Cutting Down a Windshield.

[fabr]

I've cut literally thousands of pieces of float and plate glass but never laminated safety glass like in a car windshield. I can ,no doubt,score and break the glass on both sides but what is the trick to cutting the plastic between the panes? Help!

[D Walker]

Heat it slightly and cut with a razor blade. A bit more work to cut a curved windshield.
Youtube has lots of videos on how to do it.
DW

[dsrace]

denatured alcohol is what we use and a razor blade. after cut on both side squirt a healthy amount of alcohol down the crack but bend the glass down slightly to let it down to the celluloid and wait a few seconds while a small amount of tension is still on it. it will almost disolve in front of you.

[fabr]

I've watched a lot of those. I have also tried it on flat laminated. Works ,OK. On curved ,I'll just say it must take a lot of practice and experience with a stack of windshields to eff up first. LOL!!!!. It is an art for sure. Most say to cut the glass first and then build the frame to make things more forgiving. Hell with that. That would be fine for a street rod or custom but I'll likely break one and need an exact copy for replacement later.
 I read a couple of places that suggest using a wet cut tile saw. One of the hand held ones with a continuous rim diamond blade. Any thoughts? I'm probably gonna give it a try since that would allow almost exact duplicates.

[fabr]

denatured alcohol is what we use and a razor blade. after cut on both side squirt a healthy amount of alcohol down the crack but bend the glass down slightly to let it down to the celluloid and wait a few seconds while a small amount of tension is still on it. it will almost disolve in front of you.

How do you dress the edges of the glass after?Flap wheel,wet sand,??? I like the wet saw thing from what I watched but who knows? The "clean" edge is what I like .What are your thoughts on that method?

[Carlriddle]

I've seen belt sander used to clean up bad spots.  Wet sand for the polished look.  The diamond sanding pads would work great and last forever.  And good continuous rim diamond bade will wet cut it like butter.  Would deff use water to cut glass, air powered  grinder with a water hose if you dont want to buy one of the saws will work. 

[D Walker]

Harbor Freight has the perfect tool, oh yea never mind.
 

[fabr]

I've seen belt sander used to clean up bad spots.  Wet sand for the polished look.  The diamond sanding pads would work great and last forever.  And good continuous rim diamond bade will wet cut it like butter.  Would deff use water to cut glass, air powered  grinder with a water hose if you dont want to buy one of the saws will work.

I've read that antifreeze makes the best coolant/lube for wet cutting glass also.

[Carlriddle]

Harbor Freight has the perfect tool, oh yea never mind.
 

 

[dsrace]

i use an up right belt sander that is as tall as myself but a hand held one will work too. wet the sand paper belt with silicone spray lube or wd 40 but we use a grinding lube spray. the upright belt sander is 2000 grit that we have a water line to so it is a wet sander. when you score each side of the glass do not bend the glass anymore that absolutely necessary to run the cut and then when you squirt the alcohol down the crack wait 20 seconds and light it. pull straight back on the glass to enlarge the crack and squirt alcohol again and wait 30 secs

[BDKW1]

Waterjet.
 
There is a place down the street from My work that has a 4 axis water jet and they do a lot of hotrod windshields. Main trick is to start off the material, piercing usually tries to separate the pieces.

[fabr]

Ya but at what cost? I have a fair amount of WJ work done each month for things not buggy related but they don't have but a 2 1/2 axis machine. I really like WJ but it's not cheap,at least not here.

[dsrace]

that would be easier but for with  what you have for tools on hand what i said will work well! been doing it for 20 years so i do know what i'm talking about lol

[fabr]

OK,you convinced me with flattery. I'll try the tried and true method first. The WS I'm using  doesn't have much curvature and I'll only need to cut approx 2" from each end/side is only 120 bux or so new .I won't be out much if I prove to be an incompetent oaf.

[dsrace]

I know you can do it