Welding table thickness

Is 3/8" too thin for a good table top? Not making frame jigs or suspension mockups, but would be nice if it would stay flat.

Hot rolled vs cold rolled steel make a difference?

I *believe* hot vs cold won't make a big difference, though the cold working may contribute a little.

I think at 3/8, depending on how big it is, a lot of it will come down to the structure it's attached to.

Mine's about 2' x 4', 1/4" plate that wasn't entirely flat, but is much flatter now that it's welded to a 2" x 3" (IIRC) 0.125-wall apron that runs between the legs.

What you mean by "stay flat" is also a good question. What are you going to do to it that it needs to fight through to stay flat? Once 1/8" is flat, it'll stay pretty flat if you're not using it as a jig...

Note also the Certiflat type tables that are something like 3/16", but have a grid of webbing on the bottom that provides the rigidity. So, that's sort of the second data point for doing something other than relying on having a plate heavy enough to do all the work.

In reply to Jesse Ransom :

I guess I should clarify, surely I'll be making small jigs at some point. Just nothing huge.

I've been looking at this ad for a few days, and keep thinking "I have a plasma cutter, cut it down to 4ft sections and double the width that way, then just weld it together"

I guess this is more a save me from myself kind of post.

Mostly I fix tools, or build brackets. I would like to expand into other things, but I'm not good enough to sell my services.

This really depends on the type of work you're doing too...if you're pumping a lot of amps into thick steel joints that are really close to the table with heavy clamping, then there's a chance 3/8" won't do it. 

The sort of welding work I do has never needed an extensive welding table. Exhaust work, tubing welds, small bit fabrication stuff...no fancy table needed for any of it. 

3/8" would be enough if the bracing/table underneath it is built appropriately.  If you cut that piece down I would not weld it together.  Leave a gap down the middle so you can clamp things down.

Wait, so you want to weld together sections to make your own fab table? If you're welding it up, it's going to be a LONG way from flat right out of the gate. 

How do you want to use this fab table? Are you tack welding material to the table itself to act as a jig for the work itself? If you're doing that, then flat matters less since you ruin the flatness a little every time you tack a jig on and then grind it off. 

I feel like we're over thinking this. I usually weld on a 4'x4'x1" thick aluminum plate because it's what I have. Small stuff, I use a 1'x6"x1" aluminum plate. I only use these so I don't catch more combustible materials like a plywood workbench on fire, but also because they can sometimes make it easier to ground a part I'm trying to weld. 

In reply to Mezzanine :

Right now I use a chunk of giant I beam, lots of vice grips and clamps, with the occasional ratchet strap. 

Realistically, I've used the harbor freight folding table before and it would work for me as well as be cheaper than this and easier than my current situation. 

But I basically want a big metal table and the price is right on this 3/8". Haven't been able to get into the metal shop to look for drops since we bought the house thanks to the virus and moving further away, so I'm stuck on Craigslist

Thicker is always better, but an 1/8" thick table is better than none. 3/8" isn't too bad. we used 3/4" in the welding shop I worked in and they are bombproof. But yeah, if you're seaming it, it won't be flat.

In reply to Jesse Ransom :  Mine's not even .200  and it's held up to my abuses since I built it back in 1976    The frame is 2"x2"  .250 wall. It's on 2 wheels and I use a floor jack to lift it and pull it around to wherever  it's needed, then roll it back out of the way. If you notice all my welding gear is on it Stick,  Gas, and MIG  Excuse the stuff that's on it  that's what happens when not it use  

Even when I was welding up industrial machines that were 16 feet long and weighed several tons I only ever used  a decently braced 1/4" thick top surface. If you have enough heat running away from your weld and warping your work surface something is very wrong. Heating parts with a rosebud on your table top will do it, but why would anyone be doing that anyway?

I feel like the 1" thick blanchard ground welding tables that are all the rage these days are ridiculously overkill and pretty much just a flex by the owner.

I am a certiflat user because when I needed a table, they happened to be on sale and the price difference was within $150 of the raw materials.  I LOVE IT. 

Regarding the materials you hotlinked.  If you are welding up a work surface from 7 and 8 inch wide pieces you can pretty much throw the idea of flatness out the window. 

