Braze Solder R410a

Techman

For a tin-knocker, I contacted the mfg of the units he had installed. The units  are 13seer, r410a which I am going to pipe and start up .The factory engineer said that I could use a "refrigeration grade silver solder"{staybrite #8 ?] instead of brazing and purging with nitrogen. Is this a shift in the brazing/nitro  policy? Does anyone know of any mfrg's that allow this soldering policy?

Kevin_in_Denver_2

Silver soldering is silver brazing

Check the melting points to be sure, but the words are used interchangebly when silver is involved.

TonyS

# 8 is a silver bearing solder

I know guys that use it. They are the same ones that are always having trouble with reversing valves and txv,s. They like to bring out the point that solder doesn't anneal the tubing and is actually stronger than phos-copper. Yea yea Ill remember that when I am hanging off a bridge by a piece of copper. If you set yourself up on a bench and solder some joints with flux and then a few with silphos and a  nitrogen charge and then look inside the tube.  It becomes quite clear why we purge and use silphos. I think the companies still want the hack business so they tell them they can do it with solder and flux.

sasman

tony

I think you may be onto something there

hehehe

Techman

Tony

By soldering w/ flux there  is no oxidation w/ flaking inside of the tubeing,but, there will be the flaking inside the brazed tubeing without the nitro purge and no flaking when brazing  with the nitro purge, I agree.

bockchoi26

stay brite 8

I've been in the industry for 14 yrs and was brought up through the ranks brazing all refer lines with a nitro purge, but within the last 2-3 yrs ive been seeing more and more of stay #8. I've used it on number of jobs, 410a included, with no problems. In some instances it was required that I use stay #8 instead of brazing the lines. Stay brite #8 has a melting temp at 430* and a tensile strength of 15,000 psi vibration making it more than strong enough to handle the vibration of discharge lines. You just want to keep temp of pipe while soldering at 430* or close to it, not to overheat, and get full penetration. That is of course if you are using these lines for refrigeration and air conditioning and not for hanging off a bridge

Techman

boch

I have been using staybrite #8 since 1975 with fabulous results and in my own business since 1980. I guarantee my joints for YEARS and YEARS with only a hand full of no charge repairs.I have brazed and soldered ( #8 ) R410a systems w/o leaks, some are 8years and running

TonyS

Harris states clearly

that #8 is stronger than sil-phos because the lower temps dont anneal the tubing, that is if your not using annealed tubing to begin with. Either way both are strong enough but the problem lies in the fact you have to use flux with #8. How do you keep the flux out of the line?

Techman

flux

same as always,i only put a slight film on the copper, no globs ,no little piles,no hills. it works 4 me because i dont change out very many compressor  on any  unit that i have installed .and the few that i did change out did not have any acid in them.i have comp's that are 10,15,20 25, years old and still running and i even have 1 that is31 years and running

Eugene Silberstein 3

Nitrogen while brazing

The proof is in the pudding!

Eugene Silberstein 3

Nitrogen while brazing

The proof is in the pudding!

TonyS

Beautiful pic

and as always....worth a thousand words!

geno54

Any Pics

Anybody have any pics using Staybrite 8?

geno54

Any Pics

Anybody have any pics using Staybrite 8?

TonyS

What is the advantage?

Even if you super critical when you solder, what is the advantage? What if you just happen to get a leak in an awkward spot and have to disassemble the joint? Now you have a chance of burning the copper. Even when you are finished soldering, dont you put a few hundred pounds of nitrogen in to soap your joints. ACR tubing comes from the factory with nitrogen sealed in, you may as well just use plumbers tube, its cheaper.

Techman

braze/solder

i do braze/nitro in some and solder (below 750*) in some.burning the copper to repair a solder leak is not nice, staybrite #8 flows @ 430* and there is no flaking @ that low temp. and to unsweat an existing #8 joint the flow temp  is around 535* ,still below the oxidation point. now, using 20-30 feet of a 50' roll of tubing doesn't leave much nitrogen left in the remaining tubing . plumbers tubing does not have caps or plug to keep debris out of the tubing. a hard to get to fitting to braze is a little harder to repair than a soldered fitting due to the 1200-1500*  of the braze.don't get me wrong here , i do braze/nitro most of the time, and it was the equipment mfg that said i could use a refrigeration grade silver solder, and i was just wondering if others had been told this also.don't taze me bro!

Wayne_16

Plumbing is not refrigeration

Tony in refrigeration work, it is all about keeping the system clean, no dirt, debris, copper oxidation flakes etc.   A small piece of debris wherever from a piece of dirt, copper flake etc. will plug a txv, reversing valve piston or a compressor valve.  These are just some of the many possible places debris can cause problems.  Trying to locate them and make repairs will take a lot of time and money to correct.  Even though it is copper tubing, we are not plumbing, it is refrigeration and the standards have to be maintained to a higher level.  Whatever is in the system will stay in the system until its death.

The nitrogen charge in the tubing is for shipping only, once the cap is removed from the end, the nitrogen purge is gone and new nitrogen has to be introduced into the line, fittings prior to welding.

As always maintain a nitrogen purge when welding joints to maintain the integrity of the system.  R 410A systems all use a txv to meter refrigerant.



Minnesota Wayne

TonyS

Wayne

If you read my post, thats what I have been saying. I was saying that if your going to use soft solder and flux, you may as well just use plumbers tube. You just missed my point.

TonyS

Welding, brazing and soldering

One other point Wayne that needs to be cleared up here.

Soldering takes place at below 840f below the solidus state of the base metal.



Brazing takes place above 840f and also below the solidus of the base metal.



Welding takes place with the melting of base and filler metal.

