Tips for cutting clear plastic

[bh1701]

I have this window insert from a Mini Cooper model kit. I am going to modify this kit (which is the hardtop version) into a convertible. I will need to remove everything except for the front windshield and the portion with the sun visors.

As I seem to remember, cutting clear plastic can be a little tricky. If I am not mistaken, clear plastic seems to be a little more brittle and can be prone to cracking when you try to cut it.

Any suggestions on the best way to do this would be appreciated!

Thanks,

Bart

 

[Casey]

Use a fine tooth razor saw to cut the piece free. Any tool which doesn't remove material, and merely separates it (like, a sharp #11 X-Acto knife blade), is going to stress the clear plastic and stress leads to cracks...not good.

Adding a three layers of masking tape at the edge of the cut line, covering the windshield area would be a good idea, too, just in case.

[89AKurt]

I have a hot-wire cutter, original purpose is to cut styrofoam for train layouts.  You can use a steel ruler as a guide for straight cuts.  When I cut "glass", cut beyond and then sand down to the line.  I use it for cutting bodies, use a saw for only a few cuts.

[Snake45]

1 hour ago, Casey said:

Use a fine tooth razor saw to cut the piece free. Any tool which doesn't remove material, and merely separates it (like, a sharp #11 X-Acto knife blade), is going to stress the clear plastic and stress leads to cracks...not good.

Adding a three layers of masking tape at the edge of the cut line, covering the windshield area would be a good idea, too, just in case.

What he said--fine-tooth razor saw. 

[Pete J.]

I just had to do some very precise cutting on a clear aircraft model canopy and it needed to be spot on.  I bought Hasegawa'a Trytool photoetched saws many years ago and they are so thin and have almost microscopic teeth that are very sharp.  This is my tool of choice.  You need to be patient and use something to guide the blade.  I often use DYMO label tape because it stikes well and it think enough to guide the blade easily.  It is good on single curved pieces such as yours,  but no so much on compound curves as it is not very flexible.  For compound curves I use blue Fine line tape. 

 

[slusher]

I have a project I want t try but first I need to cut the kit class. I was going to use a unused hacksaw blade. Is that the best way?

[NOBLNG]

 

[Plowboy]

I always use a Dremel with a cutoff wheel. Then trim with a knife and sand. The thing about using a saw blade of any kind (razor saw, photo etch etc.) is they're prone to binding and causing you to break the glass.

[gman]

I too use a Dremel with a cutoff wheel to do the rough cuts. I then place some masking tape on the glass with the final cut line marked on the tape, and get as close to that line as possible using a drum sander on the Dremel. It helps to remove a little bit of material and then let the plastic cool down before continuing, as the Dremel can build up a lot of heat in the work surface. I gently use Flexi files to clean up the rough plastic left behind by the Dremel, straighten out the cut with rough grits and take it down to the final cut line, then polish the edge using progressively finer grit files.

It helps to go easy, use as light a pressure as possible with the tools (Dremel and files), and take your time, unless you have a spare kit glass around. The Flexi Files even allow you to bevel and thin the edges of the glass for a more in-scale appearance. Rinsing the glass as you work with the files keeps any grit shed by the files from scratching visible portions of the clear plastic.

[slusher]

5 hours ago, Plowboy said:

I always use a Dremel with a cutoff wheel. Then trim with a knife and sand. The thing about using a saw blade of any kind (razor saw, photo etch etc.) is they're prone to binding and causing you to break the glass.

Roger,  do you mean those thin brown disc? I have used them but they break easy…

[Plowboy]

6 minutes ago, slusher said:

Roger,  do you mean those thin brown disc? I have used them but they break easy…

Yeah. I use the thicker discs. They don't break nearly as easily. I've never broken one on styrene.

[slusher]

I have some I will use them. Thanks Roger.   I am going to get a razor saw to have..