded over a three dimensional form but cut flat from sheet with an identical second piece edge bonded on top. Probably stampt out using a hot metal wire shape pressed thru two sheets of the 5 layer plastic laminate that also melt-bonds the hand shape together. Couldn't rate these sacks for dexterity. There are seams everywhere when on your hands. The thumbs don't really 'oppose the fingers'. These are finger bags.

Least pricey throw-away I've seen is from LSS - $51.10 bag of 10pr. Sizes up to 11.
Come in three lengths. Purely by chance got the 16" which gives the glove a decent cuff. 14.5" and 29" also available.
Mine came from Northern Safety & Industrial delivered for $66.28. Catalog price about $5.50pr.
McMasterCarr has them on pg 1770 - but only in sizes 7,8,9 - mil thickness 2.7 and similar lengths - so they probably are North Silver Shield.
You can buy a single pair for $6.60 or a 10pr bag for $6.14ea. Fastest delivery time on earth, and probably only vendor selling single pairs!
[MMC never mentions brand names - which allows them to provide generic and comparative descriptions of products without brand hype.]
These stamped out gloves are not handed, so you can replace a single glove.


Ansell is probably the best known glove maker. Their "280 chemical resistant" gloves are called
Ansell Barrier 2-100 - at 2.5mil, also 5 ply laminate of PE/PA/PE (polyethylene & polyamide) films - they are lined with Tyvek inside. Believe these are flat thumb but supposedly a 'second generation' Barrier version with opposed thumb is in the marketplace, which would make them easier to wear. Haven't found them. Don't have a spare sixty bucks to try them out just now.


Both these gloves are not built over a liner. They are thin films that probably could easily be punctured. Lit suggests an over glove or under glove be used.
Most of us won't be batheing in solvents, so a nitril or butyl glove could be pulled over the barrier glove to protect the expensive disposable for multiple use. But good luck holding on to anything. Immobilized hands get tired quickly.

Aromatic solvents (naptha, xylene) will also seriously degrade nitril if you soak the rubber, which will expand and fall apart. Desperation found that in a pinch nitril gloves can be doubled up (two ply!) and the outer glove sacrificed - if your exposure is short term, like maybe 2 minutes max.
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Coating mast with Aluthane:
Final wipedown prep immediately before each recoat, to remove dust*, is done with the coating's primary solvent on a soaked rag gripped in a SilverShield glove. Logic has it that any lurking solvent left on the last coating is recognized as family by the next coat being rolled on.
Logic also has it that this method is based on ignorant superstition & faith - because
De-dusting could just as thoroly be done with sponge & water & clean rags - smarter & safer in a number of ways. NEVER EVER use a tack rag.
(*Outdoor shade for mast work is provided by a couple poplar & liveoak trees, both of which drop, drip & ooze on hot days. Project manager assumes that xylene cuts and dissolves these natural resins better than the saner stuff.)

[ebb]

I'd like to have a photo here - because litlgull's mast is now coating complete.
8 coats of Aluthane and 7 of System3 WR-LPU clear satin.
The mast, waiting for its attachments, looks like a normal galvanized spar.... blank.... but it GLOWS!

For the record, as I sanded each coat of the aluminum filled (25%) one part moisture cure urethane, it's single mat shade of gray strangely changed into uneven darker grays with lighter gray continental google-earth formations. Like a bad job of sanding.
Using 220, there isn't a significant amount of material coming off, but because the coating is so extremely thin, it is too easy to sand too deep. Very mild toothing still produces a cosmetically nasty looking surface - which is OK as long as it's only a mode in 'perfect prep.'
This paint officially requires no toothing or scotchbrite scouring to recoat. After fiveorsix coats of perfect prep between each, the last three rolled one on top of another without sanding. You wouldn't know it.

