I have a 49 chevy coupe that I will be removing 2 - 3" from the top some day... hopefully before I die of old age. I have no problem cutting up sheetmetal and welding it all back together, but the gl***... that's another thing. so the other day I have a cracked vent window and frame in my sandblast cabinet to see if there was enough metal left under the rust to save the vent window frame. well the frame was junk just as I thought, but just for ****s and giggles I sandblasted the gl*** to see what would happen. I blasted an inch long slit in one side of the gl*** in about 2 minutes or so, turned it over and blasted another slit on the backside. the plastic in the center stayed intact until I poked it out with a screwdriver.. so I'm thinkin it can't be this easy to sandblast gl*** for a chop top or I would have heard about it before. so who has done it this way,, and how did it work out?? I'm not doing a one piece windshield, so this gl*** should fit in my blast cabinet with no problem. what would work well for taping off your line? right now I have 3 or 4 "junk" windshield halves to practice with. ( bubbles or chips) looking for a few pointers to get me started. once I do one I'll report back to let others know how it works out.
I think there was a tech week thread on this a while back... Slonaker EDIT: http://www.jalopyjournal.com/forum/showthread.php?t=124116&highlight=sandblast+gl***
I did one with heavy duck tape on both sides worked great still broke on one side then a week later broke on the other side ? I hate gl*** !
Cutting windshields is a black art. 80% luck 20% skill and knowledge. we go over and over on this subject. I would love to teach you what I know, it took me over 40 years, you wouldn't believe me if I told you. here goes anyway. I have lost (broke) 17 windshields out of several hundred. the number one thing I can tell you is any car can be chopped, not every windshield can be cut. If I break a windshield, the next one will be from a different manufacturer (there are many different companies making gl*** for cars) one of the most common manufacturers of old car gl*** is AGP (tm)out of South America. 3/4 of that 17 broken windshields are AGP's that were customer supplied. I have only had success with one AGP (tm)and that was a very simple cutting 53 Buick windshield. Good news is most of the stuff coming out of China is high quality and has been a pleasure to whack. another thing about the current re-pops are most back windows are available in Laminated gl*** and can now be cut also available in grey, green tints or clear Vericon (tm) is my all time favorite and PPG (tm) is fairly good. I like original gl*** if it is clean and clear (and not from Texas or Arizona) the heat hardens gl*** over the years. there is 50% of my skill factor. use it with any method that you've heard or read and your success rate will be based on the 80% luck factor. For me personally I'm just an old school (I hate that word about as much as Grey Beard and Old ****) gl*** guy. my only method and I've tried most ways that I've heard about (except the Tin Snips Under Water Method) and have never found anything that worked better than my old Gl*** Cutter. check out my website from time to time I'm working on a "Windshield cutting page" www.oldcargl***guy.com Jim Arnold "The Old Car Gl*** Guy since 1965 Oregon City Oregon
I'm an old fart gl*** guy also. The oldest fart gl*** guys used sheep's urine and a point to run a score in the gl***. never tried it my self. A good wheel cutter and some light oil is all i ever use. A line of napha to burn the laminate.
back to the question, use some mask, best to use sandblast rubber mask, vinyl contact paper could work. mask and blast from both sides, go slow and let the media do the work. will not work on tempered gl***.
I wasn't trying to promote gl*** cutters. I was saying pick your fights, start with the knowledge that some windshields will stress crack no matter what system you use. find a brand that will give you a chance for success. a seasoned used gl*** (unless it's lived in a hot climate) is the best shot for a beginner. I don't want your business I just like to help you build your ride!
Sandblasting works, but not always! The best tape I've found, got from an outfit that does Tombstones. Go very slowly and have the W/S well supported. I'm like Jim and just dive in with a gl*** cutter........OLDBEET
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