How to: build a sheetmetal tank

[Ratfink1962]

This is one method for building a sheetmetal tank. It requires using a welder (mine is mig) and basic tools such as a body hammer and dolly, clamps, grinders, tin snips etc.

Start with making a pattern... as you can see I made the pattern 1/4" small all they way around, which should leave a 1/8" gap when finished since the sheetmetal will take up the other 1/8"


Transfer the pattern to some 2x material and cut it out with a scrollsaw...


Since the tank I am making is going to be fairly thick, I cut two blanks then clamped them together and sanded them to match... keep in mind, the tank will only be as good as the buck you build it over.


Then rounded off the edges to make a left and right side...


I also added a block on the backside of each half so that I could clamp it in the vise...



So now that the forms are done, Its just a matter of clamping the metal over the form, hammering... cutting and welding, trimming, whatever it takes to get it to lay down and match the form. This is where a shrinker/stretcher machine would have come in handy.


So at this point I have the right side panel completed, now go back and make a left side, then join the two with a strip of sheetmetal to get the width you want.




And this is what it looks like on the bike...


And here is a shot with it all smoothed up and painted...

[KZ1000]

Nice work

[Ratfink1962]

As far as the mounts... I decided I wanted a tank early in the build, so I welded in two crossbars before I finished the frame...



So its just a matter of sliding the tank in the opening, then marking the location of the two mounting holes on the tank, then I will weld in a couple of nuts, with two screws holding it in place, it shouldnt go anywhere.

[Ratfink1962]

Nice work

Hey thanks

[bikeriderx]

Dude! I had thought of doing it just like that!! Now I know it will work! You rock! THANKS!

Here's some of my (busted) ideas:




Tried foam, NOT!:




I'm so psyched...Thanks!

[Ratfink1962]

You can do it!

Its not hard, but it is time consuming... at one point I was wondering why I didnt just join the two wood forms and use that for the tank!
Ive probably got something like 10-20 hours into this project.

I also realize my "how to" is short on how to actually bend the sheetmetal and make the corners, Once I got on a roll I failed to take pics of the progress, So I am planning on adding some pics in the near future to help explain how to do it.

[bikeriderx]

Nah, Dude! I get it...Great work!!

[Pawel]

lol I just woke up, and Im going go to do that now. hahaha.

[Ratfink1962]

Get after it.... and take pics!

[UncleKudzu]

I also realize my "how to" is short on how to actually bend the sheetmetal and make the corners, Once I got on a roll I failed to take pics of the progress, So I am planning on adding some pics in the near future to help explain how to do it.

i'd love to see more photos, but this is very useful info as is. i'm thinking about trying a tank in fiberglas, and this how-to gives me something to think about.

[Pawel]

I started to do this, then gave up I dont have the patience lol Im gonna build / fill tank in on next one.

[B607]

I had a 20" straight bar Schwinn frame years ago and used the "fiberglas" method to make a tank. I used some stuff I got at the automotive paint supply called Kitty-Hair. 2-part epoxy that is thick and really heavy. I cut a piece of plywood to fit the opening and then did one side at a time with the fiberglas. I made the tank permanently a part of the frame. I didn't use a form..I just kept working it until it got stiff. After it hardened I used a hand grinder to shape it, then sanded it. Before I painted it a friend saw it and begged me to sell it to him, so I did. I never saw how he finished it but I'd bet it came out nice. Gary

[Philphine]

that's one for the mental "i want to try that" file. never tried shaping metal though. i'd probaly take the lazy way out and lay fiberglass over the wood. good idea though.

[Ratfink1962]

I do plan on adding more pics that should explain how to shape the metal, just havent got around to getting it done.

BTW even though this tank is purely for looks, it could also work as a real gas tank for a mini-bike. Just have to go over the welds and make sure its completely sealed up.

I may end up cutting a small access door in the bottom (between the frame tubes) and use it to house a battery for my lights.

[bikeriderx]

I do plan on adding more pics that should explain how to shape the metal, just havent got around to getting it done.

BTW even though this tank is purely for looks, it could also work as a real gas tank for a mini-bike. Just have to go over the welds and make sure its completely sealed up.

I may end up cutting a small access door in the bottom (between the frame tubes) and use it to house a battery for my lights.

Yea!!