Building a Coffin Tank

[TheMKoi]

Hello CC

I am gathering information on building a coffin tank. I have Googled and come up with some information. So far, make a template out of cardstock/cardboard, once I like the fit or design break it down and cut it out of steel then weld up. My only hesitation is that I have an arc welder and a lower quality mig welder(which I haven't even used). Would the mig be fine for the tank? Also any pointers for a first time tank builder would be appreciated. I am pretty sure my welds will be shitty so I probably plan on using body filler and trying to round off the sharp corners.


Also just a heads up I am not a total noob, I chopped and stretched out my frame and I am not afraid to get a little dirty and a little weird. You could check out my build in the jap section to see what I am working with.

Thank you,

Matt

p.s. This will most likely be next winters' project. Riding season will soon be here once the snow stops.

[Tattooo]

Be sure and practice on your welding skills this summer as the tank has to be sealed and bondo won't hold in fuel... Good luck...

[shank1kole]

I did the templating and cut the aluminum pieces out. Drove an hour to use a brake and have a pal weld it up. don't forget mounting points, petcock bung , fuel neck/cap. I went through (Lowbrow customs) for these fittings rather than make them. Very happy with going that route ! also pressure test the tank before you seal it. Gas tank sealer does not hold back leaks for long. Basically do it right once on a tank because the more rewelding, the more heat distortion, the more work.

[TheMKoi]

Thanks Tattoo and Shank1kole for the responses

I definitely plan to do a lot of practice with the mig and even try our a couple ways to make seams or bend what I can. It appears to be pretty straight forward, I just need to start.

One question for you shank1Kole, have you had any corrosion issues with the dissimilar metals? You said your tank is aluminum, what type of bung, mount, and filler neck did you use?

I was planning on just using regular steel.

[shank1kole]

Thanks Tattoo and Shank1kole for the responses

I definitely plan to do a lot of practice with the mig and even try our a couple ways to make seams or bend what I can. It appears to be pretty straight forward, I just need to start.

One question for you shank1Kole, have you had any corrosion issues with the dissimilar metals? You said your tank is aluminum, what type of bung, mount, and filler neck did you use?

I was planning on just using regular steel.

lowbrow had aluminum bungs, etc. I cleaned the tank with lye and then lined it with an epoxy that NASA uses for their fuel tanks.