Welding Thin Sheet Metal

[singlepentode69]

I have recently purchased an arc welder does anybody know of a way of welding thin sheet steel with it.I may have to go down the road of buying a brazing head for it , but I have thought about G clamping a large price of steel under the plete to resist the load while using smaller dia welding rods.
Robin

[AlanBeckett]

Robin,

It depends how thin it is.
Small (thin) rods, low current and tack it first , then weld it in short runs to avoid banging holes in it. It's generally a lot easier with a MIG.
An automatic helmet makes it a lot easier to see what you're doing.

Alan

[pwdrive]

Arc welding thin stuff is a pain, striking the arc at low amps, heat distortion etc, if it's a small job take it to someone with a MIG or borrow one.

Lawrence.

[singlepentode69]

I have successfully welded small holed in grass boxes before using carbon blackened steel . I was going to fold up a chassis and weld the corners.instead of soft soldering or brazing them .
Robin

[Retired]

Hi,

Arc welders are not intended to weld thin gauge steel Robin for the reasons given by Alan and Lawrence above.

Many years ago I've welded patches onto rusty silencers using a small SIP arc welder but it is difficult and I'm experienced. As soon as you strike the arc the metal is gone. Using a base steel sheet won't help either although I can see your reasoning.

I've also tried carbon arc rods these being an attachment to the welder and these are dire. The arc "Flame" has a mind of its own and doesn't melt the metal where intended; I threw the attachment away.

If you are not experienced then even "tacking" as Alan suggests can end up with lots of blow holes; I would agree with Alan that a "Mig" is the way to go on thin gauge metal although I've never used a Mig. I keep intending to buy an automatic welding helmet and these are available at Rufforth Auto Jumble for around £35 but I'm too tight.

I was taught gas (Oxy/acetylene) welding as an apprentice and gas welding is even more difficult to do. Distortion is the main problem as the metal curls up once heated by the flame; on top of this gas cylinders are dangerous.

Brazing affords a good joint but tends to leave a messy joint with lots of distortion and the flux is extremely difficult to remove.

Electric spot welders are a good option but too expensive for a home workshop.

I'd much rather weld an RSJ than thin gauge steel sheet.

Are other options open to you Robin such as pop rivets? Good luck.

Kind regards, Col.

[singlepentode69]

I may try silver soldering I can braze was taught it many tears ago at school.i later mug welded the chassis for the quad revival amp before they got gold plated at vines and welded the stainless steel chassis for the pap worth audio amps which we had a welder at work for and a plasma cutter to cut the sheet . Thank you for the advice about the carbon arc I will not buy one now. I have tack welded before as I had to use this technique to weld a cast iron roller back together for a lawn owner with a serious crack drilling out we're the crack stopped to avoid further cracking.
Robin