Cracked Lexan

[Rule62]

I've got a small crack in my windshield that runs from one of the bolt holes for about an inch. I don't know how it got there.

Should I shoot some SuperGlue in the crack to keep it from spreading, or should I go ahead and start planning a purchase in the near future? Or is there (more likely) another way to fix this?

[Gummiente]

Whoever assembled or installed the windshield torqued one of the bolts too tight; over time the Lucite hardens and become less pliable and that's what caused the crack. Once it cracks there's nothing you can do about it, except to loosen off the bolt a bit so it doesn't keep as much pressure on that area of the windshield. Glue will only make the area around it harder and it will eventually spread further out. The only way to stop a crack is to drill a small hole at the end of it, but this is obviously not a nice looking fix.

Best to just order a new windshield and make sure all the bolts are snug, not tight. What I do first is remove each bolt that passes through the windshield and apply a drop or two of removeable strength Loc-Tite on it before threading it back into place. That way you don't have to worry about them backing off if they're a little too loose.

[Nibblet99]

The only way to stop a crack is to drill a small hole at the end of it, but this is obviously not a nice looking fix.

Thats rather cunning, I never really thought about that

[ofblong]

Whoever assembled or installed the windshield torqued one of the bolts too tight; over time the Lucite hardens and become less pliable and that's what caused the crack. Once it cracks there's nothing you can do about it, except to loosen off the bolt a bit so it doesn't keep as much pressure on that area of the windshield. Glue will only make the area around it harder and it will eventually spread further out. The only way to stop a crack is to drill a small hole at the end of it, but this is obviously not a nice looking fix.

Best to just order a new windshield and make sure all the bolts are snug, not tight. What I do first is remove each bolt that passes through the windshield and apply a drop or two of removeable strength Loc-Tite on it before threading it back into place. That way you don't have to worry about them backing off if they're a little too loose.

acrylic glue does not make it harder and does not make it crack further. I have used acrylic glue and many many many cracks and never had an issue with the crack going any further. Course I have only been using acrylic glue on cracks for 7 years now but in that time I have nver seen one keep going or spreading.

[Starsh]

The subject says cracked Lexan, not Acrylic.

There's nothing you can do to save a windshield once it cracks. You've got to get a new windshield. I've been a plastic fabricator for over 20 years. Drilling holes at the ends of cracks to keep them from propagating works great, on METAL not Acrylic.

Over tightening bolts on Acrylic will definitely cause cracking.

If you use loctite on the bolts make sure you don't get any on the windshield, the solvents in it will attack the plastic.

Good Luck!

[ofblong]

The subject says cracked Lexan, not Acrylic.

There's nothing you can do to save a windshield once it cracks. You've got to get a new windshield. I've been a plastic fabricator for over 20 years. Drilling holes at the ends of cracks to keep them from propagating works great, on METAL not Acrylic.

Over tightening bolts on Acrylic will definitely cause cracking.

If you use loctite on the bolts make sure you don't get any on the windshield, the solvents in it will attack the plastic.

Good Luck!

acrylic is lexan but not all lexan is acrylic.

[Gummiente]

acrylic is lexan but not all lexan is acrylic.

No, Lexan is a polycarbonate thermoplastic resin. Acrylics like Lucite and Plexiglass are a polymethyl methacrylate. Lexan is similar to Acrylic in appearance only, not composition.

[ofblong]

ahh ok I dont work with it a whole ton and was just taught that everything is lexan lol.