SOT: Anyone here ever cut down a windshield?, VW Kit car needs a new windshield Options

[914rrr]

My recently purchased VW Kit Car needs a new windshield. It's possibly available new and $$$$, like $2.5k expensive.

I saw a Wheeler Dealers episode where a guy has a auto glass warehouse and evidently cuts / modifies windshields all the time to fit hard to source / NLA glass. Has anybody tried or done this, know of any old school hot rod glass shops, etc.? TIA

[Superhawk996]

Easiest - find a machine shop that can water jet it. It’s the best method but not necessarily cheap.

Or your back to the old hot rod method of score both sides of the glass almost perfectly then heating the plastic laminated layer in the middle. Unless you have someone that is very proficient - you’ll likely need easy / cheap access to a couple pieces of glass.

[930cabman]

Water jet might be an option, or find a decent glass cutter.

It's laminated glass, score and run one side, score and run the other side, denatured alcohol, flame, done

[Superhawk996]

Water jet might be an option, or find a decent glass cutter.

It's laminated glass, score and run one side, score and run the other side, denatured alcohol, flame, done

@930cabman

You are a window & glass guy right?

Have you ever done laminated? I’ve had parts water jetted for prototype automotive stuff but have never done hands on laminated myself the old school way. I had a friend that tried it through a glass shop but they wouldn’t guarantee success and it took two tries to get glass cut for a chop top project. Fortunately for him, he was cutting cheap junkyard windshields.

Wondering if there are secrets you can pass along if you’ve done it on laminated glass.

In any glass cutting I’ve done on flat glass (very limited) it either works perfectly or the glass gets a mind of its own and refuses to break cleanly along the score. I understand how running pliers help on flat glass - will they still work on curved laminated glass?

[930cabman]

Water jet might be an option, or find a decent glass cutter.

It's laminated glass, score and run one side, score and run the other side, denatured alcohol, flame, done

@930cabman

You are a window & glass guy right?

Have you ever done laminated? I’ve had parts water jetted for prototype automotive stuff but have never done hands on laminated myself the old school way. I had a friend that tried it through a glass shop but they wouldn’t guarantee success and it took two tries to get glass cut for a chop top project. Fortunately for him, he was cutting cheap junkyard windshields.

Wondering if there are secrets you can pass along if you’ve done it on laminated glass.

In any glass cutting I’ve done on flat glass (very limited) it either works perfectly or the glass gets a mind of its own and refuses to break cleanly along the score. I understand how running pliers help on flat glass - will they still work on curved laminated glass?

Yes and yes, it's mostly a feel and sound thing for me. I would not call myself a "glass cutter" but I have been doing it for over 1/2 century and I am ok. Being in the historic window restoration biz we see curved windows and complete all aspects of a project from fabricating radius sash to installing the finish product.

just like anything else, once you know, ....

one tip: glass must be clean ( I mean clean) and free from defects prior to scoring, but there are several more


back to the OP, find a decent local glass cutter (often glazier, but not always) and let him/her have at it. Far cheaper than a water jet

[dr914@autoatlanta.com]

Once, years and years ago, my younger brother Pete (many of you met him at Teener fests over the years) and his buddy Alan (two 6'3 giants) were hotrodding Pete's copper 75 914 home after a night at the bar and decided to see how fast they could take the exit loop, knowing that the 914 was legendary for taking the sharpest of decreasing radius curves. Unfortunately for these two giants of the animal world, they weren't the fastest curve takers they thought they were, the 914 was tripped by the edge of the pavement, and gently and slowly rolled over, coming to rest on the roll bar and the bent windshield frame. The two wild and crazy guys crawled out of the car, both grabbed the wheel wells, rolled it back over (yes these workout masters were able to do it) and drove the wreck home, escaping all of the consequences except for the damage to this formerly pristine copper beauty.
Nest day, they towed it to the body shop, where Sam thoroughly experienced in 914 repair, had one of his body man fix it, sectioning in a windshield frame from a dearly departed donor. After immaculate paintwork, the car was ready for its new windshield and for this car only a new Sigla would do, and after installing the 19 clips, the cowl buffers and a butyl tape kit, they carefully grabbed the windshield and laid it in the hole......but alas it was too big for the hole!!!! No one knew what to do fearing that they would have to cut the newly installed and painted windshield frame back off, get another one and start the whole process over again! A disaster. The savior came in the form of and expert auto glass installer. He simply took the 914 windshield, cut it down a bit and fitted it perfectly into the smaller hole, reinstalled the chrome and my brother drove off, saved by the bell, and learning a lesson, YES A 914 WINDSHIELD CAN BE CUT TO FIT!!!



