Tig welding small thin aluminum tubing; tacking / clamping

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So I am in need of some advise here, I am starting to do more and more aluminum work and lot of air intakes and intercooler piping. In the future I will also be doing similar jobs with Titanium. Now the issue lies with getting the initial fit and multiple tacks. Since a lot of my bends are multiple miter / pie cuts I need the ability to get them situated perfectly.Is there a good set of clamps that can hold my work allowing me to get everything tacked up nice and pretty without crushing and changing the shape of the tubing? With these appearance is everything so small set screw holes in the pipe is no good. Sizes range from " to 4" and 1/16" wall or less.
Reply:Anyone.... anyone.... Buler
Reply:Something like this?http://store.cyberweld.com/sthalopiplpg.htmlTorchmate 2x2 CNC with Flashcut CNC controlsHypertherm Powermax45 Esab ET220i Razorweld 195 MigRazorweld 200ac/dc TigTormach 770, Tormach xstechRazorweld, Vipercut/Vipermig, SSC Foot Pedal Dealer
Reply:Tack in subassemblys, then tack them to the main structure autogenously. You probably won't be able to add filler until later. PIA, but that is the rub.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Originally Posted by GambleSomething like this?http://store.cyberweld.com/sthalopiplpg.html
Reply:While the clamps pictured are very useful they're not a lot of use when dealing with sectioned bends and/or segmented/lobster back bends like this random google example...As said one way to deal with this sort of thing is to tack in sub-assemblies... so for something like the above pic you could clamp a couple of sections/gores together with vice grips. Tack and add the next section etc. Keep going until you get to a piece that'll be easier to clamp with a pipe clamp i.e. a straight sectionPersonally i tend to just hold things by hand for the initial autogenous tacks. Fit up needs to be spot on but then if it isn't it'll be a headache regardless as things will move around more. Ally tube is typically a 6xxx series which is very prone to solidification cracking when no wire is used so can 1) take a bit of practice to produce tacks that don't immediately crack and 2) the tacks will be far more delicate than autogenous stainless/TiOther tricks for holding tube close to a bend tangent include a wide jubilee/mikalor clip with some holes punched/drilled in it so you can tack 'through' the clip. Can also use two clips to make a miniture version of this sort of clamp...Sticky tape is also very useful. High temp low tack stuff is better with regards to minimising the odds of leaving a sticky mess in the joint- powdercoaters tape for example. Personally i use tape with a backer (or make a backer with another piece of tape) and leave the backer in place across the joint. It's cheaper than the 'right stuff' and can be found anywhereAll of the same techniques can be used with Ti but Ti is extremely sensitive to contamination i.e. if you're tacking the stuff without a purge you really need to be thinking very small, partial pen autogenous tacks to avoid getting the back of the joint hot enough to oxidise
Reply:That clamp is good for straight pipe/tube runs but how is that used if you have pie shaped pieces that you are tacking together?  What if you used a 3/8th or 1/2 inch piece of spring maybe 5 or so inches long. On one end, slide a piece of bar stock through the end so it is at right angles to the spring (through the loop) the bar stock is larger than the pipe/tube.  now this spring is passed thru the pieces to be tacked together and a piece of maybe18 guage flat stock (larger than the pipe/tube) is passed through the spring on the other end (sort of cutting through) after some tension is applied to the spring. Now the spring is holding these two pieced together and the tack is made, release the spring and add another pie cut piece the the assembly.  Pass the spring through this again and continue till you have the pieces completed.  By laying this on a table as the tacks are made, the assemby is fat and true.  Hope I explained this clearly.  Best Bob
Reply:When I did my intercooler piping I used blue painters tape, tacked the opposite sides of the painters tape, removed the tape and tacked again before the weld. Flush fitment was crucial on those.Hobart EZ-Tig newbie.
Reply:Guys I have used these clamps for  tacking piping.Not cheap, but pretty much the best thing for smaller pipe and tubeMiller Diversion 180Hobart Handler 140 (Soon to be replaced with Miller 211?)Miller Spectrum 625 Extreme
Reply:[ame]http://www.amazon.com/dp/B006RAFSM2/ref=sr_1_sc_1?s=industrial&ie=UTF8&qid=1341071104&  sr=1-1-spell&keywords=powdercoating+tape[/ame]i use this to hold it
Reply:i use this to hold it
Reply:Originally Posted by Hollywood_XJust bought 3 of those to give them a shot  thanksNot quite sure what you mean, can you walk me through the procedure?
Reply:Originally Posted by shovelonTack in sections(subassemblies). Try to do this so that you can hold 3 or 4 pieces to another 3 or 4 pieces, and so on. I do this so I can get more people(stations) involved in the assy process.You can add a small amount of weld rod to the edge of one cut to make a bump, then melt that bump into the next piece when you are holding them together autogenuously. That way when the seem wants to melt away, you have already melted that bump into it.Use pencil marks to line up the orientation of the bends. When you approach it with the weld, the etching of the arc will clean off the graphite.Do I make sense????
Reply:I've used various dia screw hose clamps.  i weld a tab on some and use a standard one to hold both together similar to some of the holding devices shown.  You can get pretty tight bend this way.I do lot of stainless ex and use anything i can find that will do the job.  I even use some of the HF little 1"sq t'bolt weld clamps.  they leave about an .040 gap but if you carefully fit parts and back purge it works very well.  You will use a horrible amount of gas back purging but charge extra for the deg of difficulty.I also use special clamps made for the job when fab and welding tanks.  I have a complete fixture for assembling combination fuel and oil tanks.  Works great and allows duplication and relatively quick replacement of damaged tanks without making new patterns.
Reply:How about using a automotive cylinder hoan with the stones removedit might hold the walls in good allignment for the initial tacksIts spring loaded outward  Tim