Fiberglass cowl lay-up ?

[Andris Golts]

Hi all im in the process of making a fiberglass cowl for my micro hydro i have shaped the cowl from a piece of 2'' thick Dow foam .The cowl is 8 3/4'' long x2'' wide x1 1/4'' high i started laying 2 1/2 oz fiberglass cloth over the foam laminating with Pacer's finishing resin and when finished i will carve the foam away. My ? here is how many layer's of 2 1/2 oz cloth should i be laminating together to get decent strength and not put a whole lot off weight into the lamination? Regards Andris Golts.

[LuckyDuc]

I use 4 plys of 1.5oz followed by 4 plys of 6oz cloth. This is for cowl making using a mold. If I was you I would cover the foam with two plys of cloth, primer and sand to a high luster finish and make a mold from it. Once you have the mold then you can make parts from it with varying amounts of ply/cloth to see what you like the best.

[Andris Golts]

Thanks for your reply LucKy Duc. Regards Andris Golts.

[yurkanip]

I am finishing my 29" rigger mold, right now. (for the MOLD ONLY) It is being layed up with 5 layers of 1.5oz mat, and 1 layer of 6oz cloth to top it off. When laying up the parts, it is usually over kill it you lay them more than 3 layers. 3 layers of 6oz, each one layed down at 45degree angles, different than the previous adds strength in all directions. You could also, lay three layers of 6oz cloth and top it off with a final layer of 10oz for a very strong cowl.

Just my .02 cents.