# How To Repair Cracked Plexiglass



## JIMMIEM (Apr 4, 2010)

Any suggestions on how to repair cracked plexiglass? I have a 3 inch crack in a 1 piece storm window. It starts at the edge so I was thinking maybe spread it apart and use crazy glue?


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## kp91 (Sep 10, 2004)

Plexiglass Acrylic Glue - IPS Weld-On & Plastic Adhesives Online

I would do a bit of checking on which adhesive is best for the type of acrylic you have. There is a decent guide on this link.

Mask as close as you can to the crack to avoid the glue from 'melting' the surface of the acrylic when it squeezes out.


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## JIMMIEM (Apr 4, 2010)

kp91 said:


> Plexiglass Acrylic Glue - IPS Weld-On & Plastic Adhesives Online
> 
> I would do a bit of checking on which adhesive is best for the type of acrylic you have. There is a decent guide on this link.
> 
> Mask as close as you can to the crack to avoid the glue from 'melting' the surface of the acrylic when it squeezes out.


Thank You. I looked at their web site and will give them a call next week.


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## CharleyL (Feb 28, 2009)

I would replace the Plexiglass with clear Lexan. It doesn't break. They make bullet proof windows from it, although those are much thicker than you will need. (Don't expect 1/8" Lexan to stop a bullet). 

Charley


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## Stick486 (Jan 4, 2013)

CharleyL said:


> I would replace the Plexiglass with clear Lexan. It doesn't break. They make bullet proof windows from it, although those are much thicker than you will need. (Don't expect 1/8" Lexan to stop a bullet).
> 
> Charley


agreed but it is nick sensitive as is plexi...


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## Gene Howe (Jul 10, 2007)

A cop told me that 1/4" Lexan would stop a 30-30. He used it behind his uniform shirt.


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## Stick486 (Jan 4, 2013)

Gene Howe said:


> A cop told me that 1/4" Lexan would stop a 30-30. He used it behind his uniform shirt.


good luck w/ that...


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## RainMan 2.0 (May 6, 2014)

Gene Howe said:


> A cop told me that 1/4" Lexan would stop a 30-30. He used it behind his uniform shirt.


Maybe a BB gun lol .
On myth busters they shot a box made out of 1" lexan and the 30-30 went threw both sides like it was butter . Would stop small arms fire though .

And the only window that will stop a 50 cal is 1.6" thick transparent aluminum .


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## Cherryville Chuck (Sep 28, 2010)

Drill a small hole at the end of the crack or it may keep running. The hole distributes the stress.


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## RainMan 2.0 (May 6, 2014)

Cherryville Chuck said:


> Drill a small hole at the end of the crack or it may keep running. The hole distributes the stress.


Good call Charles , 
I going to mention this also , as I swore I heard that before to


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## TenGees (Sep 12, 2012)

In the sign business we used to use what we called "methylene". It's thin like water. I found a video of it being applied: https://www.youtube-nocookie.com/embed/3KzZDi-aXD4. If you get a spill or a run, it will ruin the finish (gets cloudy etc.) We used to drill the end of cracks too, as already mentioned. If you soak drill shavings in it, you can make a thick glue (not good for getting into cracks). The trick is to watch it enter the crack and move along as it fills it. Linger too long and it will run or puddle. Too fast and it won't go all the way in. Once you partially glue, it's hard to get more glue in the crack. Keep the crack that you're gluing off of your bench (or anything) because it will make a mess on the bottom.


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## schnewj (Nov 18, 2013)

TenGees said:


> In the sign business we used to use what we called "methylene". It's thin like water. I found a video of it being applied: https://www.youtube-nocookie.com/embed/3KzZDi-aXD4. If you get a spill or a run, it will ruin the finish (gets cloudy etc.) We used to drill the end of cracks too, as already mentioned. If you soak drill shavings in it, you can make a thick glue (not good for getting into cracks). The trick is to watch it enter the crack and move along as it fills it. Linger too long and it will run or puddle. Too fast and it won't go all the way in. Once you partially glue, it's hard to get more glue in the crack. Keep the crack that you're gluing off of your bench (or anything) because it will make a mess on the bottom.


Methylene Chloride is great at this. However, is is highly toxic and is a carcinogen (cancer causing) chemical. If you do use it, please wear the proper gloves and do not get it on your skin.

NASA banned it from their facility, however, I got an exemption for the carpenters to use it in the shop. It was the best glue to make plexi display cases. There were only two people who we allowed to use it, and the supply was kept under lock and key.

I would not try and spread the crack apart. This could cause it to run even more then it has already.


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## kp91 (Sep 10, 2004)

Cherryville Chuck said:


> Drill a small hole at the end of the crack or it may keep running. The hole distributes the stress.


We "drill" small holes using hot nails, and larger holes using bits that have been ground at the cutting edge corner to prevent it from catching and cracking the plexi.


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## Gene Howe (Jul 10, 2007)

Stick486 said:


> good luck w/ that...


Hey, if it made him feel better.....


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## OPG3 (Jan 9, 2011)

*I DO NOT KNOW IF THIS IS 100% ACCURATE,*
but I paid serious cash for a guy to build me a very nice reptile display case. It had a waterproof floor and four transparent sides. He used Plexiglas. Somehow he had made it where the corners were free of gaps. There was also a top frame on all four sides and a piano hinge allowed the top to lift upward for servicing. I was amazed at the quality of his workmanship! When asked how he affixed the Plexiglas corners together, his simple answer was, "I used formaldehyde". I never got any more details, but I do know that working with that stuff is quite dangerous! 

Otis Guillebeau from Auburn, Georgia


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