polishing the sunfish

[73sunfish]

i used to work on airplanes and had to polish a Diamond Aircraft, which is made entirely of fiberglass.
The only polish i could use was this stuff called Klasse, which is an acrylic made to not clog up the pores in the fiberglass, unlike wax and or anything with silicone. once the pores are clogged with normal wax or silicone you can't repair the fiberglass..

i just wanted to post this and ask for your input on the issue of using this for your sunfish..

 

[Webfoot]

I use to work on aircraft also. Sounds correct, aircraft are 'mission critical', any repair has to be 100 percent correct. You'll see SF in all states of repair from mint to recipicating saw bait, most somewhere in between. By the time you get a used SF there is no telling what has been used on it. I'd say if you have a brand new SF Klasse would be good. Otherwise, the stuff you put on you Corvette is much cheeper. Personally, I don't wax the deck because it makes my butt slide all over. As for the hull bottom, some just go with 600 grit sandpaper and call it good.

 

[Wayne]

. . . once the pores are clogged with normal wax or silicone you can't repair the fiberglass.

That must be why nearly every fiberglass boat that's been repaired in the last half century has sunk without explanation. And I always thought it was the Bermuda Triangle.

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I think in a marine environment, because all polymers (even epoxy) are susceptible to slow permeation of moisture when exposed for long periods of time, sealing the micro-pores helps to guard against blistering. I believe that's a desirable quality whether it's achieved using a silicone, teflon, or wax.

As for the hull bottom, some just go with 600 grit sandpaper and call it good.

That would be one school of thought for a boat that's raced, however, the practice sacrifices longevity for competitive performance on a hull that is destine to be retired early. But what about those boats owners wish to preserve for many many years? Doesn't gelcoat, like all polymers, need protection from UV and rejuvenation with a chemical treatment to prevent oxidation chalking and cracking?

 

[73sunfish]

imagine a leak on your centerboard trunk. now, imagine someone using marine adhesive or sealer as a quick fix and then finding out that such quick fix was the permanent fix because you will no longer be able to bond both the new resin and fiberglass with the old on that centerboard truck..

you might have to sand down much of it in order to get a grip.


i bet most people here don't have new gel coats..

 

[Wayne]

imagine a leak on your centerboard trunk. now, imagine someone using marine adhesive or sealer as a quick fix and then finding out that such quick fix was the permanent fix because you will no longer be able to bond both the new resin and fiberglass with the old on that centerboard trunk.

I'm not following the logic here. Are you saying if someone temporarily mud-pie patches a hole with, say, Marine-Tex and later wants to go back and lay up a fiberglass repair to add back better structural support and blend the whole job to be seamless with the surrounding area, they cannot?

you might have to sand down much of it in order to get a grip

Hmmm..., wouldn't that be the normal prep work step for any fiberglass repair ... according to all the repair guides ... WEST system, Fiberglast, US Composites, Don Casey, any professional.

i bet most people here don't have new gel coats

What's your definition of gelcoat?

 

[73sunfish]

gelcoat: the outer layer of your boat, the colored part before the resin and the cloth.

i'm not asking people to go buy this product, i'm just stating that silicone clogged fiberglass or resin is non repairable.
you won't get a solid bond.

sure, you can sand away at it till you find fresh resin or cloth but what if you can't sand deep, due to a chip or crack? "fix the crack> then use 3M wax if you wish."

 

[Wayne]

gelcoat: the outer layer of your boat, the colored part before the resin and the cloth.

Gelcoat is still fiberglass resin, it just doesn't contain any glass fibers, only pigment.

i'm just stating that silicone clogged fiberglass or resin is non repairable. you won't get a solid bond.

No one knowledgeable about fiberglass repairs would try and lay a patch straight onto an un-cleaned, un-sanded surface. So in that respect I agree, you wouldn't even consider taking that approach no matter how the surface had been treated against the environment.

sure, you can sand away at it till you find fresh resin or cloth but what if you can't sand deep, due to a chip or crack?

That's exactly how you DO prepare to fix a crack..., sand back the surface to reach good material for your new resin to adhere to.

This is text book stuff.

WEST System prep tips...
http://www.westsystem.com/ss/surface-preparation

Marine-Tex, How to prepare surfaces for bonding...
http://www.marinetex.com/Marine-Tex_how_to.html#Anchor-How-48213

 

[73sunfish]

I'm not following the logic here. Are you saying if someone temporarily mud-pie patches a hole with, say, Marine-Tex and later wants to go back and lay up a fiberglass repair to add back better structural support and blend the whole job to be seamless with the surrounding area, they cannot?

MarineTex is an epoxy, and will hold the new patch. Epoxy good, silicone bad.