Original Posted By: BARNSTMR(at)aol.com
A little info for those contemplating welding:While at Brodhead I was party to a discussion regarding the suitability ofthe use of TIG welding for 4130, and concerns about edge hardening, whichleads to cracking. No question that this is a bad thing. There weremisconceptions that 4130 should ONLY be welded using gas. The main problemwith TIG welding 4130 occurs when the improper filler rod is used. If theproper procedures are followed, TIG will produce excellent welds with 4130.(Remember also, that only by following the proper procedures can properwelds be achieved using gas!)Following is a handy link that seems to clarify all the concerns.http://www.lincolnelectric.com/knowledg ... pBasically, these are the criteria:1) fit your joints with minimum of gap2) clean the edges to be welded3) metal should be at 70F or higher4) USE THE PROPER FILLER ROD (ER80S-D2, ER70S-2, ER70S-6, or stainless310 or 312 --- DO NOT USE 4130 filler)5) Slow cool the weld in still air - DO NOT QUENCH.6) No heat treatment (stress relief) required for thicknesses of .120"or less.The techniques apply up to .120" thickness (okay for the piet fittings!).TIG can provide such a nice clean job of welding, without the need forpre-heating (other than room temperature), and it's not that difficult tolearn.Bill________________________________________________________________________________Date: Wed, 28 Jul 2004 11:43:49 -0400