Durable Flat Construction

[3cats1pug]

Many years ago I worked a summer at Houston Stage, building touring scenery for a musical. I am currently the production manager at our local community theatre, and our flats are in horrible shape. I want to build new flats like the touring flats we built for that show so they'll hold up over an extended period. The trouble is, I can't remember all the details, and I'm hoping for a little feedback here so I can get on this.

We built the frame same as usual, 1x4 with corner blocks, stiles, and rails. We applied 1/4" ply for the surface, and then applied something like contact cement to the face. We then applied muslin and pounced the entire surface. When it was dry, we were able to apply the glue/water mix, and then let the scene painter have it.

What I can't remember is whether we used regular glue or contact cement to apply the muslin, and I'm thinking that it probably won't matter. I'm also not sure what we used for pounce, but then again that may not matter, either. Wouldn't it work just fine to apply white glue to the plywood, stick on the muslin, and then do the sizing all in the same step? Once it's dry, it seems like it would paint quite well. I'm not sure why we would have used contact cement, like one would use on a laminate top, but my memory is that that's what we used. Anyone have an opinion as to why that would be better?

Thanks for any thoughts.

Mark Mills
Production Manager
Backdoor Theatre
Wichita Falls, Texas

[sound_nerd]

We build ours the same way, except we lay masonite over the plywood as opposed to muslin. Our paint crew seems to prefer it, so thats how it gets done.

It shouldn't matter between contact cement and glue for the muslin, if anything I'd use yellow carps glue. Or check www.thistothat.com to see what will work best.

[sound_nerd]

Alright, well i checked thistothat.com and they said to use 3M 77 spray adhesive if you dont want the fabric to get crisp. If you dont mind the crispiness then just use carps glue.

[sandals1621]

When I've built Hollywood flats (the traditional term for a hardcovered/muslin covered flat) i've done the contact and sizing in one step, 2/3 part white glue to 1/3 part water.

[Drmafreek]

I tend to use wood glue and water mix when sizing up the muslin. It seems to work fine, and the stiffness is not a problem due to the fact that you are putting it over luan, maso, or ply.

On a side note, it sounds like what is being built is actually called a Broadway Flat. A Broadway has the 1x on face and a Hollywood has 1x on edge. Just a bit of info.

[ship]

Interesting new term for me this “Broadway” style. Never heard of it before but it’s a good idea to have a term for hard flat on flat as opposed to “Hollywood” on edge hard flat in style.

I have not professionally done a muslin cover over luan (over foam at times yes) but did muslen to plywood at times for side gigs. Did so recently to give a more soft texture to a door. I used a white/wood glue/water mixture and noted it did not stick to the AC plywood very well. Peeled off fairly easily as if a old style Dutchman seam. The contact cement than could be some type of bonding agent given it will allow the latex based wood or white glue plus water vehicle or thinner to bond with it. Water based contact cement might work better with latex glue for this than oil based stuff, otherwise I remember a blue contact cement that was used for about everything but it was more for use in working with foam. Wish I knew what the blue contact cement was still - good stuff.

A question might be if the glue is doing much sizing in a traditional way by way of removing sag and stretching the flat as if a canvass as opposed to just shrinking while gluing to plywood slight discrepancies in wrinkles or lay. Those areas supported by and drying first to the plywood would not have much need or chance to really shrink much. Sizing might work well on a soft flat, but might not work well in otherwise diluting the glue used to attach it to the plywood.

As opposed to contact cement that might just work really well, pre-gluing and letting it dry the surface of the plywood, than adding the dipped in glue fabric might have advantages in adhering it to the plywood. Otherwise at least wetting the plywood might help. For some reason at least in my last attempt in soaking in a glue/water mixture fabric did not attach as well as wished to to the plywood. A bonding agent might help.