Titanium Welding

[eyecandy]

I was wondering if anyone on here has welded Titanium. I was searching the web and reading thru some books I have, it seems to get mixed reviews. Some say it can be done in an open atmosphere with proper shielding, back purge and trailing cup, others say it can only be done in a vacuum chamber or similar where the oxygen can be displaced.

Where can I find a trailing cup? or is that something that has to be made myself? Whats your thoughts on using a sandblaster cabinet for a closed chamber?

If you have welded titanium I would appreciate some feedback along with information regarding materials used and machine/machine settings, if it was done in open or closed atmosphere. And how is the weld pool/flow compared to steel and stainless steel?

Hmmm that does it for now, thanks!

[nfinch86]

I was wondering if anyone on here has welded Titanium. I was searching the web and reading thru some books I have, it seems to get mixed reviews. Some say it can be done in an open atmosphere with proper shielding, back purge and trailing cup, others say it can only be done in a vacuum chamber or similar where the oxygen can be displaced.

Where can I find a trailing cup? or is that something that has to be made myself? Whats your thoughts on using a sandblaster cabinet for a closed chamber?

If you have welded titanium I would appreciate some feedback along with information regarding materials used and machine/machine settings, if it was done in open or closed atmosphere. And how is the weld pool/flow compared to steel and stainless steel?

Hmmm that does it for now, thanks!

eyecandy; HI , sorry man thats way above my pay grade!!!!.... Norm :

[Showdog75]

You can weld Ti in a open enviroment . You must have good purge with a large gas lense and preferably a trailing rig . You can buy trailing rigs but for the money I'd make my own , they aren't very complicated . As far as settings you should give a idea as far as what you are welding . There is a local bicycle manufacturer that builds Ti bike frames and they use pretty low amps but it is very thin wall tubing .

[Burnt hands]

Hi eyecandy,

Here are 2 links.

First one id here at Miller's site and is a great source of information.
Titanium 101: Best GTA Welding Practices
http://www.millerwelds.com/education...rticle120.html

This one is a post I made May 22, 08 showing a 6-4 sculpture I made. Weighs 80 lbs.
http://www.millerwelds.com/resources...ad.php?t=13065

I have done a bit of tig welding of titanium but am not in any way an expert as the cost of the material and wire makes mistakes very expensive.

I have found these steps help me when tigging titanium:

1 - Use the lowest amperage setting you can for the material thickness. ti has lower thermal conductivity than stainless steel so it gets hot quickly.
Too much heat will burn the welds.

2 - Clean , clean and clean the metal. Grind, sand and use acetone on the pieces and wire. Clip the wire end before starting a new weld.

3 - I use a long post-flow to try to keep the weld covered until it has cooled below 800 deg F.

4 - Some say to use 2% lanthanated tungsten but I use 2% thoriated as this is what I have.

5 - Use a stainless brush to brush the metal and dedicate this brush to titanium much as you would for aluminum.

6 - A good weld will be shiny and have a silvery color. A purple, bluish, or golden color is signs of poor shilelding gas flow or short post-flow. I use 100% argon.

good luck,

[c wagner]

I haven't had the opportunity to weld any titanium but from what I've read it looks like you have received some solid advice from some of the other guys with titanium experience.

[Dave reynolds]

I've welded titanium for several years for the aircraft industry, what burnthands and showdog say is correct. Cleanliness is very important. As is gas sheilding, titanium will react very badly to air. It will become embrittled and porous to the point that it is unusable.
i've done vac chamber and "open air" welding with good results, just keep the argon there and stay out of drafty places.
One other thing, it's kinda strange stuff in that it gets sticky when hot. The wire will fuse the the parent material near the weld zone so aim carefully or prepare to be frustrated.
Just my .02 worth.

[Burnt hands]

Hi Dave reynolds,

Thanks for the great tidbit of information in your post.
I too have noticed that my wire would tend to "stick" to the weld pool on occasion when tigging titanium and I figured it was something I was doing wrong. I have not had the same problem with stainless so I thought it was me. Thanks for the help.

And to everyone, if you look at my welds, they may be pretty with the "rainbow" effect but strictly speaking they would fail the AWS standards.

I make titanium sculptures but would never attempt to do any aircraft quality welds as this is way beyond my expertise.

I do not have a weld chamber so I made a poor substitute out of plexiglas. Looks like a glass bead box or the baby incubators for premature babies.

I have learned the hard way that argon is a lot cheaper that titanium.

The more I learn, the more I strive to make my welds better and I'm sure this is why everyone is here also.

thanks,

[Dave reynolds]

quite right, argon is cheaper than titanium. Keepit clean and keep it covered with argon,the 2 cardinal rules.

[eyecandy]

Thanks for the replies!

I have been doing a bit of searching the last few days, I have found some decent information. I guess I could get more indepth of what I am planning on welding. I am looking to build a 3 or 4" exhaust, am possibly some other little mounts and braces. Right now I am having a hardtime finding the appropriate tubing, mandrel bends, mufflers etc for the exhaust, all the tubing is either smaller 2"or less or the wall thickness is around .028". I know typical steel/ss exhaust is .065" I am sure I can get away with a thinner way since Ti handles heat better, higher tensile strength, and better corrosion resistance. I think I have seen some Ti exhausts out there with .045" built by various tuning companies, but naturally I am not having luck finding those links again...

Mainly its beeing built for lightweight so a thinner wall, if it can be used, would help weight reduction. Any thoughts on this?

As far as the welding aspect, with it being tubing I will have internal purge, and buy or build a trailing rig, any ideas? I figure I sould be pretty good interms of the gas coverage, if there is an issue I figure it should be alright since its an exhaust and not subject to any kind of physical stress, rather some thermal and holding its own weight.

I know I have more to discuss, but I don;t want to bombard you guys with too much.

[captain bondo]

Your chances of finding titanium manrdrel bends in 3" or 4" are slim to none.

Especially in diameters that large, titanium is EXTREMELY hard to bend. That is why you see a lot of it with bends that are made from multiple pie cuts of straight tubing.

You can certainly use 18ga. You could likely use 20ga except for the downpipe which would still be worth using 18ga.

Since you generally need to do pie cuts for bends, making a Ti exhaust is a very expensive and time consuming operation.

I would make a 16ga stianless downpipe and then use 16 gauge aluminum if I really wanted a light exhaust. It's be lighter and cheaper and easier to make.

Durability is fine if you are careful about hanger placement and etc. Use stainless steel hanger that clamp around the aluminum. Aluminum hangers welded to the tube will break. Otherwise you're good.

I would guess aluminum would be roughly 1/10th the cost, 30% lighter, and 1/4 the work.