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View Full Version : BB Ply for Desktop - How thick?



Russ Filtz
06-13-2007, 3:40 PM
I was thinking of using BB ply as a substrate for a laminated computer desk top. Approx. dimensions would be about 30x60 plus 2.5" of solid cherry edge "banding" around the whole thing.

Can I get by with 1/2" BB or will 3/4" be needed for strength? Will have simple side panel supports, with a stiffener partial vertical panel under the top closer to the rear edge.

I prefer ply to MDF as it's not so heavy and should be more stable right? (less saggy over time?)

David DeCristoforo
06-13-2007, 3:57 PM
Half an inch is too thin for a desktop. And since I am completly opposed to the use of MDF for anything other than crude jigs, etc. I would suggest laminating two thicknesses of the half inch ply for a net top thickness of one inch.

Russ Filtz
06-13-2007, 4:07 PM
I could do the 1" section, seems like a good compromise. I'd have to up size my edging lumber to 6/4 or 8/4 to cover it.

Jim Heffner
06-13-2007, 4:17 PM
Russ, If you want it good and strong I would use two 3/4" layers of
bb plywood or mdf, either will make a very good solid top.
To finish it off, laminate a good piece of formica of your choice to it,
and you will have a top that will take a lot of abuse and last for years.
Jim Heffner

Cliff Rohrabacher
06-13-2007, 5:28 PM
I'd use 3/4" and run some 4" x 3/4" around the edge under the top. That'll make it plenty sturdy while not too heavy.

Doug Shepard
06-13-2007, 6:10 PM
Another option would be a torsion box. More time consuming, but it would make the desk a lot lighter as well as probably more stable.

Bert Johansen
06-13-2007, 11:56 PM
I'm going to go against the previous replies and suggest the unthinkable--only because I have been successful with a different approach. I used MDF for the substrate. I ordered 5/8 inch MDF, but my lumber supplier delivered 3/8 inch instead. Well, I used it and it worked just fine.

My desk project is 66 inches wide and 29 inches deep. The top sits in a wide rabbet in a substantial frame. Unseen in the photos is a center support that is mortised into the frame. I opted to add a 1/4-inch flat glass to protect the veneer.

Russ Filtz
06-14-2007, 7:54 AM
Nice table! Not sure if I want to go that route. Just something simple, yet look nicer than the crumble wood, cheapo veneer/laminate you get at the stores.

I made a stereo rack the same way so it'd be nice to match styles (although they're not in the same room!), nice Wilsonart black laminate with a wide solid cherry strip around the perimeter.

Joe Chritz
06-14-2007, 9:16 AM
MDF will make a fine substrate for a desk top if you properly support it.

If you go with plywood, BB is the best choice. Minimum of 3/4 with 1" being better.

A desk should be heavy unless you specifically design it to be moved around.

Joe

Bill White
06-14-2007, 9:56 AM
Use mdf (3/4"). You'll have no problems if the structure of the base is sound. I build all my paint-grade mantles from mdf 'cause I don't have to worry about warping, shrinking, swelling, etc.
Just my opinion of course.
Bill

Russ Filtz
06-14-2007, 2:16 PM
I'm going ply because the design I'm thinking of doesn't have the apron support all the way around. A good part of the desk will not be directly supported and I didn't want it to sag. Using high pressure laminate both top and bottom should help a little there too (if I use resin glue). Resin glue OK for laminate I assume?