Cutting Styrene Wall Joints

[Anonymous]

What is the best technique/tool for making a clean 45 degree angle along the edge of two wall sections to be joined together as a corner (90 degrees)?

TMan

[Anonymous]

Tried and true method is to scribe and snap the sheet, then hand file the 45 deg. angle by hand with an 8" or 10" Mill *** file.It's surprising how well you can get on to this after a little practise.It is possible to use a "Sanding Center" [ small machine with belt and disk sanding capabilities ] as long as it has work tables that will tilt to 45 deg.Extreme care is required to avoid melting the styrene, and to avoid end-curve toward your edges.Use 80 grit to rough cut, then 120 / 160 grit to finish.
Good luck/Mike

[BNSFNUT]

I'v use a tool that had a 45 degee angle (usualy part of ane carpeners combo square) to hold the part at a 45 and the run it over sand paper to put the bevel on. You have to be carfull not to let the tool get on the paper as this will ruin it. I've been thinking of building a fixture to do this job but I have not got round to it.
Later Jerry

[CNJ831]

Actually...producing a 45-deg cut on building end walls is needed only for certain cases of stone or brick buildings. Nearly any vintage wooden structure will have corner or trim boards where two walls meet, hiding any simple butt joint. Likewise, the use of corner boards makes for a much more realistic looking building.

Even butt joints of block or brick walls can be hidden in this manner using pilasters.

John

[Anonymous]

I see I asked this question last month and forgot that I did.

I gather there is no inexpensive mitreing tool for cutting 45 degree angles on the edges of plastic sheets.

I'll try the filing method and see how it goes.

Yes, I know how to conceal joints with various structural elements, but unfortunately, this is a scale rendering of an actual masonry structure which does not have any such elements on some of its corners. This'll be a lotta fun.

[CNJ831]

OK Gary, if the joint can not be hidden in any manner, and the styrene sheet isn't too thick, here is a method that will give you a good first approximation of the necessary joint angle.

Art supply stores carry an item called a handheld mat cutter (about $15 locally) used, as its name implies, for cutting beveled edges on picture/photo mats. It uses a retractable razor blade in a cast housing and is designed to run along a clamped straight edge, such as a metal ruler. I believe the angle of the blade to the cutting surface is 50-55 degrees. Working with relatively thin plastic sheet (up to 0.040" perhaps?) will result in an error so small that it should be corrected with just a couple of passes of a fine sanding block.

Considering the edges will come out dead straight and even by using the cutter, I'd say this method would be far better than any attempt at sandpapering in the proper 45-deg angle for the joint.

John

[Anonymous]

The handheld mat cutter sounds like an excellent possibility. I'll look into it. Thx.

[Anonymous]

Hi Tman!
The method I use is simply cutting, & filing, as described by Mike Meaford.
I don't think the degree of the angle is as important as the corner being square, & having a clean corner on the outside. As long as the edges meeting at the corner are filed nice & thin, it's easy to acheive a clean joint.
In addition to this, though, I like to reinforce all corner joints by cementing pieces of strip styrene on the inside of the corner.
Art Curren's book, Kitbashing HO Model RR Structures is filled with a lot of good tips on working with styrene.