Unless your plan is something like this

Then carry on, those are rad and very handy

In reply to frenchyd :

Oh, for back up I have 10 feet of stone countertop I picked up for $35 from a remodeler. Yes I have to put the ground clamp on the work but it's always gonna stay flat no matter what. I'm looking for a second piece for a framing jig. 

My last weld job was my Opel's headlight mechanism. I welded it on an old cookie sheet. Ground clamp on the tray. I laughed a little.

frenchyd said:

In reply to frenchyd :

Oh, for back up I have 10 feet of stone countertop I picked up for $35 from a remodeler. Yes I have to put the ground clamp on the work but it's always gonna stay flat no matter what. I'm looking for a second piece for a framing jig. 

Until you focus a bit too much heat into the stone and it starts popping little chunks of granite into your neck...

Bought a 30" X 60" X 5/16" steel plate at a farm auction near Rev's old neck of the woods. Had to weld up some holes but price was worth it. Welded to a 1" X 2" X .120 " W frame w/ 1" X 1" cross pieces. Steel caster wheels ftw. I don't tack to it, it's narrow enough to rig clamps. Beat and bang factor is good. General fab work, not pro welder shop grade. Makes a great shop table/ beer drinking station also.

Built a 4' X 8' X 3/8" steel shop bench for a pipe shop I used to work at. 2" X 2" X .250" W legs and crosses. Weighed in at 600 pounds, didn't need bolted to the floor even when cranking on 4" pipe in the vise. I'd like to have that one at home. 

I wouldn't use 1/8", 1/4" minimum for a small table. 5/16" to 3/8" for GRM shadetree work. Thicker if ya luck out. Wouldn't buy new. Scrap yards, CL, FB Market place and auctions. I use auctionzip.com 

Wait for a deal, might take a while.

I have an old 3'x3' grate from an old house. It used to be the return air for the furnace. I just need to put legs on it (and have a bigger shop).

At home I have 4'x4'x¼" on a 2x1x.120" frame. Plenty thick enough to stay relatively flat, mount a vise or tube notcher, and what have you, but it rings to beat the band if you hammer things on it, or even just drop tools on the surface. My plan is to lift the top and add a couple layers of plywood underneath and thru-bolt it to the frame to keep my ground circuit.

At work I have a 5'x9'x2" table. Drilled for tie down points. It is an astounding amount of overkill and I love it. Came from some agricultural auction, a million years ago.

In our fab shop we have 1/2 thick tables and they are flat but not super flat. They're on a strong under structure and I made them bolt on to that so I could shim them flat...

I also have an approx 4x10 reclaimed machine table, cast iron, very thick and webbed. It's super flat and you can tell vs a pc. of plate.

FWIW steel is about as cheap as it's going to get IMO...I'm paying .37 cents/lb so some of those CL deals aren't deals if you can drive to a steel service center with a trailer.

Also, the best weld table is the one you have...I've worked on 1/4" thick tables...

I have a 2' X 4' Snap On rolling welding cabinet /table. It has a slotted 3/8" top.

In reply to NOT A TA :

I have the same cart.  Once you put a vise on one side and two welding bottles on the the other side it becomes almost useless.  I'm going to put my welders back on thier own carts and just use it as a fab table.  I've even considered having the place where my brother works cut a new bigger top for it on the plasma table that will bolt up to the same hole pattern.

3/8" will likely be fine. The local community college has 1/2" tables that get used by ham handed students  10 hours per day that show minimal wear after 15 years

Streetwiseguy said:

frenchyd said:

In reply to frenchyd :

Oh, for back up I have 10 feet of stone countertop I picked up for $35 from a remodeler. Yes I have to put the ground clamp on the work but it's always gonna stay flat no matter what. I'm looking for a second piece for a framing jig. 

Until you focus a bit too much heat into the stone and it starts popping little chunks of granite into your neck...

I'll be sure to be careful about that.
The main purpose of stone is to ensure the chassis is flat. 
I wound up junking my first race car chassis because I did it on the floor and started welding at the front and by the time I got to the back it was banana shaped.  Tough lesson to learn. Now I don't focus on stacking dimes as much as I make sure I don't warp the work. 

In reply to frenchyd :

Damn straight. As long as you have good penetration no overlap no underfill no undercut doesn't matter what it looks like

However it would look pretty damn nice without all those discontinuities