The DUNGBTL Build

[Yarkle]

those popout windows are a great idea. i was looking at them a few days ago for when i put poly windows in my thing
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JuadaLupe 1974 Thing [o\==/o]

[DUNGBTL]

[bruceo98]

Looks like it came out nice . Had it in my race car . Good thing is if they get scratched, you can buff them out . What’s the 50 dollar charge for select mounting?
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I may not be the best, but when the top 10 get together, they all talk about me.

[DUNGBTL]

Polycarbonate Windows (aka, Lexan, etc.)

Some good weight savings was made by using 3mm thick hard coated (abrasion resistance) polycarbonate to make the quarter windows. The OEM 0.190” thick quarter glass weighed 10.4 lbs/2 windows…the 0.118” thick polycarbonate replacements weigh 3.3 lbs/2 windows. A solid 7 lbs of weight savings from a good distance above the CG of the car…in the rear…

The material was purchased from TAP plastics…who will custom cut sizes. They will even cut specific shapes if you send them a cardboard template.

I ordered 2 14x27” sheets

I used the OEM glass as a template…

Experts will tell you to use a jig/band saw with 6 or more TPI to cut the plastic. I found my 4 1/2” angle grinder w/a well used .040” abrasive metal cutoff wheel worked just fine…your mileage may vary…

Wear a respirator because this generates a lot of plastic powder…micro plastics! I used 220g sandpaper to smooth and slightly round the cut edges.

3.3 lbs for both poly quarters…

I taped the 2 windows together and made a template for the 3 1/4” diameter Popit vent. Decided on a vent location that I could reach from the door opening. With the roll cage and fixed back seats it’ll be a reach…but I think it will be easier than trying to reach and operated a OEM style pop-out window! RACECAR(ish)!

Stacking the two windows and drilling a pilot hole for the center location ensured perfect symmetry.

Used a hole cutter to cut the required 3.25” hole…

…cut half way thru…

…flipped and cut thru from opposite side.

This prevents a ‘break-out’ ridge on one side. Used soapy water as lubricant (do not use oils when cutting poly) and low speed (540 rpm) to make clean cuts.

I used ‘Cal-Look’ rubbers from West Coast Metric. Since the poly windows were cut the exact same size as the flat OEM glass ones, the rubbers fit perfectly. However, they were a PITA to put on as the 0.188” poly windows are very flexible in their unmounted state…

INSTALLED!

I’m leaving the protective film on the windows and not installing the vents until the car is done…I still have some painting and grinding to do, so I want the windows protected.

I want to thank everyone who replied and suggested different cords/wires/ropes, et al, for installing windows. I appreciated the tips as this is actually the first car where I’m installing these kind of windows myself. The Porsches I built I hired a glass guy to come to the shop and install. Of course he made it look easy!

I tired 7/32” vinyl coated clothesline…too thick, no go. I found that surveying line wrapped twice around worked great!

However, I learned that the technique is to pull the string, or whatever you’re using, such that the rubber lip is pulled out and over the window flange. I think on my previous attempts, I was just pulling the chord thru the rubber…DOH! I believe I’ve got the technique down now!

The polycarbonate windows in the Cal-Look rubbers are solid and taught…surprisingly so considering how flexible they are compared to the glass. Summer time and triple digit temperatures will be the test as the polycarbonate will expand and, from my experience, take a more concave appearance. But I have no concerns about them popping out.

I was going to buy a formed polycarbonate rear window from Plastics4Performance in the UK but with the shipping AND the ‘new’ import tariffs it isn’t cost effective. So I installed the OEM glass rear window. I’ve since removed it.

Removed it because H20SB told me about a domestic producer of poly windows for Beetles…Ron Lummus Racing…RLR. They sell a 0.188” thick flat rear window. I priced out the cost of my making my own flat window, however for the 20x38x0.188” hardened polycarbonate sheet required, it was only $50 more (shipping cost) to have RLR ship me one of his. So that’s what’s happening…it gets delivered on Wednesday…

The 0.190” thick OEM glass rear window on my ‘72 SB weighs 10 lbs. I anticipate the poly window will be at least 1/2 that. That’s another 5 lbs removed from even higher up from the vehicle CG! …12 lbs total loss for polycarbonate quarters and rear windows.

To quote Colin Chapman (Lotus, etc.): "Adding power makes you faster on the straights, subtracting weight makes you faster everywhere."

J.

[DUNGBTL]

…have to finish mine first!

[bruceo98]

[H2OSB]

[bruceo98]

Now you can just reach over and flip it. Nice job.
Wiring looks great. you need to take a vacation to here. lol
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I may not be the best, but when the top 10 get together, they all talk about me.

[DUNGBTL]

RE. Battery cutoff switch…

[DUNGBTL]

Drape forming…I hadn’t considered using a two window sandwich to capture the compound curvature. Cool idea…thanks!