SYSTEM 3 WR-LPU CLEAR SATIN is a ridiculous water reducible, almost zero viscosity, polyurethane... that ebb hopes will mate with a completely crazy and - until now - virtually unknown and non-yachtsie rusty piling & barge paint.
Tested using an Aluthane coated piece of aluminum tube with vertical paint tape separators - brushed some unthinned & uncrosslinked transparent coating onto three sections: 1. unprepared Aluthane, 2. (3M 7447 maroon very fine) Scotchbrite mesh scoured section , and a 220 grit sanded. The 220 with LPU still looked nasty and uply. The lightly scoured section had a slightly darker overall hue than the unprepared Aluthane BUT was even and UNBLOTCHED. Might have guessed that applying clear urethane on top of aluminum urethane would produce no changes in shade. LPU takes a couple weeks to completely cure, but it seemed bonded-as-one to each test strip and hard as nails the next day. Will it wrinkle, bubble, or squeek?

SO, a light tickling of the 8th metallic seal (which had cured on the mast a few days) with a new piece of maroon pad became the transitional prep. The aluminum coating out of the can isn't smooth like varnish when dry. There is a texture produced by the metal filler. A light going over made it slightly, shall we say, smoother. But aye knew it was going to be a number of LPU coats that would really get the mast looking visually and mechanically... smoother. That's what clear coat is all about.

WR-LPU
is not strictly a 2-part like they advertise. Part two is a crosslinker added at 8 drops to an ounce of first part. Ap guide suggests that normally it's added to the last couple coats of a session to leave a really hard abrasion resistant film. The drops aren't essential for part one to set.
Made up in turn three 4-ounce batches. This being the first time for quantities, it just worked out as an unintentional seven coats on the 30ft mast. Could have continued making batches! 17 total wet ounces with water thinner. No prep necessary between coats within the guide's 8hr window.

First batch, while there still was some cool cloud cover, 32 drops were added to 1oz of tap water, and then mixed in with the fab 4oz. Rolled on using the 4" Whizz premium foam roller with a half-sized plastic tray. Immediately tipped with a 2" foam Jen Polybrush. Second and third batches had 32 drops of linker added to 2oz of reducer, because the day heated up. The Whizz spreads evenly and leaves no ridges like a short-nap hard roller (that they recommend in their guide) on the curved surface of the spar. Spreads the coating beautifully, but wants tipping right now.
Open can is casually covered between stages, and the roller seranwrapped while breaking for lunch - one roller, one foam brush for the completed session. What's that?.... approx 38sqft of mast surface coated 7 times = 267sqft total. 12oz, of a 32oz $59QT. $3 in applicators.
Right!.... & my labor is cheap too!
Of course, with the coatings super-thinned, the resulting number of coats would be superthin also! Maybe that's OK on metal?

Has to be celebrated - this mild melon scented waterborne S3/WR-LPU is a delight to use. NO PETROLEUM SOLVENTS. What a relief! Worth every feeftynine dollar. Keep it off your skin, bonds to it very good.
[Silver Shield gloves - used with xylene to wash down the mast before Aluthane coatings - worth every $5.50pr, easy to slip on & off & use again.]

Tipping seemed easy, altho there was some tugging as the material immediately began setting. Armspan sections at a time - applied wet on dry and rolled into the previous wet edge. Second and third batches had two ounces each of water added as thinner. Those are 50% reductions! Twice the recomended 25% limit. Of course, coatings being super-thinned, rssulting total thickness super thin as well. LPU already is a thin paint.
Because the Whizz is so efficient spreading liquid evenly, application and tipping goes quickly. Had to: the coating is setting while tipping... it was bone dry at mast top - ready for the next coat - while still slopping it on wet at the heel. There seemed to be barely enough time for the application to flatten as it set up. Every batch was crosslinked so every coat is crosslinked.

Clear coating the lightly scrubbed aluminum paint in no way changed the gray color, first to last coat.
After seven coats of WR-LPU clear satin there is now a dolphin skin like glow to the stick. Every imperfection hoped to disappear is fully present. Yet the original filled & sanded ancient surface is under 15 coats of hi-tech can magic.

