Thinning windshields

[dragstk]

I have been working on the Lindberg 64 Dodge 330. The windshield is way,way to thick. And it is really distorted. (Actually all the glass is bad but the windshield is worse)

Anybody have a technique to thin the glass? Yes, I know I could be making a new one from thin Evergreen or something similar. But I'd like to use the stock glass but also maybe learn something new.

Thanks

Jeff

[64SS350]

I'm having the same issue on the AMT Blazer. I have some sheets from HL, but it scratches so easily, even with a soft cloth. I'll be following to hear suggestions 

[StevenGuthmiller]

I suppose that there might be a way to thin kit glass if you really want to do a heck of a lot of work for absolutely no reason, but I wouldn’t know how.

I’d be interested, and very surprised, to see if anyone has ever attempted it.

I have my doubts.

 

 

 

Steve

Edited December 5, 2023 by StevenGuthmiller

[NOBLNG]

I have not tried it myself. I do however have a horribly thick leftover windshield from a Corvette that I replaced with sheet plastic. I will give it a try sometime just to see if it can be done. I think if flat sheet cannot be used due to compound curves, then vacu-forming one is likely the best option.

Edited December 5, 2023 by NOBLNG

[bobss396]

Vacu-forming one is probably the answer. Make up a simple smooth wood buck and give it a go. You could try sanding the kit piece thinner, but they get fragile fast. And you'd be polishing it forever.

[Ace-Garageguy]

13 hours ago, dragstk said:

Yes, I know I could be making a new one from thin Evergreen or something similar.

 

13 hours ago, 64SS350 said:

I have some sheets from HL, but it scratches so easily, even with a soft cloth. 

Use PET available for FREE from soda bottles...and it doesn't scratch easily.

 

[64SS350]

15 minutes ago, Ace-Garageguy said:

 

Use PET available for FREE from soda bottles...and it doesn't scratch easily.

 

I have used product plastic when I built slot cars, but to heat shrink it like that.....genius!!

[Bainford]

I've done this a couple of times. The biggest issue is properly supporting the windshield, especially during the polishing stage. It is also more difficult when working with significant compound curves, as it is often the inside surface of the glass that exhibits the most optical distortion. And it is a very tedious process.

I attack it with files and course sandpapers, though try to limit the work done with course sandpapers as a roque bit of grit can put a deep scratch in the glass. First get the inside as 'flat' and smooth as possible to reduce optical distortion. Once the inside has been resurfaced to satisfaction, then do the majority of the thinning on the outside surface. The biggest issue is repeatedly over flexing the plastic while working with it, which causes micro-fractures in the glass that can't be removed, and show up when the light hits it just right. When the 'glass' is thinned, begin working it by wet-sanding with fine sandpapers and MicroMesh pads, being sure to work each grit thoroughly before proceeding to the next. Finish off with all three grits of Tamiya polish and a good dose of Tamiya wax.

Definitely a tedious process, and very easy to damage the glass. Compound curves are more difficult, as it limits the amount of work that can be done with a flat file. However, non-compound curves are also the easiest to make from scratch. I recommend re-making from clear sheet stock whenever possible. I thought I had more photos of the process, but all I can find is a Chaparral windscreen on which I did all the work on the outer surface only.

The windshield on this Mustang exhibits the micro-fractures from over flexing during polishing. It can be seen as a cloudy area just above the driver side wiper. I went through three windshields for this car (since I had a bunch of them), each suffered the same issue. There is also still optical distortion, as I tried to go much lighter on this attempt to avoid the micro-fractures. It didn't work. Some kit windshields are much more prone to this micro-fracturing than others. Some can take a lot of abuse, and others, none at all.

Edited December 5, 2023 by Bainford

[espo]

There are times when it may be easier to create replacement clear windows rather than trying to thin out what the kit provides. Evergreen Scale Models is one supplier that offers sheet styrene that can be used. They have .010 x 6" x 12' sheets in clear as well as tinted colors. The material has just enough rigidity that it can be bent slightly to match the curve of a windshield or back glass without showing a bend line and stays in place with just a touch of clear glue and remain unseen. 

[peteski]

Thinning kit's entire windshield (or any "glass") is pretty much impossible because you woudl have to be able to reduce the thickness of the inner surface by exactly even amount. I just don't see that being possible (especially on a windshield with complex curves). If you don't have it done evenly, it will cause optical distortion.  Plus all the smoothing and polishing would take a lot of time.

Also, even if very thin, the kit's windshields are out-of-scale thick anyway. Best solution is to use the windshield as a buck for forming a new windshield from thin clear material (such as PET).  Vacu-forming or similar heat-forming method should produce a scale-thin clear windshield.

[StevenGuthmiller]

For a ‘64 Dodge, there’s no need to go through all of the work of making bucks and vacuum forming glass.

The windshield is relatively flat without any compound curves and should be pretty easy to replicate in clear sheet plastic.

I use .007 “Lay Film”, tape it in place, glue with clear epoxy where there’s no tape, and once cured, remove the tape and add more epoxy.

once done the glass should be perfectly formed in place, and with the epoxy, it’s not going anywhere.

I’ve used nothing but variations of this technique for some time.

Haven’t used kit glass for any of my builds for some years.

 

 

 

 

Steve

Edited December 5, 2023 by StevenGuthmiller

[dragstk]

Thanks for all the replies and ideas.

@ Trevor -What you went through was kinda what I saw happening. Unfortunately, I only have 1 windshield to work with. But you did have some nice results

@Bill- Thanks for the link. I read this through and I might try it just to learn something and maybe Ill get a windshield out of it

@David- This is another thought I had as a possibility. I just wasnt sure it is clear enough or had enough rigidity. But its on my list to try.

@Steven - What is "Lay Film" and where would I find some? This sounds like a good way to go about this.

 

Thanks again for all the options. I think sanding will be my last resort. But I have enough options to keep me busy for a while. ?