Heavy fiberglass mat

[tartuffe]

By all means, use the csm in addition to the biax. If you plan to use polyester, you need the csm for waterproofing anyway. I would wet out my csm and then immediately lay a layer of 17 oz biax on top, roll it out, then repeat laying the csm then biax going in another direction. CSM is great for building thickness. Thats not a real heavy mat like I was imagining. Just make your design with nice big radii to make glassing easier.

[jasoncooperpcola]

I just realized my mistake. I said i needed 1708 and all i need is 17oz biax to go with my csm.

[gw204f]

On exposed surfaces, make sure your layup consists of one or more layers of CSM just under your finish coat of gelcoat/paint/etc. The CSM helps to prevent print-through of heavier cloth/biax and if you are laminating from the inside out, you will be doing your final sanding/grinding on the mat instead of on the long fibers of the cloth/biax.

[jasoncooperpcola]

I am understanding it now. Well a little bit. My main concern on the bracket build is how to attach my stringer extensions to the existing stringers. Right where i plan to put the extensions is a step in the hull. I thought it would be to my advantage but now am getting worried about it. I will take pics when i get home. Whatever width the stringers are apart is how wide my bracket will be plus a total of six layers of 3/4 ply (3 on each side) for a total of 4.5" plus the outside stringer width. Its gonna be a massive bracket.