[BigHG]

I decided to weld up a steel fuel cell with my Miller 185 using .030 on 16 gauge. I tack the thing together and start stitching it up. I am doing a few inches at a time starting on the inside at the middle and all is good. Then I get in close to the corners and I proceed to blow huge holes through the thin metal. All this work cutting everything and prepping everthing and now it looks like shit!

I have turned the welder down to its lowest setting and played with various wire speeds. Still making holes.

I have been told it was lack of oxygen in the area of the weld that was causing the holes. If this is the case, what is the solution?

 

[Old Scout]

I'd try 023 wire.

 

[twistedmetal]

I weld steel gas/hydro tanks for "extreme terrain material handlers" all day long, every day of my life. While we use 12ga steel, I still have a few tricks I can share, most of them are obvious. turn your wire speed up just SLIGHTLY higher than you normally would--but not enough to cause signifigant splatter or make it cold roll/develop blisters. Also try to turn the corner with the wire, rather than to run right into it-stop-then try to go again. This also ensures that you will/may develop a leak in the corners. The most important tip I can give is to check your style. The best method for me is to keep the wire speed down a bit(keeps the weld fluid and flatter) and shoot ahead about 1 inch, back track about 1/2 inch, ahead 1 inch, back 1/2 inch, etc. this does two things: preheats the metal, and basically makes the material thicker while filling in any gaps that may be ahead.
I don't know what your duty cycle is on your welder, but DON'T STOP. Every time you stop a weld, you increase your chances of a leak. When your all done, plug all of your holes, and test the tank with about 5-10 psi and some soapy water.

 

[Hickeyjones]

his duty is 60%, I looked for that welder today, but they basically merged it with the 210. Not available any more.

 

[xj4rocks]

.023 wire should definitely help. Also using C25 gas instead of CO2 will help make a cooler weld. and keeping wire stick out low. (1/4" or 3/8")

also but joining thin sheet sometimes is more difficult then bending a small flange on one panel and putting that flange towards the inside. sometimes when the metal is cut to butt join the ends it's not square leaving a pointed edge that is thinner metal (burns through easy)

 

[thecarman]

Yep, .023 wire has helped me with the thin stuff.

 

[Bill Schueler]

If you wer'nt such a whimp that fuel tank would be done and mabeye you would be out wheeling with me instead whinning about your sore wrist and sore neck, WAAA! HE HE HE.
how is it coming now?
bill

 

[Rock Taxi]

OR....keep the .030 wire and use 1/4" plate. :flipoff2:

Ed

 

[gunracer1]

i usally run the welder pretty hot and weld downhill. you need to practice this, because you will be welding fast. and don't do a bunch of starts and stops, it will leak. i like to do a seam from start to finish in one shot, and i don't care how long it is. just plan it out. mike

 

[BigHG]

Allright, thanks to almost everyone for the advice. (Schueler :flipoff2: )

I will be off to the store for a roll of .023. I am going to try twistedmetals technique and see how it goes. I am probably going to have to redo this thing anyway so I might as well use it for practice.