GJ inspired table/bench

[DirtyWhiteBoy]

I am building this primarily as a welding table, but it will have many uses in my garage. I have been watching for a usable top in area fabricators "scrap piles". I finally scored one, its 31 x 41 x .5 after they trimmed it with their cnc plasma rig. $35 for the top It's smaller than I wanted, but it'll beat the heck out of crawling on the floor.

I plan on expanded steel shelf and drawer, receiver type tool mounts, and most likely leveling feet (wheels don't lock). It'll be a few days before I get back to it, but hope to be using it in a couple weeks.

One question, the top has a slight bow approximately center lengthwise. It is 1/8th" or less, should I attempt to level it out (if so how), or mount it crown up/down?

 

[willysrule]

looks like a great start!!

I see a rat rod in back...

 

[airbuff101]

Very nice!
1/2"!!
Far Manlier than most.

I'd maybe mount the top crown-down and tension a bottle jack under it for a spell to help straighten it out over time. might work...........

Your gonna have to start a thread :

"What kind of steel top should I put on top of my steel top..............?"

airbuff

 

[Garage5.9]

Would it be possible to heat the sheet up in a big fire then rapidly cool it with water with the hopes of making it come back level or would it just crack

 

[Jack Olsen]

You could blanchard grind it for $80-90, probably. But you'll want to do that while it's still just a piece of plate.

If 'close enough' is okay, then have it bow upward, and clamp it down very tight to try to bend it back -- then do long, slow welds on the concave underside so that it heats up and the warpage works in the direction that will make it more flat.

 

[DirtyWhiteBoy]

Thanks for the comments guys!
I don't think I'll have it ground flat. I live in a very rural area, for example, it's 44 miles to Lowes and 50 miles to the fab shop where I buy steel. I have no idea where to have it ground within 100 miles of here.
I've been thinking about the heat-n-warp correction as a "good enough" solution.
I am also considering welding nuts to the frame to help "inspire" the plate a bit with bolts screwed in from below.

 

[pirana]

With no more bow than you have you could probably get it out by dogging it to the frame with a wedge when you weld the top on. Start in the middle & work your way out.

 

[toolchaser]

Check out Tom Lipton's book "Metalworking Sink or Swim", it has a great section on flame-straightening

 

[DirtyWhiteBoy]

thanks guys!

I ordered the book.

I don't claim to be a welder, machinist, or fabricator; so I hope it shows up

 

[rocklobster]

I am not a pro weldor but here are some humble suggestions:

It would be probably best to weld the convex side of the plate up, and with a good set of clamps and welding the frame from inside out you should be able to pull it down.

Another take on this idea is called a strong back and that technique is where you weld a heavy piece of channel to the bottom of the plate along the long axis from the middle out while using heavy clamping pressure.

And you said that the table is not as big as you would like; have you thought of making extension arms of large angle iron or square tube that would pull out from the side of the table for welding larger pieces. Or the idea I like is to build part of the top out of square tube sitting flush with the metal plate and spaced 6 inches or so apart with expanded metal welded to the bottom side so that you have pockets on the top to keep your tape measure(s), speed square, marking tools etc. without them being knocked off onto the floor.

I haven't built a welding table yet but when I do I plan on having only 1/2 of the top surface metal plate and the other 1/2 square tube as I described above. I thought since I am right handed I would work with the square tube top to my right and then when I set something down in a pocket it will stay put and not go MIA.

Anyway just giving some suggestions, and BTW nice shop!

 

[Cougar]

I assume the plate is like A36.
Lay on the ground with the bow up.
Put some shim under each end, start with something thin maybe 1/4".
Drive your truck up on the bow to press it down. If it springs back up add some more shim.
Would be like putting it in a press, your truck would be the ram.

 

[mike13u]

If you can, leave the top 'floating' on the frame for a few weeks laying convex. With the heat of you welding on the top and weight applied it will probably reduce itself quite a bit.
If you dont brace a piece of 1/2 plate underneath and weld on it it will bow downwards just from the heat of you welding things on top.
Its looking good man.

 

[Dying Fetus]

Good work!

My table top is 4'x8'x1/2". It had 3/4" of bow in the middle of it, running the entire length of the plate. I was able to take the bow out and it's now completely flat. I put the plate on the table skeleton such that the highest spot was in the middle (convex). Then I clamped several pieces of I-beam across the top and welded the underside of the plate to the bracing of the table skeleton. When I took the clamps off, I tested for flatness with a streight edge and a piece of paper. It was completely flat!

 

[DirtyWhiteBoy]

Great ideas guys! Thanks a million!!

I am out of supplies for now, but it will be used with the top floating for now. I NEED to build a kayak rack.....so I'm told

I'll post up more pics once I round up the bits I need to finish it up.