Here in UK Everbuild

Here in UK,  Everbuild Lumberjack Polyurethane Wood Glue 30 Minute 750g - excellent but it does foam and expand a bit out of the edges of joins - use clamps and no screws/nails/staples till dry. I use it for building baseboards

"The wall is on 16 inch

   Will the backdrop be straight or does it have curves?  Adding a center horizontal to a curved backdrop will be more difficult than  to a straight one, the middle horizontal/vertical joints might telegraph thru the masonite if they are not faired in really well. It might be easier to leave out the middle horizontal and just space the verticals a bit closer. Unless it's a sharp curve I'd use 3/16 or 1/4 inch masonite or hardboard instead of the very thin 1/16 stuff to help eliminate any bows between the framing members. Construction panel adhesive in the  caulking gun tubes is an easy way to glue the stuff to studs. I just shoot some brads into it with an air nailer to hold it till the glue sets,.....DaveB

curves

There will be several curves and the plan is to possibly let the masonite hold its own shape in the curve or cut specific radius sections for the curve areas. In the past I have curved corners by just supporting the masonite on the ends and letting it form the curve as I pushed it in. Its easy with two people, a challenge with just one.

I am using 1/8 masonite. I didn't think about telegraphing but it is a concern. I could add more verticals just as easily as adding more horizontals.

Adhesives

Have used both Loctite and Liquid Nails adhesives for a similar situation with equal success.  I have tried both the soslvent based and water based adhesives and the water based are just as good with easier cleanup.  And I agree that small brads from the air gun do a great job holding the panels in place as the adhesive dries.  You can't see the brad at all and once you paint the backdrop it definitely disappears.

"I didn't think about

     I've had areas where the thin masonite bowed or telegraphed the framing but once painted with some random clouds in a flat finish they got lost in the sky . They might be more of a problem if you plan to glue up photo backdrops which could wrinkle over them? I just try to minimize the unfairness but know some will creep in somewhere ........DaveB

I think I have both

I think I have both Loctite and Liquid nails. Good time to finish off those tubes.

Yes, most of it will get photo backdrops glued to it. I think I will add more support behind the masonite. Adding extra lumber behind the masonite is real easy before and impossible after. I will take a picture when it starts to look like something.

I just used Liquid nails and

I just used Liquid nails and put brad nails in to secure it.

Regards Phil

Here is what I ended up with for support walls.

Its sort of 16 inch centers but I put in 2x4 where they would fit and in some cases added 2x4 and 2x2 so I would have a lot of wood to make the seems. The curves took quite a while to make using a jig saw and laminating pieces together and then using the belt sanded to clean them up as round as possible. I also had to shave some of the pieces as not all 2by2's are the same width. We went over it with flat blocks to make sure it was all even and there are no high or low spots. This has been the difficult part of this project so far. Soon we will be on to roadbed and track. We did test fit some sheets of masonite and it looks really square. The masonite was in the unheated garage for several days so I am going to let is acclimatize to the basement for a day or so before we hang it. Likely not necessary but we got a lot done today anyway.

Very nice.

  I have to build something similar for my layout peninsula, I hope it comes out looks as good as yours. Now that you have it in place does the top height seem about right for viewing angle and room atmosphere? ...DaveB

Top height

The top of the wall is 77 inches. The room has a couple of stand up air filters with fans so that should be plenty to circulate the air. The ceiling is 8 ft so the gap will help. The tracks are typically at 44-46 inches with some just a little higher. I wanted 30 inches above the track height as we plan to purchase 24 inch backdrops. Some areas I will hand paint and possibly color match the backdrop sky with oil paints. One thing I read about priming masonite is to clean it first with pure alcohol. 100 %. I have some denatured alcohol and will try that. The reason is masonite is made in a mold and there is traces of mold release on the surface. At least that is what I read on an artist site where they use masonite instead of canvas for paintings.

The vertical 2by's were bolted into place. As level as possible. Then a strip of 1 by two was run along the top and screwed to the verticals, again as level as possible. A second layer of 1 by 2 was glued to the top of the first with caulk. All the 5 inch long pieces of 1 by 2 were glued with regular wood glue. They were slightly shaved so as to not interfere with the masonite and adding warps. The 2 by 4 and 2by 2 cross pieces are not structural. So they were all glued with loctite or liquid nails. No clamping or screws. The liquid nails hold them just fine and you have about 10 minutes working time to get them straight and flush. I did a lot of sanding as I used some pieces of wood that had seen better days. My small belt sanded makes short work of high spots.  I added lumber where the seems are. I wanted a few inches to glue down the masonite. The trick is getting all the verticals level with each other. I used a 6 ft level. And then using the top 1 by 2's to get them all straight and level and square with each other.

The supports are 30 and 1/4 inches top to bottom. With the masonite flush at the top, I will have a 1/4 inch telltale at the bottom.

Backdrops and facia

Putting up the backdrop wall and the facia really makes it look like the rest of the work is going to be quick and easy. Nice start Phil.

Very nice work!

Your benchwork looks great! Nice work!  I especially like the curved backdrop section.

