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Old 08-10-2018, 11:41 AM
crystallographic crystallographic is offline
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Join Date: Dec 2010
Location: Western Sierra Nevadas, Badger Hill, CA
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Default TIG-tacking aluminum - no peek and no filler

This is for those situations where because you are holding one large panel up against another you have only one hand to tack with.


For instance, when adding a formed dash panel onto a cowl section and the weld seam will be 36 to 44 inches long (90cm to 110cm). If you can perform this little skill it will save time you will expend on a clamping fixture.
(I showed this on video/dvd back in 1995 - http://www.tinmantech.com/products/d...g-aluminum.php)

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Porsche spyder #030, F2 car, new dash going in - but had to fight to keep alignment while making tack welds.


Later on I learned the Better Method from the L.A. car builders - (guys like Phil Remington, Nye Frank, Tom Hanna and others had been doing this since the 1960's) : TIG-tacking - no peek and no filler...


Set your TIG machine to AC, 60-70Amps, hi-freq start, gas flow 8.
Sharpen a clean 1/8" tung to a 45 deg angle (2% Thor - or Lanth, or Zirc or Pure - any will do just fine )
Withdraw the tung back up in the cup about .050" - 1.2 mm.
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Hold the TIG torch smack dab square on the panel joint. This downward pressure is very helpful when forcing two shaped panels into alignment - with the edges touching - the panel edges must touch when tacking as the molten metal will not leap across open space because you want it to ...

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Hit the pedal/trigger and wait 3 heart beats.
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You have a no-peek fusion/autogenous/no-filler TIG tack.
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And as many as you want.
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CAVEAT: Solvent clean FIRST with 99% isopropyl ....

(WARNING: using chlorinated hydrocarbons such as brake cleaner in the presence of high frequency welding currents will create Phosgene Gas - Mustard Gas and if you breathe this it will give you a hospital visit/stay.

This is a nifty time-saving and elegant tack-welding method.
Success and joy!
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Kent

http://www.tinmantech.com

"All it takes is a little practical experience to blow the he!! out of a perfectly good theory." --- Lloyd Rosenquist, charter member AWS, 1919.

Last edited by crystallographic; 08-10-2018 at 12:49 PM.
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