fiberglass repair question

I’m repairing the hull of an old kevlar Necky Tesla. The owner has applied some kind of clear grease to the old aluminum slider style footbraces. I need to put some layers of glass on the interior below the footbraces and near the deck/hull seam where it’s been crunched but I’m concerned that the grease might be anything from vaseline to silicone and I"m not sure if it was applied to the aluminum slider or sprayed onto the plastic rail and the surrounding kevlar. I can’t feel any grease on the kevlar but it’s all close enough to where I need to lay down some glass that I have to make sure the kevlar is absolutely clean and uncontaminated with unknown lube. Any suggestions on solvents for ensuring the old kevlar is uncontaminated?

I clean my fiberglass repairs with
I have repaired/modified a few glass kayaks (including a Tesla !) and there is nothing that can’t be cleaned with acetone except silicone. I remove silicone mechanically (scrape it off) until I start getting in to the resin.

Wear gloves when handling acetone and don’t be afraid is if it starts to melt a bit the surface of the vinylester (I believe Tesla is vinylester).

Acetone disolves my gloves fast
I got a box of gloves (non-latex, forgot what kind) that work all right for epoxy and other messy stuff. But acetone eats them almost instantly… So make sure you get tougher/chemical gloves that don’t react with acetone…

Interlux 202

Dissolves everything.

Truly wonderful nasty stuff, but if you want a clean clean clean surface to work with it’s the thing to use.

Nitril gloves with acetone.Great solvent


get the longer heavy duty gloves …

– Last Updated: Feb-17-11 11:34 PM EST –

...... like the orange ones (non-disposables) . The thin little disposable multi-pack nitrils or latex ain't worth a damn doing any heavier duty work . The best gloves for prolonged acetone contact are the heavier Butyl Rubber or Neoprene , but the orange ones whatever they are work well too .

Any chance of removing the foot brace while doing the repair (re-install it after) ??

Acetone will NOT remove PVA or
amine blush for fiberglass related starters g-dog.

Lee, a quick wipe with acetone and then light sand to prep. DO NOT wipe again after sanding.

More than that is WAY overthinking.

Do the patches up into seam though if close just because.

Squeegee peel ply or clear unwrinkled plastic sheet over rapair for nice clean edges with no need to knock sharp stuff down and bring up the surrounding kevlar on those early Neckys.

I use lacquer thinner
It’s less volatile than acetone and probably a bit less dangerous, as it doesn’t absorb into your skin as readily.

my concern is possible silicone spray
silicone is kind of insidious. It’s interesting working on these old kayaks that were built without core materials. I think I’d rather have a kayak that’s made with a bunch of cloth of the appropriate type than big sections of core covered by thin cloth.

Rubbing Alcohol
I’ve just been using that and I think it has been OK. Is use the 91% isopopyl alcohol. Is that bad?

not bad, but not very strong
I use alcohol as well, when I’m not worried about much surface contamination. denatured alcohol will take off light surface contamination, like greasy fingerprints.

But for dirtier surfaces I’ll use acetone, or MEK.

Patrick, why do you recommend NOT wiping the surface (with a new, clean solvent-dampened rag) after you sand? I definitely get the no-sanding-before-de-waxing rule, but why not wipe off the dust after sanding?

Thanks, Nate

Denatured Ethanol
Essentially grain alcohol with a little methanol added to make it poisonous. Readily available at your neighborhood, locally owned, friendly hardware store. With the right permit, you can buy it nondenatured (i.e. 200 proof).

Cheap and effective, and smells good to boot.

You got an open ‘grain’ surface now
No purer than that. ASSuming it was clean prior to sanding that is.

Wipeing it with anything after sanding just smears stuff around and sort of ‘seals’ that grain back up by micro melting the resin thats there back into the raw, sanded fibers that you really want the NEW resin to attach to clean surface before or not.

I figure I will get a couple counter reply to this but this is my experience.

If you want to test this out, do a couple 4" x 4" patches with sanded and sanded + wiped. Then fold or bend them to see which one lets go first.

Same story for those poor folks who cannot get good, even flow ( fisheyes ) when rolling resin on for fill coats with some resins. Sand and do not touch. West Systems is very forgiving and you may never experience this … The higher performance, UV stable epoxys are a little more finicky. If youv’e just gotta wipe I would say to use DNA.

Makes sense. More tooth for some mechanical connection.