mikeread

Hi

I built up a frame about 10 years ago and it has now passed 60 000 km and still going strong. Built from Reynolds 631 fillet brazed with a lugged bottom bracket:



I am now getting the itch to build another, but I no longer have access to oxy acetylene gear.
I am considering tig welding my next frame but know little about this method.
Can anyone give me an idea what sort of gear I would need to tig cycle tubes and how difficult it is to learn to the required standard?

Thanks

Mike

unterhausen

That's really nice looking. I have thought about buying TIG equipment, but it seems like $2k is the absolute minimum estimate I can come up with. And then a lot of practice. Some people seem to take forever learning how to do it. And then I would be tempted to learn how to do Ti, which is madness for me. You can get an oxygen concentrator and a propane tank for significantly less, probably $500 including torches if you shop around

CliffordK

Nice bike.
Is that before or after the 60K Km?

In a sense, tig welding is similar to oxy acetylene.

Bicycle frames will be thin wall, so you don't need much power. AC is only needed for aluminum.

So, you'll need:
Power supply. 220V is nice, but low power 110V is probably ok. High frequency start/stabilization is also nice.
Torch & Regulator & Tungsten & ground cable.
Tank, 100% Argon (some dealers may exchange a used oxygen tank for an Argon tank).
Welding Hood. I like those auto-darkening hoods from Harbor Freight.

I find it is pretty easy to blow holes through everything.

If you skimp, you might be able to get your gear for under $1000.

You'll still have to deal with your braze-ons. I've tried tigging bronze, with moderate success, but it is probably better to plan on brazing your cable stops, cable guides, and water bottle mounts.

I am good at blowing holes in EVERYTHING

mikeread

Thanks for the advice Cliffford

The pic shows the bike as it was a few months ago, a lot of parts have been replaced over the years.

I am amazed how some stuff lasts. The Ultegra mechs and brakes and campag headset are still original and working fine.

I replaced the £10 shimano bottom bracket recently but it was still smooth and play free! Amazing considering this is my winter bike and is often ridden through rain, mud, ice and snow with salted roads.

unterhausen

Oxygen/acetylene bottles in the UK are expensive to rent, which for me makes them impractical, this is why I haven't built another frame in ten years. I can use disposable argon bottles with tig which avoids the ongoing rental expense. Also I do quite like the idea of moving on to Ti. I would love to build a Ti frame.

Having said that I will look into oxygen concentrator/propane - I have never heard of that before. Thanks

I don't mind investing in tig as it will be useful for other jobs too.

Can tig set ups be used for mig or stick welding as well?

CliffordK

TIG Welding is usually done with CC (Constant Current). Stick welding often uses the same CC, and the two are frequently packaged together.
MIG welding is usually done with CV (Constant Voltage)
You will also need a wire feeder, or a spool gun for the MIG.
Some power supplies will do both CC & CV, but most don't.

For steel, TIG is usually done with 100% Argon, and MIG with an Argon/CO[sub]2[/sub] mix.

Anyway, for the cheaper power supplies, Mig and Tig are different enough that they probably won't share equipment. Sometimes one sees TIG & Plasma Cutters using a single power supply, although probably not highly applicable to bicycles.

In the USA, the big tanks are usually rentals, and the small ones are personally owned (exchanged). Mine frequently have the hydrotesting date expire between refills, but as long as one goes back to the same supplier, they usually wave the hydrotest fees.

mikeread

That is ideal, if I can get a machine that tigs and stick welds it would do everything I need.
If it can also be used as a plasma cutter, even better. I also make knives and this would be very useful.

dsaul

For more info about propane and oxygen concentrators, this thread at VSalon has it covered. acetylene vs propane