beginning tig

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Ok I see these photo 0n here and they all look good compared to where I am at. I started out here burning holes, then I got so I could get a puddle, along the neck I used a ss rod. The rod along the neck looks more like brazing more than welding. Does that make a difference in strength? any comments would be appreciated I think I am on about 120 amps max with a foot pedal, and the gas is about 15 to 20 psi, it is a top of a beer keg.
Reply:ok the pics didn't upload let me figure that out.
Reply:Hmmmmm, All of the beer kegs I have ever seen I think were aluminum, but that does not mean there aren't stainless ones as well. Posting the pics would help, but what exactly do you mean by "THE ROD ALONG THE NECK LOOKS MORE LIKE BRAZING THAN WELDING" ?  Do you mean the color of the material or are you refering to something else?   If the keg is stainless, and you've burned holes in it, you may have to purge the inside of the keg with argon to get a good weld.  However, I think if you could get the pics posted, someone on here could give you some good advice as to how to handle your problem.
Reply:Pull the pictures into a photo editor and reduce the size.  I had the same trouble with pics just the other day.  As for the keg, I have never seen a stainless keg, and I really like beer.  Stainless would be pretty heavy without beer.  I bet you have aluminum there, but only you can know for sure.  Arent you required to pay a deposit on a keg? To tig alum. requires 100% argon and really good surface prep and an aluminum filler and ac/hi-freq.BTW, are you starting big and trying to work your way down to beer cans or something? Smithboy...if it ain't broke, you ain't tryin'.
Reply:the beer keg is stainless, you can get damaged ones online. Really tough to cut the top out, I finally found out about plasma cutters and they work great. They are very thin, and not that heavy, maybe 15 pounds. I will have to get a thickness for you so I can get some help. I want to weld a nipple so it would be thick to thin. I have the wire coming. I also got a bunch of scrap SS to practice on. I would be happy to be able to do the keg, beer cans will probably always be light years away!
Reply:I have found that if you tig a six pack together, it saves trips to the fridge............................................  .Just waiting for someone to call me on that one.Well, I never saw a stainless keg, but it could have been because of the fact I was drinking around them.On thin stainless, yours is probably pretty thin, you might not even have to use a filler.  I dont do stainless tig, but I have a buddy that works on restaurant equipment and he fixes and tacks lots of stuff without filler.  He says he just heats it up and uses the pressure from the gas and the natural flow of the metal to do the job.  I'll call him and see what he suggests.Smithboy...if it ain't broke, you ain't tryin'.
Reply:thanks I would be very interested in the gas flow rate for that. I have the filler rods coming also. I will try to get a thickness on the keg too. Thanks for the help.
Reply:ok looks like the stainles is 16 guage there abouts if I am figuring the sheet metal chart right, I get about .0065 of an inch.
Reply:I have a buddy who made a crab cooker out of a stainless steel keg. It looks pretty to say the least. He can cook a bunch of crabs in it too.
Reply:Are you purging it?  Shielding gas on the inside opposite the side your welding.StephenLast edited by wirehunt; 08-14-2005 at 05:35 AM.
Reply:Here is one the boy's are into at  the moment, easy as to make to :-)Edit to fix link
Reply:Ok caosesvida,My friend gave me a bunch of info that culminated in him saying that it will be kinda hard to do a really good job without big-time warpage.  He found a website that you might want to take a look at.http://www.brewingtechniques.com/lib....6/palmer.htmlHe said, not knowing the nature of the project and the equipment you are using made exact recomendations inappropriate, but this may cover most of the initial problems that you are having.  He mostly said that brazing it most likely the best alternative for you to keep everything stainless if you intend on heating it.  He also said that you may have to use pure argon on front and back (back purge) to get a weld that is reasonably good.Smithboy...if it ain't broke, you ain't tryin'.
Reply:thanks, no I was not shielding it from the back also. I took one to the local welder and he did a fantastic job on it really good looking. That is what got me interested in it. I have read the john palmer article, thanks.   By the way what is the method used to shield in the back also??  a tee off the argon?
Reply:Yes, basicly.In the field, I dont know what he uses to back purge.  In his shop, he has a few devices (like metal cups, boxes or a bowls with a gas nipple) that he slides along the back of the seam to keep the use of gas down.  Different shapes for different jobs, I guess.  At least I think that's what he uses them for.  I have never actually seen him at work, but I have seen some of the results.  My guess is that you could try to purge the whole inside of the container with argon if you can make it reasonably air-tight, i.e., put something non-flammable in the openings that will slow the escape of gas, or you could just blow gas on the back surface while you are doing the seam (either one off a tee).  I dont know which would be less costly in terms of gas, though.  He said that you should consider welding in intervals to keep from overheating and damaging the characteristics of the metal and to check the back side for problems.Smithboy...if it ain't broke, you ain't tryin'.
Reply:thanks.
Reply:In the Navy doing Nuclear welds the back side of the welds were purged with Nitrogen which works great and is far less expensive than Argon. Just throwing that out there. The important thing on the back side is to get rid of the O2. The weld will then look as good as the front.
Reply:The paper masking tape works well for sealing, the purge rate should be around 7 litres per minute.  If your really stuck get someone to hold a purge hose on the back of the weld and just follow you along the weld.Personnally I would put the keg together and purge the whole thing but remember to have a very small hole somewhere so the preassure doesn't build up when you close out.Stephen
Reply:thanks guys, the nitrogen is a great help have some access to it, also the top of the keg is open so no pressure build up to worry about, I guess you could fill it with N2 and purge while you do it. Do you purge the back side all the time with stainless? I thought the guy whole welding the last keg I had did an excellent job , and to my untrained eye I thougth he did both sides. I was really impressed how he got into the keg and was able to do that, now maybe I am thinking that he was able to do it from just one side. If I can get my phot thing working I will post pics of his weld.