Oxy-Acetylene Brazing relacement

[mbreward]

Hi I'm new to RE

I have been using Oxy Acetylene for all refrigeration brazing repairs and installations

Current factory policy is to phase out all use of acetylene so I am looking for a replacement gas

Oxy-propane has been suggested but i am douptfull that it will heat the larger pipes adecuately

We have all pipe sizes from 1/8" to 1 1/2"

Thank you for your help

[The Viking]

Well the smaller stuff can be done with Mappgas burners but for proper brazing on anything above ~5/8, you can't beat Oxy/Acetylene.

[Chunk]

I heard that when Heathrows terminal 5 was being built,they wouldnt allow oxy/acetylene on site.

Someone mentioned before about a gas called apachi from http://www.airproducts.co.uk which is primarily used for cutting but is safer than acetylene and you get more heat than propane.

You cant beat acetylene,but if you cant use it,theres always something else.

[monkey spanners]

Rpw sell a oxy mapp gas set which may be worth a look. uses a small refillable oxy bottle with disposable mapp gas.

Jon

[Andy AC]

Never had a problem with oxy-propane, does up to 1-1/8 no problem with a decent nozzle. Have you tried the pepperpot nozzles? - worth a try on the bigger pipes. The kit I use all the time is a modified microflame kit running propane and using a rothenbeger roxy torch. Its so much better than the microflame torch, and you don't use as much oxygen as you would using the microflame nozzles.

Andy

[taz24]

Hi I'm new to RE

I have been using Oxy Acetylene for all refrigeration brazing repairs and installations

Current factory policy is to phase out all use of acetylene so I am looking for a replacement gas

Oxy-propane has been suggested but i am douptfull that it will heat the larger pipes adecuately

We have all pipe sizes from 1/8" to 1 1/2"

Thank you for your help


There are oxy-mapgas torches or simlar to map gas.
I have a small one that will braze any diamiter pipe but the duration of the small bottles is limited.

taz.

[mbreward]

Thank you I'll investigate it.
Do you know if it can be used with the same torch & regulators?

[Plank!]

what about TIG on the larger pipe sizes?

[taz24]

Thank you I'll investigate it.
Do you know if it can be used with the same torch & regulators?


No the one I have is a small unit that is complete. You just order the bottles from the likes of NRS, HRP and other trade counters. The flame source is mapgas the same yellow bottle and the O2 can be bought or topped up from a larger O2 bottle.
About £80 new I think.

Cheers taz.

[mbreward]

what about TIG on the larger pipe sizes?


Has anyone experience on using TIG, I do have access to a TIG set, what pipe sizes will it work on?

[nike123]

Has anyone experience on using TIG, I do have access to a TIG set, what pipe sizes will it work on?

You mean for welding of steel pipes?:confused:

[expat]

TIG will give you localized intense heat around the rim of the joint. It will have the effect of brazing the rod onto this area but it won't give a uniform heat across the entiire joint and you therefore won't get a capillary action to give you a good strong joint.



Never had a problem with oxy-propane, does up to 1-1/8 no problem with a decent nozzle. Have you tried the pepperpot nozzles?


This sounds good! Also try a search on this site for Lockring solderless joints.

[Plank!]

TIG will give you localized intense heat around the rim of the joint. It will have the effect of brazing the rod onto this area but it won't give a uniform heat across the entiire joint and you therefore won't get a capillary action to give you a good strong joint.

I've not tried TIG on copper myself, infact i doubt i even use a brazing torch more than once or twice each year, however I've been told that some manufacturers are using TIG to weld (NOT braze!) joints.
It requires different fittings and rods to the normal brazed joints, so capillary action is not an issue, these would be butted joints not sockets.

[Grizzly]

As Far as I know TIG and it's sister Mig are for Ferrous metals (steel).
Brazing is for copper and it's alloys
(inc. Silver solder)
You can learn to braze very quickly
but learning to TIG weld is another matter.
Besides on fridge kit you have to be coded.
Cheers Grizzly

[Plank!]

TIG is the best way to weld aluminium, thats certainly non ferrous.
Steel and its alloys can also be brazed.
The equipment and methodology differs but both welding and brazing can be used on any metal, brazing just uses a rod with a lower melting point that the base metal.

Brazing is on the whole easier and cheaper than welding for copper etc, but when you get into the bigger, thicker walled pipe sizes TIG would become a viable alternative.

[skags]

we use lpg at work not sure if you have it there but i think its a mixture of propane and butane and alot cheeper than acetylene, you need special torch for best result tho

[frank]

TIG (Tungsten Inert Gas) will not weld/braze copper.

I use a thick piece of copper (6mm) under thin stainless (20SWG/22SWG) when TIG welding the stainless sheet - it prevents the s/s 'blowing through' and helps dissipate excessive heat build up in the thin sheet.

The copper is unaffected by the TIG process.

[chemi-cool]

For copper TIG welding, you will need to switch to AC and use suitable tungsten rod. Not all TIG welders have this option.