Jim P

Jim P

Well Known Member
OK, I made the big cut on a Tipper. Whoo-hooooo! Turned out pretty good but I need a little trimming since the bubble settled a bit (per plans)

From a technique perspective, what's the best way to trim about .125" off the aft side of the forward bubble? The cuttoff wheel seems like almost overkill, but even 100 grit sand paperdoesn't do too much with the plexi.

Any hints?

Jim
 
I used a hand-held belt sander when I got down to removing small amounts in straight lines. Makes a mess, but worked well!

Paul
 
Sanding the canopy edges is definitely time consuming. I used 60 grit on a long sanding "block" when trying to remove material like you're talking about (then rounded off the edges and tapered down to 600+ grit).

My gut tells me not to use power sanders on the canopy edges because of how it could heat the material up, but I could be wrong about being a little paranoid of it.
 
Melt down

Like Dan, I had my doubts about power belt sanders, but mate Pete Pendergast, who had successfully done his own RV7 tip-up canopy, attacked mine with a "man's" belt sander. It simply did melt as sanded and I felt it reduced the risk of cracks. You don't get cracks in fluids.

Pete.
 
I used the belt sander approach & it worked fine. Next step was to cut a "V" notch in a hacksaw blade with a dremel to make a scraper. It produced a nice smooth rounded edge with minimal work. Much less work than sanding.

Derrell
RV7A
Finish
 
Mark a straight line where you want to cut to, then use a 1/2" Dremel drum sander with coarse drum, followed by emery paper on a sanding block. Use progressively fine grits for a nice, polished edge.

Roberta
 
I've used a small hand held carpenters plane on lexan, it worked very well. I would try it on a piece of scrap first.

RV 8 fuselage
 
Sanding Disk

I used a coarse 2 inch disk on a cheap air powered angle die grinder.
Worked well to get close to the line, the large grit cuts more than melts, and won't "catch" and cause cracks. Then you can switch to a medium disk to get it sort of smooth, and finish off with wet and dry - used wet - on a hard rubber sanding block. Start with pretty coarse wet and dry, I think I started with 100 and then worked down to 400 or 600, taking off the sharp edge at the same time. Use lots of water.
Be careful, Plexiglas can cut you easily.... :(

Almost took longer to write than to do it..... :)

gil in Tucson
 
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