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It looks like an ablative. If you run your finger over the surface and it flakes off as powder it probably is an ablative. If it leaves little or no residue on your finger it is probably a modified epoxy. In either case an ablative is a safe bet to coat over the existing paint. It you try to overcoat an ablative with a modified epoxy it will come off in sheets. If you put an ablative over an epoxy it should work just fine. I'm personally not a big fan of ablatives but in this case it is probably the safest bet.
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electric motor with 40 #s of thrust. Is it enough?
I uploaded three picture of an electric motor sticking out of the outboard well. If there are no waves, no wind and no current, will this electric motor be able to slowly move my commander?
Want to use this electric until I have the money for a 7hp or higher gas motor.
http://www.pearsonariel.org/discussi...0&d=1482545002
Last edited by joeniver; 12-23-2016 at 08:23 PM.
Reason: typos
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oomph formula
According to Minnkota:
"you can approximate HP rating of any electric motor
by multiplying motor amp draw times voltage to find wattage of motor.
Divide wattage by 746, gives you hp rating of the motor.
746 watts equals 1 HP".
There is no direct correlation of thrust to HP.
When you get a gas 8HP OB for a displacement boat,
you want the propeller on it with a pitch for thrust,
rather than the usual speed prop.
Electric trolling motor propellers are set up for acceleration... push.
Response is immediate,
props designed for thrust not speed.
Motor on your boat there looks like it has enough thrust for a kayak!
some Commanders on this web site have electrified their propulsion.
Look em up.
Last edited by ebb; 12-24-2016 at 09:08 AM.
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Ebb:
The rust stains on the hull are from the Long Island Oak leaves that accumulated in the cockpit. That's one problem solved.
I went to the store and I could not find which ablative paints were sloughing and which were copolymers. Any hints on what ingregent point to which one?
Another question: How can I test my thru hull depth sounder to see if it is working? Should it click-click-click if I listen by the hull like some say?
Thanks
#38
joe
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Ebb:
I have seen Xmatt mentioned a couple of times. Where can I find the stuff.
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X-mat
Have gotten 85% of my plastic and glass from a West Coast brick and mortar called
TAP Plastics. They have Knytex X-mat 1808. I think the 4 digit is used to ID various
weights and widths of the product. It also comes in various inch widths of 'tape' rolls,
which are prefered for tabbing. Knytex can be used with any resin. If you are buying
generic, check to see if it is specific for polyester only, which won't work with epoxy.
The material is supplied as a double layer of a kind of flattish roving, loosely stitched
at a 45degree bias with a light scrim of matt. Perfect for forming difficult corners and
curves as it can be wet formed around difficult angles. You can do beautiful work when
tabbing compound surfaces by push/pull persuading the fabric to stay straight while
laying it up as tabbing, say, for hull to bulkhead bonding, I got mine in 18oz and 24oz
50" wide cloths. Different widths of roll tapes are expensive, but imco worth every
penny for ease of application. TAP X-matt tapes are no longer selveged, but the 'tape'
which wants to come apart still holds together better than scissor cutting.
Compared to woven fiberglass the material is thick, and won't finish smooth. You
can grind on this stuff without loosing its strength, like you wouldn't sand through
the weave of glass cloth (unless designed for, as when layering in a dished hole repair,
where a number of woven fabric wafers are used.)
You can wet out two square feet on a piece of seranwrap, pick it up and position
exactly using the plastic wrap to handle it. Once pressed in position you can leave the
wrap in place or attempt to peel it off wet, so you can layer on the next. Often fit
paper patterns first, use to cut the fabrc, using a fat Sharpie to transfer up and down
arrows and dashed lines indicating fold places on the dry initially stiff X-matt.
Generally want to butt join pieces, and lap the joints with the next layer. If you are
precutting a lot of pieces, red and green pens.
Can cut and lay on DRY light-weight woven cloth at a 45 degree bias onto your wet
X-matt lay up. By hand, brush, spatula -- tidy things up, make sculpting neater by
pressing and teasing the fabric without picking up loose threads. Use the dry cloth
to keep things neat and soak up extra resin. You may be able to use the spreader, if
not to stroke, but press into shape. This is done with a certain aplomb, because the
epoxy is setting up. Once it does, immediately stop, toss containers, bristle brushes.
Save your stir stick and favorite spreaders by wiping with paper towel for next mix.
Wipe wet drips, globs off the work area to avoid grinding, Have a couple small carbide
blade scrapers (Bacho*) handy, to avoid the grinder. Clean-up with 91% drugstore
isopropyl alcohol. Far less lethal than denatured with toxic methyl alcohol in it.
