What oz cloth for glassing over 1/2" plywood?

[mosquitolaGOON]

Built front and back decks as well as a floor for my boat, 1/2" plywood, what OZ mat should I use?

[alan white]

If you used plywood, you only need to join (fillet, tape, etc.) the plywood pieces, and otherwise if you glass, do it for abrasion resistance, not strength.
Mat will soak up a lot of resin (cost and weight) so use cloth. 8-10 oz will do.
Several coatings (usu.3) of epoxy are recommended to seal the plywood even if no cloth is used. Fill the weave of cloth completely, or leave it textured for better footing (if you do, do a couple of epoxy coats before glassing to ensure protection from moisture).

Alan

[PAR]

Alan as usual has got it right. Pre-coat all the wooden elements with at least three coats of epoxy, then apply fabric. Mat is a waste of materials when using epoxy.

If your deck or soles will receive lots of traffic, then two layers of 6 ounce cloth (both can be applied at the same time). If normal use is expected you can get by with one layer of 8 ounce, but multiple layers offer much better protection.

Don't be tempted to install carpet. It the easiest way to have to redo your soles again in a few years. Textured paint, texture applied over paint, texture applied over or added to the last coat of epoxy or the best is truck bed liner. Yep, Rhino Coat, LineX or similar, which can actually be used instead of cloth and epoxy to seal up the wood.

I must offer a disclaimer on the truck bed liner. I'm working with a manufacture, using just this type of material (think of it as aerosol 3M 5200). My preliminary tests show it out performs thin fabric sheathings in abrasion and moisture vapor resistance. Now the jury is still out, but it's looking very good, having excellent thermal qualities and it's ability to absorb movement (without breach) is astounding.

[the1much]

did ya see the show where they made a house resistant to a outside explosion ( like a car bomb next to the embassy) ya should have seen the blast it took,,,and kept the walls intact. didnt know it was a good waterproofer tho,,,Thanks Par
and sorry for the off thread thingy,,hehe

[alan white]

PAR, that coating sounds great. Is it a one part or a two part? I've been looking for a coating likr that for years. especially if it would roll on with a texture (or plain) roller.

[PAR]

Currently I'm not permitted to say much about the material. It can't be brushed or rolled and must be sprayed. The manufactures have maintained a tight control on application, but deals can be worked out, especially with our present economic climate. It's not especially cost effective on very small craft, but is on boats over 20' or so, where sheathing and bottom painting costs can absorb a substantial amount of the build and maintenance fees.

[alan white]

Originally Posted by PAR

Currently I'm not permitted to say much about the material. It can't be brushed or rolled and must be sprayed. The manufactures have maintained a tight control on application, but deals can be worked out, especially with our present economic climate. It's not especially cost effective on very small craft, but is on boats over 20' or so, where sheathing and bottom painting costs can absorb a substantial amount of the build and maintenance fees.

Okay. Thanks Paul.