When you have a layup with an inside corner, you need a fillet with a radius that is 1/4" larger than the thickness of the layup. If it is thick layup you have the possibility of an exotherm too, so you might be putting the fillet on in a separate step. I installed a 1/2" radius fillet out of a "rope" of rovings using a model airplane wheel as a roller and it worked very nicely! This technique might also work well with micro/flox fillets. Thanks go out to Orion for that one!
Here is a detail on technique. Sand the surfaces that are to get resin and fill gaps and voids. Chose a tire that matches the desired radius of the fillet. I got enough epoxy on the rovings to wet them, but only barely, pulled the rovings into a rough "rope", and settled them into place. After manipulating it into a rough fillet, I put the peel ply on and worked the glass rope down into a nearly perfect fillet, first with my fingers, then with the roller. After several passes with the roller, I got the shape I wanted, and excess epoxy started to migrate up through the peel ply. I kept rolling and blotting up excess epoxy. Once the fillet felt firm, I stopped in order to avoid ending up with a dry layup.
I did this on both inside corners in my drag spar in preparation for a vacuum bag layup of a beefy shear web.
Thanks again for Orion for passing this to me!
Billski
Here is a detail on technique. Sand the surfaces that are to get resin and fill gaps and voids. Chose a tire that matches the desired radius of the fillet. I got enough epoxy on the rovings to wet them, but only barely, pulled the rovings into a rough "rope", and settled them into place. After manipulating it into a rough fillet, I put the peel ply on and worked the glass rope down into a nearly perfect fillet, first with my fingers, then with the roller. After several passes with the roller, I got the shape I wanted, and excess epoxy started to migrate up through the peel ply. I kept rolling and blotting up excess epoxy. Once the fillet felt firm, I stopped in order to avoid ending up with a dry layup.
I did this on both inside corners in my drag spar in preparation for a vacuum bag layup of a beefy shear web.
Thanks again for Orion for passing this to me!
Billski
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