OK I'm convinced about brazing...

[oilman52]

Just went out and bought the set up. B tank,turbo torch. Still haven't found a place that handles nitrogen. I'm installing a 2.5 ton split system,talked with 2 techs. One said go ahead and use Staybrite 8 on anything under 4 tons. The other said he just installed a 2.5 ton unit and brazed. Do you guys also braze at evap.? My other question is what type of tip on torch and also what kind of brazing rod do you suggest? Brazing flux?

[Wild Leg]

6% to 15% silphos with no flux will work on copper to copper.
Also on copper to brass, with brazing flux.
Copper to steel, 45% and brazing flux.
Heres a link:
http://www.jwharris.com

Welding supply houses will most likely have nitrogen.

[oloenneker]

You got a B Tank from where? Must have been a welding supply shop, right? They should also sell the nitrogen tank and the regulator as well. At least that is where I got my original set up when I was an apprentice years ago. My shop gets all their gasses from a welding supplier, including nitrogen, oxygen and acetelyne... Try some welding retaillers out there.

I use silfos 15 for all my joints on residential units, and yes I braze ALL joints, no matter where they are.

Make sure that when you are cutting the tube with a tubing cutter, that you ream out the burr left inside the tube with a reamer. The ones that come on must tubing cutters are garbage. Get a special reamer designed especially for reaming copper tube and you will be set. Just make sure that the chips and stuff you ream out does not fall into the tube, since this could cause a restriction at a metering device or get jammed in the compressor.

Tip size depends on what size I am brazing. For my turbo torch, I have an assortment ranging from A3 all tthe way up to A32. I mainy use the A8 or A11 size most. Sometimes when I am afraid that I am gonna burn siding or wood etc. I will use the A5 tip, but it takes alot longer to get the job done with that.

[oilman52]

I got the B tank at a supply house that deals with mainly plumbing supplies. They didn't carry nitrogen,there is a welding supply house close to my house. I will try there. What is the difference between Air/Acet. and Oxy/Acet.?

[Wild Leg]

Oxy/Acetelyne has two bottles (oxygen) and can support use of a cutting torch.

It burns hotter, therefore is easier to overheat your joint.

[oilman52]

Thanks for the help.

[Wild Leg]

You're welcome.
Most of the HVAC contractors around my area use Oxy/Acetylene with an R oxygen and MC acetylene.
Plumbers use air acetylene and B tank.

If you had a need to use oxyacetylene, it would require a different torch, with dual hoses & valves.

(Fill out your profile. More people will respond, and quicker.)

[t527ed]

every joint we have done for the last 30 yrs has been silver soldered or brazed. we get nitrogen at united refrigeration, don't know if you have them in your area. if not welding supply will have. only problem with welding supplies around here is they make you buy tanks, and every time you turn around they charge you for hydro testing.

[conrad1]

First there are supposed to be no DIY questions on this site and when you're done filling your line set with noncondensables call a professional to replace

[tinknocker service tech]

with out running nitrogen through system while you braze i would recomand useing staybrite. it will hold up to any size system and with very little flux you will have a better job. brazing with out nito running will oxidize the inside of the pipe and could cause a problem at the orfice screen

[oilman52]

Not a DIYer Conrad. Went thru a year of school,worked for a company and just started my own business. Busting my tail and barely making it thru my first year. People tell me I'm doing great for a first year because all my bills are paid. EPA Cert. and a Massachusetts Licensed Oil Burner Tech. You never stop learning Conrad and personally I think line sets look like crap!

[square2round]

I use a B-tank.

I have used the oxy/ace on a couple occasions. I'm much more accustomed with the B-tank and I've just stuck with it and have no problems using it.

I use an A-11 tip for the torch. The girl at the welding supply house said that's the biggest tip that is sold for the turbo torch...but I see she is wrong. I'll have to have a talk with her.

Here are some tips and specs

http://www.professionalequipment.com...CMP=KNC-Google

I use silphos 6% or 15%.

The local hvac supply houses here carry nitrogen. Check with them if it's closer than the welding supply house.

[conrad1]

Originally posted by oilman52
Not a DIYer Conrad. Went thru a year of school,worked for a company and just started my own business. Busting my tail and barely making it thru my first year. People tell me I'm doing great for a first year because all my bills are paid. EPA Cert. and a Massachusetts Licensed Oil Burner Tech. You never stop learning Conrad and personally I think line sets look like crap!

I am still of the opinion NO FLUX IN ANY REFER SYSTEM!!!!!

hope that was loud enough!!!

[Wild Leg]

Originally posted by conrad1
[B I am still of the opinion NO FLUX IN ANY REFER SYSTEM!!!!!

hope that was loud enough!!! [/B]

Conrad, what do YOU use to join steel to copper?
Steel to steel?
Copper to stainless?
Stainless to stainless?

If all you ever work with is copper, then copper/silver/ phosphorus alloys work great, with no flux.
However, in the presence of phosphorus, steel becomes brittle.
Because of this reaction to phosphorus, a brazing alloy with no phosphorus must be selected.
The most commonly used is 45% silver.
It requires a brazing flux.

Brazing flux is not painted inside of the tubing, like a plumber would do it when soldering.
Instead it is applied only to the male portion of the tubes to be joined.
A good technique is to clean the joint, inside & out, then slip the joint BARELY together.
Next, brush the paste flux over the male portion of the pipe. Then slip the fitting together.

Contamination by flux will be minimized by using this method.

"Refer" manufacturers braze with flux every day when, dissimilar metals are used.

[tinknocker service tech]

brazing flux or solder flux is not where the acid problem comes from it is from lack of knowlege in the applacation of it. most guys think they are plumbers and just glob it on and go. this is where the acid contamination is from. if applied properly acid is not of any concern as a little flux will go a long way
best way to apply it is as been told in privious post
poor workmanship and lack of knowlege is the biggest problem in any system braze or solder

[square2round]

Originally posted by bwal2
6% to 15% silphos with no flux will work on copper to copper.
Also on copper to brass, with brazing flux.
Copper to steel, 45% and brazing flux.
Heres a link:
http://www.jwharris.com

Welding supply houses will most likely have nitrogen.

Great site.

Much information.