Basic Welding Fab Ques

[Gordon Gould]

I don't have a welding bench. I make do with a 5' length of 3/8 plate 12" wide and a couple saw horses. Move it around, outdoors, garage, or basement like now. It gets old. I saw this thread and got inspired to build a 2' X 3' welding cart.

http://www.tractorbynet.com/forums/...-work-weld-table-post4019112.html#post4019112

I weld up little do-dads and repair stuff so it should be good for me.

I welded up an upper and lower 2' X 3' frame. When I was done they were flat working off my table saw bench. I welded 4 legs in the corners of one frame. Braced them in a crude way while welding.



Now my question - when I finished welding the 4 legs the frame was racked so if I put it down like a 4 legged table one leg was off the floor 1/2". Understand I don't have a feel for what is or isn't a problem. My background is carpentry. The material is 1-1/2" X 3/16 angle. If I kneel on a short side and support my upper body on the other it takes very little pressure to straighten it out. If I clamp the other frame to the legs as if to weld it and let the structure free stand it becomes flat again. I plan on a 1/4" top and a 1/8" lower shelf with some belly bands.



I weld with a torch so expansion and contraction is a factor. Should I just go ahead and weld it up and hope for the best not having much to clamp it to other than a 12" plate. Or should I try to straighten the racked frame first. If I need to straighten how do I do that ?? heat or brute force??
Thank you.

 

[Shield Arc]

I'm generally pretty good at heat shrinking things back in shape. But not being there to see the whole frame, take measurements, and use a straight edge, I really can't help much.

You may have to cut 1/2" off the other three legs.

 

[Big Barn]

I'm generally pretty good at heat shrinking things back in shape. But not being there to see the whole frame, take measurements, and use a straight edge, I really can't help much. You may have to cut 1/2" off the other three legs.

Here's some encouragement.



Terry

 

[Ed of all trades]

Try putting some weight on it to hold it in place and heat the places that flexed and let them cool while held in place. It seems to me that would work.

 

[Shield Arc]

Angle iron generally moves fairly easy with just a little heat. 2 tricks to it tho! Where to place it, and how much.

 

[Gordon Gould]

Thanks for the responses !! But I don't under stand why would I want 3 short legs and one long - please explain.
From what you are saying I may need to clarify what I said - when I clamped the assembly together I removed the racking with my weight then clamped the bottom frame on. Everything was square and parallel. When I removed my weight the clamped up structure did not move it remained square as in the picture.

Should I go ahead and weld it or should I straighten the racked frame first so I don't need to apply any weight or force while clamping the bottom frame on. Sorry for my ignorance.

 

[PILOON]

You should never weld all the way from one end to the other. Best is to tack weld corners (when straight and level by whatever means) to 'lock' your geometry in place and then complete your welding. Also complete seams generally don't help and you will notice that pros sort of skip and weld 2-3" strips every 5-6" or so when attaching large surfaces.

IE, if your table geometry is OK and weight sets the table right then tacking the 4 corners while weighted should lock it in place.
If you still have distortion after tacking, grind a weld or 2 and correct with shims under a leg, re weight and try a new tack.

Later with a good level table all you will do is clamp your work to the table top and every weld will be great.

A suggestion is to make your table top such that it overlaps by about 2" the frame on all sides to facilitate clamping.

The nicest welding table that I have seen was made up of many strips of 4" flats that over hung the sides and had 2" gaps between the flats. He then had clamping just about everywhere.

When that old welder could not clamp he simply tack welded his corners to the table, finished the job and ground away the tacks.

 

[Gordon Gould]

Thank you very much PILOON. That was very very helpful info. As you can see I am lacking some basic knowledge !
What you say makes sense and gives me a good plan to proceed which is what I needed.

The reason I ran the angle like I did with the legs inside was to give me good rigid clamping around the perimeter of the table from the double thickness of the top plus the angle. Your suggestion to make the top from slats is great ides. Thank you again.

gg

 

[pat32rf]

My best solution for leveling a table like that is to use it on a dirt floor......

 

[Gordon Gould]

Dirt floor :laughing: That would work.

Actually it came out pretty good. I took PILOON's suggestion and got it all clamped up square and then tacked it all around. Once it was tacked securely I completed the welds and it stayed square. I added a bottom and some 8" casters. Now all I need is the top.