Jockey Journal Forum banner
1 - 12 of 12 Posts

·
Registered
Joined
·
44 Posts
Discussion Starter · #1 · (Edited)
I'm probably nuts and might wind up over my head, but screw it. I had the tank, and decided to chop the thing up.
Anyway I got a tank off an FXSTI that wound up getting dumped at a dealership, and was told.. have fun. So I am.
I decided to split the tank and pull ~1/4" out up front and 3/4" out from the back of each side to give the tank more of a tear drop shape versus the more squared off stock shape.
I do have the other side off now as well, along with a bit more done on the shaping of the invert tear drops, but this should give you a general idea.



I started my layout by staring at the thing and somehow came upon the conclusion that I was capable of doing it first of all, and I could make it look better than stock without making a major change to the overall shape, as I do like it, it's just too squared for my tastes.
With this tank I decided to pull about 1/2" total width out of the front, without messing with the width of the tunnel, or the gauge mount pod area - as if it does get run I will run the speedo in that location, so I decided to say fuck it, go against the true chopper wisdom, and kept it. I decided to split the tank apart near the seam about 1/2" over from the tunnel start and run that line straight back and taper out to about 3/4" width for the pie cut that will be removed, thus sectioning the tank. I was an idiot and didn't take pictures of how I laid out the bottom, as I just plain old forgot. I'm still not positive I did it the "right" or easiest way, but I think I can get the fitup to work on the bottom and get her sealed up fairly well once I start throwing it back together.
Splitting the tank I used a 3" cutoff wheel and went at it. The cut line in this pic is rough, but I was able to clean them up and get them right to where I wanted with a grinder, I just don't have pictures of that uploaded.
Sometime this weekend I'll update with more pictures of how everything is going together once I finish up caving the sides and get it tack welded together (if it works.. lol) and start the finish welding.
Anyway, I cut the tank halves apart and then started to fix the crease above the big dent. Got that out, using the last out first in school of thought. I just used your typical beater bag, body hammers and dollys. I still have some final work to do, however it was close enough for now that I got somewhat impatient and started the layout and beating in of the tank side.

Ignore the somewhat sloppy cut. My initial cut looks like crap, because well.. it is.
Anyway.. this is what it looks like once the tank half is moved in, and the pie cut section has been removed. Gives a decent idea of what the final shape will be - hopefully.

I took this pic before loping off the other side, just to make sure I was on the right track.. once it looked like it would work in theory I hacked off the other side.



With the tank caving I did it real back yard garage like, using a few body hammers, a ball peen hammer and a big bag of sand. The sand I used to support the tank half, and just worked my way around beating the tank half starting to shape and form the steel into the desired tear drop. Still have a ways to go, but the basics are starting to be visable.
That's where it stands right now.. I'll have more updates as they happen, and as I get time to type them up.

Any suggestions would be greatly appreciated, from your f'n insane just give up to insight on the final fitup / welding of the tank and how to pressure test it. I'm thinking 10-15psi of compressed air submerged in a water tank before dressing the welds, and then again after cleaning up the welds??
 

·
Registered
Joined
·
44 Posts
Discussion Starter · #3 ·
That tank looks good man! Thanks for the advice on getting the inside epoxy coated. I was wondering what to do to seal it up, now I know. Appreciate it. I'll have a bunch of updates probably Sunday or Monday as I've been doing a little here and there but Sunday I'll be spending a few hours on it straight through, so there will hopefully be a decent bit of progress.
 

·
Tiny Member
Joined
·
1,453 Posts
GaryC said:
I was wondering what to do to seal it up, now I know.
What you do to seal it up is fit your two halves PRECISELY, and then torch weld them. You'll chase holes until the end of time w/ a MIG welder. Not to say it can't be done, but the majority of really good sheetmetal guys still hammer weld.

Having the tank sealed should be considered a preventitive, not a fix for poor sealing due to bad welds.

Some friends and I are putting the finishing touches on a tank we cut every which way...I'll post pic.'s shortly. No less than five people have worked on it and there's approx. 20 hours of labor in it to date.
 

·
Registered
Joined
·
44 Posts
Discussion Starter · #5 · (Edited)
Sorry, I should have clarified. I know it should be welded and shouldn't leak once it's finish welded. I was talking about sealing it up to keep it from rusting from the inside out as the years progress - after it's been pressure checked. What I was wondering is what material you use and how you seal the inside of the tank once it's finished.. I originally had planned on mixing up a slightly over reduced epoxy primer and sloshing it around, but I figured there had to much a much better & right way of doing it.

With that said, is my thought process on the right track? Finish welding it up, and check it with 10-15 psi of compressed air in a water tank before cleaning up the welds to see if / where it leaks, and then check it once again after cleaning up the welds? Any suggestions as far as that goes? How exactly are you guys sealing the tank up to pressure check them, if you do. I've got a couple ideas, but any tips would be appreciated. Thanks again.

Anyhow, definately post up picture of that tank, I'd like to check it out!

edited because I spell like a drunk monkey.
 

·
Registered
Joined
·
3,991 Posts
Tony Bones said:
What you do to seal it up is fit your two halves PRECISELY, and then torch weld them. You'll chase holes until the end of time w/ a MIG welder. Not to say it can't be done, but the majority of really good sheetmetal guys still hammer weld.

Having the tank sealed should be considered a preventitive, not a fix for poor sealing due to bad welds.
right on, no substitute for solid welds. i do the epoxy thing as pinhole insurance and to prevent rust in the tank later.
 

·
Registered
Joined
·
2,888 Posts
We've talked about tank sealer before, you might do a search. I looked at a few sealers and decided on National Tank Sealer (Por 15 product).
I think I'd check the tank with 5 lbs or so of air pressure. I balloned a Sportster tank once. I don't know exactly how much pressure I put in it, but it wasn't much.
Anyone tigged a tank together?
 

·
Registered
Joined
·
886 Posts
Gary

I used the plastic cap that came with the tank. I drilled a hole in it and tapped it for a compression fitting so I could attach it to my compressor hose. Install the petcock and set the compressor to 5 psi. Dunk it in water and see how good you really are. After all the holes are sealed send the tank out to the car shop to get sealed. Not worth using any of the sealing kits. If they start to peal you are screwed. good luck.
 

·
Registered
Joined
·
1,152 Posts
And this is what I was going to go with (but with a single gas cap) However I got lazy and never finished it. Next bike I guess.

 

·
Tiny Member
Joined
·
1,453 Posts
You're on the right track w/ the pressure testing. Take the unpainted tank to a radiator shop when it's done and have them seal it. Works better than Kreme or other similar products.
 

·
Registered
Joined
·
44 Posts
Discussion Starter · #12 ·
thanks for the tips guys, I greatly appreciate it!

Mike V - you gotta finish that thing up, that'll be a bad ass tank!
 
1 - 12 of 12 Posts
Top