I think it’s around 300-350F that the poly becomes formable…getting even heat throughout the sheet seems to be the issue from my research. That and not forming tiny bubbles in the plastic from overcooking. Could be a fun ‘experiment’…might have to try it! Not now though…trying to focus on getting a rolling chassis.

Thanks!
J.

[SnowDaySyncro]

Setting a curve into polycarbonate for the rear window may not be necessary, but it's also no too difficult, well within the abilities you've already shown on this thread. I used to bend sheets of it for outdoor signage with a plug in heat strip.
To replicate that curve, I'd cut a piece a bit larger than necessary, then I would either make a matching curve from smooth metal or a rear window supported from below. Next, I'd lay the flat sheet of polycarbonate on top of it, then set the rear window on top, then confine them at the ends to limit lateral movement. Next, I'd warm everything up with a space heater to reduce the chance of breaking the original glass with abrupt heat, then introduce more heat with a heat gun or a propane torch with a diffuser until the polycarbonate softens and slumps, getting sandwiched between the two windows or the window and curved support (if you lived nearby, I'd happily give you a late rear window. Also, if you can find a non-defroster window, put that one on top, as there's a possibility the lines could make slight imprints. A mat of some sort or even thin plywood would also work. It's been long enough that I don't recall what materials I used as buffers, but I know that wood didn't stick. You do want to avoid synthetic fleece that could melt or fuse.

If it was summertime, you could do the pre-heating with a solar hot box. Once you get the curve, make a template from the outside surface of the original glass with kraft paper or other non-stretch sheet with a perimeter of painters tape. Transfer to the polycarbonate, trim, and install.

[DUNGBTL]

Thanks for the input guys…appreciate it.

After the install I examined both the 14g insulated wire and the .080” weed-whacker line. Both had nicks/gouges along their length from pulling over the pinch weld. Enough to explain all the hang-ups while pulling. I’ll try either the 1/4” nylon rope or the cloths line for the quarter glass. Doing the windshield last.

For the quarter glass, I’ll be making 4.5mm thick polycarbonate windows using the OEM as templates. I’ll be using Cal-Look rubbers to mount them in the opening (4.5mm thick allows for this). The stock quarter windows weigh ~10 1/2 lbs total…

I anticipate ‘adding 5 lbs. of lightness’ with the polycarbonate windows.

I thought about doing OEM pop-out windows, however the cost of the OEM pairs, and the cost and ‘sealing’ issues of the re-pops turned me off…not to mention the added weight of the extra frame & hardware.

I had pop-outs in my ‘64 KG and really enjoyed them in the summer. I came up with a lightweight solution…

…by added these to the quarter windows…3 1/4” dia hole.

Originally I was going to install a polycarbonate rear window…heat formed to OEM curvature, not just a flat sheet, CNC cut to fit in the stock rubber…

They’re made in the UK…with shipping the cost is doable…but now with the additional import ‘tariffs’ not so much. So, I’ll wait. The rear window is ~16-17 lbs and is up high (raises CG). The poly window is ~1/2 that so there’s good CG lowering weight savings to be had…but right now the cost is too high.

J.

[SnowDaySyncro]

The smooth white plastic clothesline from Ace Hardware is the best window seating cord I have ever used. No fibers or ridges to snag on the pinchweld like rope and trimmer line, respectively.
A tall, large friend with large hands is my go-to helper for VW windows.

[bruceo98]

Yeah , about 3/16-1/4 will work .
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I may not be the best, but when the top 10 get together, they all talk about me.

[vwuberalles]

I've always used 1/4" nylon rope. We just did my bus rear window this past weekend in fact!
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1973 Superbeetle: 1st car, owned since age 12. Update thread --> https://www.thesamba.com/vw/forum/viewtopic.php?p=9919140#9919140
1967 Kombi: Owned since age 17, Dad's retirement project.
1966 Beetle: My new project. (SOLD) Build thread--> https://www.thesamba.com/vw/forum/viewtopic.php?t=678040

[VW_Jimbo]

Weed whacker line and some wire slime! Works great!

I wrap the inside of the rubber groove twice. Just in case! Easy enough to pull out!
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[H2OSB]

I have flexible wire, maybe 3/16th inch, long enough to overlap by a foot on the windshield. Then, on each end I tied on 4 inch gray PVC pipe as handles. I chose the wire because it has a plastic covering that I thought would slip easier. I used it for years. On a windshield or rear window, I'll have a kid push in where I'm pulling on the wire.

IIRC, the wire may have been automotive speaker wire. The kind you can split into two separate wires.

H2OSB
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(o\_i_/o) Funny thing about pigs, they're cleaner than you and me. Well....you.

[67rustavenger]

I've used para cord to install windows in the past. It worked a treat.
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I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!
2003 Astrovan? GFYS again, Xevin!
Don't let your bad ideas remain, ideas!

[DUNGBTL]

[bruceo98]

Yeah they can be a pita sometimes. I use nylon rope with lots of lubricant. Set the lower in first and have someone gently press down as I pull the rope . Looks good .
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I may not be the best, but when the top 10 get together, they all talk about me.