your thoughts..fixing warped plexi..Will this work??

p1899m

New member
Joined
Jul 12, 2007
Messages
9,119
Reaction score
72
Location
Rocklin, California
your thoughts..fixing warped plexi..Will this work??

So I have played with plexi and a heat gun know it's pretty easy to take a flat piece of plexi and heat it to where it can be bent to whatever shape is desired. I have a bagman cpo that is pretty warped and was wondering if I took the cpo and placed it on a flat surface then heated it with a heat gun if the plexi would flatten. I'm kind of guessing it would. Although I have doubts about weather or not the screened art would be destroyed, damaged or
uneffected. I've never tried heating screened plexi before. Your thoughts?
 
There are 2 methods that work to varying degrees of success for pinball plastics.

Method 1 - Put the plastic between 2 flat pieces of glass, in the hot sun.

Method 2 - Put the plastic on a flat, smooth baking sheet and put it in the oven. YOu'll have to search rec.games.pinball archives for details on this, but I did it and had good luck. I heated the plastic, on parchment paper actually, until it started getting softer. I then took it out, carefully put it between 2 pages in a book and weighted it down with stuff on top of the book. Lots could go wrong, but it worked great.

Research this, but there's risk involved.
 
They were F-14 Tomcat pinball plastics, and I 'believe' I layed the top/non art side against the baking sheet. Careful that something on there could imprint into the softened plastic. Yes, silk screened art, with the white layer. The artwork didn't get affected. I'd think this way could easily go bad, so I tried one small, really warped plastic first. With your situation, it's all or nothing. I'd seriously read up on this in the rec.games.pinball archives and google search 'flatten pinball plastics' and stuff. I'm just saying what worked for me, not that you should necessarily try it.
 
I'm a DJ and we use the two sheets of glass method on warped records. Heat from the sun is usually enough to get it flat. You definately don't want to overdo it.
 
I had a buddy that used to make plexi (or polycarbonate, I forget) speaker enclosures for competition stereo stuff. They used a heat gun to bend it. Apparently it's not difficult to do, but requires a bit of practice (read: screwing stuff up) to get just the right the touch. Apparently the coup de grace is to hand bend a 90° with a smooth surface and no bubbles inside the plexi.
 
I've straightened some pinball plastics and one marquee in the oven. The key is to keep the oven temp low and watch it.

I found the best stuff to use was Reynold's Release aluminum foil to put on the bottom of the cookie sheet. It has a silicon release coating on one side so the plastic didn't stick. I used a brand new heavy gauge cookie sheet so it was perfectly flat and some small steel weights on top (with release al foil on the bottom).

As I recall, in my oven it was about 15 minutes at 225 degrees, but start low as oven temps vary a lot expecially at the low end and check it every couple of minutes. You just want it soft enough to have the weights bring it flat and hold it while it cools down.

ken
 
Back
Top Bottom