Backdrop Coved Corners

I am looking for a template or cutting directions for coving the corner on a backdrop that I am getting ready to install.

I am planning a 12" radius curve in 1/8" masonite at the cieling to wall joint and want to cove the one corner that I have to deal with.

Any suggestions would be greatly appreciated. I have seen that there is an old Model Railroad Craftsman article on the subject but I do not have access to it.

Regards,

Amby N.

My recommendation… Shove it in place. I’m not sure that a ‘template’ is in place.

I’ve just finished a masonite backdrop, and all we did was mark the 12", push a 4’ sheet of masonite (cut to height) into place until the each side of the curve began at the 12" mark, and fasten in place.

I wasn’t clear in my first note.

I am looking for a template for the corner where two walls and the ceiling meet. I am all set with the one wall and ceiling and have had success just shoving it into place. I have in the past made some curved backups out of plywood to make sure that it is a smooth curve.

Amby N,
You should be able to get a photocopy of the article you desire from the NMRA’s Kalmbach Memorial Library :
http://www.nmra.org/library/
The rates are reasonable, even if you’re not a member. They will stamp it with a copyright notice. An alternative would be to look for a back copy of the issue.
Bob
NMRA Life 0543

I think the article you are looking for is in Railroad Model Craftsman March 1986, p.60.

I have the article. I can scan it and e-mail it to you. Let me know if you want it and send me your e-mail address.

dgwinup@charter.net

Darrell, quiet…for now

Do you really need to put a plywood backer at curves to maintain the curve configuration when using 1/8" Masonite? I would think that the Masonite would be stiff enough to hold the shape of the curve when installed per kchronister’s description above. Also there used to be tempered and untempered forms of Masonite. The tempered form was a dark brown color and was relatively smooth on both sides, similar to what is used to make peg board, whereas the untempered form was lighter brown in color and had a more porous appearing surface. I don’t know if both forms are still available. I assume that it’s the tempered form that is used for backdrops and fascia.

I’ve seen complaints in this forum about joints between pieces of Masonite in a backdrop cracking, even after taping and spackling. Does this happen if you use a Masonite splice plate on the back of the joint to hold the joint together?

The masonite should hold it’s shape without support after you shove it in place. If you need a template, make one with an oversized compass. Take a yardstick and two pencils. tape/clamp one at the end and the other at the radius that you want to use. Then you can draw your curve on the wood that you want to use as a template.

Amby N.,
Perhaps you’ve already realized this, but I don’t think you’ll be able to curve 1/8" Masonite to form the dished, gore shaped piece where the three surfaces meet. I checked my copy of that issue to make sure, and they did that “cyclorama” corner in plaster. You might be able to do it in sheet metal, a la tin ceilings or plastic. Please let us know how it turns out.
Bob
NMRA Life 0543

I think this could be done in Styrene if you cut a deep V shape into it and then glued ti together. The March issue of MRR uses styrene, though not quite like this. It does have lots of good tips for working with it and where to get it.

I just fastened it on both sides. Mine is 1/8 masonite:

I placed 1x3 inch strips on the wall behind the masonite and countersunk #8 wood screws in place. Get a couple people to assist you and hold everything as square as possible while you “lock” the backdrop into place.

And here’s how it looks with some “blue sky” painted on!

And here’s how the benchwork fitted in the corner …

Good luck!

Ambyn,

A day late and a dollar short, but I just noticed your posting on coved corners as I searched for same. I have the same problem, uh, opportunity.

Backdropwarehouse has a series of tutorials on installing backdrops, including (2) that deal specifically with coved corners. The ones I find most helpful are at
http://backdropwarehouse.com/mounting2.htm and http://backdropwarehouse.com/mounting4.htm

I’m going to use .080 styrene for my backdrop. I’m a beginner with no particular woodworking skill, but to determine the curve radius I’m going to cut a square of poster board (from a stationery store) to fit into the corner, bend the styrene around the corner, and have a helper trace the curve on the bottom of the poster board. I’ll then cut (2) or (3) pieces of plywood or pine shelving to match, position those in a corner frame I’ll make out of 1x2 #2 pine, and hopefully be off to the races.

If not, I’ll shoot myself.

Rick Krall

UPDATE: Build the frames over the weekend (2’x5’; 2’ x 9’); used this reference as a guide:

http://backdropwarehouse.com/mounting5.htm

Used 1x3 #2 pine for the girders; 1x2 for the spacers 15" o/c. Carefully squared the frame then used #8 3/4" wood screws into 1" mending plates to join all pieces. That was the only way I could assure a square frame. Per the directions I followed, I’ll use 1x2 crutch blocks to support the coved plywood in the corner. Squaring took forever, but the rest of the construction was a snap.