Welding table top not flat

[HockeyDave13]

I've been reading all the work bench and welding table threads as I get ready to build my welding table. I had square tubing but didn't have a top. Before I bought new I thought I'd try to find used. A buddy that owns a body shop have me a piece of 1/2" diamond plate that is 28" by 60". Since it was free, I couldn't pass it up. However I just loaded it up and it's warped. I'm looking for ideas on how to flatten out this hunk of steel. Any thoughts?

 

[nickleone]

I hope you are putting that diamond plate face down.
Build your table with stringers across the width drill thru the diamond plate and thru the stringers. Counter sink some long bolts thru the plate and tighten them till it is flat and level.

Nick

 

[NUTTSGT]

Flip it over and park something heavy on it for a while ?

 

[HockeyDave13]

Yes plate side will be down. Got it in the shop at lunch. Smooth side has some welds I need to grind off and I'll trim the end off that has the holes in it.

 

[Perrorojo]

if it's 1/2" thick you are going to need something really heavy to park on it. I'm thinking you're going to need lots of bolts and a real sturdy base.

 

[djd99]

Throw it on the floor and drive a truck over it that might take some of the bow out of it.

 

[loply]

Build a big plywood torsion box - like 6 inches thick - and bolt your metal to it.

Would flatten right out I'd imagine...

 

[readhead]

In this case free is not a good deal. You would need a very stout frame to try and pull this down flat. Go get a flat piece and start fresh.

 

[EOC_Jason]

In this case free is not a good deal. You would need a very stout frame to try and pull this down flat. Go get a flat piece and start fresh.

That's what I was thinking. The time, effort, and money sunk into trying to get that thing flat. You would be better off getting a new piece that IS flat and didn't have to fight with. Save that for another project.

 

[1/2 Cup]

1/2 " would be difficult to get straight.
I was in a similar situation with mine, a donated piece of 1/4" that had a slight bow in it. I was able to clamp it down against the bend to the frame and it ended up not to bad.

View media item 36384

 

[Hornman]

All those welds on the smooth side have probably puckered the plate. Grinding the welds off and careful application of heat in the right places could straighten out the plate, but you will have to be very good with the torch.

 

[Spareparts]

I just done that, used some 3/4" X 4" flat bar and heated and bent 2" legs 4 1/2" apart ID forming a short legged U, you can make the legs longer if you desire.
Then I used 2- 3" heavy channels 1/2" wider than the plate. Drilled 3- 1/2" holes on the 3" side of the channel, Bolted the channel together with washers spacing the channel wide enough to pass a 1/2" bolt thru it. Welded the short leg of the Flat Bar to the channel. What I made was a bridge across the warped plate, I put long bolts thru the channel with a nut and a couple of flat washers between the bridge and the plate and started tightening them and straightening the plate. I made 2 of these and progessively worked my way down the plate welding the crossmembers as I moved down the plare.


if you decide to try this and have any questions feel free to ask.

 

[BD1]

Did you build the frame for it ? Hard to tell if it is bowed or if is or wavy. Setting the plate on the frame will give you a better perspective on how bad it is. I flatten one out by setting I beams on top and clamping it to frame. Another way is to use a bottle jack and chain with hooks on each end. Cut a short piece of angle or channel 3'' or 4'' long. Then weld a piece of pipe to it that will fit over the bottle jack top screw. Set bottle jack on highest part of bow. You'll need a chain and a couple of hooks that will fit over the plate edge. Hook one end of chain on plate edge and run it on top over the bottle jack and let it set on angle or channel. Now you can see how long the chain needs to be to hook the other end to plate. So you'll have two hooks on plate with chain setting on top of jack. Start jacking and the jack will force the bow down and bring the edges up. Depending what you have for steel you can substitute that for chain and still use the jack.

 

[NUTTSGT]

If you attempt at driving/parking on it, don't do it on that nice floor. If it decides to move, it'll scratch the **** out of your nice floor.

 

[A_Pmech]

I can straighten that without laying a hand on it.

1) Survey the sheet to determine the nature of the bow.

2) Line heat the bowed areas along the axis of the bow on the convex side with a rosebud to a mid cherry and cool the back side sparingly with a water stream.

