Quote:
Originally Posted by drmiller100
My problem is when I am building something new, I often have to take 1/8 to 1/2 inch off to make the body right, which means I need to eat into the glass.
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The people who have built Vari-Eze planes have gotten pretty good at this. The idea is to get the foam nearly perfect in shape, before using any filler at all. This is right about at my patience limit -- especially on something like a wing that has to be a particular size at each point. On stuff like an autobody, if you sand too deep, just go to the other side of the car and make it too deep there too. If you need to, make up a name for that aero feature -- any German name should do. I used to have a windsurfer with an Ophibi dent or some such... to promote earlier planing. I think they just dropped the plug and didn't want to fix it.
(You can translate the stuff below for polyester -- it can be a little different, and I rarely use it, other than as Bondo) Once the shape is right, coat with microbubbles in epoxy, and lightly sand that. If there are places where you've gone through the micro, recoat and sand some more. Then lay on the cloth and squeegee on the epoxy. Unfortunately, this is when the waves show up that you didn't see when it was micro surfaced, which is flat, not glossy. I've painted things with glossy paint prior to glassing just to see the surface better. Then that can be sanded to matt to allow the epoxy to bond well. But the better the surface prior to any glass, the easier things go.
But I have never really gotten the hang of it, anyway. However, on boats, where the substrate is wood, this works more easily. One sanding after the glass goes on, followed by rolling on another coat of epoxy, followed by one more sanding is usually enough that the boat can be varnished without any filler used at all. (If you need to use filler, you simply convince yourself that you really wanted a painted boat anyway.)
BTW June sounds good. I'll reply also wherever you mentioned the trike fest.