Warping styrene

Treadhead · Post by **Treadhead** » Tue May 26, 2009 12:00 pm

When I cut out bulheads in sheet styrene, I find that the part ends up warping. Usually the warp is mild and I'm able to work around it -- but it would be nice to not have this problem in the first place.

Anybody have any ideas that might help?

Kylwell · Post by **Kylwell** » Tue May 26, 2009 1:09 pm

How thick of a sheet are you using?

Andrew Gorman · Post by **Andrew Gorman** » Tue May 26, 2009 4:44 pm

For thicker plastic I'll cut parts out with a little bench saw. Works great, everything comes out flat and I can cut multiple identical pieces if I layer several sheets of plastic together with double stick tape. I have a Proxxon that I got years ago at some insanely discounted price from Model Expo, but others are available.
http://www.minicrafttools.com/37006.html
Yikes! The price has gone way up.

Treadhead · Post by **Treadhead** » Tue May 26, 2009 5:02 pm

Kylwell wrote:How thick of a sheet are you using?

I'm using .080 in styrene.

TREKKRIFFIC · Post by **TREKKRIFFIC** » Tue May 26, 2009 5:59 pm

What are you using to cut it with ? I assume these aren't straight cuts for bulkheads ?

Treadhead · Post by **Treadhead** » Wed May 27, 2009 10:46 am

TREKKRIFFIC wrote:What are you using to cut it with ? I assume these aren't straight cuts for bulkheads ?

The bulkheads are half-ellipses. I cut a rough border around them with an exacto and break them on a flat surface. I use a dremel sander to shape the curve.

The pieces are pretty much flat when I cut them out -- but they tend to warp when I have the framework assembled. The warpage is not that severe -- nothing that can't be fixed with a little putty.

Would it work better if I laminated thinner styrene together instead of using a thick piece?

Kylwell · Post by **Kylwell** » Wed May 27, 2009 11:11 am

Probably not. I'm trying to see if I can duplicate your results so that I might be able to figure out the issue.

Treadhead · Post by **Treadhead** » Wed May 27, 2009 11:20 am

Kylwell wrote:Probably not. I'm trying to see if I can duplicate your results so that I might be able to figure out the issue.

Thanks, Kylwell. This would really be a big help to me.

Devin · Post by **Devin** » Wed May 27, 2009 12:49 pm

I'm interested in this as well. I'm starting a scratchbuild that will utilize a plank-on-frame approach using styrene for the frames and sheeting. Been wondering myself if thick or thin styrene is the way to go.

seam-filler · Post by **seam-filler** » Thu May 28, 2009 1:13 am

If they're not warping until they are installed, I would suspect the glue.

It may be that the glue/cement you're using is a bit too aggressive.

Treadhead · Post by **Treadhead** » Thu May 28, 2009 11:03 am

seam-filler wrote:If they're not warping until they are installed, I would suspect the glue.

It may be that the glue/cement you're using is a bit too aggressive.

I'm beginning to suspect bad craftsmanship on my part. And here's why:
I have a base piece which has a keel glued perpendicularly to it. Along the keel, I have formers attached. (click on the www part on my profile and you can see the skeleton build up) Some of the formers I suspect are not exactly 90 degrees -- and when glued in place may be warping the plastic.

The warping is not a show stopper. I've become somewhat of a magician with A+B putty and can fix these problems -- but they are an annoyance.

srspicer · Post by **srspicer** » Mon Jun 29, 2009 9:30 pm

Hey TH,

Your hands & fingers must be screaming after all of that x-acto work. I would suggest you purchase a jewelers saw with a heavy, course blade. Rough cut your shapes. Use a disc or drum sander to finish the shapes.
I also see that your flat plan view sheets are warping as well. Make sure your work surface is flat and that those plan view sheets are flat before gluing. Also, if you glue a large number of your profile or shaped pieces in place at the same time, your solvent will warp the larger flat sheets. Pin or tape your flat sheet down so the drying process does not warp things.

I also suggest that you draw or scribe a series of parallel lines at equal distances to help keep your sheets straight and at 90 degrees. use a small square to keeps things true.

Good luck,

Scott