HVAC_Journeyman

Stay Brite vs Brazing

I don't think this debate will ever get resolved. But I also believe that using the proper techniques in both soft soldering or brazing will give you good results.



Having said that, I've used BOTH methods in my 30 years of experience. And I've had leaks using both methods, ( anyone that tells you they have never had a leak is a liar).

But, and this is a big but, the leaks I have had were not because of the soldering material I used. They were caused by a poorly prepared joint, or a blow out during my nitrogen purge. Further, I have never seen a joint fail in either method if you've done the proper preparation.



I tend to use Stay Brite 8 for smaller systems ( 5 tons or less) and joints where

I don't want to anneal the copper or disturb a factory joint like a distributor.  On the

industrial equipment I work on, we braze everything as it's almost always spec'd that way.



As far as the flux eating away a system from the inside out, never saw that happen. I've installed systems using Stay Brite 8 that are still running after 20 years with no leaks. I've also used it on 410A systems without any problems at all.



To quote a JW Harris rep I met at a RSES meeting, if you are worried about the solder joint's strength, Stay Brite 8 has a tensile strength of 10, 000 PSI and a melting point of 425 degrees. So if your system is running at 10, 000 PSI or 400+ degrees, you've got other issues with the system to worry about rather than what solder you have used.



If you use proper refrigerant practices , keeping everything clean, both types of solder are acceptable. I also use filter driers on every installation, or anytime I open up a system to the atmosphere. I admit though, for connections directly made to the compressor, or within a foot of the compressor, I always braze those joints.



Brazing is nice when done properly, but takes just as much time to prepare as does

soft soldering. And contrary to what some tech's say, you really should clean your joints even if you're going to braze. Soft soldering is nice if you don't want to anneal the copper. I've got two 3 ton systems in my own house, both are 410A based, and I soft soldered both.



I should also mention that I've seen jobs where some idiots have used 95/5. Eventually the chlorine will eat through the joint and cause it to fail. But I suppose there's always going to be someone out there that does questionable stuff like this, and give us all a bad name.



In closing, this debate has existed when I first started out in this trade. And in my opinion it will never be resolved. Use what you like, and take pride in your work.

That's my two cents.....

HVAC_Journeyman

Forgot to mention

I forgot to mention, when using Stay Brite 8, you should only use Stay Clean flux. I've seen utility flux used, and it does work, but Stay Clean seems to stay in the joint better than utility flux. Just don't glob it in...a nice thin coating will suffice. 

HVAC_Journeyman

Nitrogen in linesets

BTW, the nitrogen that's in the lineset/acr copper is to keep moisture out of the pipe during shipping, not to use during brazing. 

TonyS

and stop internal oxidation

The point I was trying to make was even the tubing company has gone the extra mile to keep oxidation from forming and keeping the tube in an almost sterile condition, why would we get to the job and use flux? I can appreciate someone really taking their time on every joint and using a minimum of flux but... flux serves two purposes it preps the metal for soldering and it pulls the solder into the joint but it does not dissapear. It cant leave out the face of the joint and it doesnt become part of the joint, it must exit somewhere and that would have to be inside the system. Maybe it vaporizes under vaccum and exits through the vac pump... I dont know, you would have to check with the flux manufacturer. 

Techman

flux

Tony,when brazing in moisture indicators, hand valves, service valves ,solenoid valves ,TXV's and some filter drier shells  a seperate brazing flux MUST be used. Sil-phos brazing rods are part flux.Just as the HVAC guy said I, also,  have systems that are running troublefree for DECADES.I am not a plumber or a hack, I am considered a pain in the dupa by most that know me because of my professionalism and my desire to do better all of the time. I even clean my solder and braze rods before use! And for years I have  save all of my caps and plugs to put on every piece of scrap copper that I carry on my truck,even the 3-4" pieces.Again,it was the mfrg that said  it was OK to solder,maybe because too many hacks brazed w/o nitro and screwed up their units . I don't know.But I do know what works!

HVAC_Journeyman

Where does the flux go

I hear what you are saying about the flux...

But unless you've drowned the fitting with flux, there really shouldn't be much left

( if any) inside the joint. I'm going to do a few joints and cut them afterwards to see

for myself, because I am curious now.



Bear in mind though, once you've pulled a vacuum and charged the system, there

is no oxygen or any other catalysts to activate the flux. And the filter drier will capture

any foreign substances that might have been left behind.



Think of a hot water boiler, closed system. If there are no leaks, and the system is air

free, you won't have to worry about the cast iron or steel pipes being eaten away by

the oxygen that is present in water. Yet open it up to the atmosphere, and oxidation takes place. Have a large enough leak and a constant flow of fresh water, and soon you'll find every steel pipe rotted from the inside out, and the cast itself will eventually rot through.



Lastly...if you've ever had a severe burn out of a compressor, now that's acid!! Yet we clean it up, put in driers and hopefully change them a few times while monitoring the acid levels. I've had that form of acid destroy manifold sets, and can even contaminate a healthy system that has has a set of gauges connected to them that were previously connected to a burn out system. I learned young, so I now have a set of gauges that are strictly for burn outs. Acid neutralizer works well too.



But I'll say it again...I've never had a system fail simply because of the soft solder I used. I will post photos of the solder joints soon.

 

TonyS

I believe you

I have no doubt you are a more than qualified Tech and are fully aware of how to solder a joint..its just for every guy like you there are 100 guys that solder because its easy, they know nothing of the proper flux or how thin to apply it. Most times when I see a slop job...its soldered. This is just an observation! Most times when I see a nice looking job...its brazed. As always there are exceptions to this rule.