Looking at McMaster-Carr's site, 0.063" thick 3003 aluminum in a 24x36" sheet is $33.22. It seems a lot of mistakes and rework is possible considering the cost of materials. For me, this would be an opportunity to practice and improve my mig (GMAW) welding aluminum skills. In for a penny, in for a pound. But, that is me.
FWIW, I have about four (or six?) books on sheet metal work and (eventually) intend to make some items. Your tank tank is a challenging item, but it looks like you have a good approach. From what I have read (all book learning), a rawhide mallot is a very useful tool for sheet metal forming.
The home build aircraft types have some online information about aluminum sheetmetal forming along with the tinmantech.com website (which seems mostly about welding). There is also a metalshapers.org website, but I have not found that especially useful. However, you may. A decent torch to anneal the aluminum after working and figuring out the annealing technique is also useful. I will be following your project with interest. Good luck!
We had a visitor in my welding class the other day--a local fabricator who makes Moon-style tanks for vintage Top Fuel dragsters. He gas welds the tanks, which the sanctioning body prefers, as the weld area is more ductile and less likely to rupture in the event of an actual emergency.
He says the key to it is the right filter in the welding goggles. The right filter will show a color change in the flux at the right puddle temperature, apparently.
Not being an advanced enough welder myself, I did not inquire further. But I do want to try making a tank someday to go with my Blinged-out (alu parts) Airhead.
898, I'm really curious.... are you "annealing" this material as you work it? It really improves the form-ability of all metals, but especially aluminum.
Put some of your "scrap" to work and give it a try.... it will take a bit of experimentation (which you obviously love) and I think you'll be pleasantly surprised.
Here's that link again > [url]http://www.tinmantech.com/html/aluminum_alloys_continued.php[/url]
[QUOTE] ... then you got the problem of holding onto the hot piece. Just pounding does away with the torch, [/QUOTE]
Let the piece cool [B]before[/B] you wail on it... .. it doesn't need to be hot when you work it. Annealing "softens" the metal so you can form it more easily.... I think you owe it to yourself to try this 898... it really [B]is[/B] the "trick" to panel forming. And it will allow you to realize what's in your head (concept wise) without fighting the material. It's a lot more gratifying, not to mention [B]encouraging[/B], when sh*t starts to work the way [I]you thought it would[/I].... Just sayin'.
Torch in the garage...? Same as working with sharp tools. Just be careful... . . [img]http://boards.core77.com/images/smilies/icon_wink.gif[/img]
Annealing is the hot ticket (pun intended).... it REALLY makes the process work. Again, it's akin to working wood with sharp tools.
"Annealing" [B]is[/B] [I]technically[/I] "heat treating". You are using heat to change the molecular structure of the aluminum; in this case, it's ductility (softness). It's generally at a lower temperature; aluminum anneals around 75-775??F. Also note that the whole sheet does not need to be raised to a uniform temperature simultaneously, it can be done in small sections.
"Heat treating" as referred to in the (3003 material spec) means that the material can not be [I]significantly[/I] hardened/strengthened, or the chemical make up of the material changed, by elevating it's temperature to an extreme degree. Other aluminum alloys [B]can[/B] be altered (i.e. like for aircraft landing gear forgings (2000, 5000, 6000, 7000, 8000 series alloys))
3003 hardens as it is formed, and needs to be frequently annealed to "re-soften" it so that it can be formed. If you don't the material only becomes harder and more brittle ... prolly not so good for a motorcycle tank.
Found this on YT; another technique, more predictable than using the soot method; coincidentally, the material in the video is 3003.
<iframe width="420" height="315" src="http://www.youtube.com/embed/QPe6rBPOnx0" frameborder="0" allowfullscreen></iframe>
[B]Tempilstik[/B] temperature indicating sticks. You can probably find them at your local welding supply outlet. They're available on eBay too. $5-7
<iframe width="560" height="315" src="http://www.youtube.com/embed/WIMqVIM39I0" frameborder="0" allowfullscreen></iframe>
Recall that some British panel beaters (aluminum body builders) wipe a bar of lye soap on the aluminum when it gets too hard. They then heat it until it starts to look charred. After it cools down, it is back to its original soft state and unlikely to tear or crack. Hope this helps!
[QUOTE=8ninety8;836507]I just heat it until my HF glove starts smoking, then let a cool off a little, and it seems to take a good bending at that point. Thanx.[/QUOTE]
thats funny right thar...
seriously though, cold work, anneal, douse in pickle solution, then cold work, repeat. I think you've probably figured that out. Also, turkey fryer burners make great annealing stations.
you're doing well man, really well.
if you were closer, I would let you use my wheel, and you would be done by now.
[QUOTE=8ninety8;837120]Back from the welder, great craftsman, difficult to find such an artist, lucked out. Here's the side.[/QUOTE]
fat, wide and stiched. cool
Everyone wants that stack o dimes look, but you can see where he stiched this together an inch or so at a time. which, btw, is correct.
try not to have to form near the welds now, as cracks are inevitable when that happens.
[QUOTE]Everyone wants that stack o dimes look, [/QUOTE]
In case anyone was wondering what beater means by that.
[QUOTE=8ninety8;837164]Aren't a stack of dimes evidence of a robot? When you see the frame welds on an airhead you can see the human hand.[/QUOTE]
No, they can be human in origin. One of the keys I've found in learning MIG processes is "be the machine."
Professional welders were stacking dimes long before robots showed up on the factory floor.
Here's a couple more. If you look closely the "dimes" are not robotically-perfect in size, and in the second photo the welder changed work angle and while gorgeous, the part would have been rejected because the weld failed to fill the joint. I work at a nuclear power plant and see this kind of stuff daily in our fab shop. These guys [I][B]never[/B][/I] cease to amaze me.
i have seen more pretty welds fail than ugly ones...
My favorite a few years back was when the rock crawling world got big, was small shop welders were using mig to get a tig look by starting and stopping, or laying dots. Looked pretty, but lacked penetration.
That said, aluminum is my least favorite material to weld. it's heat properties lie on a razor's edge, and in my world, where the shapes, materials and environment is less than perfect, it's a giant pain to work with.
Now, let's get back to tank porn please.
[QUOTE] ... tank porn ...[/QUOTE]
:dance :dance :dance
Just a thought, but could you cover your plug with paper mache and cut it off into manageable pieces to use as templates to cut your sheet stock into? An other thought into forming can be found here. [url]www.eurospares.com/frame.htm[/url] Use it to form the section shapes you need and cut out and use what you need. I've enjoyed reading your thread. frank coleman P.S. article 8
[QUOTE=8ninety8;837586]Pulling the plug on this try. Just occurred, caveat, the double seamed welds are no good. If the outer weld ever leaks, it can't be rewelded because it could blow up. Might be strong, but not the way a tank should be built. Butt joints only. This one looks like frankenstein on steroids.
Have to start all over. Gonna hang this one on the wall, take a deep breath, and start over. It's been a learning time, the next try will have fewer welds and butted. Maybe it can be entered in a sculpture contest for abstractions? Hey, nothing ventured, nothing whatever.[/QUOTE]
Think about it before you trash this... TIG welds don't leak if they are done right. Finish the tank up, pressure test it with water & air, coat the inside with POR 15 tank coat & run it! It won't leak & will last a long time...