acetylene vs propane

[David Tollefson]

I've had good results from a #4 tip with propane (brass crown to steerer, 56 silver crown to fork legs).

[rauce]

Good to know, should have mentioned I'm on propane too.

[Doug Fattic]

Some professionals like to do the crown to steerer and blades all in one go so the big heat of a rosebud can get everything up to temperature fairly quickly. Speed increases profits. This is not an approach I would recommend for the less experienced because there is too much going on for them to recognize everything at once and then know what to do before things have gone too far.

When I was making some forks in Ukraine a couple of weeks ago, I used a Victor TEN-4 tip brazing steerers to twin plate crowns with silver using propane. I had no problems at all. I was also teaching a guy that had been to the Bicycle Academy course in the UK before and it worked better for him to use a TEN-3 tip because it slowed down the process a little more so it was easier for him to understand what was going on so he could react in a timely way.

When I was fillet brazing the main triangles I preferred a Victor TEN-1 tip. I can use a #2 tip just fine but I felt the #1 gave me a bit more control.

[rauce]

Thanks Doug, interesting that you mention the #1 tip. I was thinking I should get a #1 to try with fillet work instead of the #2 I'm using now. Rosebud idea came about because I was trying to think of what else I could order at the same time to make it worth it.

[JGabriel]

Hey Mr Fattic, I just wanted to thank you for all the great info on using propane and oxygen concentrators to power a torch. I can't keep oxy/acetylene tanks where I live, so the propane and oxycon setup is huge help for me.

I put together a torch rig using disposable camping propane bottles and a concentrator I found on craigslist for $150. I bought a Victor j-28 torch, un-j mixer, and a a 2-ten tip. It all works great.

Now I just need to figure out how to get make good fillet joints...

[rauce]

I'm also using the disposable camping bottles with an adapter I found on ebay. Much to my surprise I did 2 and half frames plus a decent amount of practice before I finished one bottle... and 4 packs cost $15.

[bambuko]

I've had some difficulties sourcing small hoses (similar to those offered by Tinmantech or Smith in US) here in UK.
But the problem is now solved - I found the source:

Mirco Hoses Set

This is Welding Direct , also known as Cheltenham Welding Supplies, trading on interweb as Noz-Alls.
They are happy to supply any length, with any thread you might want, including US sizes as well as the more common (here) UK sizes.

Arrived today:



Photo shows them next to my original setup with 6mm (1/4") hoses and lightweight torch.
I've had them fitted with quick coupling connector at bottle end, and US A size connectors at torch end in anticipation of my Uniweld 71 torch arriving soon.

[William Chitham]

This is Welding Direct , also known as Cheltenham Welding Supplies, trading on interweb as Noz-Alls.
They are happy to supply any length, with any thread you might want, including US sizes as well as the more common (here) UK sizes.

That's a stellar job Chris, a UK supplier who can provide US fittings is great news. Your new hoses do look nice and thin, how is the flexibility compared to the standard sized ones, and did they work out much cheaper than importing a TN set?

William.

[bambuko]

Yes, they are very flexible and light.
Without a doubt cheaper than Smith hoses (although they are not Kevlar, so perhaps direct comparison is unfair).
As for Tinmantech - I didn't go as far as getting proper quotes from them, but with the Sterling down in the dumps, plus duties, VAT and postage I have calculated that it is cheaper buying locally.

These hoses are normally used in micro torches and you can get them without fitting as spare parts for Oxyturbo brazing sets.
The main advantage of Welding Direct is their ability to supply with any fittings you want.
Very fast delivery as well - I called them on Monday to discuss my needs and the goods arrived today

[waterlaz]

Very fast delivery as well - I called them on Monday to discuss my needs and the goods arrived today

And it looks like they are sold out already :)

[bambuko]

And it looks like they are sold out already :)

no, no
They want you to call to discuss your requirements, so that they can quote you!
Mention my name when doing so!

[bambuko]

Just an update...
Cheltenham Welding Supplies (Noz-Alls or Welding Direct) have listened to our comments about crappy webpage and have updated it, to show full range of microbore oxy propane hoses, with prices shown.

Micro Bore Super Flexible Hoses American A fittings
Micro Bore Super Flexible Hoses G1 4 x G3 8 fittings
Micro Bore Hose Set 3mm bore G1 4 Fittings

and no, I am not connected and I do not get any discount for sharing of this info

[waterlaz]

Just an update...
Cheltenham Welding Supplies (Noz-Alls or Welding Direct) have listened to our comments about crappy webpage and have updated it, to show full range of microbore oxy propane hoses, with prices shown.

That's nice. I didn't realize that American A fittings are different from G 1/4. Anyway, I have m12x1.25 on my torch.
Meh, what a mess with all these different standards.

[waterlaz]

Doug,
I've made a mistake when I wrote about metric threads commonly used for brazing equipment in xUSSR. The M12 thread is usually M12x1.25 and not M12x1.5

[bambuko]

One thing that I lacked when deciding whether to follow the usual torch recomendations here, or whether to stick with what's readily available locally was side by side comparison.
There are plenty of photos of Victor, Harris, Uniweld, Meco, etc, etc but none of them side by side with typical "lightweight" torch in UK.
So here it is (for the UK guys):



As you can see the lightweight shank is almost exactly the same length as Uniweld 71 (freshly arrived from US).
Both knobs are suitably chunky, although Uniweld ones are not colour coded.
Close proximity of the knobs on lightweight torch is PITA and often causes propane to be knocked out of adjustment when using oxygen knob (and vice verse).
Uniweld (and similar) torches seem very much better in this regard.
The weight of Uniweld is 185 grams and lightweight torch is 275 grams - not much in it afaic.
The shape of the handles - I've never yet used Uniweld in anger so it will be interesting comparison, specially since I got used to flat handle of my old torch.
Main decider is easy and plentiful availability of fittings - I am finding now how expensive is having to buy everything from US...

One solution is Harris 15-4GB (i.e. old Harris 15-3 with UK fittings. The only such combination available for sale, as far as I know)

[Tman]

Paging Doug Fattic, your PMs are full! Got a problem with my Devilbiss oxygen concentrator guys. I went to chang to new hoses and my Oxy line is stuck! Trie to turn it off and the threaded male part wants to turn inside the machine. Anyone dealt with this? Don't want to wreck this thing.

[eagledriver50]

Mr Frattic...you are the one that got me to thinking about using oxy-propane in the first place. It was a sentence of ... "if something goes wrong there is a time to recover with propane". I follow the law...if something could go wrong, even with all the planning, it will. Thanks for the knowledge you pass on!!!

[czernysz]

Super late to this thread, but I'll throw this in. I turn off fuel gas first, but before I do, I increase the flow of fuel gas, then oxygen, and then shut off fuel gas. It's become my procedure, and no 'popping'.

[timto]

Bumping this thread for the following question related to storage... I have a basement workshop now after a recent move and plan to bring in my propane tank from outside where it is kept for use just when brazing then returning the tank outside. Any issues given the drastic temperature difference in the winter? It’s minus 20 c often in chilly Ottawa!! Basement is heated and unfinished and I’ve put in some venting in anticipation of bike making

Thanks in advance

[Andrew R Stewart]

I don't have O-P experience but I have used my O-A set up outside in sub freezing temps many times with no equipment issues. Andy.