Slow progress on getting the train room ready for trains, but today I picked up the masonite/hardboard for the backdrop. I plan to cove the corners, but have a couple of questions.
About what radius can 1/8 masonite be bent to before it needs softening?
I have read that if you want a tight radius to soak the back for 15-20 minutes before bending. I also know that untreated masonite can warp over time unless sealed in some way. Can it be soaked successfully if once sealed? Or how does one soak the area, bend it in place, then, when dry, seal the back?
I'm getting a little ahead of myself, but my help comes in spurts and I'd like to be ready when it is available.
Thanks for the ideas,
Richard
Do not kerf the back of masonite/hardboard if you are going to curve it to a tight radius. That will create a stress riser and it will snap.
Wait to see what Wayne says. He has some beautiful hardboard work on his layout.
-Kevin
Living the dream.
No need to soak or kerf 1/8" Masonite for coved corners. I drywalled my entire train room using 1/2" board (vertical) everywhere but at the room's 10 corners. At those corners, usually around 16" (or less) on each abutting wall, I used the 3/8" thick drywall.I then used a tape measure to create a curve at each corner, and then cut a piece of Masonite slightly wider than the width indicated on the tape measure.
To install the Masonite, I abutted one edge of the Masonite against the edge of the 1/2" material on one wall, then pushed the centre of the piece towards the corner, until it simply snapped into place on the adjoining wall.
I then used a countersink along each edge of the Masonite, at intervals that I considered suitable, followed by use of a smallish drill bit to penetrate through the Masonite. This allowed me to install drywall screws to secure the Masonite in place. I followed up with some drywall mud and tape, and once it had hardened, sanded off the excess as needed.
This sketch should illustrate the set-up...
(The red line represents the drywall tape, while the green is the drywall mud.)
The room was done, if I recall correctly, in 1990, and none of the corners show any sign of cracking, including those on outside corners, like this one...
At some corners, the Masonite is does extend further, usually just because that's the way that the stud spacing worked out. The gap, shown below, was left to accommodate a partial second level of the layout, which was finally added a few years ago...
I also used the 1/8" Masonite for fascia on the layout and to hide most of the storage areas under the layout, too...
Some of the storage area has sliding doors, but most of it is lift-off panels. The shelves where the rolling stock is stored is open, though...
As for curving the layout fascia, this corner is about an 8" radius...no soaking or kerfing required...
...and, as you can see, the one above, where the partial second level was added, is not much bigger.
Here's a couple of views of the same corner, with the partial upper level in place...
Here's a sketch of the layout room, which is roughly 560 sq. ft....
...the areas in grey are where the partial upper level was later added. While the sketch doesn't show the coved corners, all 10 corners of the room are coved.
Wayne
Kevin, thank you for your kind comment. It's much appreciated.
Two tiny additional options:
(1) You may want to use a small piece of ½" thick wood at the edge of the 1/2" nominal drywall panel (note the taper in Wayne's drawing, which is to facilitate joint taping and spackling but can reduce the face area the edge of the Masonite 'snaps' against). You would screw or glue this to the stud, with a small piece of the ⅜ drywall beyond, to make a 'hard' corner into which the Masonite would snap -- you might not need anything other than a vertical bead of caulk in the corner of the joint to elastically seat the Masonite effectively for an inside corner. I think Wayne's paper tape would suffice to cover the joint before painting.
(2) Paint the back of the Masonite with one coat of thinned Kilz allowed to soak in, followed by a full-strength coat just before you go to install it. That will seal the back as well as it needs to be, and give a little 'softening' action during the install.
Not to be a wiseacre, but don't kerf 1/8" Masonite. If you were daft enough to try, you'd need a great number of relatively fine kerf cuts, all to the same depth, not far apart, with careful attention to the shape at the bottom of the kerfs. Otherwise you'd see visible 'aliasing' in the desired smooth curve of the cove, and the risk of stress raising would be as described.
All that, to get little if any better bending effect than just doing what Wayne says to do.
Now, if this were plywood, the situation might be different. But we're not discussing plywood.
You might want to take a look at Joe Atkinsons backdrops on his new Iowa Interestate RR where he used rolled vinyl for some smaller radius coving and also a peninsula backdrop.
https://forum.mrhmag.com/post/iaiss-4th-sub-easy-backdrop-coving-thanks-bernie-halloran-12219491
What he has done looks better than anything I've seen to-date.
Rio Grande. The Action Road - Focus 1977-1983
doctorwayneKevin, thank you for your kind comment.
I am constantly amazed at how good your construction looks on your layout.
Thanks again for all the pictures you have shared.
I tried hardboard on my Dream House layout, and it looked bad. I gave up on curved backdrops and fascia after that.
I would not kerf or moisten hardboard.
I used 1/4" inch hardboard attached to the bench with 10/32 machine screws and T-nuts. I chose 1/4" so it could be free-standing as I did not want to have to fill holes in the walls when we move. In 15 years it has not sagged by just being attached at the bottom.
