Shopsmith Forums

My dad knew I've been keeping my eye out for an old solid core door to potentially use as a workbench top. He came across one and brought it to me today. But as I was checking it out, it looked like it had a bow in it. I put my straight edge across it, and sure enough it did. On the concave side, the middle of the door is right at 1/8" below the straight edge.

Is there any hope of either flattening it to make it usable as a workbench top? It is 36" wide and 83" long, but I want to cut it down a little. Maybe 32"x60".

I used a s-core door on my new bench, and I don't think I could have flattened it. Mine was a s-core fire door from an old clinic. The outer layers were much thicker than a residential door, but I don't think I could have planed off 1/8 and still had a solid surface. The outer surfaces were a plywood of three layers. The inside was hard as heck and not easy to cut. I cut mine to 60 inches and it took 4 passes and pretty well finished the blade on my circular saw. This door would have been 30 -40 years old and was dead flat to begin with. I did not do anything to the " finish" on the door, because it had a pretty think accumulation of some really hard "stuff" in it. I did not want to risk opening it up to moisture. It might be worth a try if you have time, and can get the top off the bench if it doesn't work. All the effort to get a good bench was worth it for me, only because I had a good surface. I can get mine off if I need to as well.

I finally got the industrial heavy doorknob off and can see that it's not solid wood. Looks like partical board. Denser than Ikea furniture, but not as dense as MDF. Is that common?

Very common in new doors. Any more unless you special order something almost all doors are going to be a particle core with a veneer face. On the better ones there will be solid or finger jointed wood rails and stiles. The "funny" thing is they do that because the laminated doors are less prone to warping than solid wood ones.

I used a "solid core" on my w/b. Worried a wee bit while building it (the B) that sag might be a future problem. But onct I got the top frame done on which the Top rests I worried no longer. It (frame) uses a 3 x 3-1/4 lam that's 15" ea. end and ~~5" ea. side short of the door dimension, which I left at 32 x 80. I'd hafta park my XS750E on the dang thing for a month to get any sag outta it, I reckon.

Point bein, if you take your 'new' solid core door and mount it convex side UP on to a very solid top 'base-frame', with a good number of 3" screws (2 more than necessary on each side) all way around, you may well be able to get the 1/8 'bow' out of it for ever.
I take the extra caution of marking the top surface right around where the legs are to indicate a good-as-granite surface to beat on things at. (Legs are the same 3 x 3-1/4.)
The S-C door veneer will not give you as durable a surface as butcher-block end grain, of course, but I Danish-oiled mine and slathered a bunch of Verethane over that, for a very tough surface. Dings get either ignored or filled in, depending on size, and coated w/ Verethane too. This bench, as you no doubt have noticed, is for workin, not for lookin, and it works quiet well for me. (Actually looks pretty good too, imho.)
Weight: not a problem, what with the S-C door itself, and then about 20 or so 8 ft 2 x 4's making up the base etc. It doesn't do a lot of budging.

by the way- on the Verethane: I like to be able to move heavy things easily while they're on the bench (when not clamped still) and the top coat of Verethane applied with a ROLLER did the job. Those warnings one hears about V-T and rollers are true- you get a lot of tiny bubbles. Let it dry like that and you get a zillion very hard little casters to slide stuff around on!