3) Allow plate to cool below 200F and survey again.

4) Repeat 1 thru 3 until flat.

How it works:

By heating the steel from one side, the side with the higher temperature plastically deforms when restrained by the cold side. When the section temperature equalizes, the heated side of the plate becomes shorter across the section neutral axis, which pulls the bend straight.

 

[A**holes Garage]

I can straighten that without laying a hand on it.

1) Survey the sheet to determine the nature of the bow.

2) Line heat the bowed areas along the axis of the bow on the convex side with a rosebud to a mid cherry and cool the back side sparingly with a water stream.

3) Allow plate to cool below 200F and survey again.

4) Repeat 1 thru 3 until flat.

How it works:

By heating the steel from one side, the side with the higher temperature plastically deforms when restrained by the cold side. When the section temperature equalizes, the heated side of the plate becomes shorter across the section neutral axis, which pulls the bend straight.

Yup, I built a few welding tables but with only 3/8" plate. Had one that was a bit warped, heated it and cooled to straighten and flatten. Long, tedious process. Going to be more difficult with 1/2" plate, have a big rosebud and 5/16 gas hose.

 

[rcalmus]

All those welds on the smooth side have probably puckered the plate. Grinding the welds off and careful application of heat in the right places could straighten out the plate, but you will have to be very good with the torch.

Agreed heat is going to be key but with that much surface area you need a lot of it. I have 3 anchors in my floor for situations like this. As you apply heat you use chains and couple ratchet binders to get that puppy flat. Maybe you know someone with a set up like this?


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[Steroblan]

I can straighten that without laying a hand on it.

1) Survey the sheet to determine the nature of the bow.

2) Line heat the bowed areas along the axis of the bow on the convex side with a rosebud to a mid cherry and cool the back side sparingly with a water stream.

3) Allow plate to cool below 200F and survey again.

4) Repeat 1 thru 3 until flat.

How it works:

By heating the steel from one side, the side with the higher temperature plastically deforms when restrained by the cold side. When the section temperature equalizes, the heated side of the plate becomes shorter across the section neutral axis, which pulls the bend straight.

^ What A Pmech said: and you don't need to heat the whole thing at once. One parallel line at a time so you don't over do it. Initially it will appear to bow the wrong way but when it cools, the shrinkage brings it back. Don't use heat around that cool floor. It was free, what do you have to lose?

 

[HockeyDave13]

Thanks for some good options, like Steroblan said, it was free so I'll try something and see what happens. I'll give you an update one whether it straightens or turns into a very large paper weight!

 

[brownbagg]

its a welding table. it doesn't need to be flat

 

[HAY YOU]

If it's a welding table you must have a welder. In that case I'd frame the table out as suggested, drill holes or torch them get some wedges, make some dogs & dog it down & plug weld the holes to the frame. Or even better dog it from the bottom side & stitch weld it with out drilling holes.

 

[sberry]

I would do the best I could and live with it, doesn't really need to be flat.

 

[tcianci]

its a welding table. it doesn't need to be flat

I don't have a welding table, but after years of shimming up and clamping stuff to be welded into some sort of position where I could lay a good bead on it, you can bet your **** that if I were to make one, it would be flat.

A welding table has to be flat, not surface plate flat, but reasonable enough so that it is an aid to getting the stuff you want to weld together into proper alignment. What better tool for aligning things you want to weld together than a flat table top?

 

[NUTTSGT]

its a welding table. it doesn't need to be flat

I disagree unless you're just welding some fixes but if you're making stuff, it's a serious PITA not having a flat surface to build **** on.

 

[readhead]

It is hard to make straight, square stuff without a flat table.
Do you want to mess with this scrap or make stuff on a nice flat table? I would sell you a flat piece for $98.00.

 

[jsaw]

its a welding table. it doesn't need to be flat

Not sure I understand, how would you set things up and get things straight if your welding table isn't flat?

 

[HAY YOU]

Even if the table top is flat, what if the floor the table sits on is not. You still have to use a whiskey stick (level) & square to make sure your project is straight & plumb. Shim up the project on the table where needed before welding.

