Table top to frame sequence?

[Debs.]

I`ve been to my favourite scrapyard today and picked up a nice 4' x 2' x 3/8" piece of plate, with which to make a welding table; I`ve made a 2' x 4' rectangular frame out of 4" x 2" box; mitred and welded tidily at corners.

The plate and the mitred-frame are nice and true/flat; I wondered about the best way to weld the top-plate to the frame whilst minimising warpage.

Obviously, I can begin by tacking....but, is it best to begin proper welding runs in the middle of the sides, running a 'balanced' sequence of shorter beads (on opposite sides), working towards the corners, gradually joining them up, rather than long runs all on one side/edge?

 

[runnach]

Why not use coach bolts or c/s hex screws, handy because you would have the option to turn top over if it got too messy with spatter and the like?

 

[Robotstar5]

Why not just leave it at some decent tacks / short runs, that way you can change it / turn it over in the future with a bit of grinding.
Talking from experience with the sacrificial bench tops at work, bored welders like to fully seam weld them, took me 2 hours to grind one off last year!

 

[Debs.]

Why not use coach bolts or c/s hex screws, handy because you would have the option to turn top over if it got too messy with spatter and the like?

Now, that`s a very good idea!

Thanks runnach

 

[Hitch]

Dont put big runs on it, just a few 20mm long stitches will be adequate, dont put them right in the corners, you wouldn't get a grinder in to cut them off again should you wish too.

Runnachs idea isnt bad CSK set screws. You could guarantee that coach bolt heads would interfere with every single thing you make.

 

[Shox Dr]

Light tacks, spread about. I wouldn't use screws, they'll just fill up with dirt causing stuff not to sit flat on the table

 

[Archie]

As has been said, there's no need for anything more than a few good tacks. I put an inch in each corner of mine and that's ample. It's only got to stop the top sliding after all. I thought about CSKs but decided I'd want something like M8 and countersinking seemed like too much effort!

 

[Welderpaul]

Our 4m x 2m 20mm plate top has very few tacks on it - maybe 8 20mm tacks in all. We've still managed to pick the bench up a few times, including the bottom frame, by accident when somethings been welded down and we lift it with the crane!
Minimal tacks then - it won't bend!

 

[Bsmith]

Holes through the top plate and frame, countersink top plate, pieces of threaded rod through, weld threaded rod in countersink holes in top plate and grind flush, nut below, no worrys about distortion with 3/8" plate. I did this on a circular saw bench.

 

[runnach]

I wouldn't use screws, they'll just fill up with dirt causing stuff not to sit flat on the table

With most welding benches I have found more problems with spatter and arc strikes being problematic when trying to keep stuff flat than c/s screw heads. I've always found screwed down far better, you can remove outside for dressing purposes, keeps horrible fine grinding dust away from your important precision machines.

My opinion only!

 

[Debs.]

Holes through the top plate and frame, countersink top plate, pieces of threaded rod through, weld threaded rod in countersink holes in top plate and grind flush, nut below, no worrys about distortion with 3/8" plate. I did this on a circular saw bench.

Ok....I went with our favourite Orcadian`s suggestion of drilling, countersinking and welding-in some studding*.....`worked a treat, and the completed worktop is rigid and still as 'flat as a pancake'.

*I actually found a dozen (or so) 5/16" UNC exhaust-manifold studs, which coincidentally were the perfect length for the frame.

Thanks for all the suggestions, guys!

 

[Weldingartisan]

With most welding benches I have found more problems with spatter and arc strikes being problematic when trying to keep stuff flat than c/s screw heads. I've always found screwed down far better, you can remove outside for dressing purposes, keeps horrible fine grinding dust away from your important precision machines.

My opinion only!

Blimey runnach, your welding must be much better than mine if you never have to grind anything on the bench! W/A