Doing a Hatz asks: "I'm considering a Hatz as my next project, so I'm interested in melting pieces of metal together....In the Sport Aviation I received  today, there was a lengthy article pushing TIG welding.   What are the advantages/disadvantages??

Tin Man answers:

TIG has become more popular in the last 20 years for two reasons:

1) They make more money for the supply houses

2) More welding is done on thick (>.090") than on thin (<.090") material.

Since the skill and craftsmanship for thin sheet has greatly diminished because of increased demand for fiberglass and plastic since the 1960's, few salesmen understand what is really needed for thin tubing, sheet steel, aluminum, etc.

However, because of superior penetration and workability of the weld joint, the oxy-acet torch has remained the first choice among those remaining professional craftsmen who build the stuff for a living. They will use the tig for a few fast tacks, or to make a fixture, or to make some stout brackets in a situation where excess heat would be detrimental, but it's back to the torch for panel construction.

On 4130 chromemoly, the TIG may be used, but it's highly recommended to postheat to 1200 deg F with the old torch for stress relief. One may then reason that since the torch needs no postheat, it would be quicker in the long view, and for that reason many do not use the TIG on 4130 . AND, BTW we have just finished filming 5 hours of Aircraft 4130 Chromemoly .

Incidentally, one Hatz builder in NY built his first fusellage as a "learner", and then built the second as the real flyer! I commend this attitude.

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