aluminum repair

[ebb]

Used Caswell's Lab Metal to fill corrosion in the window frames befor powder coating. It's an open the can and use it aluminum paste. When it's set up, you file it and it looks like bright aluminum.

Recently discovered aluminum repair brazing rod. Been around a long time.
There's a verbal hype war going on between an expensive second generation material called HTS-2000 and a number of 'first' gen rods made by Durafix, Alumaloy and some others.

The HTS-2000 folks are very precious about ordering their kit. I want to speak my bank numbers over a land phone - but they avoid that. Their stuff sounds great but cruising their site is a game.
I called Durafix and got a guy who said call later because he was on a cell phone. Cool! So, here we go!

I believe the cheapest trial 'kit' is a small number of alloy sticks and a s.s. brush. Videos show how it is used. Let's use the mast for example (which I haven't done yet!).

You clean the area around the gaping bolt hole you want to fill with the s.s. brush (the scratching acts like a flux!) It HAS to be with stainless steel. Then take your mapp torch and heat the area around the hole in circular motion. Then touch the rod to the work to see if it melts. Aluminum melts at 1200 degrees - the stick melts at 750 degrees.* You rub the stick around until it is melting real good....
THEN you draw the puddle over the hole with the stick!!! THAT"S MAGIC.
It does not fall or flow into the hole. And it's fixed better than a piece welded on. The surface tension of the alloy keeps that from happening. This is from the video. We'll see on our stick. But it looks like we'll be able to doll up the mast real nice for painting. There are youtube type video demos on both sites. Fun to see anyway.

The site also shows the Durafix being melted onto a flat surface, another piece of aluminum being set upright in the wet stuff - then after a certain time has past the harleydavison guy doing the demo takes a 5# hammer and beats the living hell out of the joint.
But hell don't come out.
The 1/4" plate is bent 90degrees horizontal but the joint is still born again 100%. That's amazing.
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* part of your investment will be (this taken from the FAQ page on the HTS-2000 aluminumrepair.com site) a yellow mappgas bottle and a recommended TS4000 Burnsamatic turbo tip. $40 Walmart, Lowes.
OK, good info, but it's still funky ole Durafix for me.
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Dim flickering lite...Something was bothering me AFTER I ordered the Durafix kit from the lady with a Jamaican accent who couldn't get the spelling of my name right.... Like a dozen times. Up in the corner of the download page with the prices and the phone number is a picture of the very turbo trigger-start "Bernzomatic TS4000" torch that I will now have to go to Depot from Hell to find. The cheapest Durafix kit goes for $45 delivered, but if I had included the 'torch combo' it would have been only $26 more. Loosing it..... That "torch combo" didn't register....:confused:

[ebb]

As usual, after the fact, I've delved a little deeper into these magical repair rods.

Most traditional metal workers won't trust them. (probably because rant amatuers can use them.)
Most forum posters who put them down do not do so with experiencial data.
Most forum posters are opinionated, disappointing and
even if what they were saying was true, how can you know if it is CREDIBLE?
It's a problem.

Evidently these rods have appeared at boat and trade shows - and guys who put them down on forums mention that fact - as if that makes the rods suspect.
It is also true that the ALL the '3 alloy' aluminum rod people: Durafix, Alumiloy, and others - AND HTS2000 ('9 alloy') - use a lot of flimflam to get your attention but give very few actual facts about the product. Real data, rather than seven colors of ink would make the product less suspicious.
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Durafix and the other '3-alloy' rods are composed of aluminum and zinc with a little copper.
Aluminum and zinc have little separation on the anodic end of the galvanic scale. Virtually next to the other.

This stuff does not mean that it is compatible with the old mast!
If the old mast is ALMAG 35
(does anybody know what alloy our masts are made of?)
then it is an aluminum alloy containing silenium, iron, copper, manganese, magnesium and tin - NO zinc. We know already that you can't put dissimilar aluminum pieces together.
(The most infamous is aluminum poprivets. You never use these on an aluminum mast because the small area of the poprivets will get eaten away right now. "The rate of galvanic corrosion is related to the ratio of cathode area to anode area." (Deuschle) We have to use stainless or monel with Tefgel, even tho the metals are far apart on the galvanic scale.
I have not found anecdotals on long term use of Durafix. Must be out there....
730 degrees seems hot enough to enter aluminum pores and cauterize (confuse) the old alloy molecules for an invisable repair. Theoretically.
Right....for how long? Any thoughts on this? The spreader sockets cups have to come off and they're a mess. Actual welding is out of the question because the temper of the mast can be compromised. And is there an "age factor?"


