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Straightening out a warped styrene body


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#1 stevefzr

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Posted 23 February 2006 - 05:35 PM

Guys,

What's the technique for straightening a warped styrene body? This one is warped so that it doesn't sit flat. It needs to be "twisted" about 1/8" along its length. I've heard other people talk about putting a cut in the body and adding in a sliver of styrene to force it straight. How does tat work? How do you know where to cut?

Regards,

Steve

#2 Jairus

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Posted 23 February 2006 - 06:10 PM

Unfortunately there is no easy fix for such a warp. Most modelers will glue in the chassis and interior which are much more "boxy" and that will force the body into a correct stance. How ever, I happen to know that you’re a slot racer Steve and most styrene bodies you use are attached loosely about the middle of the chassis so there is nothing available to "force" the body.

Do not use heat in any way shape or form. Styrene plastic has a very low melting point and when you get it near heat it will want to draw back to it's natural state ... which is a blob of plastic!

Instead I would place the body on a flat board with something to force it into correct position. Rubber bands will work just fine. Then set it out in the sun or on a window sill. Have patience because it will take a couple of months!

This WILL work but I didn't say it would be easy....
:D

#3 stevefzr

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Posted 23 February 2006 - 08:01 PM

a couple of months? Is that all? The guy who was going to do it for me has had it for over a year already. I could have done 6 in that time! I'll report back in a couple of months. Sun is not usually in short supply down here.

Regards,

Steve C

#4 Jairus

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Posted 24 February 2006 - 05:37 AM

Steve, the reason that this works is the sun will warm up the body and soften it very slightly. Just make sure that the rubber bands are not tooo strong or you'll be creating a worse problem!

I had an award winning 1986 Mustang convertible that I was retiring. A local hobby shop wanted to display it with a bunch of other models in the display window. The problem was... the 1986 Mustangs used a prop rod instead of spring loaded hood hinges. Sooo... I replicated the prop rod, including storage space along the top of the core support. Just like the real car!
2 months later I picked up my Mustang from the hobby shop and the hood was soooo warped after sitting in the open window.... in the sun.... with the hood propped open!

My car sat in a display window, which slightly multiplies the heat factor, but I live in the Pacific Northwest, halfway between the equator and the North Pole. The window sat on the east face of the building and there was a slight overhang. I do not remember what time of the year it was. I estimate that the window had direct sunlight no more than 4 hours each day..... after that it was too high in the sky to have much effect.
You might take these factors into consideration and make sure that your car only gets periodic doses of the sun.

#5 stevefzr

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Posted 06 March 2006 - 04:45 PM

I've had someone else recommend a two person job with a hair dryer. One twists/bends and the other heats. Has anyone ever tried that one?

Regards,

Steve C

#6 kod38

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Posted 06 March 2006 - 06:02 PM

How about warm water? Then cool it while it's strapped down?

Jairus,
That is an excellent fix.
I will try that on one I have if the sun ever comes back out.LOL!
That makes perfect sense.
Doug R

#7 jlsinz

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Posted 07 March 2006 - 10:46 AM

Do not use heat in any way shape or form. Styrene plastic has a very low melting point and when you get it near heat it will want to draw back to it's natural state ... which is a blob of plastic!

Instead I would place the body on a flat board with something to force it into correct position. Rubber bands will work just fine. Then set it out in the sun or on a window sill. Have patience because it will take a couple of months!


How about warm water? Then cool it while it's strapped down?


Jairus,
The sun is just another sorce of heat. You have little or no control over the amount of heat your model recieves. If left in the sun you could end up with a plastic blob, which you almost had when you left your model to be displayed in the store window.

Doug,
The warm water is a excelent idea.
I have used this mant times to straight warped parts or to stretch the sides of a body to fit over a slot car chassis.
I use hot water out of the tap to warm the body then let it cool while holding it a little past the position I need it to move to. (need to allow for a little spring back in the plasic).
This method gives a lot of control over how much heat and for how long.

#8 stevefzr

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Posted 08 March 2006 - 07:14 PM

The warm water is a excelent idea.
....I use hot water out of the tap to warm the body then let it cool while holding it


!!! Maybe my tap water is hotter than yours. I once impatiently dropped a Tamiya Ford Spyder into a bucket of hot water and caustic soda to remove paint. Well, I was left with a paint-free blob :-( Now I let the water cool first.

Regards,

Steve C

#9 Jairus

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Posted 08 March 2006 - 08:23 PM

John,
No offense, but the Mustang is not a blob of plastic! In fact it is still a very nice model, albeit with a warped hood that without a working hood latch would look like it had a permanent crooked smile.
Sitting in a window under the sun all day will warp anything if sufficient and consistent pressure is placed upon it. Which explains the warped hood on the Mustang. Due to the prop rod being only on one side of course! However a car simply resting on four wheels will not suffer any ill effects under the sun because the temperature simply cannot get high enough to do any damage.
That is why the body on the board will work and why hot tap water may not!

#10 Turbo590

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Posted 16 April 2006 - 01:57 PM

A 2 person combination with the "hair dryer" works very well. This is a good case where the wife does come in handy. Use the high setting..keeping the nozel several inches away from the plastic..once it becomes "warm" start to twist a-little. This may require "several" heating applications. It does work. Good Luck

Kurt

#11 MonoPed

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Posted 16 April 2006 - 03:26 PM

Get a big pot of water, enough to submerge the body, and heat it to around 170-180° (do not boil). Have another pot of cool tap water ready. Dunk the body in theh ot water for a few seconds (use tongs!), remove, give a twist in the oposite direction past where you want it, then dunk in cool water. repeat as needed. Don't leave it in the hot water very long, or the plastic will shrink. I can't count how many Monogram NASCAR T-birds I've fixed this way, adn the ones still on my shelf are still straight going on 7-8 years later.
Brian

#12 bobss396

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Posted 03 May 2006 - 07:01 AM

I like the hot tap water method. You might want to wear dishwashing gloves though. I let the water run over the section with the problem, twist the body beyond where it should be and rinse it off with cold water.

It might take a couple of tries, but it has always worked for me. I don't like to immerse the whole body as some of the thin sections may permanently deform.

Bob