Dan,
Thanks much for the good data. I was just looking at the pics I have of the stainless steel MIG welds done on the hyperbaric chamber done by my great uncle. I can see that I will want to get a TIG machine for this sort of work the welds are not that smooth. Of course in the hands of a very skilled welder, a MIG machine can do wonderful things. I've always admired the welds done on my 4130 chromoly bicycle, and wished to be able to reproduce those results in my weldment's.
The through hull stainless couplers on this chamber are painted and of a small diameter. The larger through hulls, like the view ports are all carbon steel.
http://www.frappr.com/?a=viewphoto&id=2628470&pid=4663625
http://www.frappr.com/?a=viewphoto&id=2628470&pid=4663626
http://www.frappr.com/?a=viewphoto&id=2384531&pid=3842954
http://www.frappr.com/?a=viewphoto&id=2628470&pid=4663726
I've used stick welders with the 15 to 20 amp click adjustments and I understand your dislike for them. As a beginner I thought I was having trouble just because of being a beginner and now I'm thinking it was partly the machine to. I have another relative that manufactures new custom backhoe buckets using a 400 amp. Miller MIG with a 100% duty cycle for thick steel weldment's. He has a larger power supply service than I can get here, so I figured I would have him weld my pressure boundary seams. Do you see an advantage of using a 250 or 300 amp SMAW welder over using his 400 amp. MIG? I'm pretty sure he has a big SMAW welder as well and he grew up stick welding, but he likes the MIG allot better.
Regards,
Brent
From: "Daniel Lance" <lanceind@earthlink.net>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: RE: [PSUBS-MAILIST] Re: Welding machines for submersibles
Date: Fri, 16 Mar 2007 22:54:21 -0400
Brent,The typical stainless steel penetrations on a K-250 or K-350 are of relatively small diameter (1" to 2" ) . I believe the "average" welder in a home shop not using a welding positioner would have a difficult time twisting a mig gun around that small of a penetration and still produce a quality weld. In my opinion tig welding in this situation is even more efficient than stick welding. No cold starts , no splatter all museum quality weld. Stick or Mig does have its place on the larger diameter stuff like a hatch ring or group electrical penetrator ring.DL----- Original Message -----From: Brent HartwigSent: 3/16/2007 6:35:28 PMSubject: RE: [PSUBS-MAILIST] Re: Welding machines for submersibles************************************************************************ ************************************************************************ ************************************************************************ The personal submersibles mailing list complies with the US Federal CAN-SPAM Act of 2003. Your email address appears in our database because either you, or someone you know, requested you receive messages from our organization. If you want to be removed from this mailing list simply click on the link below or send a blank email message to: removeme-personal_submersibles@psubs.org Removal of your email address from this mailing list occurs by an automated process and should be complete within five minutes of our server receiving your request. PSUBS.ORG PO Box 53 Weare, NH 03281 603-529-1100 ************************************************************************ *********************************************************! *************** ************************************************************************Dan,
I've seen pretty good results with using MIG to weld the stainless steel through hulls to carbon steel using stainless wire on a hyperbaric chamber. What are the advantages of using a TIG machine for this? Is it that TIG has less chances of inclusions and a smoother finish?
Regards,
Brent
From: "Daniel Lance" <lanceind@earthlink.net>
Reply-To: personal_submersibles@psubs.org
To: personal_submersibles@psubs.org
Subject: [PSUBS-MAILIST] Re: Welding machines for submersiles
Date: Fri, 16 Mar 2007 06:26:01 -0400
Ray,I would recommend the smaw welding process for all your pressure boundry welds , tig for the stainless steel penetrations and the mig welding process for everything else.A good used stick welding (smaw) machine with an amperage rating of 250 to 300 amps will cost somewhere in the neighborhood of one to two thousand dollars. It has to have a duty cycle of at least 60 percent. As a bonus you can also do your tig welding with the same machine, utilizing a scratch strart technique. To save money you can do without the mig machine and do everything with stick . Stick welding (coated electrodes) is the most versitile process for doing equipment repair too. Miller, Lincoln , Airco, Hobart and Esab are some of the more common brand names . Be sure to get one with an infinate type amperage adjustment versus one that only adjusts in 15 or 20amp "clicks" . I would not take a click type even if someone wanted to give it to me. Is not enough fine adjustment for the critical work that you will need to do.Dan LanceDaniel LanceEarthLink Revolves Around You.