Oxy hydrogen torches

[John RutzenParticipant @johnrutzen76569]

Hi, has anyone any experience using the oxy hydrogen torches commonly available on amazon and eBay? I am looking for a source of heat for sifbronze brazing small steel items,

[John RutzenParticipant @johnrutzen76569]

[Roderick JenkinsParticipant @roderickjenkins93242]

I used to use a Johnson Matthey Oxy Hydrogen torch at work. Great for welding thermocouples but useless for brazing. Although the flame is very hot, there is very little energy in it so you just can't get the job up to temperature. Even bubbling the gas through MEK didn't provide enough heat to braze even small items. I think you would be better off with a MAPP type torch such as this **LINK**. It's what I used to silver braze the two parts of my Lorch type milling spindle together.

HTH,

Rod

[John RutzenParticipant @johnrutzen76569]

HI thanks Rod, Is the MAPP gas that much hotter than propane? I have sievert propane equipment but the job doesn't get hot enough to use the sifbronze no 1 on steel.

[JohnFParticipant @johnf59703]

John R, Mapp gas is a little hotter than propane but the real difference is whether is gas/air or gas/oxygen ! Its the oxygen that makes the flame considerably hotter plus of course the fuel gas burn temperature,

It also depends on the work size/mass

I have Oxy/Acet and for small work purchased a Smiths little torch , not the genuine one but a clone, it works well for my application

John

[John RutzenParticipant @johnrutzen76569]

Thanks John, I don't do enough to justify the exorbitant rental on cylinders. I'm always looking for ways to save money on what can be a very expensive hobby. I was thinking of using the sifbronze , which was very cheap, as an alternative to silver solder on small prefabricated steel parts.

[duncan webster 1Participant @duncanwebster1]

There are companies who don't charge rental on bottles, you pay a deposit (returnable) then just pay for refills. Depends where you are.

[Keith HaleParticipant @keithhale68713]

Hello John,

Before making any decision, seek advice from Amazon and eBay as to the thermal characteristics and brazing capability of the equipment you plan to purchase. Then follow it.

Alternatively seek advice from a company that will understand what you think want to do. History shows that despite its apparent high cost, silver solder can produce the cheapest cost per joint.

I declare an interest. I have for nearly 50 years been selling silver solder and brazing alloys including sifbronze type alloys.

Unless you intend producing a considerable amount of steel components, on balance, buy a simple propane torch and use a silver solder.

Talk to CuP Alloys. They will put you right. Declaring another interest – I used to own the company.

But unlike other companies,they have a reputation to maintain in this market. Amazon and eBay have built a reputation in what field?

Regards

Keith

[James AlfordParticipant @jamesalford67616]

I needed to do a lot of brazing on a large copper structure, but could not justify the cost of oxygen bottles or the gas. I fabricated a compressed air-propane torch which I ran off from a small compressor. It was no doubt less efficient than oxy-propane, but was still more than powerful enough to braze the structure well.

I made the torch using ideas from the web. It took a while to fine tune it, but the cost was negligible.

James.

Edited By James Alford on 23/05/2019 07:18:03

[John RutzenParticipant @johnrutzen76569]

Hi James, that sounds very interesting, Please could you give me a link to the websites you found the information on. Thank you.

John

[Nick Clarke 3Participant @nickclarke3]

Posted by James Alford on 23/05/2019 07:16:22:

I needed to do a lot of brazing on a large copper structure, but could not justify the cost of oxygen bottles or the gas. I fabricated a compressed air-propane torch which I ran off from a small compressor. It was no doubt less efficient than oxy-propane, but was still more than powerful enough to braze the structure well.

I made the torch using ideas from the web. It took a while to fine tune it, but the cost was negligible.

James.

Edited By James Alford on 23/05/2019 07:18:03

Interestingly when I first joined a ME society 50 years ago or thereabouts, air/town gas torches were commonplace (as were fearsome paraffin blowlamps) Nowadays, like most other people, I use propane and while for silver soldering it is the bee's knees, it is not hot enough for brazing.

Perhaps a step back in time is not that bad a thing from time to time, especially with the easy availability today of propane and cheap compressors.