Even 1/4" bends to a pretty tight radius.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Thank you for the replies. The room was too far along to use the different thickness of sheetrock (that's good planning ahead).
By the sounds of it I won't have too much problem in the corners as it should bend easily to the radii I am aiming at.
I'll seal the back (fuzzy) sside and undercoat the smooth side Once in place I'll put the finish sky blue on and add any distant hills, etc.
If you have other suggestions, I'd be glad to hear them.
Thanks again,
I've got some 2 sided hardboard I got from Lowes, and it doesn't like to bend real tight, at least in wide sheets. I've got some 4 inch wide strips so I'll have to see if it will make a 24" radius.
Yes,, I planned to keep the seams away form the corners. Had the 4x8 sheets cut into 2x8 strips (thought about 16: strips, but decided to go higher for only $14) and one strip into 2x4 pieces to fill in.
Since none of it wil be a scenic divider, the one sided will work fine.
Now off to working on the entrance gate and set a layout height.
Thanks for the thoughts,
cowmanSet a layout height.
That is a topic with 1,000,000 different points of view!
I would love to hear what you decided on, and how you arrived at that decision.
All my layouts have been at different heights for different reasons.
SeeYou190 cowman Set a layout height. That is a topic with 1,000,000 different points of view! I would love to hear what you decided on, and how you arrived at that decision. All my layouts have been at different heights for different reasons. -Kevin
cowman Set a layout height.
It is of course personal preference but at the time I had to decide, I was thinking of joining a local modular club. I made my layout height to the requirements of the modular club thinking I would have a spot on my layout where I could plug in any modules I may make and run it as a short line. Of course, one can put legs of any height under the module at home, but I thought why have two sets of legs.
LastspikemikeI've got some 2 sided hardboard I got from Lowes, and it doesn't like to bend real tight, at least in wide sheets. I've got some 4 inch wide strips so I'll have to see if it will make a 24" radius.
The two fascia curves in the distance, on the upper level of my layout, were done use 1/8" Masonite, smooth both sides. The fascia strips are 10" high and the curves at each side were easily bent to a 10" radius...
All of the lift-off panels and sliding doors hiding the stuff underneath the layout were done with the smooth-both-sides, stuff, too.I actually preferred the Masonite with only one side smooth, as those with both sides smooth were difficult to carry in multiples, as they'd slip and slide all over the place.
I have used masonite for my background. At first, I just convered the joints with mud plaster and within days, it started cracking. I am mentioning this because instructions in a book on the matter () said that a coat of mud over the joint would suffice. I applied a tape over the joint (the netting type, which is super easy to apply), covered that with mud and it has not cracked since I installed it four years ago.
Simon
Given the nature of hardboard, it needs to either be solidly mounted or in my case you need to add a splice on the back. Mine were free-standing and had a four-inch-wide splice glued to the back to give the joints strength.
If you do the quick and dirty tape and mud on a hardboard joint you will get cracks and ridges. What I did are mud and sand (no tape) and once smooth, then apply tape and go over it again to cover the tape.
Close your eyes and run your fingertips over the joint, if you can feel it you will see it once painted. Click on my photos above and see if there is any evidence of a joint.
I don't use Masonite as a backdrop, but only for the coved corners. All of those joints are mudded and taped, and then re-mudded, too, just the same as is done with drywall, when installed properly.
In 34 years, none of the drywall that I've installed (all in the basement) has shown any cracks at all.The rest of the house, done by professional drywallers, isn't too bad, but it's definitely not perfect. Their installation of drywall board is done with larger sheets, place horizontally, which does speed installation, but with no tapered relief at those vertical joints, the tape and mudding there is not only not flush with the surface, but also more prone to cracking because of those shortcuts.
I think that if I were using Masonite as a backdrop, I'd use a countersink for all of the screws holding it in place, and definitely make the countersink deeper where the panels meet.Then, with the Masonite all in place, I'd use a belt sander to remove material from the surface of the Masonite at all joints, which would better allow depth for an application of mud, followed by tape and then more mud...very similar to what you'd have with drywall installed vertically, with a tapered surface where the sheets meet.
Another option to consider is styrene. I used .060 styrene to cove my corners. The joints were smoothed out with lightweight spackle. They still look good despite the crazing caused by the use of the wrong brand of spackle - use UGL 123, not the cheap HD stuff...
The plastic was easy to work with and install and will take a very tight bend if you want it. I have used masonite and 1/8 plywood for fascia and valences with equal sucess. The Masonite will curve tighter than the ply but is heavier...
Contrary to what has been said previously, taping joints is not trivial even with fiber tape (don't ask how I know this).
Have fun,
Guy
see stuff at: the Willoughby Line Site
Wow, that has got to be the most pointless and boring off-topic Forum fight I have ever had to clean up. No more drywall discussion, please.
--Steven Otte, Model Railroader senior associate editorsotte@kalmbach.com
Sorry Steven, Sometimes I need to show more restraint when it comes to the forum Jokers.