Welding thin to thick

[Haywire]

I've asked this question before, but can't find it now. I'm welding those sheet metal legs to the 1/2" plate. I don't want to blow through the leg material, so I thought about using 1/16 7014. Any penetration in the plate thicker than the sheet metal is a waste anyway. what do ya think? Sorry about the bad low-light cell phone pic...

 

[yomax4]

You could do it that way. Lay a filet weld up tight to the sheet metal to get good bite. Then lay another one next to it overlap a bit with a biger hotter rod. Or. Just run bigger rod and just let the puddle flow over onto the sheet metal and keep the arc on the plate. Either would work I would use option 2. Good luck. I would like to have that table.

 

[k0ua]

Well if it was me..I would choose some 3/32 7018 at about 75 to 80 amps and start in by pointing the stick more at the 1/2 and hit the edge of the thin stuff on the edge of my movement. More time and direction of stick on the thick material and less time and less direction on the thin. You might take scrap 1/2 and the sheet metal and practice first before you start in on the nicely cut out project. Haywire you know my experience level so please take my advice with the caveat that I am not a lot more experienced than you.

James K0UA

 

[BXpanded]

Those legs look far too weak for a welding table. No matter how well you weld that sheet metal to the top, the slightest push from the end of the table could result in the legs folding sideways and the whole thing collapsing.
Bite the bullet, buy some square tubing, heavy angle, etc. Build a complete table frame with stringers in both directions. Stitch the plate to the table frame
Just my opinion. We've built a few.

 

[Gary Fowler]

I am with KOUA, 3/32 -7018 would weld that fine if you concentrate the arc on the heavy side and just flow it into the thin stuff. Just remove the paint and rust first so the weld metal will flow without having to burn thru the rust and paint. Dirty metal is hard to weld on thin material due to the arc blow.

Also add some boxed braces near the bottom to steady the legs and some vertical cross braces to strengthen the legs from folding up. That thin sheet metal wont take much to bend and your table to collapse

 

[PaleFX]

I am with KOUA, 3/32 -7018 would weld that fine if you concentrate the arc on the heavy side and just flow it into the thin stuff. Just remove the paint and rust first so the weld metal will flow without having to burn thru the rust and paint. Dirty metal is hard to weld on thin material due to the arc blow.

Also add some boxed braces near the bottom to steady the legs and some vertical cross braces to strengthen the legs from folding up. That thin sheet metal wont take much to bend and your table to collapse

Agreed! I too would use this method and gusset the legs for lateral stability... should be a fine table!! :thumbsup:

 

[Haywire]

Those legs look far too weak for a welding table.

Yes, that is a concern. I was wondering how I was going to cross brace them. I've got the 2" pipe that were originally legs on that table before I cut the plate up to rearrange it. I guess I could use them. Those pre-made leg sets take the guesswork out of getting them straight though.

Ian

 

[deereman75]

I am going to finish my welding table today, I will post some pictures so you can see how I made the frame.

 

[Gizmo2]

Well if it was me..I would choose some 3/32 7018 at about 75 to 80 amps and start in by pointing the stick more at the 1/2 and hit the edge of the thin stuff on the edge of my movement. More time and direction of stick on the thick material and less time and less direction on the thin. You might take scrap 1/2 and the sheet metal and practice first before you start in on the nicely cut out project. Haywire you know my experience level so please take my advice with the caveat that I am not a lot more experienced than you.

James K0UA

I am with KOUA, 3/32 -7018 would weld that fine if you concentrate the arc on the heavy side and just flow it into the thin stuff. Just remove the paint and rust first so the weld metal will flow without having to burn thru the rust and paint. Dirty metal is hard to weld on thin material due to the arc blow.

Also add some boxed braces near the bottom to steady the legs and some vertical cross braces to strengthen the legs from folding up. That thin sheet metal wont take much to bend and your table to collapse

Agreed! I too would use this method and gusset the legs for lateral stability... should be a fine table!! :thumbsup:

Yep, I call it "favor the heavy piece".

 

[Shield Arc]

7018 is a good choice here, I'd run a J-motion, keeping the long side of the J on the 1/2 inch material, and just bounce up onto the 1/16 inch material.