Fixing acrylic

[Esser]

Has anyone successfully fixed acrylic? I just made a 1" crack on one of my bubble doors at the rear. Do I drill stop the crack and then repair? Or just use the acrylic repair stuff without drill stopping the crack.

[David47]

Josh, I'd recommend stop drill the end of the crack. Probably 1/8" (minimum) drill size should be ok. Use the very end of the crack as centrepoint for the hole. Maybe use a magnifier to make sure you identify the crack end point.

[Esser]

Sounds good. Then I'm going to try my hand at injection methyl chloride into the joint which should fix it up

[jmodguy]

I used to fix acrylic avionics faceplates when I was in the Navy.
This is what we would do.
Stop drill it, grind some scrap into a powder and stuff in the hole and apply your fusing chemical. Don't use sandpaper, you could end up with silicon bits in your powder.

[Esser]

Thanks for the tip Jeff, you think if I use a file to make the powder it will work? Will tape be good enough to stop the shavings from dropping through? Or do I need something more substantial with the chemicals involved?

[efwd]

I see you glueing the tape to the acrylic if you do that. Think youll need to find something thats not going to adhere to your chemical. Maybe silicone or wax paper or something.

[jmodguy]

Teflon tape or glass. Sticky side away from the repair. Easy on the chemical. Use a natural hair bristle small paintbrush and dab it on. Test the brush first to make sure it doesn't melt!
A file is good. Make sure it is clean is all you need to do. The size of the 'teeth" will determine the size of your filings.

[Guy Buchanan]

The glider guys at my field stop drill then adhere an interior patch over the entire crack, It looks to be about .06" thick. It is usually 1" outside the crack.

But here's a much more elaborate repair:

http://www.soaridaho.com/Schreder/Construction/Canopy/Canopy_Crack_%20Repair.htm

[Esser]

So I fixed it. Definitely not a pro job as I spilled a little and clouded the acrylic a bit, I tried to fill the hole as you can see. Not great but beats a new $500 door! I may try to buy some thin acrylic to put a small patch on the inside to hold everything together. The drill stop is probably enough though

[efwd]

Well I think I could live with that as well vs $500 replacement. I actually have two cracks straight out from the screw holes to the edge. hoping the screw hole was deburred well enough to not allow it through.:confused:

[efwd]

Well while were here, let me tell you, I didn't even put hardly any pressure on that screw as I tightened it and the acrylic snapped straight out the edge. I think you kind of have to think "allow the adhesive tape do the bonding and let your screws be there to keep it from flying off". I will probably go back and use the elmers glue trick on the screw in place of loc tite. They can really be that loose when you start seeing the plexy flex.

[David47]

Well while were here, let me tell you, I didn't even put hardly any pressure on that screw as I tightened it and the acrylic snapped straight out the edge. I think you kind of have to think "allow the adhesive tape do the bonding and let your screws be there to keep it from flying off". I will probably go back and use the elmers glue trick on the screw in place of loc tite. They can really be that loose when you start seeing the plexy flex.

You're right Eddie, you really do need clearance holes in the door window and need to go gently on tightening up the screws. Temperature variation will make that panel expand and contract so the clearance holes allow for that. The tape adds some flex when tightening the screws. I'm starting the door window installs in a few weeks. It'll be a case of gently, gently I think.