HWS Update Part 9

Time to glass the fin:

 So here is how I start; I put my template on a piece of plate glass and trace the outline with a dry erase marker

Here is the outline

 This also gives me an easy way to cut my fiberglass cloth to size

 Now I go approx 1/4" outside the line and lay down my resin dam, I'm using foam rubber weather stripping

 Important to then erase the black line or it will smear into the resin

2 layers of 4oz cloth that I cut out earlier. This is a real important step because this cloth will bind the pieces together for the rest of the build-up of the fin

 The cloth is thoroughly saturated and the backside of the wood is basted with resin before setting them firmly onto the wet cloth.

Then the plate goes under the UV booth, notice the mirrors I want as much UV light hitting the plate as possible, I even put a mirror under the stand so the light can reflect up through the glass

After just a few minutes the tinted resin goes in, filled up to the edge and a bit more so it "domes". The foam rubber will soak some up so you have to let it sit for a few minutes and keep adding a little resin at a time. You want to keep that domed effect because once it starts to cure it will shrink.  Note: this resin has some milled fiberglass mixed into it for strength. You can use cut up fibers from scrap glass or fin roving to accomplish this. Not too worried about it being really strong at this point just want it to hold together for the rest of the process. This of course now goes in the UV booth for what feels like forever!  Good thing about UV it will cure thick resin without getting too hot and cracking.

Wow it didn't fall apart!  So anyway after it has cured under the UV I really leave it alone for several hours. Then just start wedging some razor blades under the edge and it will gently pop right off the plate glass. Now I'll leave it to fully cure for several days before I start to laminate layers of 4 oz cloth to make it structurally strong.