Topic: stainless steel gas tank??

[babyfood1217]

Does anyone have one, or has anyone ever seen one?  Assuming good penetration and all, there would be no worries about getting it coated (Kreem or POR-15) to prevent rust.  I'm curious because I have a decent supply of #304 SS (18-20 ga.) and just got a full bottle of Tri-Mix for my shop welder (a little Hobart Handler 135 - small, but good enough for thin material like this.)  I have a feeling this project may take a little while, just because of available time, but I think it will be fun.  I'm hoping my metalsmithing skills will help tremendously, but I found out real quick that raising/forming SS is no fun...at all...ever. 

I was thinking that, for the most all of the panels that will make up the tank will be relatively flat, so I would start by making tank out of cardboard, then use each piece as a template for the SS.  I'll keep round corners round using hand dollies and raising stakes, but any little dents/dings I can't get out can be filled with body filler before painting.  I wonder if, after fabricating, I could use the tank as a plug for a fiberglass mold?.  Then it would be pretty easy to make a basic blank for other people to use/modify if they want a new glass tank.

Just curious if you all have any thoughts.  I suppose it wouldn't be a bad idea to document this build.

-Chris

[paulages]

stainless is very hard to work, but if you're not planning on doing much shaping, it shouldn't be quite as bad.

[BobbyR]

Stainless is harder to work, it tends to ripple on tight radius bends.  Having said that, you would have a great tank with no rust issues. 

[ws6transam]

Sounds like a work of love, dedication, and passion.

Hats off to ya!

...As for the plug, I'd rather you do some fiberglass side covers for the CB750F. They are harder to find!

[paulages]

if you're just looking for a rust-free alternative,  aluminum is considerably easier to work, especially after annealing.

[Andoo]

aluminum is easyer, and lighter.

[babyfood1217]

Aluminum is a good point, as we've all seen the super awesome tanks done up by OhioCafeRacer.  They do look great, and while aluminum doesn't rust, I could have sworn I saw a post regarding still needing a liner treatment, maybe I was wrong (Ohio, any thoughts?)  Aluminum would be awesome to form.  Granted I've only hammered and tooled some into belt buckles, I would imagine the larger sizes would be just as easy.  The biggest thing I'm concerned with right now is cost however.  I just don't have the money for Aluminum.  Metals prices are still hovering high and with speculations as they seem to be at the moment, they won't be coming down any time soon (to be fair however, a few international metal handlers and their falsifying inventories (and resulting mulitbillion dollar lawsuits)) aren't helping the market.  I have the stainless, it was free, and I may have a source for more for free, and hell, since I already got the bottle of gas shippind in, I might as well right?  

Actually, right now I'm forming 16-18ga mild steel for some sculpture pieces I'm working on and it seems to be moving pretty well for me.  Granted, I had to make my own heavy-duty stakes from 2" bar stock and I'm swinging a 2.2lb pattern hammer (fancy sledge), but I have considered using just the mild steel for this tank project.  The rust issue probably wouldn't be a huge issue, but you never know.  The nice thing is that I have a pretty decent quantity, and if the outcome looks anything like the few designs I've come up with, I'll actually have a larger capacity tank.  It won't be huge, but maybe an extra gallon/gallon and a half.  I'm sure my butt will need a break long before that on a trip, but heck, why not.  

[Andoo]

Polish the steel and clear coat it. Then line it like any other tank. Remember stock tanks are stamped steel.  I'd still rather have aluminum but if you have the materials in steel i don't see a problem.

[Jinxracing]

Aluminum is a good point, as we've all seen the super awesome tanks done up by OhioCafeRacer.  They do look great, and while aluminum doesn't rust, I could have sworn I saw a post regarding still needing a liner treatment, maybe I was wrong (Ohio, any thoughts?)  Aluminum would be awesome to form.  Granted I've only hammered and tooled some into belt buckles, I would imagine the larger sizes would be just as easy.  The biggest thing I'm concerned with right now is cost however.  I just don't have the money for Aluminum.  Metals prices are still hovering high and with speculations as they seem to be at the moment, they won't be coming down any time soon (to be fair however, a few international metal handlers and their falsifying inventories (and resulting mulitbillion dollar lawsuits)) aren't helping the market.  I have the stainless, it was free, and I may have a source for more for free, and hell, since I already got the bottle of gas shippind in, I might as well right?  

Actually, right now I'm forming 16-18ga mild steel for some sculpture pieces I'm working on and it seems to be moving pretty well for me.  Granted, I had to make my own heavy-duty stakes from 2" bar stock and I'm swinging a 2.2lb pattern hammer (fancy sledge), but I have considered using just the mild steel for this tank project.  The rust issue probably wouldn't be a huge issue, but you never know.  The nice thing is that I have a pretty decent quantity, and if the outcome looks anything like the few designs I've come up with, I'll actually have a larger capacity tank.  It won't be huge, but maybe an extra gallon/gallon and a half.  I'm sure my butt will need a break long before that on a trip, but heck, why not.  

One idea for cheaper sheetmetal...

Have you spoken with any commercial HVAC companies? I've bought 4'x8' sheets of polished and brushed stainless, galvanized steel, and aluminum in the past as well as smaller offcut freebies. Might not work out with the companies where you are, but it's probably worth a phone call or two. A six-pack of beer can also do wonders to foster relations with some of the warehouse personnel. 