*Klingspor (currently, online print cat. pg 52) www.woodworkingshop.com/
Other glass suppliers sell similar stuff with a different name. You can create great
strength with just a few layers with this fabric. And it being in bias makes it easy for
any problematic layup. Like tabbing right angle rib or panel to the curved hull, without
a radius joint fillet. Add a plain cabosil thickened segue later to create a nice looking
curve in the angle. Make your own fillet-curve-maker by carving a pliable (green)
spreader.
For narrow bulkheads, advisors agree that a large curved fillet should be layed in
before any Xmatt, with fabric reinforcement pasted on top. Hard bulkheads can
imprint thru the hull, show up as a vertical bump on the topsides, making the joint
visible on the hull... after your expensive Awlgrip job!! Some professionals will not fit
a major bulkhead without including a thick closed-cell foam rubber gasket along the
length of plywood edge that will bear on the hull - then a wide epoxy/cabosil fillet on
both sides of the blkhd - then X-mat tabbing.
Look at Commander sites for some incredible work.
TAP Plastics imagines themselves as another kind of plastic products store. They are
not oriented to the marine trade. Have exclusively used their 2to1, 100% solids no
solvent Marine Grade PREMIUM EPOXY RESIN on the Ariel, inside and out, for years,
without an amine blush prob, in cold and hot temps, without regard to humidity.
Tho not sure, in rain storm, in very high humidity, it could blush. It's a bit extreme
to work epoxy outdoors when it's raining.
Buy guaranteed no-blush 2-part epoxy from epoxyproducts.com. MAS EPOXY is another.
Biaxial Cloth is another more common name for X-mat. But if the vendor is selling theirs
with the 4 digit number indentifier, it's probably what I'm familiar with.
Jamestown has another brand of biaxial, but looks different in their thumbnails. Etc.
When you find a vendor, you want to see ounce weight describing the 'fabric'. 24oz is
really very heavy material. It will gobble up epoxy. Try 17/18oz first. Make sure it's
all-resin compatible. Some vendors have sample packs ...that you have to pay for.
Last edited by ebb; 03-31-2017 at 07:59 AM.
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Concern about the gap at the top of the rudder and the gap (less) at the bottom of the rudder.
First picture is the shoe. Seems OK
Second one is the bottom of the rudder. Narrow gap.
Third is the top of the rudder. Wider gap.
Should I be concerned?
Last edited by joeniver; 01-25-2017 at 06:19 PM.
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A-C yachts are not precision pieces of engineering as you might find in a German automobile.
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so true, so true. Would you care to venture an opinion?
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If the rudder swings freely, then in my opinion, there is no problem.
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Ebb: would you care to venture an opinion?
While I value Bill's opinion, a diatribe is more what I am used to on this lovely forum. Hence my appeal to Ebb.
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what is the difference between the white and the green? They both seem to be non-ablative paint.
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difference between Green and White.
Trying to figure out what the difference is and if it matters for putting on an ablative coat and launching my commander.
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venture opinionator
joeniver suh, Have to get a smell of things first. If your hull hasn't gone through an upgrade, the white is probably original gelcoat.
If the white surface sands suspiciously easy, makes white dust, it's probably epoxy barrier coat. White because most bottom paints aren't.
And white is expected when removing bottom paint for recoat.
Gelcoat, when you scrape at it, won't act like a coat of paint. Even old gelcoat, is pretty hard and very smooth. It originally was sprayed
into a well prepared mold, it looks and behaves different than any rollon coating.
I've on-and-on'd about chemical paint removers. Never use methyl chloride. Really, NEVER. Non-toxic, orderless, bio-degradable, $20qt Soy-Gel is a safer chemical stripper, maybe OK for small jobs like the rudder, but messy. But so is sanding, unless you have a Festool sander matched to one of their vacuums, or a Fein which does not draw dust up through the tool. But is an excellent vacuum$$$$ for the shop, boat, and connected to the useless bag outlet on any sander.
So I can't recommend a method (it's all a PITA) to remove old green/black bottom paint, which could be hard or could be ablative. You'll know when you start sanding. Ablative = easy. May be it all comes off easy.
If you are going to barrier coat with a white epoxy you have to remove all paint. You do not have to remove the gel coat. You'll be scratching it. What ever you're doing next, that 80grit on a fast moving ocillator isn't a bad scratch to put a new coating on. Imco 80 grit
does a better job removing paint than coarser grits, which have less grit per square inch. Want sharp grit, don't sand with a worn disk.
My new coating insurance is to wipe down the project FIRST with 91% isopropyl alcohol before sanding. Remove dust (vacuum and/or soapless wash or clean damp rags). Then just before new coat goes on, wipe it down again with isopropyl and clean rags. It's possible that coating failures
happen often enough because of contaminated products like coated sanding disks, dirty rags, local contaminated dust in the marina or off the
highway (where copious deposits on my project are black granules, which has to be tire rubber and unburnt diesel) Contamination can also come from the garlic fries you had at lunch. There are many more, of course, surface temperature, humidity/dew point, etc.
