Titanium welding !

[Jimbob]

Hello everyone , first time posting today after having been quietly reading in the shadows for a while now !

Firstly I'd like to introduce myself : I'm Jim , hobby framebuilder living in the U.K enjoying the learning process whilst making bikes, this place has helped me so much and I'm very appreciative of the wealth of knowledge which is passed on so freely by all those who participate and particularly the professional builders generosity.

I've always had a thing for Titanium bikes so my very long term goal is to slowly work my way up to building one, but I appreciate there is a lot to know and learn with regards to Tig welding compared to steel so I'm trying to commit to a few hours a week on refining my tig welding on this material. So far I have built 4 steel bikes , 1 really crap hardtail as a first attempt ..., 1 gravel bike , 1 road bike and recently a 29r hardtail .....

When I started down this path I wanted to try and start the right way, and although self taught I have tried to get it right by reading up as much as possible on sites such as this ! so my Tig setup on steel has alway been as follows :

- super clean tubing and sundries , clean , clean , clean !
- argon back purge inside frame
- gas lens on tig torch, Furick cup
- brass heatsink in head tube etc with gas injection
- Pulsed and non-pulsed (still can't decide which is better for my skill level)
- 1st pass for tacking and fusion pass ,non pulsed, 70amps max , foot pedal , occasionally adding small amount of filler if my mitres are not perfect
- 2nd pass once material is cooled down, pulsed , 120 amps max , 1.8 pulse per second (hz) , 5% background , 28 -30% on time / duty cycle, filler rod 1.0mm thick

I've tried to transfer this methodology over to the Titanium but have also used Reagent grade acetone (Mike Zanconato mentioned this) to help with prep and cleaning.
I have attached some images of sample tubes that I've had a go at and would really appreciate some constructive criticism of the welding and straw colouring etc .. I've got along way to go but any advice / opinion would be much appreciated !!

My setup on these pieces was as follows:

- cleaned with red abrasive pad , degreased , rinsed , wiped with alcohol and then Reagent grade acetone just before welding
- Furick BBW cup , 1.6mm Lanthenated tungsten sharpened to roughly 20 degree angle, gas lens , gas flow 14 L / min (30 cfh)
- Back purged with brass heatsink inserted
- 1st pass , 80 amp max , small tacks all the way round just using fusion of thicker material into thin tube ?
- 2nd pass (once cooled down) 120 amps max , 1.0mm filler rod , 1.7 -1.8 pps , 10% background , 30% on time / duty cycle
- argon postflow 8 seconds ?

Think thats it , anyway I've gone on a bit so apologies ! thanks guys

Jim
James Egercz

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[Amaro Bikes]

Hello Jim

Hard to recommend any specific set-up as each one has different preferences and none is better than other, just depends on how your own welding technique and even each machine is different, so I Would avoid to talk about amps, pulse, etc.

Looking at your pictures, I would recommend to work on the surface sanding and prep before welding, so to get rid of the oxyde layer which you would need to "remove" before welding, you can do it with some sandpaper work, then some brown scotch britte spounge (the one for stainless and the like) and even some stainless wire brush. Once you've done that, you can then make the final clean up with acetone before welding. Even if you go with ultrasonic cleaning, you will still need to debur the oxyde layer which is natural to titanium.

Hope it helps

[Jimbob]

Hi Aimar

thanks for your advice on the cleaning , looks like I need to try harder to get it clean ! I'll go back to the tube prep and have another go !

thanks

Jim
James Egercz

[hampco]

Looking good, Jimbob! Maybe take a look at how Brad Bingham does his first pass - on Instagram - and that method could be something to consider.

And in another 9750 hours or so you'll have this thing dialed.

[Jimbob]

Thanks Steve , I'll check it out ! Good one on the 10000 hrs , made me chuckle !!!!

Jim
James Egercz

[VertigoCycles]

Jim,

There are so many variables and you have to really take the time to chase them all down to get a totally colorless weld. Sometimes, a little hay color can't be avoided, no matter what you try.

I think you're on the right path and the work you're showing is technically acceptable, if not ideal. I'm just going to share what I do knowing full well that others do things differently and get great results as well.

1. Proper deburring - Before even considering removing the oxide layer, it's important to deburr the ID and OD of the tube. I personally stay away from abrasives for that job and prefer a round tipped machinist scraper for the ID and a big, fine file for removing the "ears" and burrs from the OD. I don't like leaving any sharp edges that want to hang on to abrasive particles in the next step.

2. Abrasive cleaning - you're already doing this pretty well. I use a dynafile on the outside because I have one but some 220 grit shop roll gets the job done too. One step that helps me feel better is to wrap a dry clean cloth around the tube, grab it hard and scour the circumference. The idea being to ensure that you get as many abrasive particles off that may have gotten embedded in the surface. For the ID of the tubes, I use stainless brushes chucked in a drill.

3. Cleaning - then I use a spray bottle with a water/dish soap solution to spray the inside and outside of the tube and clean them with brushes, wipe them with a lint free towel and put them under a lamp to dry. Setting the tubes on egg pallets keeps the ends from touching anything and is a cheap and convenient way to lay them out. Once dry, I put the tube ends into an ultrasonic tank. You'd be surprised how much stuff comes off in the tank even when you think your tubes are pristine.

4. Right before welding, I wipe them with lint free wipes in 99% alcohol. A friend of mine works in a high tech lab and he'll give me weird stuff from time to time. He gave me what will probably be a lifetime supply of these wipes. I'm sure you don't need them, but they're absolutely lint free. You just don't want to use acetone on them because they'll melt and then you'll apply some nasty plastic to your clean tube ends. I like them because they're stark white and it'll show you how much yuck is still left on your parts. I should note that it never lifts anything from my tubes but...

5. wipe down your welding rod. I've used a bunch of different sources for welding rod and there's only one place that I've used that had absolutely pristine rod. Unfortunately, I can't recall the name of the supplier right now [EDIT - It's Astrolite]. You want to be using ELI rod. Even the flagged, tagged and bagged in an argon purge is dirty. It all comes from a spool that they straighten out and chop to length. I keep a bit of grey scotchbrite at my welding station to scour it sometimes too if things look like they're getting weird. I don't always scotchbrite it, but I always wipe it down and those wipes I linked above show everything that's coming off of it.

6. Sometimes your welding gear needs a good cleaning. Have you noticed that when you accidentally dip your tungsten, that it gets an oxide layer over most of the exposed length? You need to get rid of that layer when you sharpen it next. Chuck it in a drill and pinch it with some scotchbrite before you sharpen it. Drop your cup, collet and lens in a cup full of acetone every so often just to make sure they're clean. They get a little junky and need love too.

The rest of your settings look fine to me and everyone has different preferences there anyhow. Another variable is that Furick cup. I've tried a few of that style over the years and at best (for me) I've never been able to get them to work any better than a standard #12 with a decent gas lens. UBI sells some very pricey cups called Tika cups and while I'd like to say that they're perfect out of the box...they need a little work to make the collet system easier to use and more reliable. That said, the cup and packing make for very nice coverage. At one point, Brad Bingham was making and selling cups as well. My buddy Jim was using one, I got to play with it and it's fantastic. Rody from Groovy posted a video a number of years ago that showed how he modified cups as well to give better coverage. The point being that I have a ceramic cup shaped exactly like the FUPA 12 from Furick and it really wasn't great at all. The more stickout needed, the worse it performed. I can get about 2.5" on my tika cup with 25CFH if I use a backstop and get little to no color in my welds other than a faint, white halo that I can't seem to get rid of.