PDA

View Full Version : Recommended Torch for Brazing



hvactech
22-09-2008, 04:22 AM
I am unsure if Map or Acetylene Torch is hot enough to braze or solder to copper pipes on a residential R-22 Split System.

I have a Map Gas unit. I have also heard that oxygen and Acetylene setup gets you even hotter temperatures.

For now I would like to have a setup for both Copper, Aluminum and possible whatever other steel that R-410A would use.

Anyone have thoughts on a good setup and ifg I should braze or solder?

Any links etc would be helpful. Trying to also watch the budget.

Newbie Question. :eek:

Thanks

hvactech
22-09-2008, 04:27 AM
Here is one link I found but seems pricey and not sure what model to get?

Just put in the www

torchtools.com/Oxy-Fuel_Kits.htm

hvactech
22-09-2008, 05:03 AM
I found a few brands like Victor, Uniweld , Lenox and one below that seems to have a lot of accessories maybe more than I need but does not include the oxygen/Acetyleline tanks nor tote.


Again use www

tooltopia.com/index.asp?PageAction=VIEWPROD&ProdID=8889

nike123
22-09-2008, 10:46 AM
You should braze. Best is with oxy-acetylene torches. I have setup with Oxygen and acetylene bottles of 10L, pressure regulators, 10m of hoses
and oxy-acetylene handle with flexi tips no. 2 and no. 4-6
It covers all my service work even brazing at Rotalock valves copper tube of 54 mm.
And, I also have one small brazing Refco oxy (1,5l)-propane (Weller propane bottle) set for small repairs capable of brazing 22mm coper pipe with double tip.

reefertech
17-07-2009, 04:49 PM
Use Stay Silv 15 hard solder with their white flux. Soft solder is good near sensitive parts where heat may cause damage.

WaterholeWally
21-07-2009, 03:03 PM
Learn from others mistakes...

Rent a few DVD's on brazing and oxy-acetylene welding from Smartflix or some similar online outfit.

You'll wind-up buying smarter tools and getting it done quicker, better, safer.

I took classes and still boogered-up the works.

You won't have any regrets.

Wally

Haden4ever
29-07-2009, 10:54 AM
mapp gas is fine for small stuff, especially where access is poor, ie work at heights, oxy acet is the only right choice for most stuff, chose the nozzle according to pipe size, whatever gets it red quickly will reduce carbon build up, i prefer a multi hole nozzle, and please whatever you do never use soft solder as suggested

tL9f8G2NBFX9bdh
30-07-2009, 03:56 AM
On refrig connections silver braze. On sensitive parts, exp. valves etc. silver braze with something to such as heat isolating compound or wet rags wrapped around components to keep them cool and un-warped. Do NOT over-heat connections. Brittle work or heat hardened (crystallized) copper will eventually break. If you have never brazed before, make several practice joints to use. Just enough heat to make silver braze flow easily and remember that it will flow toward heat. Use Nitrogen at low flow/pressure to keep copper from oxidizing and the carbon deposits from forming inside which WILL mix with oil and abrade all internal surfaces. On your last joint on each section, you can and must turn off the Nitrogen or else the slight pressure will force your siver braze out of the joint. Once the Nitrogen is in the system and you're sure all O2 is purged you can then turn off Nitrogen altogether.

Haden4ever
31-07-2009, 09:23 AM
That's all pretty much by the book and i would agree with all except the use of silver for all connections, this is expensive and unnecessary, use phospher bronze, eg rothenberger rolot s2, for all copper to copper joins, and use cad free silver rods for all dissimilar joins, and obviously always purge with nitro to prevent internal oxidisation, on a big system a surprising amount is produced :D

jdunc2301
31-07-2009, 03:29 PM
I have an oxy acetalyne rig on the van using a number 13 lightweight nozzle, also carry a map gas torch for smaller stuff, i mainly use rothenberger S2 braze, and for more sensitive brazes like TEV, 4 Way valves etc or brazing disimilar metals i use silver solder, sometimes prefluxed rods.

If you do use a map gas torch get a decent heat shield they help.

paul_h
31-07-2009, 04:30 PM
mapp gas torch will do anything below 5/8". Though it takes a lot longer so heaps of carbon buildup, nitrogen being purged through the system is extra necessary.
An oxy acetylene rig is always better though.
Faster to heat up, the solder flows better and you get a cleaner braze joint.
Regulators, hoses and hand piece can be bought for under $200, I pretty much use a size '12' for everything lol. I use the 'brown tip' 15% silphos for almost everything.
You just have to rent the oxygen and acetylene cylinders where I am (only AU$20 a month or so for me).