[babyfood1217]

Interesting idea.  I've done the cut-off freebie/cheapie thing before, but never for these materials, just for steep and plastic scrap.  Good idea, but how about this one...

Local junkyard/salvage yard has tons of awesome materials (which junkyard doesn't.)  Now, I know I'd have to do some research, and perhaps even get a materials test done, but what about the aluminum they use for street signs?  It's 3/32" thick, and I know there are quite a few larger signs at this yard.  A weed burner and some fun chemicals would get the vinyl and paint off, and then a little elbow grease to clean the surface and I would be good...no?  Some of the signs I've found there have been in the 3'x4' range, and something like that would be perfect.  Still, I don't know if I would need to seal the inside with anything.  I know with the stainless I wouldn't, mild steel I would want to for sure, but I'm not sure about aluminum.  Thoughts?

[Jinxracing]

Interesting idea.  I've done the cut-off freebie/cheapie thing before, but never for these materials, just for steep and plastic scrap.  Good idea, but how about this one...

Local junkyard/salvage yard has tons of awesome materials (which junkyard doesn't.)  Now, I know I'd have to do some research, and perhaps even get a materials test done, but what about the aluminum they use for street signs?  It's 3/32" thick, and I know there are quite a few larger signs at this yard.  A weed burner and some fun chemicals would get the vinyl and paint off, and then a little elbow grease to clean the surface and I would be good...no?  Some of the signs I've found there have been in the 3'x4' range, and something like that would be perfect.  Still, I don't know if I would need to seal the inside with anything.  I know with the stainless I wouldn't, mild steel I would want to for sure, but I'm not sure about aluminum.  Thoughts?

I couldn't say one way or the other about sealing the inside...my gut instinct is "no", but that opinion is worth what you paid for it. 

However, I really like your recycled street sign idea...I'm a big fan of repurposing unusual materials to make something cool. I guess the unknowns would be whether or not the particular aluminum alloy used would be friendly to shaping and/or annealing. If it's cheap, I suppose it couldn't hurt to try. In fact, there are street signs all over the place near my house...just sitting there mounted on poles at the side of the road, free for the taking! 

[Dr Rockso]

he's right , i used to get new floor pans for my volkswagen off those wooden poles .

[CrisPDuk]

Two points I think I should raise here:

If you really fancy having a go at building the tank from 304, and I don't see why you shouldn't Do not use a MIG welder to assemble it, the resulting welds are so hard compared to their neighbouring steel that it's almost impossible to grind them totally smooth

Contrary to popular opinion Aluminium does rust, or more correctly corrode, that's what that white powder is that forms on your unprotected polished parts when they are exposed to inclement weather, if you don't seal the inside of an ally tank, you will eventually end up with that stuff bunging your carbs up


PS; make sure you thoroughly clean any tools you plan on using if they've previously been used on mild steel, cross-contamination is a #$%*

[ohiocaferacer]

Came across this thread and thought i'd chime in.....

As for sealing the inside of aluminum tanks......you dont need to do it. I've been running an alloy tank on our red CR350 bike for around 5 years now and the inside of the tank still looks as new as it did when it was made. Yes aluminum does oxidize and that rate of oxidation all depends on you location, but if your keeping gas in the tank on a regular basis there shouldnt be a problem.

Welding aluminum is another thing.....definately dont try and weld the thin aluminum with a MIG. You will just be fighting yourself the entire time.....been there done that. TIG welding in my opinion is the best way to go, as you have so much control over your heat and can control the weld pool so much better. As was mentioned before.......when welding aluminum you have to be very aware of cross contamination. Dont touch the aluminum with anything that has had contact with steel(need to use a stainless steel brush). Aluminum needs to be very clean to get nice welds and if you use a wire brush on it, that has just been on steel.....you will have small little iron particles in you welds.....not fun.

Hope some of this info helps........hammer away!!
Greg 

[babyfood1217]

I know the TIG approach would be a much better idea, however, all I've got is my little Hobart, or the monster of an arc welder, or ox/acy.  I did at one time have an idea that would allow for minimal MIG work.  If I could form the pan of the tank and set it aside, then mostly form the panels for top of the tank, I could tack them together and then find someone with a TIG to finish the weld.  I would get the top piece back, all welded together, and I could finish forming it (smoothing of curves, bumping and whatnot...)  Make sure it fit the pan I made earlier, and then tack the two sections together and have those welds finished up by said TIGger. 

Greg, I'm curious what ga./thickness you fabbed your alum. tanks from?  My browser is finicky right now, otherwise I'd check your site (I think it says on there.) 

-Chris

[paulages]

you can oxy/acetalene weld aluminum using flux, but it's tricky. for a tank, i'm told you would want to bend a flange inward on both mating sides and then flux the joint and weld the two sides together kind od like sweating. i haven't done it myself. you won't be able to use your hobart unless you also have a wire puller attachment, as the aluminum wire is too soft to be pushed through the torch cable. i learned to TIG on aluminum, so ironically it feels easier to me than steel. greg is right about wanting to use TIG though.

greg--are you using a power hammer/ planisher, or do you have a wheel? i emailed you a while back looking for an aluminum CR tank source, and instead set out to begin making them myself. so far, i've only made my own seatpan, but i'll be done building my english wheel here in the next week or two, and will start making them to sell. your 350 tanks look great--i'm curious to know what method you use for shaping, and how you are making the tunnel. any chance you have any underside shots you could PM me?