Welding Tips and Tricks

building a new shop / welding table for the garage, my top plate will be a 3/8" 3x6 foot plate. (275 lbs)

had settled on 1/8" wall 2x2 square tubing to build the base, but after calculating the weight incurred by adding shelves to one side (130 lbs) I am not sure i shouldn't go with 3/16 wall 2x2.

I know you could build it out of 16 gauge if you really wanted to go overboard on gussets and support, or as heavy as you want with minimal gussets.

as a general rule of thumb how heavy should the base be in relation to the work surface?

want this table to last a lifetime but I am active duty and not sure how the movers are going to do with an 800 lb table every 3 years.

Ill post some sketches as soon as i get back to my office.

I think you will be fine. I have a 500lb lathe-mill-drill 3-in-1 machine on a stand I made from 1/8" wall 1-½" square tubing, and it just fine.

You’re fine with 1/8”. Remember, in a vertical orientation you have the benefit of all 4 widths for strength (1/2” Total).

HVYMTL wrote:had settled on 1/8" wall 2x2 square tubing to build the base, but after calculating the weight incurred by adding shelves to one side (130 lbs) I am not sure i shouldn't go with 3/16 wall 2x2.

I use 2x2 .093" and 1x2 .093" and it's incredibly strong. 2x2 .125" is probably way overkill, but it won't hurt.

Tube is a lot stronger than you may think, even stronger than angle.

HVYMTL wrote:I know you could build it out of 16 gauge if you really wanted to go overboard on gussets and support, or as heavy as you want with minimal gussets.

I will say that I'm no structural engineer, but I think 16 gauge is .063 and if so it's way stronger than you give it credit for. I like to use .093" as the price is not much different, but .125 is a bit more. I just feel .093 is a good compromise.

I built my 3x4 3/8 table out of 1/8 square tubing, and it's plenty strong enough, I can pile some steel on top to make it weigh as much as yours will if you'd like, but I'm pretty certain I still wouldn't detect the slightest bit of flex or give to the legs.

how does this look?

also, is there any reason not to do the 45* joints on the top of the base, under the work surface as depicted, or should I stick with the standard 90 and cap the ends? as long as the welds are good it shouldn't matter from a stength standpoint correct?

HVYMTL wrote:also, is there any reason not to do the 45* joints on the top of the base, under the work surface as depicted, or should I stick with the standard 90 and cap the ends? as long as the welds are good it shouldn't matter from a stength standpoint correct?

It's your preference, IMO. I like miters as you don't need to cap the ends, but if you run the corner legs up to the top, the top will cover the end and you could fillet weld the other pieces in place. if you welded a frame to sit on top, as your miter frame appears to, and didn't miter the corners you would have open ends to cap.

In general I prefer miters, but they're harder to cut and fit together, and take a bit more welding possibly to prevent the last piece to blowout when it's all sealed. Some folks will drill a hole to allow the air out, then cover that with weld after done. Heat buildup inside the tube is a consideration, but nothing you can't work through.

Others may have better advice to offer you.

If you leave the ends open, you can always in the future slide tubes inside to make a slide out table extension bar for long work pieces or maybe a removable vice or saw mount.

Structurally, you should be just fine. 11ga 2x2" square is one of my go-to stock sizes for most utility builds like that (and 11ga 2" angle). You can make almost anything out of that stock and it is both strong and cost efficient for that purpose. However, for a table like you are building, there can be value added in having the base as heavy as possible, so even though thicker wall stock would be overkill structurally, it can also be a benefit. Just something to consider.

Spartan wrote: even though thicker wall stock would be overkill structurally, it can also be a benefit. Just something to consider.

can you elaborate on the benefits of the heavier base?
I imagine it probably has something to do with remaining stationary no matter how much you lean or bang on it, but there must be a point of diminishing return in that aspect, an object can only be so immovable by a single person.

thanks you all for your comments. this has been a very educational thread. and I'm very much looking forward to taking on my first big project.

I'm still fairly new to this, with welding the top to the base, how do i ensure i get good penetration on the 3/8 without burning through the 1/8 supports?

2 inch bead every 12 inches is what im thinking. Is there a better rule of thumb? 1.5 every 8? what's best here?

what's the best method of tacking and then welding to ensure I don't warp the top?

HVYMTL wrote:I'm still fairly new to this, with welding the top to the base, how do i ensure i get good penetration on the 3/8 without burning through the 1/8 supports?

2 inch bead every 12 inches is what im thinking. Is there a better rule of thumb? 1.5 every 8? what's best here?

what's the best method of tacking and then welding to ensure I don't warp the top?

Run multiple stringers from front to back. Tack the top to those, working center out. Keep the top clamped to the horizontal structure while you tack it. You do NOT need to weld the dog piss out of the top to the table, just several decent stitched tacks, 1/2" every 2' is PLENTY.

I would give serious thought to making it a 'bolt on' top, and maybe a bolt together frame too.
I grew up as a military brat. It will be easier to make new friends at your new duty station, if you don't start out giving them sore backs and hernias.
With proper design, it can be a solid feeling table that breaks down to manageable size pieces.

HVYMTL wrote:

Spartan wrote: even though thicker wall stock would be overkill structurally, it can also be a benefit. Just something to consider.

can you elaborate on the benefits of the heavier base?
I imagine it probably has something to do with remaining stationary no matter how much you lean or bang on it, but there must be a point of diminishing return in that aspect, an object can only be so immovable by a single person.

thanks you all for your comments. this has been a very educational thread. and I'm very much looking forward to taking on my first big project.

