OK, this may be a bit embarrassing, but here goes. Yes, my cheapo welder is still working like a charm and I've been putting considerable mileage on it for I think about two years now.
When I was looking for a welder I started out looking at Lincolns and Millers on eBay because they were so expensive new. In those searches I noticed some cheap Chinese machines that kept popping up under all sorts of different brands, but which were evidently the same machine from the photos. I surmised they were all made in the same factory, and each importer was putting a different brand on them. There were about half a dozen of these sellers, each of which had sold hundreds. There were virtually none of them offered second hand. In my experience, if you buy something on eBay that turns out to be bad, you return it to the seller if you can, or failing that you resell it on eBay (I've done that, with full disclosure). So the high volume of new sales and lack of used sales told me folks might be happy with these machines, and I decided to take the plunge. As to which seller to buy it from, since the machines were all identical the only thing that mattered was price. The guy who was getting the lowest prices was of course the one who had come up with the worst possible of all the bad brand names these things were selling under. You'll think I'm pulling your leg, but the brand on this one is "SMILEY TOOLS". Really. I dare not show up at one of Dan's work sites with a Chinese-made welder called a Smiley Tool -- I think the guys would chase me all the way to the Canadian or Mexican border.
To be more specific, this is the "Super 160P" model. The various brands had the same model number. It's a combination tig, smaw, and plasma cutter. It also has square wave mode for welding aluminum, which works well. The price as I recall was about $850 including foot pedal, pressure regulator, etc. The only thing not included was the argon tank.
I've had trouble with two things:
1. Understanding the manual. It's utterly useless, expect to figure the thing out by trial and error.
2. I tried the plasma cutter once and promptly melted the nozzle. I was probably doing something wrong -- blame the manual!
:)
Alec
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Hey Alec. Which welder did you find? If you like it and Dan likes it then I like it. I'll start looking.
Vance
-----Original Message-----
From: Daniel Lance <lanceind@earthlink.net>
To: personal_submersibles@psubs.org
Sent: Thu, 16 Apr 2009 8:01 pm
Subject: [PSUBS-MAILIST] Re: Pressure vessel welding
Glen,
A 200 amp MiG welder is not adequate for the purpose of welding together the pressure hull of your submarine. The GMAW process commonly known as "MIG" produces very brittle welds when applied to metal thicknesses past the "sheet metal " range ( 10 gauge being the maximum ). A MIG weld might have an excellent appearance but if you cut out some sample "coupons" and subjected them to a "side bend test" you would have an unacceptable failure rate.
Yes, you could TIG (GTAW) weld your whole sub. Tig done properly produces some of the highest quality welds possible, but , it is really slow. For the average person who wants to build his own sub ( and is on a budget ) TIG welding the "roots" and "stick" (SMAW) welding the remaining passes is the way to go. Combination SMAW/GTAW machines are a real bargain and very versatile. The "inverter" types have excellent arc characteristics , are energy efficient and can be plugged into your clothes dryer electrical outlet. Alec has a terrific unit he bought off the internet and to my knowledge is still going strong. He might be willing to share some info on it. I have welded with it and I like it alot !
Use 7018 Low Hydrogen welding rods and 70,000psi tensile strength TIG wire . 3/32" and 1/8" diameter are the recommended sizes. While welding, multiple small passes are much more desireable than one large single pass. Large single passes over heat the metal and sets up stresses , conversely each successive smaller pass tends to anneal the one prior to it. ( Less heat , less stress ) .
If you have not done much welding then by all means take a welding course and practice on some scrap first.
When you do start welding on your hull ; bevel, fit , and do the majority of the welding from the inside of the sub so when it comes time to back grind the roots you can be on the outside. Weld the joint completely ( root, hot pass, filler passes and cap passes )before you do any back grinding.
Daniel Lance