It's quite obvious both unrelated 'thanes like cooler surface and air temps to apply. [System3 formulated in Seattle. Aluthane in Alabama.]
Applied all LPU coats one right after the other at 70 to 85F (temp rising) - and 70 to 50 RH (humidity falling).
These numbers are within application guidelines - and the resulting roll and tip surface looks OK
- but imco the coating would have relaxed more AND the worker been more relaxed applying 25% thinned paint in cooler temp and higher humidity.
Time will tell. Next mast, I'll roll all those Aluthane coats one right on top the other NO prep, same as the System3.

But it's DONE. Looks seamless with no staggers, lap marks or ridges in coverage. Spar appears more sprayed than painted. But because it's aluminum colored you have to look twice to see that it is actually coated! If that's a grace.
A few runs. And all the prep booboos.... never went away. If not impeccable, it's righteous.
Hope this is useful!

Maybe post a pic.

[mbd]

Yes Ebb - please post some Little Gull pics! Some of us haven't gotten to see ANY in the last few YEARS! BTW, how is the interior coming along?

[ebb]

Thamks Mike, maybe something will happen on that front.
Commodore Bill has reminded me that it's time for a visit, have to see.

One last thing about mast coating and whether it's easy to create an environment for corrosion, finally steered away from introducing epoxy primers and fillers. The possibility that a little scratch in an LPU-coated mast could get infected and create all too common crevis corrosion that cancers the expensive coating and eats aluminum.... guess it got to me.
Introducing epoxy primers and hi-build, possibly porus, sanding primers between aluminum and hard water resistant paint is probably not smart.
Because scratches and dings do happen. And the miniature moisture activated anode/cathode effect - creating a positive/negative electric charge - enhanced by the micons of capillary electrolytic separation the epoxy layer likely produces....convinces me.
It is certainly not proved, that not fully water proof nor fully bonded paint layers are the flaw in LPU mast paint syatems.
However when the coating is breached - thru to the aluminum metal - it no longer protects against corrosion - in fact it generates & enhances the problem - makes it worse than imagined. That does seem to be the case.
[To aid remembering: Maximize the anode, minimize the cathode. Large area of cathode-to-anode accelerates corrosion - large area of anode-to-cathode can be acceptable. When you paint the mast and it gets scratched you have a small anode and a very large cathode. S.S. fasteners in AL are normally considered safe. AL rivets in S.S. is a no-no.]


litlgull's mast is sanded with aluminum oxide.
Repaired up top (fingers crossed) with aluminum Durafix.
Filled with aluminum LabMetal.
Coated with aluminum urethane, Aluthane.
That coating scrubbed a number of times with Scotchbrite aluminum oxide coated maroon mesh 3M7447.
The pads as well used through all stages of prep. Maroon has the finest grit.

Only after that all-aluminum jazz is a waterborne non aluminum LPU iced on top.

We'll see if we have 'battery effect' when an accident goes thru to the metal. Or a screw or fitting or bolt hole goes bad.
(Did have that maybe 'failed chromium coating' I choose to ignore - with maybe unknown consequences.)
Do believe Aluthane is a very superior bond coating - versatile - unique - bonds better than any epoxy. So what tests has this fool done!?
Literature says it can be used as a primer coat. Paint whatever your heart desires over this urethane bond coating.
Suspicion still is that the required epoxy core in the schedule for flawless awlgrip-type solvent LPU coatings
is the culprit in common aluminum crevis corrosion on boom & mast. imco
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EDIT. Mast has rested quietly for a week or so. Transit of light during the day shows the mast sometimes looking gorgeous, other times shows painting was done. More coats of Aluthane wouldn't have hurt.
More standard coats of S3WR-LPU would have been better too.
To ADD more LPU at this point, requires sanding. In this case, thinking of maintenance, and that time will wear LPU thin, and that breeching the aluminum paint with abrasive is a big problem , doubling the number of primary clear coats would have been really smart.


