Can old yellowed window plastic be cleared?

[imkruzn]

I have an old 1959 Buick Dealer's model that I am rebuilding. The clear plastic window glass has yellowed over the years. Is there a way to clear the yellowed plastic?

[imkruzn]

Thanks for your suggestions. When I said 'clear the yellow' I didn't mean clear coat. I was just asking about removal of the yellow. What is Future?

[Art Anderson]

I have an old 1959 Buick Dealer's model that I am rebuilding. The clear plastic window glass has yellowed over the years. Is there a way to clear the yellowed plastic?

It sounds like your model is a promotional model, and if that is the case, it's molded in acetate plastic. However, by 1959, AMT (and just about every other promo mfr) was using clear styrene for the window glass. You might consider this, however:

Back in the day of that promo, tobacco smoke was prevalent in a lot of places where this promo model might have been displayed--in the dealership, or in someone's home. Tobacco smoke, along with the airborne fumes from cooking, can "yellow" plastics (and in many cases, literally "eat" the plating off chromed plastic model trim!). To check this, if you have removed the glass from the model body, look to see if there is a "shadow" effect where the clear part was hidden under the body itself (at the bottom of the windshield and back window, where it was "trapped" between body shell and interior, and on the area of clear plastic that joins the windshield and back window together as a single plastic part). If those hidden areas are still clear, then simply polishing the "glass" with say, Micro-Mesh polishing compound and their flannel cloth, on both sides of the glass should remove the yellow staining. If the entire clear part is yellowed, I know of no way to return that to clear, as most likely the "yellowing" is within the clear plastic itself--going all the way through the part.

Many older AMT 3in1 kits, even though molded in white styrene, would yellow over time, but in my experience, that yellowing was just in the surface--whenever I would modify one of those body shells, the mere act of cutting, filing or sanding the plastic would expose white plastic beneath the original molded surface.

If you cannot return the windshield and back window to clear, about your only choice would be one of the two: Find an AMT Craftsman Jr. '59 Buick hardtop which was molded directly from the promotional model tooling, or an AMT 3in1 customizing kit of the '59 Buick hardtop--both of these have exactly the same window glass as your promo. The '59 or '60 Chevy kit glass from AMT/SMP won't fit, due to those kits having a very inaccurate "arch" to the top of their windshields.

Art

[Art Anderson]

Thanks for your suggestions. When I said 'clear the yellow' I didn't mean clear coat. I was just asking about removal of the yellow. What is Future?

"Future" is Future Floor Polish, which is a waterborne, absolutely clear liquid made for your kitchen floor, but can be used as a clear coat in model building.

[Harry P.]

What is Future?

Future (now called "Pledge with Future Shine" for some weird reason) is liquid clear acrylic. It's meant to be applied with a sponge mop to kitchen floors, tile, hardwood floors, etc. to give the floor a protective coating and a gloss. Since it's actually nothing more than clear acrylic, many people use it as a clear coat on their models (it can be airbrushed, or parts like aircraft canopies can be dipped in Future). Because it's acrylic and not enamel, it won't yellow like clear enamels can.

[Tom Geiger]

Caution- Try this at your own risk. I once put glass from a 1960 Valiant that had some paint on it in 90% alcohol. Not only did the paint come off, but the yellow was gone from the glass! It turned clear.

[zenrat]

The Modelhaus list vac formed "glass" for a 1959 Buick Invicta.

Would this do the trick?

http://www.modelhaus.com/index.php?y=37&c=4023&pt=26&part=1&Submit=Search

[imkruzn]

Thank you all for your info and suggestions. My '59 Buick is a promo model, I think, or maybe a toy. It had a friction motor that is missing, which is OK because I just wanted it for display. I got it for a quarter of the price of new/old models or other promo models. I am re-creating my favorite real cars from the past. It appears that my 'glass' has yellowed from age. There is no clearer area where it was attached to the body but yellowed uniformly throughout the 'glass'. I will try the alcohol dunk and check out the window 'glass' at Modelhaus.

[Shardik]

Turtle Wax has a kit for restoring yellowed plastic headlight covers. It worked quite well on my 1:1 but I haven't had occasion to try it on a model.