One guy cautions: "Only use rods that have MSD sheets and a guarantee."
The composition of the magic repair brazing rod is a "Trade Secret" That's the real problem: Should we assume that the zinc content of the filler will, in the marine environment, begin its anode/cathode dance with the mast???:eek:

[ebb]

My Durafix 'kit' arrived from Weeks Distributors.

The Kit is composed of a pound of "welding" (read brazing or soldering) rods and a s.s. bristle brush. Promised "average" number of rods is 22, mine was 19. So that's $2.25 for each rod with $2.25 for the brush = $45.

Randy Weeks came up with the formula in Vietnam to fill bullet holes in airplanes. So it says in an accompaning Feburary 1999 printout from Powerboat Reports - where the product is reviewed in Practical Sailor new product fashion.

Segments of the short product 'test' report are broken into chapter headings. Under "Electrolysis" we are promised a follow up at a later date.
"However, Weeks tells us that of the aluminum hulls he's aware of that have been repaired using Dura-fix, none has exhibited failure or deterioration, although the material darkens." That statement is at least 8 years old.

That is not enough for me, of course. Bass boats and skiffs are different species than salt water interned offshore sailboats. The promised follow up is not added on to the 8 year old leaflet.

We know from copper/zinc alloys that bronze can DEzincify at 35% (mix too much zinc into your alloy and internal corrosion sets in) That's the trouble with manganese bronze in sea water. So if Weeks' formula has a lot of zinc in it, which is way easy to assume, it may have a relatively short life in a real sodiumchloride environment. It may want to start sacrificing itself.

My VERY uninformed HOPE is that the alloy filler is what will suffer, not the mast. Even tho it is touted as being stronger than the parent material, we would not want to change the mast chemistry - the braze is made at 732 plus degreesF. But what do we know?

Worth a call to Weeks if you want to fill a lot of old bullet holes in your antique stick or rebuild the corroded step. My guess is the the mast extrusion is unscathed by time - it's the aluminum castings that went bad on Little Gull's stick, top and bottom.
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Left enough holes here for some sort of discussion, but no.
OK I'm going to footnote a final loop here.

Galvanic Tables are lists of metals and alloys arranged in descending order from most active IN SEAWATER to least active. Current list (MIL-STD-889) going the rounds is 92 items long: with Magnesium(1) and zinc(4) at the anode end going to Graphite(92) and Gold(91) at the cathode or noble end. (Only nobles can afford gold and graphite.)

Galvanic (described as 'electrochemical' reaction) corrosion and electrolysis are usually separated in discussions. Electrolysis reserved for corrosion related to actual electrics, like a metal used to ground a boat's system. Illustrated by an aluminum stern drive. The aluminum mast is not used as ground for a sailboat DC.

I'm waiting for a plein english essay on alloys found on boats. I would like to know how zinc(4) and iron(31) are such a good partnership. Not even actually alloyed. But zinc melts at 786 degrees, so heat may have something to do with it, like the Durafix rod. I know galvanized iron is great in a marine setting - but why? The 40 year old mast on Little Gull has essentially NO corrosion on it, and the boat, so far as I know, has lived in a salt environment since it was born. Does have a thick, ugly oxidized (said to be) PROTECTIVE layer on it. Aluminums dominate the anode end of the Scale. And essentially are cheek by jowl with zinc.

3-alloy Durafix is not included in the Galvanic Scale.
Composed of AL(6) thru (26) - interrupted by Cadmium(10) and Uranium(11) and Indium(23) -
WITH Zinc(4)
WITH a little Copper(33) - the material could very well NOT be reactive with the mast alloy. May have something to do with the 732degreeF ALchemical interface.

Still waiting for an explanation of the old pyromaniac alchemist's reasoning that leads him to try to change Lead(29) into Gold(91). Alloys are beyond in a magical metal chef's realm. What I know comes from bad things that happen when I set one close to another. Or deprive them of Air, or touch Fire to them, or wet them with Water Even adding a teflon lubricant to a fastening can foster corrosion.
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I would not Mig/Tig holes closed on the mast. Could change the temper of the alloy and weaken it, even if you are welding plates on that seem to add reinforcement. That's what I read. Guess that the Durafix filler is innocuous, your choice. Closing a hole with a thin plate and poprivets is another way. Caswell Labmetal for small holes, and epoxy paste are probably close to inert. If your masthead or maststep castings are corroded, imco, THEY ARE NOT FIXABLE. I know it's been done with bolted plates and so forth, but you can't add strength back to an old corroded casting. Corrosion to me is an active, ongoing, untrustworthy phenomenon!
Even today, aluminum castings on airplanes are limited to 'non-critical' components because of their inherent limited strength.
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Often said of wood, isn't it, that is is still LIVING, changing? Shrinking, expanding.
Can be said about everything on the boat. Metals, coatings, plastics. Everything is always moving!
"IT'S ALIVE, IT'S ALIVE!":eek:

[ebb]

Note to the ghosts visiting here.
As of this date 338's mast has been decommissioned.
And we've taken a closer look.
Whether the mast is in good shape is all subjective.
The original anodize is very rough and assumption is that minor pitting has occured everywhere on its surface. It looks like sanding, alodine, epoxy primer and filling with LPU paint will make it look good again.
This is not a mast in good shape imco.

