Canopy Trimming

Hello Guys,

I am currently working on the canopy to my -7 tip up. The canopy has been split, trimmed to size, drilled and countersunk / deburred.

How risky is trimming a bit more material off the bottom side that bolts onto the side frames? After pulling it down and securing it I am now overhanging onto the angled part of the side frame. I fear this will cause cracking or the side skins wont sit flush. I need to remove about an 1/8".

I had been using a 3"x 21" hand held belt sander for cleanup / minor adjustments after the rough cut with the cutoff wheel.

I'm just concerned about cracking now due to the holes.

cabinet scraper. I did the entire back edge of the RV-14 canopy with a scraper.

For fine tuning the plexi cut/shape I got a nice straight piece of 1x4 and cut a medium grit belt sander belt attaching it to the 1x4 for a long sanding block. Helped ensure straightness to some of the edges. Then used a canopy scraper I bought from Avery Tools, looks like this: https://www.tapplastics.com/product/supplies_tools/plastic_tools_supplies/edge_scraper/588

Vixen file

I found a Vixen file removed material and left far fewer tooling marks.
I also used a 150 grit paddle style disk on an angle grinder.
Draw a line and stay outside it.

Trimming isn't the question, though the edge scraper looks useful.

All I am asking is how likely that the canopy will develop cracks at the holes if I trim is some more material.

A scraper you may already have in the tool box- OLFA H-1 knife, use the back edge as a scrapper.
Any of the methods mentioned will work to refine the fit, just be gentle and work the file or sander at a very shallow angle (not 90 degree to edge) and finish off with scrapers or such.

efitzgerald said:

Trimming isn't the question, though the edge scraper looks useful.

All I am asking is how likely that the canopy will develop cracks at the holes if I trim is some more material.

Click to expand...

I think I would be more concerned about cracking on the edges if they are not yet smooth AND the canopy is not well supported while working on it AND the temperature is not right. A power sander can more easily catch and snag, so a hand tool like others have mentioned will be safer and a bit slower.

But I don't see why it should specifically crack at the mounting holes if they are just empty holes without any pressure due screws or rivets. However nobody here is likely to tell you it can't crack! Maybe do a test on a piece of scrap cutoff to satisfy yourself? Good luck and please let us know when you succeed.

Thanks for the input Paul.

The edges are all straight and smooth. They are not polished but taken to a 320 grit finish and have had the sharp corners taken off.

I did a decent amount of testing on scrap. The only time I was able to get a crack started was when I pushed too hard while countersinking a hole. I am working in a heated shop. I made the big cut at 80 degrees, which was fun.

I think I am getting more nervous as I near completing the canopy with no problems. I probably will not use the belt sander, its not worth risking the time and money if I crack it.

Is it worth polishing the edges? I could easily do it, I practiced on some scrap and it doesn't take long.

All done (trimming at least) and no cracks.

Polish

320 is probably fine but look for tooling scratches.
Take a damp paper towel and wipe an edge. Look closely with a strong light. Remove any tooling scratches that show up. I wet sanded the edge to 400.