You'd be surprised how quickly an immovable 500lb table becomes quite movable when you are applying a lot of leverage to a part (if you have a vice on it or something similar), beating something with a hammer, or causing a great deal of vibration with a power tool. Certainly there is a point of diminishing returns here, though. My only point is that often times, heavier is better for tables such as those. Of course, bolting it down to the floor is also an option sometimes.

All depends on your intended use, really. Not suggesting you make your table heavier out of necessity. Just giving you some things to think about.

cj737 wrote:Run multiple stringers from front to back. Tack the top to those, working center out. Keep the top clamped to the horizontal structure while you tack it. You do NOT need to weld the dog piss out of the top to the table, just several decent stitched tacks, 1/2" every 2' is PLENTY.

Thank you that's very helpful.

If I read this correctly
clamp direct to the frame
run stringers 1/2" every 2 feet around the base and top alternating sides around the table
go back over with a standard weave or cursive E from the stringer to the top plate, alternating sides again.

Adding "struts" on 45s or at some angle from the top to the legs is a must imo. The longer the better. Don't expect right-angles to be strong, make triangles if you want it to be "forever". Ideally, you'll need 8 braces (2 ea for 4 legs). And I'd probably cut 2 different length legs and put adjustable feet in 2 of them so as to allow the thing to sit flat without rocking when it's on uneven concrete. Or you could do 4 legs all the same length with 4 adjustable feet. Weld a big nut in the bottoms and allow some threaded rod to act as the foot with a jam nut or two and a flat piece for a foot on the floor. Don't forget to add a nut at the bottom of the foot so you can use a wrench to adjust it.

So what kind of heavy metal do you listen to? At least it seems that what your nick implies. My fav extreme band is Napalm Death.

Spartan wrote: You'd be surprised how quickly an immovable 500lb table becomes quite movable when you are applying a lot of leverage to a part (if you have a vice on it or something similar), beating something with a hammer, or causing a great deal of vibration with a power tool. Certainly there is a point of diminishing returns here, though. My only point is that often times, heavier is better for tables such as those. Of course, bolting it down to the floor is also an option sometimes.

Good point and one I forgot to mention. when I want to test a weld by throwing a T joint in my vice and cranking on it with a 2 foot pipe wrench it's quite easy to tip my table up on 2 legs and I usually only use one hand with the other braced against the table because of this. It's plenty strong and rigid enough, but more weight would be an advantage. Then again it would probably balance out whenever I had to push it up a slight incline

Oscar wrote:So what kind of heavy metal do you listen to? At least it seems that what your nick implies. My fav extreme band is Napalm Death.

actually had sammy hagar's "Heavy Metal" stuck in my head while working in the garage when I created the account. Big fan of rock and metal in general, anything from Slayer to Gojira, old school Metallica, BLS, Black Sabath. Get a big kick out of Monster Magnet in the garage too. Nothing too screemo and undecipherable.

BugHunter wrote:Adding "struts" on 45s or at some angle from the top to the legs is a must imo. The longer the better. Don't expect right-angles to be strong, make triangles if you want it to be "forever". Ideally, you'll need 8 braces (2 ea for 4 legs). And I'd probably cut 2 different length legs and put adjustable feet in 2 of them so as to allow the thing to sit flat without rocking when it's on uneven concrete. Or you could do 4 legs all the same length with 4 adjustable feet. Weld a big nut in the bottoms and allow some threaded rod to act as the foot with a jam nut or two and a flat piece for a foot on the floor. Don't forget to add a nut at the bottom of the foot so you can use a wrench to adjust it.

given the overhang on the table (3") the 45* angles would only be 5" long or so at the most, hadn't planned on it because the overhang was to make clamping easier but i guess a couple of supports would be pretty easy to work around. wouldn't add any weight really and the scraps from everything else would be more than sufficient.

I was thinking of the braces going inward, not outward. You could always splay the legs some to gain more room regardless which location you put the braces. They'll make the table 100x more solid.

HVYMTL wrote:

cj737 wrote:Run multiple stringers from front to back. Tack the top to those, working center out. Keep the top clamped to the horizontal structure while you tack it. You do NOT need to weld the dog piss out of the top to the table, just several decent stitched tacks, 1/2" every 2' is PLENTY.

Thank you that's very helpful.

If I read this correctly
clamp direct to the frame
run stringers 1/2" every 2 feet around the base and top alternating sides around the table
go back over with a standard weave or cursive E from the stringer to the top plate, alternating sides again.

No. You probably only need a stringer every 12-24” spaced across the top. Stitch weld 1/2” long welds every 12” or so. A support frame is far more critical to flatness than welds. Even a 1/4” thick plate will drop through the center if you only have an exterior frame.

I have a 3/4” thick top, 4’x6’ sitting on corner posts. A couple of stitches around the tube at the corners only. I discovered about a 0.020 sag in the middle after a while. Installed some stringer of 1x2x.125 and flattened the table, then tacked then to the top. Perfect again.

ok last question (i think) to do the slide in's i dont need receiver tube? what about the welded seam on the inside of the 2x2?

Order DOM tube. It stands for drawn over mandrel. It has no welded seam.