For those who have had any luck welding sheet metal, I need some advice/help(yes, I tried a search... still dying on me <IMG SRC="smilies/frown.gif" border="0"> ).

I'm soon to be getting the "highly" recommended portable Central welding units <IMG SRC="smilies/biggrin.gif" border="0">

I've got a few holes(and other funky sheet metal projects) that I'd like to attempt.

Aside from using the lowest amperage, what are a few tips for getting good results when welding in patch panels and filling in holes?

Is there a maximum size hole that "filling" with weld will work? I've got a bunch of 3/16" holes(might be 1/8") that I'd like to fill in. Plus, I've got a couple of slighly larger holes(10mm or so)

What is the "proper" technique for "butt" welding two pieces of sheet metal? I've heard that the "proper" technique is to do a bunch of spot welds and then grind them down. Does this sound right?

Lastly, does anyone know of a good "heating" torch aside from oxy/accetlyn? (Unfortunately, I know nothing of oxy/accet other than I would have two flamable explosive tanks in the garage <IMG SRC="smilies/eek.gif" border="0"> ) I'm looking at heating up and bending some 1/4" plate.

TIA,
John

When you weld the sheetmetal, you want to do small welds and let them cool. This will help to reduce warping. Try some test pieces of metal before you try body work.

Erin

If you want to weld holes put a piece of brass behind the hole and weld over it .the weld will not stick to the brass.aluminum will work also.If you have a wire gun turn the machine down and trigger the gun,sorta like one weld puddle at a time.like stacking the puddles on top of each other.The only torch hot enough to heat steel red hot{1100 degrees} has to be oxidized,in other words oxy-acet or oxy-propane.but welding thin sheet is very hard because there is nothing to support the weld while it molten.its better to do a flange-overlap and weld it up.you can get a flanging tool from most circle track suppliers

Originally posted by hybridfjjimmy@:
<STRONG>If you want to weld holes put a piece of brass behind the hole and weld over it .the weld will not stick to the brass.aluminum will work also.If you have a wire gun turn the machine down and trigger the gun,sorta like one weld puddle at a time.like stacking the puddles on top of each other.The only torch hot enough to heat steel red hot{1100 degrees} has to be oxidized,in other words oxy-acet or oxy-propane.but welding thin sheet is very hard because there is nothing to support the weld while it molten.its better to do a flange-overlap and weld it up.you can get a flanging tool from most circle track suppliers</STRONG>
Ya. What he said. With a round of brass, copper, or aluminum it is fairly easy to fill holes. If you are welding two pieces of sheet then it is on/off the trigger a bunch.

when i first started welding i found it a big help to practice on a scrap piece it will save on your 4x4. <IMG SRC="smilies/fj.gif" border="0"> be patient you can read all the books you want on welding but practice makes perfect. <IMG SRC="smilies/fj.gif" border="0">

Small spot welds work the best and keep warpege low, or alternate 1/2 beads, the same for you holes start with a spot weld at the edge and keep making spot welds aroud the edges till its filled and then clean it up with a grinder

Terra-Izer,
Where do ya live in Penrose?
I am now in KY, but still own a house in Penrose and will be coming back when the Army lets me.
I just left in June.
Ever done Indy?
God I miss Colorado. <IMG SRC="smilies/crybaby2.gif" border="0">

Originally posted by hybridfjjimmy@:
<STRONG>If you want to weld holes put a piece of brass behind the hole and weld over it .the weld will not stick to the brass.aluminum will work also.If you have a wire gun turn the machine down and trigger the gun,sorta like one weld puddle at a time.like stacking the puddles on top of each other.The only torch hot enough to heat steel red hot{1100 degrees} has to be oxidized,in other words oxy-acet or oxy-propane.but welding thin sheet is very hard because there is nothing to support the weld while it molten.its better to do a flange-overlap and weld it up.you can get a flanging tool from most circle track suppliers</STRONG>

I second the flange tool suggestion. You can get them at harbor freight, too. You can also get a really slick punch tool that will blow perfectly sized holes in the edge for spot welding. <IMG SRC="smilies/biggrin.gif" border="0">

First off only one of the tanks contains an explosive gas. The acetylene is flamable/explosive but the O2 is not. The O2 supports combustion but will not burn by itself.
Depending on how hot you want to heat the metal you can use a small propane torch. It will get the metal redhot but not hot enough to be used for welding.

To all, thanks for some good information on welding sheet metal.... I was definately going to do a LOT of tests before I try it on the rig <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by hy_desert_4wheeler:
<STRONG>First off only one of the tanks contains an explosive gas. The acetylene is flamable/explosive but the O2 is not. The O2 supports combustion but will not burn by itself.
Depending on how hot you want to heat the metal you can use a small propane torch. It will get the metal redhot but not hot enough to be used for welding.</STRONG>

My intention is not to weld with the oxy/acet setup <IMG SRC="smilies/smile.gif" border="0"> I have seen them used to heat metal up enough to bend without a lot of effort.

Would the propane torch work with 1/4" metal(my choice for doing my brackets)? Is there "special" tips I should be on the look out for?

propane will take more time than you have to heat 1/4 plate enough to bend it