when i did my sub-floor i got the all the materials from westmarine less wood. they also had a nice how-to fiberglass book. most chain auto part stores sell glass kits and you can get how-to info off the net. glass work wasn't as hard as i thought it was going to be. 

Make sure you space any wood away from the boat itself, if you glass wood directly to the boat with a tight fit you'll be dealing with stress cracks

so i cant glass wood to the boat??? like wat i was goin to do is put 3 pieces of wood to hold down my tanks and i want goin to fiber glass them to the floor and the side of the boat...

build up some small blocks to keep the tank off the floor and level. sand the area with like 80 grit to rough it up, put some resin down, then the block, and then a little run of some mat around that and resin to coat.   id personally put some rubber on top of those so there isnt tank to metal...  but thats just me.   then u can either get flanges to the gunnel, or just fiberglass something to hold em to a gunnel. 

this is my idea for my tanks....

attatched is a pdf of the tanks

Yes you can, you gotta space it about a good 1/8". Set it with spacers, glass in between the spacers and let it set up. Then pull the spacers out and glass until your heart desires. It's called tabbing. If you are only doing blocks only on the floor and not the floor and gunnel then don't worry about it. You need to tab things that attach at more than one surface

what do u mean i need to tab things that attatch to more then one surface??

are u talkin about the tank? or fiberglass??

what do u mean i need to tab things that attatch to more then one surface??

are u talkin about the tank? or fiberglass??

what he basically means is that you use a strip of glass mat.  and lay it out so theres an overlap onto the new piece and what you're trying to stick it to. 

for example:



theres like 4" on the stringer part, and 4" on the floor.  both sides. 

Ok not the greatest pic but here's my tank mounts, see how they attach at the floor and at the side of the boat. There is a 1/8" airspace between the wood and the existing fiberglass of the boat. If the wood touches it will spider crack the outside of the boat. It's the same on the bulkhead and the same reason that the bulkhead and side supports don't touch the underside of the deck. It allows it all to flex. Derek and ray are right, you want to roll out some mat under the piece so that it sticks out on either side parallel with the joint, then glass the 90 degree sides. On mine I used about 4 layers of heavy mat and a finish layer of cloth. One other thing I did that seemed to help is I routered or sanded a little bevel on the wood piece which allowed the resin and mat to "flow" better.


Sorry these are the best I've got

Sweet

I'm no glass guy but the way I understand is mat is where the strength is, and cloth is for smooth finishing