[Scottychaos]

Using the oven the soften and bend stryrene has been talked about often..
I have never tried it before, but would like to attempt it to bend the cab roof for
my On2 forney:

gold.mylargescale.com/Scottychaos/On2-SRRL9

the styrene for the roof is only 0.5mm thick, and need to be bent into a curve with a radius of 2".
(I will find something slightly smaller..to "over-bend" slightly..)

What would be the "magic temperature" that is warm enough to distort it, but not so warm it melts?

thanks,
Scot

 

[Pete Thornton]

Scot,

The right temp is when it starts to bend (sag) - just watch it while you heat it.

I did a 1/8" square bar for my coach by putting it in a toaster oven tray with one end on the lip, heating it until it started to sag. Then I carefully took the tray out of the oven and placed the bar on my "former", a round glass jar.

Don't use too fierce a heat - you don't want to melt it or brown it like toast.

 

[rkapuaala]

I read somewhere the correct temp is 175, but I found that I get better results if I just make some shallow scribe marks in the styrene and roll it around a litle with out heat and then attach it to some curved cross members like this:

 

[Torby]

You should be able to bend 1/2mm sheet cold. Just build your cab and glue it onto the sides.

 

[Scottychaos]

Posted By Torby on 03/02/2008 11:40 AM
You should be able to bend 1/2mm sheet cold. Just build your cab and glue it onto the sides.

yeah, its easy enough to bend..
but I still want to try the heat because of the overhang on the sides..
if you dont heat-form it, you end up with the overhang being straight,
rather than "following through" with the curve..

Scot

 

[Rod Hayward]

Cold formed, 2mm roof.

 

[rkapuaala]

Mine was also cold form with an overhang. The truth is, that you need some sort of form to bend heated styrene properly or it warps and wavers due to uneven cooling or something. I

 

[rkapuaala]

Rod,
Great job on the cab, I love all the details you put in.

 

[East Broad Top]

Scott, When I need a smooth arch, I laminate sheets together. The lamination process forces the bend to stay permanent. In your case, I'd start use two or three layers of .010 styrene. Wrap one around your form, spray with 3M spray adhesive, add the next layer, and repeat for the third layer if necessary. Almost all of my curved roofs are done with lamination, and it's very good about holding its shape even without forming supports underneath.

I typically use scribed siding, 1/8" scribes and .020" thick for my laminations. The scribes keep the bend even, and the lamination keeps things the right shape after the glue's dried. It really doesn't come out "bumpy" at all, as you might expect with scribed siding, but if it's a concern, a quick once-over with some sandpaper even things out right nicely.

Later,

K

 

[Torby]

Wow. Not sure I'd have tried cold-forming 2mm styrene. I'm a little twerp who drives a mouse all day. Maybe 2 layers of 1mm styrene.

 

[W3NZL]

Back before a big batch of sheet metal snow plows were made up on a CNC machine, 
I used to make styrene snow plows out of .030 material formed over a mold in the oven..
As I recall the temp it took was somewhere in the 175-200 degree range, but its been 
a long time, 10+ yrs, since I made plows that way so I'm not real certain about those 
temps... Experment a little, U'll figure out what U need pretty quick...
Paul R...

 

[david bunn]

Have not tried the oven but I have used two methods to bend styrene with success.
1. Immerse the piece in a pan of boiling water for about a minute, then press the styrene around a former or against a work surface to form the shape,this may take two or three attempts to form a tight curve.
2. Find a willing lady,I am lucky enough to have one in the house, and borrow her hair dryer hopefully with an attachment that gives a flat blast of heat.Play the dryer over the workpiece and shape with a piece of wood,don't use fingers you will burn them,to press the styrene over the former.
I have used the dryer method for roofs,particularly where there are different radii on the same piece.Works for me.
Bunny

 

[David Buckingham]

Hi Folks
Be carefull with heat cut to size if possible after forming as to much heat can cause the styrene to shrink.

Boiling wateris the safest and what I use the most at least you know the temp.
Dave