Home brewed resistance (spot) welder idea.

[STINEY]

While fooling around with the fuel tank for the Cadistang I discovered that the baffle is loose. Upon further inspection it appears that a spot weld simply let go.

No big deal right? Just zap it back on.

Well, you can see it. Barely. If you squint just right and the light is good. In other words, its a royal PIA to get to.

But I remember using the resistance welder back in shop class. We made toolboxs and some other stuff. Simple machine, 2 copper rods bent to touch each other, stick metal to be spot welded inbetween them and press the pedal. Rods come together and the current flows for a set period of time and presto, instant spot welds.

So back to the fuel tank baffle. I'm scheming on taking a reclaimed copper ground rod from a house, bending it as necessary, and cutting it in 2, hooking my arc welder to each piece, and trying to reach in and spot weld that baffle back down. I know I'll be "timing" the weld manually and aligning and holding everything will be difficult, but I only need ONE decent spot weld out of this hairbrained idea.



This is that part where you guys tell me why it won't work and how I'm too cheap to buy a new tank.

I already know I'm too cheap, its the why it won't work I'm curious about.....

Fire away!

[TheSilverBuick]

Set a video camera up as you go to do this. That's all

[1946Austin]

Lets see; a used gas tank and a arc welder making sparks inside it. Does anyone NOT see a problem with this?

[tardis454]

I learned this trick from an old school gas tank/radiator repairman..

*Pull the tank, turn it upside down for a few days whatever..

*Get one of those hoses like the car garages use the get rid of exhaust fumes through the garage doors.

*Put one end of the hose in the top of the tank, the other end on your cars, trucks, vans, dunebuggys exhaust pipe.

*Runs it for an hour maybe 2, or until you don't smell ANY gas fumes.

The carbon monoxide displaces ALL of the gas fumes neutralizing them.

Then... weld-er-up

[STINEY]

Okay, okay.............. I neglected to mention that this tank has been open to air out for 6 YEARS that I can vouch for, and probably many more that I don't know about. Its so aired out its pathetic.

Was kinda looking for input on the home brewed spot welder idea. I got the tank fume under control...... have welded lots of tanks, still here to talk about it.

Sheesh. I must come off as a 14 year old newbie or something. Gotta work on that.

[milner351]

I think the idea has merit and is bangshifty cool - but I must play devil's advocate for a moment - what about just removing the baffle entirely?

[SuperBuickGuy]

that's easier then drilling a hole in the bottom of the tank (through the baffle) and plug welding it?

Spot welders are cool, unless you can't get pressure on both sides. If the metal doesn't clamp together during the spot welding event, the metal will blow out between the two pieces. If you're really good (should you not clamp hard enough) it'll blow a hole in the metal thus relieving you of the need to drill a hole for a plug weld. Maybe cut out the middle step?

[milner351]

SBG's Idea is probably best - with the old filling a hole in drywall trick - fish a wire through the drilled hole - through the baffle, and pull up and tight - quick tack to hold the baffle in place - then complete the plug weld.... given the light gauge of the material involved - I'd use .023" wire in the mig.

[award69129]

I say try it it will be interesting if nothing else and if you have had this tank sitting out for six plus years im guessing its not an emergancy fix. But seriously take video if you do!

[STINEY]

Perhaps I should add this to my pile of overkill solution ideas?

Especially given the simplicity of the drill a small hole/wire idea......... yeah, that's probably a lot easier and quicker.

Kind of ruins the whole RubeGoldberg-creative-vibe thing I had going though. Killjoys.

I still wonder how that arc-welder would work with a pair of 1/2" copper probes pinching some sheet metal. Might have to try it on some scrap just for kicks. See why I never get anything done? Curiousity gets the best of me every time.

Oh, and removing that baffle would be a great idea, but for the MSII EFI thing, I think it would be best to leave it. Don't want things going lean at a unfortunate time. The original carbed plan would have had that baffle out in a flash!

Definitely not on the front burner, no emergency fix required here!

[SuperBuickGuy]

you'd be surprised at how much pressure the arms put on the metal - but what you plan should work.
A dedicated spot welder, though, breaks the contact to finish the weld. It applies pressure, then contact and heat, then stops the welding process by cutting the heat, but it maintains the pressure after the current is cut - because the tips can and do get stuck if they get too hot. Also, if you stop the pressure too soon, the weld will simply pop back apart without adhering

[Russell]

Did someone have a mig spot welder on here the other day that looked like a spacer for the mig gun. Just weld on the top piece and the heat joined it to the bottom. I would try that before drilling a hole.

[BBR]

I'd be more concerned with my copper electrodes touching/arcing to stuff they shouldn't.

[SuperBuickGuy]

I'd be more concerned with my copper electrodes touching/arcing to stuff they shouldn't.

rubber hoses or clear plastic hoses over the arms fix that... only they're a b*ch to pull off after they've been heat cycled a couple times.