May try to fill the worst corrosion as an experiment. Since integrity is lost, areas like this would not be used again for tangs or fittings. This degrades a mast even further.

Just where Durafix will be used is unknown at present. If the stuff is harder than the aluminum mast, fairing will be a problem. I wouldn't use it.
Minor pitting could be epoxy filler filled.


This thread should be closed out.

[c_amos]

Ebb,

Sorry to have missed this thread... I guess it was because on the dates of your last 2 posts I was 3 days from retirement, and then out cruising (probably still in NC waters).

For the sake of any who might read this and continue your experiments with these 'wonder products' I will confess my experience.

I too was once baited by the lure of late night television. I bought a pound or so of "Alumaloy". I thought the add looked a bit too good to be true... and the few experiments (no Ariel / Commander parts were harmed) that I tried did not go well.

The one repair that seemed to work fairly well was a cast aluminum bracket on a gate. I used a full 3 rods to enclose the crack and it lasted less then a year before it broke again.

I did not have much success in getting it to 'flow' as well as they showed on TV and on their web site.

[ebb]

the experience:
From the top of the mastsheave hole up to the top of the mast was eaten away by corrosion. Just GONE.
After cleaning up and removing all suspect metal the gap was even larger.
I created an impromtu dam with folded layers of aluminum foil and jammed in a piece of 2X fir to hold it close.
Managed after wasting a lot of rods and setting the 2X4 on fire to sort of close the hole.

The trick you see on the Durafix site video is spanning a big hole in an aluminum soda-pop can with the material as it doesn't seem to want to slump or run into the hole.

Even if you accomplish this, this makes a very thin inadequate non-sandable fix. We want to span the hole with a mast thickness of new metal - 1/8" Durafix wants only to stay on top. When you heat the edges of the hole and slosh in the solder the solder will then want to drop through the hole. If you let the mast cool and attempt to bring the surface up to solder melting temp all your former filling will melt and you're back to hole one.

This is what was happening with the big hole at the top of the mast. I could never float enough next layer solder on the solder spanning the hole to get it to build up. The material melts at too low a temp. The moment it was melted it began to flow and building up the material becomes impossible. With help from the folded foil jig got some metal to congeal across the opening by melting rods as fast as possible on th foil dam. Ending by filing & grinding away the foil jig and Durafix intrusions inside - nicely accessable there at the top - but needed filing & Fairing with LabMetal paste. Figured we closer to 99% metal when it's time for the etch coat & conversion coat - without islands of plastic repair to worry about. The result LOOKS OK. The Durafix is hard metal, hard as the mast. I won't hang the original tang there.
Could possibly put a tang back above the sheavebox - but it has to be designed like a hound and wrap the sides of the mast.

THEREFORE
Won't advise Durafix for filling holes in an old mast. Somebody more handy than I may have a better outcome. Worry that stalagtites created in closing screw or bolt holes will be a major problem with interior wiring. Have to use something else.

Won't be filling holes with epoxy eventho I'm painting the mast.
Considering redrilling and retapping old unwanted holes - screwing in 6061 threaded rod with Loctite Red and cutting off flush with the mast then fairing. The threaded rod is available from 4-40 to 3/4-10. It's only going to work with the small sizes because of the mast's thinness and paucity of threads.
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Way later EDIT (3/2012) Mast restoration, as work in progress, is now being talked about on Ebb's Gallery pages, around page 20. Alvin aluminum LabMetal has been used successfully as a filler for holes, small corroded areas and depressions - no threading - and to finish sculpting the gap in the top of the mast. Thus far no 2-part epoxy has been used as a filler. This method of 'cosmetic' repair is only that, not structural.
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another EDIT (7/12) It's not possible to knife fill a 1/2" hole in the mast....
Ebb & Jerry's secret HOLE PATCH method for old 1/2" boltholes and even more mangey wire holes in aluminum spars:
Tight, non corrugated cardboard like OfficeDepot ILLUSTRATION cardboard.
Alluminum insect screening - Hardware store screening patch.
Heavy nylon leader. (RiteAid Drug store)
Alvin LabMetal aluminum patching material (from Caswell) [NOT a shill for this stuff, there are other pastes like this - but this was used here.]
A stout needle, some 60 second epoxy, 1/2 " wood doweling, and acetone or LabMetal thinner, acid brush.

