¼ Round finished edge. Dan H.?

You guys think i have enough fiberglass questions yet. Honestly, im so glad I'm tackling this early in my build rather than later!!! Im learning a ton & my tail will be 100% done & wired before my wing kit gets here next week. Thanks for all the info guys!!! Now, for my last glass question till i get to the canopy fairing . My rudder bottom is fitted & final drilled. I got a perfect fit! Not too bad just took forever filing a little at a time. Now how in the world do i get a nice finished looking edge before i epoxy coat and prime?

Sand the long edges perfectly straight with 120 or finer on a long block. Try it on the rudder one last time to make sure the seam gap is even and about 1/16 wide. Then break the edge with some 120 held freehand. That's it.

Your rudder bottom is white polyester gelcoat? Don't need an epoxy shell unless you've broken into the glass fiber under the gelcoat. Just squeegee some polyester filler into the defects and sand smooth.

Sometimes an edge will look a little scruffy....bare glass fiber showing, which won't paint well. Seal the edge with epoxy, sand lightly after cure.

How can you definately tell if the parts are fiber glass or polyester? All of my tips came as grey gel-coated... I sure as heck hope none of them are polyester because I used west-system, hysol, micro & glass on all of them. I read the manual about 50 times before I started the glass work & I believe it said the only polyester pieces-parts were "clearish" green-yellow.

Daniel S. said:

How can you definately tell if the parts are fiber glass or polyester? All of my tips came as grey gel-coated... I sure as heck hope none of them are polyester because I used west-system, hysol, micro & glass on all of them. I read the manual about 50 times before I started the glass work & I believe it said the only polyester pieces-parts were "clearish" green-yellow.

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The grey gelcoat is polyester resin mixed with ingredients like talc and fumed silica (aka cabosil). It is sprayed into the female mold prior to a polyester resin/glass cloth layup. The gelcoat and layups co-cure. When you repair minor cosmetic defects in gelcoat with any of the polyester fillers you're using like materials.

Epoxy on polyester is fine. I use epoxy resin for all structural work on polyester or epoxy parts. Remove the gelcoat down to the glass cloth for structural bonds. Removing the gelcoat is not necessary for cosmetic work. Epoxy/microballoon mix (micro) works just fine over gelcoat.

The clear greenish parts are epoxy/glass. The latest epoxy cowls are pink.

BTW, you said "fiber glass or polyester". Both resin systems (polyester and epoxy) are used with the same fiberglass cloth. Both finished products are known as "fiberglass". Best I know all polyester parts from Vans are gelcoated, so that's your telltale.