Also when removing dust: DO NOT SCRUB the tack cloth, as if it were a rag, on the surface you are about to paint. Commercial tack cloth may use linseed oil for tack, you don't want to transfer oil to your work. Just don't use them at all. Damp clean rag with isopropyl.
But if you decide on sanding the old paint off, you automatically have prepped the boat for a new coat of bottom paint. If your boat comes
out of the water regularly, or if you moor, your choice is, seriously, what everybody else is using locally. Ablative if not recoated every year
or other year will eventually just fall off, but you got to to be aware, because slime, barnacles and local sealife can be worse than any coating to remove. Hard coats leach their poison and you have to sand off the porous matrix every 3rd or 4th year, so it doesn't build up.
Around here in central Calif, the most popular is Petit's TRINADAD. Expect 2 - 3 years. Haulouts are expensive.
Many owners really want a non-toxic, just because sanding toxic paint is dumb. Environmental paints are appearing now, that are far less lethal to humans and water you sail in, that might be tried... if you have the bucks.
There's permanent Coppercoat, that guarantees 10 years!$$$ -- and an electronic device that sends a current thru or over the hull.
If you are going to sand it off, there are tools that work better than others. You want one that's not going to tire your hands and arms. I don't know anymore what's out there. But would naturally look at the latest fast charge lithium mega volt cordless sanders.
I use a corded 5"8hole Makita sander, the kind that has the motor on top, rather than the grinder-style with sidearm handle. Important are the disks, I like hook and loop. Bosch are everywhere, most Ace hardware, and are OK. Don't last long enough for me. Zircon disks that Festool has are very good, but you buy into a system that owns you. It is the best there is. And you actually can sand NO MASK DUST FREE.
Regularly order from the Klingspor WoodworkingShop catalog, BUt you have to be sure you don't buy latex, sterate, or silicone anticlog coated disks or papers from them. Klingspor has blue Zirconium sanding disks. Zirconium has a rep for lasting much longer than aluminum oxide. Have no experience with their blue disks (and I haven't sat under the boat sanding in a long time). You'll be using 80 grit, probably. Try a few of each. Trick is not to bear heavily on the sander. Less heat/longer lasting disks. Don't know what the answer is... I tend to stay with aluminum oxide closed coat grit. Don't want to sand the hull (anything) and have trouble with the coating or paint not sticking.
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ARGUEMENT FOR BARRIER COAT
The isophthalic polyester resin of our boats is not the cheaper othophthalic resin of the 70's that produced blisters & pits requiring expensive repair -- and a final vinylester or epoxy barrier coat. Our hulls don't blister. However, any polyester laminate is not waterproof. Some A/C skippers have taken it down to the gel coat -- again, do not remove the gel coat -- and barrier coat with epoxy. I look at it this way. Don't want to expose laminations (in the translucent green polyester under the gelcoat of our Ariel/Commanders) which you will do, when you start penetrating the gelcoat removing expired anti-fouling -- time after time. Glass fibers are not changed chemically in any way, merely surrounded with resin. There are grades of glass, some better at being encapsulated (like X-matt), as there are better epoxy resins to do that with.
If the glass in a laminate is exposed to water, it will capillary into the hull and probably travel web pathways of the hull's reinforcement, who knows? Thinking like that motivated me to find an epoxy coating that is designed to stop water. Use it inside the bilge too.
The gelcoat on our boat and hull is 50 years old. It's become porous. Don't exactly know what has escaped, it's generally agreed to have been depleted. Perhaps equally by sun and water. Like human skin, there's all kinds of snake oil out there to fix it. It's pretty much all BS. If the gelcoat is solid, not crumbling or cracking off, I'd guess it's OK to put a quality coating over it. 2to3 coats of tank coating, not a paint. Preservation, along with rehabilitation and refurbishment, that's what we're doing here!!! All imco!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
http://www.paints-coatings-epoxies.c...oxy_paint.html Water-gard 300. PaulOman (propr) calls this a paint. Probably as a way of describing it's application. It is a tank/floor coating that has to be applied with a short nap epoxy roller.. It's not a cosmetic. In fact I suggest a couple coats so you can pass the sander over it, to flatten it and provide tooth. It does not act like a paint. And is a PITA to apply. Small amounts of Xylene, a 'slow' solvent preferred, but Acetone... can be used to loosen it up a bit.
You will then need phenolic$$ shortnap covers if you add solvent. Epoxies themselves are made with highly toxic chemicals, that cause endocrine system hormonal damage, that you have a 95% chance of passing on to your children and grandkids -- according to the FDA!
Sorry, can't find anything funny in this!
(this post was in another style, but automatically reverted to this form.)
Last edited by ebb; 03-24-2017 at 09:13 AM.
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Top and bottom of rudder.
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