A source for a small spot welder to join thin Titanium?

[22Mike]

I'm looking for a small spot welder that can join Titanium (6AL-4V) that is .012 thick. The welder will need to reach about 2 inches down into a 1 inch diameter tube. I need to make about 750 welds a month. The weld (spot) need only be about .1 inches or so in diameter.

I'm a novice and can't seem to find a machine that will do the trick.

Some questions:

1. Will I really need to use Argon as some folks have advised me?
2. Where can I get a spot welder that will do the work on common household current and not put me in the poor house? The ones I've seen on the Web are just to large, complicated, and expensive.
3. Do you have an opinion on the PUK-III or PUK-2 spot welder as it may apply to thin Titanium? http://www.gesswein.com/catalog/catalog.cfm?cat=10&sub=7&subsub=9&catalog=1

Thank you in advance.

22Mike

[kneilson]

22mike, I think what your asking may be somewhat difficult to achieve. I would suggest learning about TI as a metal and its joining(welding) properties and problems. Considering that your working with relatively expensive materials, I think that you will come to realize a certain amount of money will have to be spent on propietary equipment to acheive good results. Care to let out what your trying to make? There may be alternate methods of constructuon..................Kerry

[22Mike]

Kerry:

What do you think of the PUK welder?

I have been studying Ti quite a bit lately. It seems that the link I posted to the PUK welder may do the trick and I'm exploring that option. Folks seem to think that Ti is not so much of a headache to join due to recent advances in welding technology. At least one manufacturer of Ti is insisting that it is not an "exotic" metal as once thought, and I am tending to agree.

I'm making frustums (cones) for use around fairly high (1000 F) temperatures. Ti was chosen because it can handle the heat and its very high tensile strength.

My intention is to join sheet Ti into a frustum and then spot weld it together so it keeps it's shape. However if anyone has an alternate idea for a strong join, I'm all ears.

Thanks for your reply.

[hosking32]

Hey Mike,
For what it's worth I was on vacation a little while back and my Fiance' and I got a chance to tour a mountain bike manufacturer. They construct all their bikes from Ti. Beings that I am interested in any type of fabrication, I asked all the right Q's and showed such enthusiasm, they allowed me to TIG weld some scrap. First of all it was awesome. Second it really was not as hard as I was expecting. They use strait Argon gas and a 2% thorated tungsten. The funny thing was the tungsten stuck out of the gas lens about 2" to 2 1/2" and the gas lens was close to 1 1/2" in diameter. The gas lens is then stuffed w/ steel mesh, like steel wool, and then finished off with a stainless screen. This is to insure perfect distribution of the gas through the lens. They said they have to special order the lenses and that they can't get them from their local welding supplier. They took extreme cautions with cleanliness. All the frames are handled with special gloves until the welding process is finished. They purged the tubes w/ argon for approx. 15 min. before starting their 2 pass weld. The complete bike is fusion welded first. Then they went over all the welds with a final pass w/ filler rod. I asked why and they replied that this was the strongest way to join the frames. They have less than 1% weld failures on their bikes. They are so concerned with contamination in the welds that they lift their hoods and exhail be hind them so they don't disturbe the purg of the gas flow. I asked if this was that necessary and he showed me how easy it was to contaminate the weld. It was easy. If their is any rainbow color in the weld, like you see with stainless, that is contamination in Ti. I realize this is structural and they have to go to the extreme for safety but I found this very interesting none the less. Hope this helps. Any Q's feel free to respond. I would like to keep the name of the manufacture under wraps if you don't mind. I don't need to be getting any one in trouble. Thanks,