# Wood movement when face-gluing solid stock to plywood/mdf



## GregD (Oct 24, 2009)

I am making speaker cabinets (subwoofers at the moment) out of plywood and mdf.

I would like to face-glue 2" wide by 5/16" thick hardwood trim along the edges of the plywood sides to create a frame-and-panel look, cover the joints of the plywood sides, and allow me to run a 3/4" radius roundover over the corners without exposing the underlying plywood.

Long term am I likely to have problems with wood movement in the hardwood trim? The cabinets are too rigid for the trim to cause any warping. I suppose the trim could split or the joints might widen. It doesn't seem too likely to me, but I'd like a heads-up if someone has some relevant experience.

Thanks!


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## CharlieM1958 (Nov 7, 2006)

Greg, you're outside of Houston, right? Your climate is pretty much like mine in New Orleans, and I find that wood movement in general is not as big a problem here as it seems to be in colder climates. I think because our temperature range is smaller, and humidity is consistently high, moisture content doesn't fluctuate as much as it does in some parts of the country..

I have done things very similar to what you are describing, and never had a problem.


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## Rick Dennington (Aug 27, 2009)

Greg…...It sounds like you've got it pretty well worked out as to how you want to do the trim….I've built a few speaker cabinets for a sound system years ago…..Back to your question: If it was me, I'd glue the trim on, clamp it up, and shoot a few pin nails to hold it…..18 gage should be fine….Then go back and fill in the nail holes, and you're good to go…..Paint, stain or wahtever finish you use…...As Charlie said, we live in the South where wood movement isn't a big factor….......


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## GregD (Oct 24, 2009)

Charlie, Rick

Thanks. Yup, I'm in the Houston area these past twenty-something years. I didn't think it was physically possible for any place to be more humid than Houston - then I visited New Orleans in the summer…

Traditional 6 panel doors have cross-grain mortise-and-tenon joints that are much wider than 2". Britboxmaker's EZ miter (trademark? patent-pending?) also ends up with cross-grain joints that could get close to 2" wide. So I figured my plan could work.

Seems kinda strange. With most projects I'm trying hard to make sure the joints look tight. On this project all the large structural joints get covered up and I just need to be careful about fitting the small joints in the trim. Maybe I'm getting a bit smarter. I'm pretty sure this idea was influence by the Woodsmith Shop TV show.


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## wapakfred (Jul 29, 2011)

That piece is not wide enough to be concerned about movement (IMHO). I think you're good to go, though I was curious about running a 3/4" radius roundover bit over a 5/16" thick piece of wood….not using the full radius?


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## GregD (Oct 24, 2009)

There is trim on both sides that form the edge that gets the roundover. So the trim forms edges similar to the situation you get with a box made out of 5/16" thick stock. A 3/4" roundover will not cut through so long as the trim is at least 1/4" thick.


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## LukieB (Jan 8, 2012)

I agree with Fred, with pieces that small, the movement should be pretty minimal.

Fred, I think this is what he means by 3/4 radius on 5/16" stock, I had to think about it myself for a second so I drew a picture, LOL









Edit-And I see Greg responded while I was drawing, : )


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## Airspeed (Mar 11, 2013)

I think you will be fine, you outa try to prevent movement in speaker cabs like these! I had to build a custom oven to bake these in before I painted them! Took forever to figure out a way to stop seams from showing through from movement in the wood, actually MDF and Masonite. Drying them out and sealing them right after was the only way I could keep them stable.


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## GregD (Oct 24, 2009)

LukieB - yup, that's it.

Airspeed - awesome! Something like that would make the rest of my house look bad!


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## LakeLover (Feb 2, 2013)

Greg.
I live in the frozen north. Today I helped our oldest daughter move.

I had a chance to look at the birch ply and solids. After 5+ years some pieces look great. some well used and could stand some refinish. But the well glued joints were tight.

I was looking at this one bedside table, then looked at again. Thought….... Did I make that?? So I asked my daughter and she said Yes. I guess I never took a pic and I should have. Spalled maple drawer fronts, and the finish on the top birch and edge banded solid, was still pristine. Even the mahogany feet were shining. Minwax poly.


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## GregD (Oct 24, 2009)

LakeLover - thanks for that data.


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## RonInOhio (Jul 23, 2010)

Airspeed those speakers are very nice. And that camper you made is out of this world
cool.


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## Arookar (Oct 28, 2011)

I was taught that 3" or less (across the grain) is the safe spot….too little movement to worry about in those widths.


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