MDF & solid wood...which adhesive?

[themrfreeze]

Hey all.

I'm adding a tall wainscot with plate rail to the dining room of our 1920s house. The plan is to make it out of sweet gum (or gumwood, as it's known around here) so it matches the existing trim in the room. Due to the room being out of square/plumb/level/etc., the wainscot will be built in-place. Plate rail on top (with a skirt board & corbels underneath it), then stiles running between the skirt board and the existing gumwood baseboard. Open areas will be filled with panels made of 1/4" baltic birch plywood, held in place with quarter-round gumwood molding.

Since gumwood is not particularly easy to find, and is fairly expensive when you do find it, I need to conserve my modest stock of wood. I came upon the idea of first installing 1/2" MDF for the skirt board and stiles (which I can screw to the wall), then face it with a 1/4" thick piece of gumwood. The question is how to fasten the gumwood to the MDF. I figured an adhesive of some sort, plus headless pin nails to hold the gumwood in place, would be the best way to go. I've not used MDF before for anything, so I don't know what the best adhesive to use would be. So, if anybody has any thoughts, I'm all ears.

TIA!

Chris

[PaulMarcel]

If the MDF is applied over the undulating wall, there'll be voids in there that could have strange acoustics in the room. I think I'd consider using a thick construction adhesive to attach the MDF to the wall before screwing it in, which will pull it tight to the wall and really hold it there.

For attaching gumwood to the MDF, I think I'd apply a solvent-based contact cement to the MDF outside before installation. You can similarly apply the other face to the gumwood outside keeping the lovely fumes out of the house (once it flashes, there's not much odor). Mounting the gumwood is then placing it and applying pressure. The pressure forms the joint so apply it lightly into position then give it some taps with a rubber mallet. Other benefit to contact cement is that you could spray it on those surfaces. If you don't have a sprayer, roller it.

[themrfreeze]

Thanks for the feedback.

When you say "strange acoustics", what exactly do you mean? I can see how using construction adhesive would improve the bond between the MDF and the wall, but don't see how it would affect the acoustics of the room. Putting something (like adhesive) behind the plywood *panels* would certainly make a lot of sense.

For attaching gumwood to the MDF, I think I'd apply a solvent-based contact cement to the MDF outside before installation.

It occurred to me that using a non-water based adhesive would probably be best, but the problem is that it needs to be 65+ degrees outside to apply contact cement, and I'm in NY. At this point, I doubt we'll see another day that warm until May. I'm wondering if solvent-based construction adhesive would be acceptable, even if I have to use headless brads to fasten the gumwood in place while it dries.

[PaulMarcel]

Thanks for the feedback.

When you say "strange acoustics", what exactly do you mean? I can see how using construction adhesive would improve the bond between the MDF and the wall, but don't see how it would affect the acoustics of the room. Putting something (like adhesive) behind the plywood *panels* would certainly make a lot of sense.

Sorry, didn't think that the MDF was the profile and ply the panels. Doesn't change what I'm thinking, just flip the words. So yeah adhesive behind the panels like you were thinking.

It occurred to me that using a non-water based adhesive would probably be best, but the problem is that it needs to be 65+ degrees outside to apply contact cement, and I'm in NY. At this point, I doubt we'll see another day that warm until May. I'm wondering if solvent-based construction adhesive would be acceptable, even if I have to use headless brads to fasten the gumwood in place while it dries.

Sorry, should have looked at your location before. To me the contact cement would be so much faster plus you could prep the glue well ahead of time; no messy and smelly construction adhesive, no compressor, no nail dents. Solvent-based contact cement would flash off just like solvent-based construction adhesive so same smell. I'd opt for the convenience. If you are working in a garage of sorts on-site, seems like you could apply the cement there. Heat the area with a portable heater.