(

My recently purchased VW Kit Car needs a new windshield. It's possibly available new and $$$$, like $2.5k expensive.

I saw a Wheeler Dealers episode where a guy has a auto glass warehouse and evidently cuts / modifies windshields all the time to fit hard to source / NLA glass. Has anybody tried or done this, know of any old school hot rod glass shops, etc.? TIA

[Superhawk996]

one tip: glass must be clean ( I mean clean) and free from defects prior to scoring, but there are several more

Good stuff . . . Keep going I’m listening and open to learning new tricks.

I have a couple beetles on deck and I really want a chop top.

Waterjetting is by far the best but in the past I wasn’t the one paying the piper. This time I might be tempted to give it a go DIY old school now that it’s on my dime . . . Being a cheap SOB and all. (IMG:style_emoticons/default/laugh.gif)

I’ve heard using heat to help propagate the score helps? Someone also told me that kerosene helps when scoring but it never seemed to be a game changer on flat pane glass for me.

Seriously I’d like to know the tricks. VW Beetle glass isn’t as cheap and plentiful as it used to be.

@930cabman

[Ninja]

(IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif) (IMG:style_emoticons/default/agree.gif)

The ability to trim a full blown laminated front window would be worth 5+ junkyard windows for training purposes.

Please start a new thread to train us properly Sensei! (IMG:style_emoticons/default/ninja.gif)

[930cabman]

It's like anything else, practice, practice,,.....

If one really wishes to undertake this task, I would suggest to practice on a small sheet of flat 1/4" laminated glass available from your local friendly glass shop. We use a table covered with indoor/outdoor carpet as a work surface. Generally the thickness of the glass is the minimum amount than can be taken off. (1/4" thick glass you can cut off 1/4" wide). Obtain a new glass cutter, we use Fletcher green/gold tip cutters for everything but I'm sure others will work fine. Lubricate your line of cut with paint thinner (we use an acid brush) and "drag" your cutter across the glass. Very important to listen for a uniform score obtained by maintaining constant (not to heavy) pressure. We use glass pliers, but Vise Grips should do the same. Tap the underside of the ending point of the score with a medium/light tap to start the run. Continue medium/light tapping to run the score across the length starting where you finished the score. THERE MUST BE A YOUTUBE FOR THIS Assuming this is successful, turn the glass over and do the same on the other side making sure the score is exactly on top of the first score. Drag your cutter across, start the run as above. Once both sides are scored and ran squirt a small amount of denatured alcohol along the cut and light it with a match. Allow it to burn out (will take a few seconds) take a straight blade and cut the PVB interlayer.

It's a bit tricky

best of luck (IMG:style_emoticons/default/driving.gif)

@Superhawk, there is no place for heat in this method

[Superhawk996]

@930cabman

Question.

Do you run the score and run on one side first via tapping only? Seems like you can’t do any flexing of anything due to the still unscored glass on the other side.

Or do you try to score and run both sort of simultaneously? Sorry not trying to be dense.

And I like your idea of finding some cheap flat glass to try 1st. Will try that.

And how do you get the 2nd score exactly over the 1st. I assume this isn’t freehand and there is some sort of edge guide that can attach to the scoring tool to offset from the edge of the glass?

Will also YouTube but I trust someone that did it for a living more than I trust YouTube which may have taken 10 takes to do what looks simple and likely can’t be done as easily in one try without editing.

[930cabman]

@930cabman

Question.

Do you run the score and run on one side first via tapping only? YES Seems like you can’t do any flexing of anything due to the still unscored glass on the other side.

Or do you try to score and run both sort of simultaneously? Sorry not trying to be dense. ONE SIDE AT A TIME

And I like your idea of finding some cheap flat glass to try 1st. Will try that.

And how do you get the 2nd score exactly over the 1st. WITH A STRAIGHT CUT ON THE BENCH IT'S EASY, CURVES ARE A BIT MORE TRICKY I assume this isn’t freehand and there is some sort of edge guide that can attach to the scoring tool to offset from the edge of the glass? NOT THAT WE USE

Will also YouTube but I trust someone that did it for a living more than I trust YouTube which may have taken 10 takes to do what looks simple and likely can’t be done as easily in one try without editing. I DID LOOK AT YOUTUBE TO SUGGEST, BUT THEY DIFFER FROM OUR METHOD.

I forgot to mention, the cutter wheel is very fragile, one cannot drag over a previous score or across another score or contact with any metal to prevent a nick in the wheel

btw, a high pressure water jet would also work well, especially if you have a connection

being in the historic building biz, we generally resort to period methods, no CNC in our shop