Tig or mig ?

[Olav]

I will modifying the fuel tank for EFI. Is it best to use TIG or MIG? Last time i did it i had trouble with leakings. And had to grind and weld again so it warped. I used mig. Now I have bought me ESAB 250 amp Twintig TIG and have my old 140 Amp Kemmpi MIG. What to use. Thanks for any input...

Olav

[Mathius]

I will modifying the fuel tank for EFI. Is it best to use TIG or MIG? Last time i did it i had trouble with leakings. And had to grind and weld again so it warped. I used mig. Now I have bought me ESAB 250 amp Twintig TIG and have my old 140 Amp Kemmpi MIG. What to use. Thanks for any input...

Olav

It doesn't matter if you are using the correct alloys and you are skilled with either machine.

There is nothing magical about a TIG welder, it just gives you more control because YOU decide how much filler to add, and YOU decide on the fly, how much heat.

You can get the same results with a MIG welder, if you know what you're doing.

So do whatever you feel the most comfortable with.

Oh, and peep in on this thread: https://www.pro-touring.com/forum/sh...hlight=Mathius

We fought out the whole TIG vs. MIG thing a long time ago.

Mathius

[Olav]

Oki! think I will try my new TIG. Must practise on some other parts first. Have only used it on Alu. earlier. How thick wolfram do you recomend for 0.8mm steel. and how many amps.
I'm working as mechanical supervisor now on a ship yard and have been working "on the floor" for 20 years. Mostly machine repairs and machining, so my welding skills are little over average mechanic. but when it comes to TIG and thin metal it's not so good.

Thanks for any input....

Olav
Thanks Olav

[Mathius]

Oki! think I will try my new TIG. Must practise on some other parts first. Have only used it on Alu. earlier. How thick wolfram do you recomend for 0.8mm steel. and how many amps.
I'm working as mechanical supervisor now on a ship yard and have been working "on the floor" for 20 years. Mostly machine repairs and machining, so my welding skills are little over average mechanic. but when it comes to TIG and thin metal it's not so good.

Thanks for any input....

Olav
Thanks Olav

Ok, first I have to ask... is 0.8mm the correct measurement?

Because by my calculations, that's like 0.0026 inches, which is thinner than 30 gauge, which is not going to be anywhere near thick enough for a fuel cell for EFI. (given that 1mm = 1/32 inches)

You need like 14 gauge aluminum minimum for a fuel cell.

Mathius

[Olav]

I will not build a new fuel cell. My plan is to modify sump/ baffle the original tank of steel....

Olav

[Mathius]

I will not build a new fuel cell. My plan is to modify sump/ baffle the original tank of steel....

Olav

I'm sorry, I thought I read that it was aluminum... still, a steel fuel cell 0.0026 inches thick? That's crazy. It's no wonder you had leaking issues.

Most guys here use 16-18 gauge for steel fuel cells (usually stainless) and 14 or better for aluminum.

I really can't recommend much for you. I don't think I've ever welded anything that thin. I mean that sounds like tinfoil. Are you sure you measured right? Are you sure it isn't 8mm?

Mathius

[Olav]

Wil measure again. But i think it's not any thicker than normal sheet metal. Have cut out a part of the stock tank and it's thin.....If I make the sump/ baffle of thicker plates than the tank is made of must i use more/ higher current and it's easier to warp the plates.

[Mathius]

Wil measure again. But i think it's not any thicker than normal sheet metal. Have cut out a part of the stock tank and it's thin.....If I make the sump/ baffle of thicker plates than the tank is made of must i use more/ higher current and it's easier to warp the plates.

Try to use calipers when you measure it, if you haven't already. Actually 8mm is pretty thick stuff, I clearly wasn't thinking when I wrote that.

Mathius

[Olav]

8mm are the same as 5/16"

[Mathius]

8mm are the same as 5/16"

Yeah, which is bigger than 1/4" inch. It'd be heaviest fuel cell I ever heard of.

Mathius

[Olav]

Hi!

Measured the steel in the Camaro tank about 0.90mm or so....(1/4" are 6,35mm)

[Mathius]

Hi!

Measured the steel in the Camaro tank about 0.90mm or so....(1/4" are 6,35mm)

Ok, that makes a lot more sense. That's about 19 gauge sheet. Still kind've thin, but not surprising.

