Fiberglass question

Group...
How do you keep fiberglass layup close to a round surface... i.e. bottom of the FAB for the drain pipe.

The fiberglass cloth tends to flatten out and ease off the round tube or any other uneven surface. Just curious if there is a trick....

Thanks,
Doug

Cut it

Cut the end where it will go around the curve. Cut about 1" deep about an inch apart. It will fold nicely around the curve. I'll try to show below.

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Use Saran wrap

For some radius the fiberglass cloth is too purous and the radius too tight for the cloth to adhere to. In this case cut a piece of Saran/plastic sandwich wrap that is big enough to overlap the area being 'wrapped' and apply the Saran wrap directly on top of the corner/radius, and use a brush or some other object to 'stipple' the Saran wrap to the fiberglass, squeeging out all of the air that forms/formed under the radius. The Saran wrap seals the fiberglass cloth and keeps it from drawing air in and helps to keep the surface tension between the cloth and the surface its being applied to. this also works on flat areas where you are having difficulty eliminating all of the air pockets/voids under the glass cloth.

Use a crowfoot (aka "4-harness" or "8-harness") weave cloth for compound curves. The 7-under, 1-over weave of an 8-harness allows the fibers to shift in relation to each other. You can drape an 8-harness smoothly over a ball.

If you have plain weave and just need to lay in or over a straight radius, lay the cloth on the bias, ie, warp and fill fibers at 45 degrees to the axis of the curve....which reduces the bend required by each fiber.

Thanks guys.... sometimes it's the little tidbits that help.

Doug

If its an inside corner you can use a fillet of flox or dry micro applied with a popsicle stick or a gloved finger. This will give a better corner transition for the cloth to lay down. Use flox rather than micro for structural type corners.

Fin
9A