How to fix warped plastic??

djkest · Post by **djkest** » Sun Dec 30, 2007 5:18 am

Okay, this is an odd question for sure but possibly someone might know. I painted my guitar hero guitar yesterday, and I threw it in the oven at 175F for about an hour. Low and behold, the plastic body pieces all warped from the heat I'm not sure how I can "straighten them out" so to speak. So here is some possible solutions I've been thinking of...

1) using the 11 body screws, attach the two body pieces together, and then put them in the oven to "meld" them to each other

2) put the pieces on a flat sheet and put some sort of weight on them, bake

3) Combination of 1 and 2.

Btw, paint fumes are gross.

Bluefront · Post by **Bluefront** » Sun Dec 30, 2007 5:49 am

Whatever gave you the idea you could bake plastic without warping?

Try using a hair drier at low settings....you can direct the heat at the section that is warped. Support it straightened out till the plastic cools.....

seraphyn · Post by **seraphyn** » Sun Dec 30, 2007 5:53 am

Isn't there a way to paint the things without having to bake them? I've seen some people paint their PC cases and Mice without a mention of having to put it in the oven.

*edit

Dug up a thread about it

http://coolercasesuk.co.uk/showthread.php?t=161

JoeWPgh · Post by **JoeWPgh** » Sun Dec 30, 2007 7:33 am

I think you're doomed to have a warped guitar body. When you heated the plastic, it expanded and softened. It's own weight caused it to sag and stretched the surface area.
I don't see how you'll get that toothpaste back into it's tube.

djkest · Post by **djkest** » Sun Dec 30, 2007 7:35 am

I'm trying to soften it up and then press down on it so it cools in the proper position.

Success! Or at least, sort of. I carefully pressed the two warped pieces of guitar base together, inserting the screws and going from one side to the other. Getting the last screw in was really hard. Then I cranked down on all of them for a tight fit. I baked it for about 30 min, then removed it and let it cool with some heavy books on top. After it was cool, I removed the books and took the screws out. The two peices are less warped, and all the screw holes line up without any manuvering.

The downside is, the edges don't quite match up. Doh!

So yeah, plastic may not "melt" at 175F, but it softens enough to take on new shapes.

And I baked it to help the paint dry, since the paint was not really drying well earlier.

I'll be sure and post some pix of it when it's done, although it's probably better suited for "noisy rock music PC review" than SPCR... :p

djkest · Post by **djkest** » Sun Dec 30, 2007 6:42 pm

Okay okay here is my finished (for now) guitar. After about... oh 10 hours of labor it's fully functioning, although not quite dry. I also need to take it apart and sand down the green fret button more, but I can do that tomorrow. Cheers!

jhhoffma · Post by **jhhoffma** » Wed Jan 02, 2008 7:42 am

You shouldn't have to bake any kind of paint unless it's powder coating.

Baking will accelerate the curing process of enamels/lacquers, but is not necessary. 48 hours at room temperature is usually enough to cure any spray paint (low humidity is key), but 72 is better to be sure.

Plastics have many transient phases. They do have a melting point, true, but the soften all the way from pure solid phase to that melting point. They also have a Tg (T-sub-g) which is the glass transition temperature or the point at which a pure plastic resin will become clear before melting. Colored plastics won't become clear (since they are impregnated with pigment particles) but they will definitely be too soft to hold a molded shape with any stress on it.

djkest · Post by **djkest** » Thu Jan 03, 2008 7:02 am

It's fully dry, but I wasn't patient enough with it and it shows, I've got fingerprints embedded all over the "guitar" from holding it during re-assembly. The low temps during application didn't help either (it was only 40F outside)