It's been a long time since I've TIG'ed, but I'd say somewhere in the 50 amp range, with a 1/16" rod. Gas at somewhere around 11 cfh or 20 psi.

But there are guys on here that do this every day. Now that we've established what size material, someone else should be able to give you better settings.

Mathius

[coolwelder62]

Does you tig welder have a remote foot control if does set the amps at 65 max.this will give you 0to 65 so you can very the needed amperage.totally tack your pcs. togather before completely welding. If the fitment is tight You can lower your amperage some. Lowing your amperage allows you to weld at a slower inches per min.Letting you have a better chance of leak free weld. You can email me or call me at 785.594.7481 days and i will try to walk through it and help you all I can Scott.

[Olav]

Thanks....my machine is a ESAB DTB250. Think I can hook up a pedal to it but at the moment i don't have. I will get one later if I will do a lot of TIG welding in the future....

Olav

[Mathius]

Thanks....my machine is a ESAB DTB250. Think I can hook up a pedal to it but at the moment i don't have. I will get one later if I will do a lot of TIG welding in the future....

Olav

I've welded with or without the pedal. When I was trying to get my 6g cert, you have to weld a fixed pipe, so you pretty much have to stand up to get all the way around it. So using the pedal was out.

I think I prefer the foot pedal, honestly, you can cut back the heat a bit when the metal starts to get hot.

I had to stop after about 2 passes, to let the piece cool down before I could weld the final 2. The heat was ok for the material, but it was too hot for me to keep my hand up there without burning it right through the glove.

Good luck with your fuel cell and let us know how it turned out.

Mathius

[Tom Vogel]

Just a reminder. More than one person has been seriously burned or killed outright by doing what you are talking about. There are several precautions one could take to lessen the risk, but none would satisfy me to the point where I would risk it. If you are feeling lucky, I would at least have the tank boiled out at a radiator shop first.
Good luck, a burn unit is a sad place.

[gt1guy]

Not trying to stop you from doing what you want. But here's something to think about. If you get in a wreck and there is a fire do to a fuel tank that you made or modified in your garage, and god forbid, someone gets hurt, your through.

"Last time i did it i had trouble with leakings"

This tells me you welding skills might not be up to par for attacking a project such as a fuel tank.

Just take a step back, and honestly evaluate your skill, and the dangers of getting it wrong.

Kevin

[Mathius]

Not trying to stop you from doing what you want. But here's something to think about. If you get in a wreck and there is a fire do to a fuel tank that you made or modified in your garage, and god forbid, someone gets hurt, your through.

"Last time i did it i had trouble with leakings"

This tells me you welding skills might not be up to par for attacking a project such as a fuel tank.

Just take a step back, and honestly evaluate your skill, and the dangers of getting it wrong.

Kevin

I wouldn't be worried so much about his welding abilities, as much as his safety procautions.

As Tom Vogel said above, people have been seriously hurt by gasoline before, and welding on a fuel tank is always risky.

If he were welding a new one from scratch, he could leak test it easily with water first. This is why I say I wouldn't be so concerned with his welding ability.

It's the fact that he's welding not only on a fuel tank that already had fuel in it, but one that had baffles, which specifically are designed to keep fuel from moving in the tank, I really think extra care needs to be taken to make sure the tank has been properly purged and cleaned out of all gasoline residue and fumes.

Mathius

[Olav]

I have cut and opened the tank. Have cleaned and opened and welded several tanks earlier.( We have a"gas analyzer" for use in ship/ tanks.) My earlier problems regarding leaks have I sorted out. Some of the problem was the galvanizing inside and outside the tank.
And some issues I don't want to tell you about :-/

There was not a big leak last time but I want to do a good job as possible and it must be looking good also.

Olav

[Mathius]

I have cut and opened the tank. Have cleaned and opened and welded several tanks earlier.( We have a"gas analyzer" for use in ship/ tanks.) My earlier problems regarding leaks have I sorted out. Some of the problem was the galvanizing inside and outside the tank.
And some issues I don't want to tell you about :-/

There was not a big leak last time but I want to do a good job as possible and it must be looking good also.

Olav

If you've already cut open the tank, then you should be good to go.

Just make sure you leak test it with something that isn't flammable before actually putting gasoline in it. Water works.

There was a nice thread on this not too long ago. You might want to do a search.

Mathius