 

[Richard D]

its a welding table. it doesn't need to be flat

You can weld **** up on a gravel drive with great results if you really have to, but a nice flat, level table makes life so much easier!

 

[A**holes Garage]

If the top isn't flat, why bother going through the pain and time of building a welding table?

 

[sberry]

Its neat how the amateurs think it must be flat and most professionals don't care much?

 

[koditten]

As for the holes, I'd leave them there. I got several in my table, I can't count the time I used those to put a quick bend on something. Much quicker than claming in the vice. Saved time=saved$.

 

[monkeywrencher]

This is my first post on GJ. I joined because of Dukers welding table build http://www.garagejournal.com/forum/showthread.php?t=193399&highlight=dukers+garage. I designed my welding table loosely on his.
When I got my top plate (1/2" thick 3'×5') it had a slight bend in it. I was a little concerned but it all turned out better then I expected. I countersunk eight 1/2" flathead bolts in the top ( 3 along the left and right sides longways and two in the middle). Once I tightened up the bolts the plate was perfectly flat.
Not sure if our plates are/were bent in the same way but with a little thought im sure it can be made prety damn close to flat.

 

[Richard D]

Its neat how the amateurs think it must be flat and most professionals don't care much?

The professionals I've worked with(including myself) prefer a flat level work surface.

 

[BD1]

The professionals I've worked with(including myself) prefer a flat level work surface.

I like a flat table too. Throw away the level and get some squares. A couple of 2' framings, some of those Swanson speed squares , try square, and a combination is nice. Can't go wrong with squares.

 

[Worsedog]

I like a flat table too. Throw away the level and get some squares. A couple of 2' framings, some of those Swanson speed squares , try square, and a combination is nice. Can't go wrong with squares.

A flat table and squares are the way to go. Years ago I built big fertilizer spreaders, sprayers and other ag type equipment. The shop floor was so sloped you could wash the shop out without a squeegee. All of the sub assemblies that were small enough to be built on the tables were easy to true and square. The frames and axles were built on saw horses with adjustable legs and we didn't level them, just made sure the top edge was exactly the same height. Just like having a big flat "table" with no top. A square leaves no doubt as to trueness, a bubble has some wiggle room.

 

[ptschram]

Its neat how the amateurs think it must be flat and most professionals don't care much?

LOL-I've never bothered to even try to square up my welding tables.

Pros know how to square up their jigs to the real world.

The real world isn't square.

 

[sberry]

I use a place or 2 that is flat for small work, any "building" is one off, don't routinely build large assemblies and I can see a twist in a plane or square. I do square off of a table not perfect but its flaw is so minor its not usually a factor.

My tables are really junk by these standards but work well enough there hasn't been a real need to stop the horses to make something better. There are 4 squares on the bench, just because one clamps a little piece and works with a 6 inch square doesn't mean the whole sheet has to be perfect.

An edge to clamp along is a high feature and square corners are good. Will agree with Kirk, a hole or 2, maybe a notch. The other part is a place to hang the tools and a bench under to be able to clear the top. In a general shop like solid top, keeps dirt and rust from falling thru, toss grinder and other things under. Keeps spatter from falling.

 

[sberry]

I have a section of floor quite flat, can build a 20 ft trailer measuring from the floor..

 

[ptschram]

My primary welding table has multiple holes drilled/tapped into it.

I can bolt a small crane , my Beverly shear, my Hossfeld-style bender and a Ridgid pipe vise, to a corner.

If I need a clamp to hold something in place, I pull out my trusty mag-drill, drill a hole, tap it and use a milling machine clamp kit to hold the assembly in place until it's welded together. If the hole is in the way, it's nothing to weld it shut and grind it flat again.

 

[sberry]

I have 2, one has some attachments the other plain flat top. In a general shop it is the "bench" as well as a welding place. My thing is location location location. Last pics are older but the benches are in the same place.
Size matters too, huge is not better . I like to reach across and be able to walk around. I will make do for a large project but its the small pit stop work that is 99% of it.

Got a welder right at the vise/benches, flip switch and weld, no set up time, used on most days.