In the solvent world of marine LPU coating, best known is Awlgrip, which is a POLYESTER based LPU - considered the hardest and longest lasting cosmetic urethanes. Awlcraft might represent the ACRYLIC LPU paints - it's what the auto industry clear coats with. Two-parts require massive amounts of aromatic solvents in makeup and application. Auto industry is rapidity switching over to waterborne paints. Coatings are equally durable, safer and easy to apply. Solvent based LPU weakest link is adhesion over solvent based epoxy primers, done awl the time in the marine world. System3's epoxy primer is waterborne. Time for a real - intellegently designed - paint test. For an intro into two part thanes:
[www.epoxyproducts.com/lpu.html
google LPU Two Part Linear Aliphatic Poly Urethane - Polyurethane Paint
read Paul Oman's - one of my internet business heros - essay on the subject!]

System 3 Water Reducible LPU is a POLYESTER urethane. Don't believe anybody has tested these two chemistries - water vs petro - with other brands, of course, side by side for appearance, ease of DIY, and longevity in the 'extreme marine environment.' Would be interesting to a number of sailors, WOULD IT NOT??? (Sadly, can't see Practical Sailor having the moxie.)
Consider litlgull's mast a test - maybe blind, but a test.
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"Tradition is what you resort to when you haven't the time or money to do it right." Kurt Herbert Adler
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some pix of the mast on Ebb's Galley, pg21
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Later EDIT. Had total failure of System 3 WR-LPU. Removed all coats including Alothane. Will not use chromates or etch toxics to redo
mast. Using PREKOTE. As someone on Van'sAirForce pointed out when using chromates in your own backyard, your children, your pets
are going to get these poisons in their systems. You are going to track it into the house, into the shop. It's going to become part of your dust and you and yours are going to breath it. It'll get into your laundry. The wash water you used to process your mast is contaminating your ground water. Your well water. It's eventually going to end up in your community runoff and end up in the bay. Look up Prekote, good credentials, use it on your aluminum... 2016

[Lucky Dawg]

Anyone have a mast base that you'd recommend? I have cheek blocks a foot or so above my mast base that pinch my main and jib halyards awkwardly. I bought a couple deck organizers from Chance ("Cieli") a while back, and I want to run my lines through them from blocks and a mast base.

Found these, http://garhauermarine.com/catalog_process.cfm?cid=68 , but wondering if there is one out there that more closely mirrors the 6x3.5" dimensions of our mast.

[Tony G]

Man, Kyle, you have tight tolerances! The MS-3 seems to be pretty ok based on dimensions. And who doesn't like Garhauer's work?
I have read of individuals mounting eyes on their mast and boom enabling blocks to be mounted "precisely" where they need them. Is that an option for LD?

[Lucky Dawg]

Ha! That's pretty dang close! I guess I imagined a lovely tapered mast plate mimicking our mast base. Sometimes my brain complicates matters.

[ebb]

Don't know if you still have the aluminum mast base casting.....in your mast?

If you do, you will have to cut a 4"x1.0625" hole in the turning plate for the tongue

Original Ariel wooden mast plate is 8"D. The MS 2 (5 3/4"x 4 3/4") would fit

without having the corners overhang the circumference...but there is that huge

round hole in the garhauer base......

You need the long square tongue in the mortise to keep the mast from twisting.

[Lucky Dawg]

I am going to ask a possibly stupid question for someone with a couple decades of sailing (though not running rigging engineering, per se) experience: Are rope clutches meant to replace the cleat at the terminus of a halyard (or other line)? I mean, I understand this set up... till the end part... Halyard down the mast, through single block attached to mast plate, through deck organizer, through (optional) rope clutch, around winch.... and at this point the line would go around the cleat just forward of the bulkhead? Does a rope clutch dispense with that cleat attachment? If I understand correctly, it is one or the other. Seems like that would be the case... The patient amongst you, please clarify for me. (I did try a google search to get the answer, but not to my satisfaction.)

Follow up question: Is a rope clutch more prone to fouling (coiled little loops - "a--holes" - as I have been taught to call them) vs. just popping a line off a halyard cleat when dropping the main or jib? I suspect it would be no more likely than the same little loops fouling a single block at the mast plate...?

Thanks,
KW

[Bill]

Clutches do away with cleats. Provide easy release of loaded lines.