Best aluminum alloy for tank ?

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I have been practiceing aluminum with the dynasty 200- kind of starting to rememberhow to do it ...I need to fabricate a small water tank ( about a 10 inch cube ) for my home madetig cooler.   I was thinking of using 3/32 sheet but I don't know what would be the bestalloy to make it easy to weld.   I have an aluminum trans cooler in the system allready.I want the alloy that would be the easiest to tig weld since I havn't done any real world projects in aluminum yet.  I am thinking that 1100 or 3003 might be the most corrosion resistent  ( will be using the pink antifreze + water I guess  )   but not sure which is themost forgiving to weld.It is not pressureised.  What alloy is easiest do yall think ?  and would you use 4043 rod?  Thank you for your opinions in advance !TimPSthe only thing better than the dynasty 200 is a dynasty 350 !
Reply:I'd use 1/8 3003.  It's a little stronger than 1100, readily available and just as easy to weld.  And as you suggested, 4043 filler.Dynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:Why not a SS tank?
Reply:My first thought was stainless because of lack of corrosion.   However I figured if Iused it - it would be relatively thin- maybe .025 - dont need it any thicker - I thinkthat thin it will be hard to keep the edges really close together - its gonna want to warpand get a scaloppy thing down the edges even with lots of tacks.  Couldn't find a stainless food bin the correct size.  My heat exchanger is aluminum so that makesthe corrosion part moot.   I think stainless would be more expensive than aluminum.Tried some 12 inch long outside corner joints with 1/8 and 3/32 aluminum and it seemedto work pretty OK and had little tendency to warp ( 2 tacks in 14 inches )The ONLY drawback on aluminum is that I can't buy from my usual scrap/ drop sources because 95% of that no longer has the marking showing what alloy it was.I will have to do to an aluminum supply house.  I kind of figured 3003 might be prettygood.   If I have any scrap I can use it to practine using it on the english wheel andforming power hammer.I guess 1/8 might give me a little bigger margin for error heatwise than 3/32 (?)Thanks for the help Guys.Tim
Reply:6061 will work and is available at most scrap yards.......I would make it from aluminum since its cheap and easy to weld.......  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Originally Posted by B_C6061 will work and is available at most scrap yards.......I would make it from aluminum since its cheap and easy to weld.......
Reply:jethro, just a note about aluminum TIG cooling tanks that I'm sure you already know. The watercooled torch head and cable are going to contribute copper ions to the resulting solution in the tank and that will mean a battery.  Even with various petroleum products in solution in the coolant the galvanic differences will make the (alloy) tank a battery.So... aluminum tanks do have a 'life span' in this application. They cool great and work fine for "that" lifetime, (whatever it is?) but usually pit inside out and become 'swiss cheese' over time.It really won't make too much difference in alloy; compared to copper all alloys have enough galvanic difference of enough to dissolve the tank.cheers,Kevin Morin
Reply:One other issue that comes up all the time, what are you going to use for coolant?The coolant specified for TIG seems to be in one of two camps.  Coolant for systems that have aluminum in them and coolant for systems that see high frequency (presumably like the dynasty).Bottom line, Go thinner on the gauge and go 304 stainless.Search these forums for discussions.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:Thanks for all the replys !I got some 1/8 3003 today and started building the tank. (for better or worse)I figured that there would be some corrosion issues anyway just because that goeswith aluminum in general.  I figured I would use pink antifreeze- maybe with distilledwater or maybe not.  I remember distilled water is slightly acidic because of ions.My heat exchanger is aluminum so I am committed to aluminum anyway ( at leastas long as it lasts - )Somewhere I have seen dis-similar metals in water situations where they throw ina third metal as a sacrificial electrode for the galvanic corrosion to work on.I remember  now it was on Iron bridges over rivers or over salt water.  I think It wason "dirty jobs"  show.     i wonder if there is a metal I could throw in to "take" allthe corrosion ????????????????Humm- more web research ......One issue yall mentioned was the possible conductivity of the fluid for thehigh frequency arc starter .  Maybe I can find someone with one of those ultrahigh resistance probes to measure it directly.  Of coarse it is probably acresistance - not simple dc.  may or may not be different for this...........I immagine the pink antifreeze has some anticorrosive compounds which willexhaust themselves yearly so I will have to change it regulary.  Thats OK -its cheap !I have been running it off city water through a 20 micron screen cartridge but I don't wat to run it too long that way because of all the chloring in our water.In college I had access to a 60,000$ ac impeedance analiser - that would havemeasured the coolant in one swoop !  Maybe a case of guiness might grease theskids intrade for a few measurements??????Any ideas what else might be good besides the pink antifreeze ?Will try to post a pick if I can figure out how !TimPS- I could slosh the tank with gas tank sealer to seal off the aluminum ???????????????????
Reply:zinc anodes is what they use on boats and water heaters in your house.maybe weld a bung in for a screw in zinc and try some royal purple coolant.
Reply:Originally Posted by gitardedzinc anodes is what they use on boats and water heaters in your house.maybe weld a bung in for a screw in zinc and try some royal purple coolant.
Reply:I had never heard of that for freshwater. My water heater has a high mounted and low mounted zinc. I was just thinking from the point the other guy made of the cooler becoming a battery.  I can't remember the boat manufacturer that made aluminum hull boats but they had a push button volt meter on the dash to check the reaction between the zincs and the aluminum hull. I may be stating that wrong so feel free to correct.