Welding Sheet Metal

I recently found a couple of rusted out spots in the passenger side
floorboard of my Jeep... I need to weld in a couple of patch pieces, I
guess... Unfortunately, the only welder that I have available to me
currently is a Lincoln "Tombstone" AC-225... My attempts so far have
resulted in either not being able to get the arc to strike or burning
through the metal... I've never had to work with this thin of metal
with an arc welder... The thinnest that I usually work with is 1/8"
thick... What is the recommended rod size and type for this sort of
endeavor? I'll probably end up putting one of the polyurethane type
spray on liners over it, so it doesn't have to be perfect, just not
terribly ugly... Any other tricks would also be appreciated...
Reply to
Grumman-581
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I don't think you're going to get results from a stick welder that would be as good as using some pop rivets. If you don't care about looks, pop riveting on a patch and painting it with rust-inhibiting primer will be easy and should last longer than the rest of the floor.
I do this sort of thing with an oxy-acetylene set, a hammer and a dolly. But my training is old, and my trainer is older.
Reply to
Tim Wescott
According to this link, carbon arc welding is sometimes used on galvanized sheet metal.
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Reply to
Home Welder
gas welding with oxyacetylene is what is used for thin sheet or tig welding.
you might get away with the thin stick weld rods that are about 1.2mm in dia. these are difficult to find in australia but are available. I've used those with thin sheet successfully. the amperage will be a lot lower than you might be used to.
use just enough amperage to get a start and try angling the rod a lot more if you are getting blow throughs. it seems to moderate the action to give a gentler arc.
thin stuff is always a bugger of a job though. Stealth Pilot
Reply to
Stealth Pilot
Tim is right; using a stick welder (AC especially!) to weld such thin sheet is like trying to put out a forest fire with a screwdriver. You oculd probably do it, but nobody is ever going to take picture. Pop rivets are fine here. If you have access to MIG you can use the 'spot' technique that works pretty well on all but paper thin sections but needs some practice.
If you absoultely insist on welding it with stick for whatever reason, start with *super* clean metal. dont use a flap disk to clean it, youve got no metal to spare here.... go with a wire brush wheel on a grinder, and go light! turn down your stick welder to the lowest setting it will still be able to strike an arc on (You *do* have neough OCV for your rods right?) then try this somewhat spastic approach.... strike the arc by either tap starting or match sticking it, then pull it back to the maximum length that the arc can be maintained, then bring it very close to the metal then snuff it out by either burying it then snapping it off, or just pulling it away again. This whole procedure is done lightning fast! otherwise you burn through as you have experienced already. chip, then repeat a few hundred times. what happens is that slowly you build up a little bit of metal on top of the existing metal to the point you can old the arc just *slightly* longer than before. Eventually you can sustain the arc for a second or so. keep going until you have welded what you want. Keep your wits about you and maintain your patience; if you burn through, it will cost you big time! If you do burn through, dont try to patch it up by welding on the edge of the hole; you'll only make it bigger. start a ways back from the edge, then build up to it. This takes a long time, so weld *very* small (like so small you cant see any difference with each consecutive 'tap') otherwise you will burn through.
I have successfully (?) used this technique to weld exhaust pipes, and you can get an air tight finish, but it will look pretty much like aforementioned forest firefighting technique. Have also welded some little things like fairing support brackets on crappy little mopeds and stuff when stuck in the middle of nowhere in south east asia.
A big improvement on this technique is using a copper backing, if the weldment has space for it. try to get a piece of copper as big as possible and as small as necessary, but at least 1/4" thick of better. Put it in the back the weld wont stick to it (much). welding this way is more like soldering.
And don't tell anyone I ever suggested welding like this
Shaun
Reply to
Shaun Van Poecke
Grumman-581 wrote in article ...
Most REAL welding supply houses - not hardware stores, not automotive stores, not Tractor Supply, Agway, etc. - have a 1/16" rod made especially for welding sheet metal.
I have some based on 6013, and others that do not have an AWS designation - but I know that they both work well on the sheetmetal that is found in automotive body work.......because that is where I used them.
Again, go to a REAL welding supply house - one that specializes in welding machines and welding supplies ONLY.
Reply to
*
HF or ENCO carried 1/6 & 5/64 6013 a few years ago that would work with your AC machine. Follow the technique that Shaun suggested.
Reply to
John Miller
Eastwood (if they are still around) used to have a solenoid contraption which used a very thin rod ( probably 1/16 ) and it would rapidly pulse the rod forewards and backwards. It would make a series of small tack welds along the weld line. I think it was limited to about 45 amps and the gun was powered by the welder. It worked ok if you could keep the rod along the weld line.
Willy
Reply to
willy
Just to add what Shawn said: Cut back to some solid metal, overlap the new piece by about 1/4", clean well, back up with a copper (preferred) or aluminum plate as a heat sink, and clamp it tight.. Use some 1/16" 6011 rod, practice on scraps to get the hang of it. Strike an arc, form a puddle about 1/4" in diameter, stop the weld, wait a second or so until the puddle solidifies, restrike the arc.
Grumman-581 wrote:
Reply to
RoyJ
You're going to have a hard time with that welder. Most of the low-end A/C welders won't hold an arc below about 35 amps, and you need a lower amperage for thin stuff. If you could borrow a small mig welder from someone, it would be easier to use than the buzz box. Also, the Synchrowave 180 (and probably the Lincoln equivalent) have a stabilization feature that allows them to hold an arc down to 10amps, which is what you need in this case.
Advertise on Craigslist. Offer the temporary use of some of your other tools for a welder that's easier to use.
Reply to
Gary Brady
Plug weld repair panels in. You can do this with your welder, using 1/16-3/32 rod. Don't try to bead a seam. Seal with undercoat. You can buy whole floor sections at
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Dweller in the cellar
Grumman-581 wrote:
Reply to
JR North
A pneumatic flanger will help. It offsets the existing sheetmetal so the new patch will be flush. Can't help you on the welding end, if you post to the welding group, Ernie or one of the other guys may be able to help.
Reply to
ATP*
You can use Eastwood's Stich Welder:
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It contains a diode that cuts out one phase to reduce the amperage by half.
Reply to
DT

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