Fiberglass cowling

[Andris Golts]

Im in the process of laying up a cowl with a pair of air scoops for my design of a 1963 version of the Miss Thriftway in 1/16 scale for .12-.15 nitro. The cowl is carved from the pink dow foam is 17'' in length and 2 1/2 '' in width layup is in 2 oz fiberglass cloth with pacer finishing resin my question is how many layers should i apply for a good weight to strength ratio ? On my cowl for my sport .40 i went with a 10 layer build up which i felt was a bit of over kill after layup i remove all foam any input would be great.

 

[mark poole]

Are you building the cowl or the mold? Sounds like from what i read you are doing what is known as a "one off" where you lay the part (cowl) over a disposable mold. If that is the case then 10 layers of anything is too much yes. I use cloth that is slightly heavier than what you are using and i build cowls out of 2 layers. One of my cowls is 26 long, 3 wide and 4 high and weighs 5 oz. painted, decaled and ready to put on the boat. Sounds like 3 or 4 layers of your cloth should be enough. Leave it on the mold for up to a week if you are not in some big hurry to install it. This way it won't distort after you remove it. Hope this helps.

 

[forresterace]

Hi Andris

Long time, no see. I agree with Mark that in using 2 oz cloth w/epoxy over foam, 4 layers should be fine. When you hog out the foam, you can leave a thin layer which will help the cowl to float if the unthinkable happens.