Repairing large window cracks, can it be done?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

Subscribe get a full year for only $23.95 Sample Free Test Drive—no strings attached

Nov. 20, 2009 9:17 a.m. Jeff Dork

The RX has a cracked windshield. It runs from top to bottom. I was going to replace it with Lexan, and may still do that, but of course that would make me illegal in SCCA ITA/7.

So the options appear to be replace with used (new is way to much) or figure out a way to fix this that will pass tech. Can you epoxy a long crack and stabilize it? What about using helicopter tape? Will that pass tech?

It's a huge pain. A used window is going to run me at least $75, that's more than the Lexan. And it's going to get cracked again. Anyway, thanks for any advice.

J
Nov. 20, 2009 9:50 a.m. mad_machine SuperDork

I am curious... why is the used window going to get cracked again? Less than $100 for a window does not seem bad to me
Nov. 20, 2009 3:00 p.m. benzbaron Reader

Get the window crack repair kit for 10$ from your local parts store. It says it will repair cracks up to 12inches. You basically suck out the air with a special syringe and it sucks the epoxy into the glass and dries clear. You put the car in the sun to cure the epoxy. It worked good on a star crack in my car, but you have to realize the purpose of the process to do a good job. You really want to get as much air out of the crack as possible. I didn't realize that untill I was done. The crack hasn't grown in the last 4years though.
Nov. 20, 2009 5:17 p.m. Travis_K Dork

Id say attempt a repair at home, and if it doesnt turn out, just consider it a racing expense. For running an IT car, occasionally spending $75 for a windshield doesnt sound that bad.
Nov. 20, 2009 6:39 p.m. gamby SuperDork

benzbaron wrote:

Get the window crack repair kit for 10$ from your local parts store. It says it will repair cracks up to 12inches. You basically suck out the air with a special syringe and it sucks the epoxy into the glass and dries clear. You put the car in the sun to cure the epoxy. It worked good on a star crack in my car, but you have to realize the purpose of the process to do a good job. You really want to get as much air out of the crack as possible. I didn't realize that untill I was done. The crack hasn't grown in the last 4years though.

I've never gotten one of these kits to work right on a larger crack. Smaller cracks and spider cracks, sure, but not the big ones.

(amazed at the lack of crack innuendo)
Nov. 20, 2009 7:27 p.m. mad_machine SuperDork

gamby wrote:

(amazed at the lack of crack innuendo)

No plumbers on the board
Nov. 20, 2009 7:45 p.m. porksboy Dork

Nust say no to crack. There it has been said. My thought is to try a repair. If it doesnt work what have you lost? $10-$15 for materials? You can spend that on lunch around these parts.
Nov. 20, 2009 8:24 p.m. Tyler H Dork

Racing is expensive.. I would hate to transport a car to a race, have a problem with tech, and then scramble to try to find someone to replace the glass on a weekend.

If it were me, I would just go get a windshield put in it.
Nov. 20, 2009 9:08 p.m. skruffy Dork

Edit: I sounded like a butthead in what was previously written here.

Not passing tech due to a broken windshield would be a really stupid way to ruin a weekend.
Nov. 20, 2009 9:55 p.m. benzbaron Reader

Wish a new winshield for my car was only 75$. Try 355$
Nov. 20, 2009 10:23 p.m. Jeff Dork

Thanks for the advice.

The Lexan sheet I need can be bought for $74 plus shipping. There are some local places I need to check too. Don't know if the price had gone up from the last time I checked or I just didn't have the dimensions correct. I'm trying to get firm quotes on a used windshield, the $75 for that was a guesstimate after talking with folks.

I know having to dump $100 bucks here or there into a race car is par for the course. I was just hoping to do it with something that I know would most likely last a fixed amount of time (Lexan, usable for 2 years before it pits/yellows to much? 3 years?) vs glass which can break the first time out on the road/track.

I think I'll try the epoxy, that should be good enough for autoX. If it looks really good, I'll get a tech inspector to look at it. NASA PT allows Lexan, so that may be the way to go.

J
Nov. 20, 2009 10:58 p.m. mad_machine SuperDork

try the epoxy.. then go with a replacement windshield AND keep a fresh batch of the repair epoxy in your tool box. This way if you get another crack or a star, you can hopefully repair it before it gets too big.