J

jimgreen

Well Known Member
I guess I just joined that 'not so exclusive' club. I found this tiny crack at the most forward hole on my canopy. How would you stop drill and repair this?
The hole is just on the inner surface at the moment, but I'm sure with time it will propagate. At the moment I am proposing to make a 1/4" hole about 1/2" away from the screw hole in line with the crack. Then wick some glue into the crack with the runny stuff. Then fill the hole with a piece cut from a 1/4" rod.
Any perspex gurus with advice?
crackedhole.jpg
 
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I'm no Guru but

I wouldn't drill a stop hole that far away from the end of the crack. I'd bet big bucks (a good beer anyway) that the crack would do it's best to run away from the intended course. I think I'd try just the glue and watch it closely. If it does run, you can stop drill the end of the crack later when it gets a little further away from the big hole. :(

Good luck...
 
Is this the most forward hole? I think every crack I've ever seen on an Rv canopy has been on the most forward hole (well, except on MINE, which is the rearmost hole). I didn't drill that hole. In this case, would using this hole exacerbate the problem?
 
Thanks for the replies.
Bob Collins said:
Is this the most forward hole? I think every crack I've ever seen on an Rv canopy has been on the most forward hole (well, except on MINE, which is the rearmost hole). I didn't drill that hole. In this case, would using this hole exacerbate the problem?
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Bob, I'm thinking I probably shouldn't put a screw in that hole.

Terry, I think you are right. I can't really stop drill it until the crack moves further away from the screw hole. Perhaps if I don't put a screw in that hole and make sure it's well supported with fiberglass it'll be OK. Yes, I'm whistling.
 
I've never had one but ...

This is pure speculation because I have never had the problem but looking at your photo and considering what I would do if I were faced with I would not be able to let it go unchecked. I don't know what kind of access you have but I think I would try to find a tool that would work in that area and try to remove the crack. Maybe a small round file, a #11 X-acto blade, a set of Dremel tools or maybe your countersink tool on the side with the crack would work. What you propose to do sounds bad to me.

Bob Axsom
 
Bob Axsom said:
This is pure speculation because I have never had the problem........a set of Dremel tools.....What you propose to do sounds bad to me.Bob Axsom
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I'm with Bob on this one. Again, pure speculation on my part, because I've never been faced with the challenge. It appears the crack is limited to a small portion of the total thickness of the plexiglas. If that is true, I would be inclined to remove the crack by just barely blending it away primarily using a small round stone, or series of small round stones set in a rotary tool. I suggest you try this method on a small test piece of plexiglas. I think you'll find that deftly using a stone in a rotary tool, you'd have to be a Neanderthal to aggravate an existing crack.
 
Just run a "red hot" wire through the whole, wide enough to consume the crack.

Not my idea, it came from someone who works with plexiglass for a living.

manny G
RV4 N146ZX
 
Yip, blend it away.

I agree with Bob, Rick, and Manuel. My very first thought was to melt the plastic. But then I thought, whoa, that's stupid. But...

If you use the grinding stone at even a moderate speed, I think you will melt the plastic - which may not be a bad thing. Sure, its going to change the stresses and structure, but we already do that the moment we stick a drill bit into it. So, I agree with these guys, just try to dress the crack out, blending it into the flat face of the canopy and then polish the area smooth. You have nothing to lose with this method. If the crack reappears, then stop drill it and weld-on glue it.
 
manuel gonzalez said:
Just run a "red hot" wire through the whole, wide enough to consume the crack.

Not my idea, it came from someone who works with plexiglass for a living.

manny G
RV4 N146ZX
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I suspect just a little bit more information is needed before this is tried. I have never heard of this procedure before and I would be very reluctant to try it on my canopy.
 
Blend it out

I'd blend it out like a nick in the prop leading edge. I'd use a 1/8 dia burr chucked up in the Dremel. Or try wrapping a small piece of emery around a toothpick and work the area that way.
Use a shim, if necessary, between the canopy bow and the plexi to keep the plexi from distorting when you screw it to the bow.
 
what about using a pencil soldering iron with a exato blade instead of a soldering tip? I got one from Home Depot that came that way. not a expert buy any stretch of the imagination but couldn't a rotary tool make it worse? Like I said NOT a expert.
 
Any chance that you can use a piece of scrap to make a similar hole that maybe, maybe, just might have a little crack? Then you could practice on that....
 
David Paule said:
Any chance that you can use a piece of scrap to make a similar hole that maybe, maybe, just might have a little crack? Then you could practice on that....
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It's pretty hard to duplicate a small crack like that, but I will certainly be practising on a piece of scrap before I touch the damaged area. By the way,for the record I used a plastics drill bit and then a step drill to bring all the holes up to size. Except for this one hole! I absentmindedly picked up a standard drill bit to enlarge this one that I had missed.
 
I had a couple of those tiny cracks when doing the canopy 5 years ago. They are still tiny cracks....it may not be worth the effort to fix them, if they can be fixed.
 
I would keep a drill with appropriate Plexiglas drill bit with you when you go flying. You never know when you might have to stop drill a crack.
 
jimgreen said:
I guess I just joined that 'not so exclusive' club. I found this tiny crack at the most forward hole on my canopy. How would you stop drill and repair this?

Why not call Todd Canopies (1445 NE 33rd St., Ft. Lauderdale, FL, 33334
Phone # : 954-579-0874

He works with that stuff for a living.
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Dealing with crack.(not that kind)

Thanks for the opinions.
In the end I blended out the crack with a round needle file followed by emery paper wrapped around the same file point.
Once you start with the file you can no longer see the crack because you lose the transparency. So it is important to take careful note how far it extends.

When I was done with the smoothing I used a little methylene chloride to help blend out any imperfections. I don't know if that actually does any good but it seemed like a good idea.
 
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