Hanging the masonite

I am using only loctite and liquid nails to hold the panels in place. No screws or nails. So far that is working well. I work by carefully clamping the board in its final location and I clamp one side real well. Then I can swing out the other side and glue it and clamp it in place and repeat with the other side. Once both sides are glued, lots and lots of clamps with boards to spread the wood smooth.

I used up the last of the loctite. After a few hours, it is still like soft putty. With liquid nails, it gets a hard coating after about an hour. My speed is one panel per day. I think both will work just fine. After 24 hours, I remove the clamps and its all smooth. I do sweep and push in the field while the glue is setting. But so far its not bowed anywhere. I did not clamp in the curve. Just put lots of glue on the frame and pushed the board hard into the curve and clamped it. It may have helped that we clamped the board into the curve and let it set overnight. Sort of gave it a memory.

The liquid nails does have a heavy smell sort of like contact cement. I got the window and door open and the fan on high downstairs to clear it out. I have enough brain damage.  Both are equally easy to use. I am also wearing rubber gloves as there is always going to be a place where you want to smooth it out with the finger.     

When I glued the inside or the corner, I clamped the flat areas and let the corner float. It seemed to work out well that way. The outside curve panel is just hanging loose. Maybe it will get a little memory after hanging all night.

Professional

Looks terrific! Very professional!

Professional? Thanks

Maybe, I have not worked with liquid nails before so I am learning as I go. Well, okay we put a bead on the 2by12's when we built the floor but then it was nailed so I didn't learn much .  It sets up fine after a day and I can remove the clamps. It is likely set after a few hours but I have so much time into this wall It would be a real nightmare if some of it didn't stick. I looked it up and it is dry in about 7 days. The instructions say to protect it from rain for 24 hours. The same with the loctite. I can handle one panel a day. Gives me time to look at backdrops which will be another post. If I only had a couple dozen more clamps?

construction

When I built the train room I added on to my house I liquid nailed all the sheathing, the spacers for the sheathing insulation, the exterior panels and the battens. I went through about 50 tubes of the stuff. 

But, I was more speaking about the quality of your construction.  I'm going to use your curved backdrop frame idea when I get to that point in my layout construction.  I'm taking a different path than you where I'm building a modular layout using the MRH TOMA technique but I will have a backdrop frame on the wall.  Thanks for sharing your methods!

Very nice work

Very nice work... keep us informed, as many would like more info on the holding power of these construction adhesives with Masonite (especially on curved surfaces). I have been nervous and always resort to drywall screws.

Good Work,

Holding power of drywall screws.

I am the same way, I have always screwed and glued. I did a small test with caulk and its just like wood glue. Once it sets, the wood is destroyed by trying to pull them apart. So I figured the liquid nails would be of similar strength. I did try to pry up a corner and cant so I hope its good. And for those who are not sure, driving in some screws would not hurt anyway. You just have to inset them slightly so they don't stick out. Even without screws or nails, there will be some mudding to smooth out the seems. I will take a razor blade and carefully bevel the joint between sections and a coat of mud should make it go away. And a few places where I put the clamps directly on the face of the masonite there is also small indentations which the mud will cover easily.

One trick I learned about using "topcoat" mud or any mud. We don't sand it. It creates too much fine dust unless someone is next to you with a vacuum. I use a wet rag to smooth out the trowel marks and high spots. Keep a bucket of water near and just wipe the rag over the joint and it smoothes out real nice and clean.

The negative of using glue vs screws is the backdrops will not be salvageable by removing the panels. The entire wall and backdrop become all one piece and you would have to remove the entire wall if you wanted to save them when moving or dismantling the railroad. I plan to leave my kids a house with a model railroad in the basement.

To glue the outside corner I glued the left side and corner first. After clamping it only on the flat area to the right, I made a simple jig to pull panel tight into the curve. See second picture. The vertical board and clamps in the middle were placed after the board was pulled tight into the corner. Then I was free to remove the right side clamps and jig and glue it. Today I will remove the clamps and move on to the next section.

One note, I am putting the adhesive on pretty thick. About a 1/4 bead and I am pretty sloppy so I also wear disposable gloves while doing this. It takes almost an entire 10 oz tube per panel.

Finally, the wall is up.

I finally got the last section up and glued. I used the same method as before with the curve. The inside of this curve is 29 inches radius. I had to feather the curved sections on both sides so they come to a point on the right side and about 3/4 inch wide in the left. I screwed a board to the stud to make a solid surface to screw the masonite to. I used liquid nails again and let the entire curve float. All the curved supports behind it were sloppily covered with glue but the panel will smooth itself out. No clamps were used in the curve.  Just clamped the right side and screwed the left once I had it pushed tight into the corned. I will leave the screws in and just mud over them. I see a little bit of mudding in my future.

I am really glad to be seeing the light on the completion of this wall. So far I have a few weeks working on it and I am in the mood to work on something else. So I started plotting out my wiring and buss and feeders and terminal boards etc. Going to read up a little on DCC wiring.

No close up pictures. The inside curve is real sloppy but the panel is square and level so who cares?