Welding table build

[CDN Farm Boy]

I got a handful of cash for Christmas and sold a 6.0L motor that I hadn't gotten around to using to buy a plasma cutter from Duncan at Everlast Canada. Still had cash leftover burning a hole in my pocket. With my birthday this past week, added cash from my wife, my folks and my mother-in-law and ordered up enough steel to build a welding table and have a couple chunks left over. Steel was ordered Thurs, delivered Friday and I started cutting today. Shipping slip says 1140 lbs. I'll measure up what is not used to calculate an accurate completed weight but it should be easily north of 900 lbs, closer to the 1000 I figure.

Overall the table will be 4 x 8 with 5' of it 1/2" plate and the other 3' will be cutting slats.
2.5" x .237 wall tubing used for top rails to accept 2" slide in accessories
2.5" x .188 wall legs
2" x .188 used for lower shelf supports

Parts cut and ready for prep and welding:



(Sorry for the dark pic)

A question for you experienced welders out there, particularly those that deal with heavy plate like this on a regular basis: How flat should I expect the 4'x5' sheet of 1/2" plate to be?

I figured it would be flat. Not flat like a milled surface but flat to eye with a 4' level. I've got roughly 1/8" gap under the middle of my 4' level when checking the 5' direction. I can pull it flat with a couple big ratchet straps and blocks of 8x8 but don't think that I should have to. I'm concerned that even if I pull it straight before I weld it to the frame, when I take the straps off, it will just return to the bow and pull the frame with it, defeating the purpose of building a flat table.

 

[FredH]

Possibly turn it over and try level again ? If it is the same , then just the shear weight is bowing it , if only supported on the edges . Possibly would need a support brace through middle in that direction .

Fred H.

 

[Shield Arc]

I don't have a lot of experience with this, but what I'd do is build the table with the bow up. Once the table is complete, I'd take my torch and use one of these two methods to correct the bow.

 

[chad22]

I don't have any advice on getting the table leveled out. But that's gonna be a nice present once finished. I need to build myself a welding table soon as one would really come in handy.

Chad

 

[FredH]

Agree with S.A. , You never stated if it bowed in opposite direction if you turned it over ? If it does , it would be much easier to bow it down than to bow it up with heat . If anything , lay it with bow up on a hard surface and drive over it ??

Fred H.

 

[Tractor Seabee]

Most of the new 1/2 plate I have encountered is dead flat from the warehouse. But then I always try to go pick one out myself. 1/2" plate with a bow in it is tough to straighten as it is probably stretched. I would get a piece of H beam, probably 6-8" and put as a strong back under the center at right angle to the bow. Get the plate pushed down tight to the beam, get innovative and figure a means to do that as there are many ways I can think of, put a series of tacks 2" long about 8" apart . That should hold it pretty flat. You will probably never get it dead flat like my smaller one is.

Ron

 

[SquirmyPug]

I don't see why the 2.5"X .237wall tube frame wouldn't hold it mostly flat if you get it pulled tight and weld it in place. If it doesn't keep it straight do like Shield Arc said, he knows his stuff about heat straightening. Or you could get a few lengths of .25" X 2" and run them vertical to the plate down the length. That combined with the tube should hold it.

 

[Arc weld]

The weight could possibly make it bow but are you building a frame the plate welds to? I made a 4' x 8' x 1/2" table but made a base out of 3" channel iron with a cross member in the middle. The frame is back 8" or so from the edge. I had it figured out so I only needed to buy one length of channel. I just made sure the base was flat and then pulled the 1/2" plate tight to the base. Then I stitch welded it. I think I put 2" welds on 6" or 8" centers so it wouldn't get too hot and warp the plate. It's not perfectly flat but close enough for anything I'd ever need. I used 1 1/2" sq. tubing for the legs and welded 1 1/8"(?) nuts on the bottom. Then I welded a piece of ready rod to 3/8" plates to attach 1000 LB. capacity locking swivel casters. I mounted a tubing bender on the table and needed to make sure the table was level. With the casters on the ready rod, I can easily roll the table around and level it. I put jam nuts on the ready rod so I can lock it in place when it's level. I cut a wrench out of 1/2" plate to adjust the casters. I welded nuts onto the ready rod before welding them onto the plates. This gives me an easy way to use my wrench for adjusting the table for level. The table weighs about 1000 lbs.

 

[CDN Farm Boy]

Its definitely the plate that is bowed. It's currently supported on the ends and the bow is up. The frame material stacked on top as on the pic did nothing to change it.

The main frame will be set back 2" from the edge for clamping. Using 2" x 3/16 for the cutting slats, I'll have 1 1/2" square crossers to set the 1/2" plate at the same height

 

[CDN Farm Boy]

I also have two 6" 700lbs fixed wheels that will be mounted on the bottom of the legs on the cutting end with solid legs on the table end. Should give the best combination of stable and portable. Going to put a hitch on the table end so I can move it with either the fel or 3pt hitch

I hadn't planned on any adjustment to the legs at this point as I only have gravel floor in the shop and won't likely have concrete for a while yet. I figured I could add adjustment when the time comes. Perhaps that is being short sighted and I should do it now?