I have bent hardboard (Masonite) to a 24" radius curve with no problem. I would guess that you could do the same with luan plywood. I have read on this forum that you can get hardboard down to a 12" radius curve without problems. Inside curves are less of a problem than outside curves. On outside curves you want to be sure that there are no sharp corners behind and in contact with the curve. These can cause the hardboard to crack at the point of contact between the sharp corner and the back of the hardboard where the hardboard curves.The luan plywood that I've seen in Lowes has a a texture to its surface, whereas hardboard is very smooth. In preparing hardboard to be painted, I applied two coats of a good quality primer (e.g., Behr brand @ Home Depot) to the surface that will be painted for the actual backdrop. Two primer coats kills the brown color of the hardboard. To be sure the hardboard will not pick-up moisture, I apply one primer coat to the back of the hardboard.
Bob
on30-bugMasonite or luan Which is most likely not to break trying to bend into a 2 1/2 ft radious corner?
Masonite or luan
Which is most likely not to break trying to bend into a 2 1/2 ft radious corner?
Without question the luan will not last if you bend it. It will splinter and eventually come apart, ask me how I know after replacing all the luan fascia on a 50'x100' layout.
I agree with Gerhard that the masonite will bend to a tighter and will provide a self supporting even curve. Luan can sometimes be unpredictable while bending. This is especially true if it is bent horizontally to the outer surface grain. Yes any ply will bend easier with the "grain" vertical but that will give you seams @ 4' instead of 8'. Masonite will bend to a tighter radius and is not affected by any grain orientation. Luan will need additional coats of primer and may grain raise. To stop any potential grain raise, use an Alkyd based primer. Many water based products may be quick dry but could result in some ugly grain showing even after 2-3 coats.Regardless of what wood product you do use, do back prime to help prevent any moisture absorbtion.
Modeling B&O- Chessie Bob K. www.ssmrc.org
- Gerhard
I wouldn't worry about curved corners, the masonite should be self supporting. You could always build a support framework of 1x2 lumber (flat) to support the long stretches.
Co-owner of the proposed CT River Valley RR (HO scale) http://home.comcast.net/~docinct/CTRiverValleyRR/
I used 1/8 masonite for mine. It has been standing straight and tall with no support for a couple of years now. It is attached to the 1 x 4 edge of the benchwork with 10/32 machine screws and t-nuts. If it does need support I would do it by gluing masonite to the back. It holds it the same way as when constructing spline roadbed. In others words if it sags push it straight and clamp a strip on the back. When the glue is dry it will stay straight when you remove the clamps.
I would not waste my time sanding. A good primer coat is all that is needed. (I have done test)
On the back of where two pieces were joined I glued a 6" wide strip of masonite down the back with carpenters glue and filled with Dap wall filler.
If you have a curve planned, cut out a piece on the bottom and curve it over the top of the benchwork.
Good luck
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
I am working on benchwork for a new layout (my first to be honest) and am wanting to use 1/8" tempered masonite for the backdrop surface. I am not concerned about fastening it along the bottom, as it will be screwed into the perimeter banding of the benchwork, I am concerned about vertical support, the overall height is projected to be 24". Also, what about a support band at the top, or will the material basically support itself. And if i use vertical supports behind the panel around a corner curve, what is the best way to attach the masonite to the support member, without the use of screws? Any suggestions appreciated. . . . Thanks