I've just scored a Zo6 exhaust. However the wrecking yard cut the pipe rather than unbolting the flanges.

The price was right (free). There's not enough pipe to roll a bead for a flange, so they will have to be welded. Can these be saved??

Craig

 

yes..... any competent welding shop can do this...with the right wire .. but you have to be careful anybody can weld... but to use a multi value wire is important for an indistructable weld.

 

There are appearantly no compedent welding shops in my area. I have called and have been turned down.

Thanks for the information that it can be done. At least I can keep trying.

I might even take a stab at it with my TIG welder. However, I am definatly not a pro welder, and I don't even know if TIG is the way to go.

Any experienced welders feel free to chime in here!

 

Tig is definitly the way to go. Never welded titianium before but a welding supply shop should be ably to set you up with the proper wire and settings.

 

I can shave off some filler material from the pipe easy enough. However, I'm not sure if I can adhere the titanium pipe to the mild steel flange. (?) :confused:

 

Most titanium alloys can be fusion welded and all alloys can be joined by solid state processes. Unfortunately some engineers still believe titanium is difficult to weld, possibly due to its particular requirements for argon or helium gas shielding, or because in the past it has normally been handled only by specialist fabricators. Titanium is actually easier to weld than many metallurgically more complex metals and alloys.

Weldability of the commonly used ASTM Grades

ASTM Grades Weldability Comments
1,2,3,4,7,11,12,13,141
5,16,17,26,27 Excellent Commercially pure titanium and low alloy grades with minor additions of Pd, Ru, Mo etc.
9,18,28 Excellent Ti-3Al-2.5V alloy grades
5,23,24,29 Fair - Good Ti-6Al-4V alloy grades

Welding and joining methods appropriate to titanium include:
Arc Welding Processes, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG), Plasma Arc (PAW).
Power Beam Processes, Laser and Electron Beam (EB)welding.
Resistance Welding, Spot, Seam and the Resista-CladTM cladding process.
Friction Welding, Rotary, Radial, Linear, Orbital, Stir, Stud and other specific jointing techniques.
Diffusion Bonding

 

Hey..let me tell you in simple plain, easy to read text...go out to a welding supply house and buy a few pieces of pure Ti. rod and use the TIG process. Make sure to purge the inside diameter of the exhaust tubes you are welding...both pieces. DO this by just using plain masking tape on all open ends of the tubes being welding... you don't want any atmosphere to enter inside the tubes being welded. From the flow meter of your argon tank there is usually a Y valve with 2 *****. one **** controls the flow to the torch on one side of the Y. On the other side of the Y valve should have a purge hose, if not, then install a plain piece of plastic hose at least 10 ft. long. Now take the tubes to be weled with the ends sealed off and punture 1 hole with a pencil on any end piece that is capped off with tape. now insert a small piece
of metal or plastic tubing into the end of the purge hose coming off the Y of the Argon tank and insert the tube into the hole you just made on the tape end cap. Now tape the small purge tubing in the end...shut sealing the tubing on to the pipe. on the opposite end of the pipe to be welded should be capped off also. now punch 2 or 3 very small holes about 1/16" diam.
turn on the purge **** of the Y valve and you should feel air coming out of that end opposite of the tubing inlet end. Use approximately 5 CFM of purge.
Wait at least 5 minutes before welding.... OH yeah... make sure the exit end is higher than inlet end for the 5 minutes...because Argon is heavier than air and will settle to bottom of the part. after this you can reposition the part to wherever you like and begin to weld. USe the largest torch cup you have... you should go and buy a gas lense for the torch if you have one already.
Titanium is only a bit tricky to weld because of it's "sticky" nature. Meaning the rod tends to stick to the part if your timing is not just right. Use higher than average argon flow for Ti as it readily "burns". any gray or milky color is unacceptable. Ideally the weld should be silver or goldish.

Good luck.

 

....in other words, make sure you choose someone who is experienced with welding titanium!

 

You mention a "mild steel flange," do you have the amputated flanges?

If not, your problem is gonna be fabricating or otherwise obtaining the TITANIUM flanges the idiots in the salvage yard cut off and apparently tossed... I would RUN not walk back there and pray to God they still have them laying around somewhere, because getting new ones made is gonna cost you something, not to mention the hassle of getting them made, then getting them installed at the proper orientation on your amputated stump.

Definitely cannot weld steel to titanium.

 

Just a chuckle for you guys ... It seems that my TIG was out of gas ... it was Sunday so no refills ... I was impatient ... so I welded the steel flanges with my MIG and no Titanium filler.

The welds looked FABULOUS! Great penstration. Nice, pretty puddles. Too good to be true? Did I cheat the reaper??

I bolted the things on the back with the flanges slightly loose. Pushed and pulled a little for alignment and the DAMN THINGS BROKE OFF!! Hah! It seems that the titanium crystallized and became brittle, or maybe the fluxcore MIG wire didn't mix well with the Titanium.

I've got my Bottle being filled and I've got some Tit filler material and flanges.

Thanks for the help guys... this was an unablashed "they told me so." speedj

 

cant you just clamps or something?

 

You know that's really a good idea.

Maybe I could cut a short section of 2 1/2 tubing; split it; weld it to the steel flange and clamp it, essentially "collaring" the titanium pipe stub.

Good show of common sense. Duh!

 

Did you use the Argon purge? You have to have an oxygen-free atmosphere on the back side of the weld or your weld is going to do this. It's like working with 300 series stainless, only worse. If it was stainless, you'd want to make a 'white weld' - no blue discoloration allowed. Same with Ti.

You might think about heatsinking it above and below the joint to draw down the temps too.


[Modified by Matt Black, 12:16 AM 7/30/2003]

 

sleeves can be obtained.
Are there curves or just a straight shot ?

 

Has anyone thought of gluing them with a sleeve?????? Today's glues will handle the temperature and the sleeve the stress.