Imagine you will make backing patches that are slightly larger in diameter than the holes you want to disappear with metal paste.
Cut OBLONG cardboard thumbnails about 1/8" larger all round than the hole to be filled. Cut screen thumbnails same size as cardboard and VERY sparcely tack the screen on top of the cardboard. (Loctite 60 second epoxy) Top being the side you will see in the hole.
Loop nylon fishing line thru two needle holes close to opposite edges in the screen/cardboard thumbnail. Thread the needle with leader - from the screened side: push the needle thru one side and back UP the other. You are making a cradle with the leader. If your hole is 1/2" diameter, the threads coming thru should be 1/2" apart - that will help orient the patch when it's all gooped up in the hole. The thread ends are used to orient & hold the oversize patch you managed to get inside the mast thru the very hole you want to fill. Magic.
Form/bend/curl the oblong screened patch - with the leader already in it - into a concave shell that will allow it to be pushed into the hole.
Better do some dry runs. The screen thumbnails should probably be cut slightly smaller so the wire doesn't catch on edges of the hole.

Before you slip the patch in
Prepare the hole. Rough-up surfaces inside and out. I used a not very serious 1/2" Dremel spherical stone slipped into the hole to brighten AMAP the mangy metal inside around the hole. CHAMFER THE HOLE INSIDE AND OUT ALL AROUND. Rat tail file works great.
Clean the wound of debis & dust with acetone or less lethal alcohol.
Just before inserting the prepared backing QUICKLY prime the inside of the hole with wet LabMetal. Narrow acid brush.
When you open a LabMetal can the material immediately skins over. Load your curled patch insert with paste- especially around the edges - then slip the mess into the hole - and with the two ends of nylon leader QUICKLY orient the patch so that it overlaps all around the edges inside the hole. If you planned where you pierced the cardboard with the needle, you'll be able to PULL the patch into position with tghe help of Sharpie locater marks on the MAST. Don't pull too hard - it's possible to pull the line right thru the cardboard - I did! Poke the patch with an awl to encourage the patch edges and screen wires to lay flat on the hole inside - thru the already setting LabMetal - doesn't have to be too tight - but has to be just rite. You will discover that it is the pair of nylon leader ends - that come straight out of the hole - and the Sharpy marks on the mast that position the leader - that are doing ALL the locating of the opaque mess you're trying to plug the hole with!
Good Luck. Tie the leader line ends around a dowel and let it get hard. Don't pull the leader when making the knot on the dowel. A little swell to the 'metal' inside won't hurt a bit! Time for a good ale. [Eye Of The Hawk, Mendocino Brewing]
When fully set, pull one end of the fishing line thru the patch, comes out easy. Fair and refill and fair.

A sanded patch is darker than the mast metal.. Chamfering helps hold the patch. LabMetal is a onepart epoxy aluminum filled paste - so maybe it sticks pretty good too - I'm not brave enough to take a hammer to it. This 'repair' imco is cosmetic. It won't be drilled again for another fastening.
The Metal fairs almost too easy. I've noticed that a wet acetone rag will pick up feathered 'fairing' months after. Don't know what to make of that! Don't like it! I would try to locate a similar paste in urethane.
Seriously don't like that supposedly cured material can be wet rag dissolved with solvent!!! Fevently hope the stuff won't dissolve in subsequent mast prep & coatings ! ! !:eek::eek::eek:

(Concept is that cardboard will eventually fall away leaving embedded screen & Metal glued as a plug to the inside of the mast.
Pulled 30' 5/16" galv chain thru the mast a few times attempting to debody LabMetal worms that form by pressing paste thru mast track holes & others. Didn't seem to have loosened or dislodged the 'large hole' patches, fingers crossed.
By definition THIS IS A COSMETIC REPAIR. Larger holes in the mast ought be welded shut, if you can bring yourself to it. Watch out that you don't try to run a fastening thru any holes patched this way! No 2part epoxy has been used so far in A338's mast reno.)
see thread 'Mast issues & renovation." Also Ebb's gallery, somewhere around pg 21 for photos.
Post #409 for top of mast repair with Durafix & Labmetal. Looks OK, but I will always consider it cosmetic.
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Disclaimer: I am not an expert in any of this. This is mostly experiencial, with ebb trying to express what happens. OK? If you are here for tips,
make sure you find as many others as you can and weigh the advice. When I went looking, didn't find what I was looking for - so this is wins & failures, not egotrip. Of course, it's opinion - if you say so.
If you know a better way, or even another way, post it, share it. This is community.