[James AlfordParticipant @jamesalford67616]

Posted by John Rutzen on 23/05/2019 08:17:11:

Hi James, that sounds very interesting, Please could you give me a link to the websites you found the information on. Thank you.

John

This is the page which set me thinking. https://sites.google.com/site/gypsytinker2012/how-to/make-a-mako

My first attempt worked well, but the flame was rather bushy and lack direction. My second attempt was much more effective. It had a longer, narrower tube and more slots. I experimented a lot with sheet rolled into a tube to slide up and down the base part to try and get the optimum length.

The details below are for the first version which I made. I shall post a picture of the later version if you wish.

I had a disused oxy-acetylene torch and made a new nozzle to fit onto a swan neck. The sketch below gives the main dimensions, none of which seems to be too critical.

I made my torch before I had my lathe working, so everything it rather loose and wonky. I brazed it all together and it works.

I connected the air line from the torch to the hose from a compressor and the gas line to the propane tank. I have blow-back arrestors in both hoses. I use the torch with the compressor and propane set to full.

The settings on the torch controls themselves is quite critical and needs careful setting. However, once the right combination of gas and air is found, the flame is quite compact, extremely hot and very noisy.

This short video shows the torch running. The flame is off-centre, mainly because the whole thing is a little wonky. **LINK**

 

 

Edited By James Alford on 23/05/2019 21:26:29

[John RutzenParticipant @johnrutzen76569]

Thank you for posting that and the link to Gypsy Tinker. I've made wast oil burners and cast iron in the past. I'm not sure that I would get more heat with blown air because it's 80% nitrogen which cools the flame. I think that's the idea of the sievert burners. We have a blown propane burner at our Model Engineering club. I think I will try that with the sifbronze the next time I go.

[William ChithamParticipant @williamchitham75949]

In the US a lot of bicycle builders are using oxy propane for brass and silver brazing using old medical oxygen concentrators. A lot cheaper in the long run than cylinders and safer too. You can find them on ebay occasionally or Tufnells Glass do new & recon units: http://www.tuffnellglass.com/contents/en-uk/p66_oxygen_concentrator.html.

[John RutzenParticipant @johnrutzen76569]

That's interesting, i've never heard of those before. Thank you for posting that.

[clogsParticipant @clogs]

just to add, have been thinking of the Air / town gas brazing units we used at school some 50 years ago….

need to braze a new custom motorcycle frame, thought about using a TIG for the job but at £2,000 for a good unit is just a touch to much……

so, was wondering …..

I have an as new BOC cutting torch, (all Brass) was thinking about having a go with compressed air and Propane….

any ideas……

[James AlfordParticipant @jamesalford67616]

Posted by William Chitham on 24/05/2019 16:51:31:

In the US a lot of bicycle builders are using oxy propane for brass and silver brazing using old medical oxygen concentrators. A lot cheaper in the long run than cylinders and safer too. You can find them on ebay occasionally or Tufnells Glass do new & recon units: http://www.tuffnellglass.com/contents/en-uk/p66_oxygen_concentrator.html.

I saw these devices, but they were more than I could justify, especially as I had a compressor.

James

[James AlfordParticipant @jamesalford67616]

Posted by clogs on 24/05/2019 19:00:49:

just to add, have been thinking of the Air / town gas brazing units we used at school some 50 years ago….

need to braze a new custom motorcycle frame, thought about using a TIG for the job but at £2,000 for a good unit is just a touch to much……

so, was wondering …..

I have an as new BOC cutting torch, (all Brass) was thinking about having a go with compressed air and Propane….

any ideas……

If you have a compressor, why not try? I was brazing a very large copper sculpture in the free air, without any firebricks.

[John RutzenParticipant @johnrutzen76569]

Hi, I remember those torches at school 50 odd years ago. I don't think i ever got to use one. James, what did you braze the sculpture with? Was it sifbronze or a silver solder ?

[James AlfordParticipant @jamesalford67616]

Posted by John Rutzen on 25/05/2019 08:55:06:

Hi, I remember those torches at school 50 odd years ago. I don't think i ever got to use one. James, what did you braze the sculpture with? Was it sifbronze or a silver solder ?

John.

I used Sifbronze. I used whatever variety was cheapest, to be honest, mostly buying it in 1kg packets from CupAlloy.

James.

[Author]

Posts