fairing compound

[HWL]

Is there a fairing compound I can use in the repair of fiberglass boat repair? I use basic car bondo now, but i'm hoping there is an easier sanding option,especially for larger areas. I am by no means a professional, just a back yard builder and repair man. Thanks for your help

[gonzo]

Nothing sands easier than Bondo.

[Eric Sponberg]

Actually, US paint, makers of Awl-Grip topcoat paints, makes a compound called Awl-Fair which is used extensively in boatbuilding on composite, wood, and metal boats.

Eric

[PAR]

AwlFair works very well, 3M Premium filler works good (vinylester and microspheres), 3M also makes a higher strength filler (vinylester and stranded glass) though harder to sand, Evercoat makes a Bondo like product called Formula 27 filler. I'm reasonably sure Marine Tex and BoatLife also make a filler, though have never used them.

I don't use Bondo type fillers (polyester) I've found they shake out in time if subject to much vibration.

[D'ARTOIS]

Not only that - it absorps water and finally looses adhesion and crumbles, finally falls apart.

[Herman]

Polyfair from ATC Chemicals. Very easy to sand. www.atc-chem.com, in the polyester dept.

[Lew Morris]

not as easy to use (you have to mix resin and filler) but a great product IMHO

West Systems Fairing Fillers:

[url="http://www.westsystem.com/webpages/productinfo/guide/Filler_select.htm"]

[Lew Morris]

http://www.westsystem.com/webpages/p...ler_select.htm

[JR-Shine]

Our builders like Quickfair by System 3, very good stuff (epoxy based).

Joel

[Capt. Chris]

West systems 410 fairing compound works well, but expensive. Buy their book on fairing and finishing has lots of good info. Good luck and don't forget a good respirator!!!.

Chris

[Phil Locker]

Originally Posted by JR-Shine

Our builders like Quickfair by System 3, very good stuff (epoxy based).

Joel

Personally I find Quickfair a bit too hard for my liking - similar to the West low density fairing compound (407). It also kicks very very fast. I've settled on West Microlight (410) and then go to a high build primer as soon as possible.

[rxcomposite]

Ask for a generic fairing compound or micro balloons and mix it with the resin compatible with the boat you are working on. I find it easy to sand.

Dont use cab o sil. It dries very hard like rock. So does resin + fiberglass dust.

After sanding finish off with gel coat mixed with wax solution. You will have to dewax it though before painting.

[HWL]

Originally Posted by rxcomposite

Ask for a generic fairing compound or micro balloons and mix it with the resin compatible with the boat you are working on. I find it easy to sand.

Dont use cab o sil. It dries very hard like rock. So does resin + fiberglass dust.

After sanding finish off with gel coat mixed with wax solution. You will have to dewax it though before painting.

what sort of wax solution are you talking about? thanks

[gonzo]

If you are going to paint, bondo is fine. It is cheap, sands easily, cures fast and does the job.

[rxcomposite]

When you coat gel coat (or resin) as an outer finishing surface it foes not cure as completely as it does when sprayed on the mold as an inner layer.

It cures somewhat but has that "tacky feel" that adheres to the sandpaper when you have to fine sand it. The trick is to add liquid wax solution to the gel coat in the range of 5 to 10%. Its available from resin suppliers.

Resin is hygroscopic, meaning it absorbs moisture in the air. The outer surface exposed to the air does not cure completely or rather takes several days to cure. Did you notice that tacky feel on the last layer everytime you laminate even though it has cured? The inner surface that is in contact with the mold cured completely because it was not in contact with the air.

Wax solution, suspended in the resin, floats to the surface as it cures and seals the resin from contact with the air. The result is a surface that is completely cured or tack free.

Try to experiment with it on a small panel to be comfortable with the effect. Try coating one panel with wax solution and the other without.

Just dont use it on the inner layers when laminating. You will get delamination on every ply.

I suspect Bondo has a wax solution. There is that waxy feel when it dries.