6% Silver Rod

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I have a large 1/2" copper job coming up.  We'll be prepping up some fan coil units with pumps and open connections.  It was initially quoted with lead-free solder. Well, someone up the ladder saw that the units are brazed and now they want all of our fittings to be brazed as well. I don't have a problem with that, but I told them that the 1,000+ dollars of solder just turned in to over 4,000 dollars worth of 15% silver rod.  I think they threw up in their mouth a little and said "Oh! Don't they make a rod with lesser silver content?"  I've never used anything other than 15%, and knock on wood, haven't had a leak with it yet.  I see there is 6% rod out there and even 0%, huh???  I don't know enough about those rods to say they would suffice. I don't like the idea but again, I've never used the stuff. If anyone has any experience with those rods, any advice would be greatly appreciated. The system won't be seeing more than 50lbs pressure if that helps . I've seen many mentions of using Silphos solder for copper fittings here in this forum. I need to check the prices and see if it would be worth it. Cutting out one less step would be a help, considering I'm looking at 5,600 joints.
Reply:I've been a hvacr contractor for forty years and have used 0% to 70%. 45% and higher all cadmium free. If 50psi is all that's required go with 0% or 5%. They will work just fine. Clean your joints fittings and pipe well, use some brazing flux, take your time and all will be fine.Sent from my iPhone using Tapatalk
Reply:McMasterCarr has it in 5% Silver/Copper/Phosphorus alloy, 1/16th or 1/8th dia. Typically 1/16th dia. is easier for me. The 15% flows better. Here is the link for price comparison. If you shop around you can get better pricing. http://www.mcmaster.com/#silver-brazing-alloys/=pepk3dWeld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Yes, 15 % really does flow better and you won't gave problems with leaks 6 to 8 years down the rode. I've see a few leaks that looked like fatigue cracks after 0% or5% was used. They just can't stand the continuous vibrations. Sent from my iPhone using Tapatalk
Reply:SIL-phos works great, no flux needed on copper, and has good holding power. That said, I don't know what it cost, though likely have 50 pounds of it out in the shop
Reply:Can you use propress ?? Material cost might be the same and installation quicker.
Reply:Thanks for the replies. I reckon I should have called it 5% silver instead of 6. Looked at the McMaster site and our vendor's site, and we can get bundles of the Harris 5% rod for about the same price. It would knock the total price down by a little better than half. We will be putting a number of the rod mounted, hinged clamps on them. So maybe the vibration stress concerns on the joints would be lessened.  And I would imagine 5% rod to be at least better than the lead-free solder. We looked in to the propress fittings a couple years back BD1.  It was kind of a tough sell with the price of the tools & fittings.  Perhaps if we did it all the time, but we don't do enough copper where we think it would be worth it.
Reply:I know a lot of men don't use brazing flux on 5% or 15%, but I recommend doing it highly. Even though you've cleaned the pipe and fittings you've laid them down, picked them back up, etc.  A small amount of flux can sure go a long way in helping to insure a leak free joint. Reducing contaminates in the welding/brazing, and solder from the start of a job can lower your job time and call backs. Call backs are lost dollars that can never be recovered. Sent from my iPhone using Tapatalk
Reply:Originally Posted by papasmirfI know a lot of men don't use brazing flux on 5% or 15%, but I recommend doing it highly. Even though you've cleaned the pipe and fittings you've laid them down, picked them back up, etc.  A small amount of flux can sure go a long way in helping to insure a leak free joint. Reducing contaminates in the welding/brazing, and solder from the start of a job can lower your job time and call backs. Call backs are lost dollars that can never be recovered. Sent from my iPhone using Tapatalk
Reply:There is a white paste called brazing flux. I usually by it in  small plastic bottle. If it dries out just put a small amount of water with it and mix. By the way, typically using brazing flux is only applied after the tubing and fitting are put together. This is done in the refrigeration, hvac trade because you don't want flux residue in the refrigerant circuit. It can be bought at any hvacr supply house. Sent from my iPhone using Tapatalk
Reply:Originally Posted by clankerrI have a large 1/2" copper job coming up.  We'll be prepping up some fan coil units with pumps and open connections.  It was initially quoted with lead-free solder. Well, someone up the ladder saw that the units are brazed and now they want all of our fittings to be brazed as well. I don't have a problem with that, but I told them that the 1,000+ dollars of solder just turned in to over 4,000 dollars worth of 15% silver rod.  I think they threw up in their mouth a little and said "Oh! Don't they make a rod with lesser silver content?"  I've never used anything other than 15%, and knock on wood, haven't had a leak with it yet.  I see there is 6% rod out there and even 0%, huh???  I don't know enough about those rods to say they would suffice. I don't like the idea but again, I've never used the stuff. If anyone has any experience with those rods, any advice would be greatly appreciated. The system won't be seeing more than 50lbs pressure if that helps . I've seen many mentions of using Silphos solder for copper fittings here in this forum. I need to check the prices and see if it would be worth it. Cutting out one less step would be a help, considering I'm looking at 5,600 joints.
Reply:By the way, what are these fan coils being use for? Are they heat and a/c fan coils, refrigeration, or heating fan coils using water as the heat source from a boiler, geothermal or heat pump fan coils? Regardless, if they are any of these, I would recommend, as I've said earlier, at least 5% silfos and brazing flux.Sent from my iPhone using Tapatalk
Reply:Originally Posted by papasmirfBy the way, what are these fan coils being use for? Are they heat and a/c fan coils, refrigeration, or heating fan coils using water as the heat source from a boiler, geothermal or heat pump fan coils? Regardless, if they are any of these, I would recommend, as I've said earlier, at least 5% silfos and brazing flux.Sent from my iPhone using Tapatalk
Reply:Don't forget the Phosphate Free, Tri Sodium Phosphate.
Reply:I think the only time I have seen hard solder used in the field is on high pressure AC fittings going to evaporator coils. Any hydronic stuff just used regular solder.
Reply:Copper-to-copper brazed joints can be made with almost any of the copper-phosphorous-(optionally silver) brazing fillers.Final choice may also depend on what solidus/liquidus temperature you are 'comfortable' with and also on the fit-up clearance and desired fluidity of the molten filler.  As well as the operating temperature of the joints (the solders typically turn liquid around 400-500F, give-or-take depending on exact filler alloy used, the brazing fillers typically stay solid up to 1190F, again give-or-take depending on exact filler used).The 18% silver is more fluid than the lower silver percentages.  5, 6, 15, or 18 % silver copper-phosphorous can all  be used on copper-to-copper and copper-to-brass joints.  The 18% runs a liquidus temperature of 1220F, while the 5% runs a liquidus temperature of 1445-1535 F (depending on exact alloy used).The brazing flux (Harris brandname is "Stay-Silv white flux") can help ensure good joints on copper and brass (do not use on aluminum, magnesium, or titanium).  Cut the pipe, clean and deburr well  (remember to clean the ID of the fittings as well), add a tiny smear of the brazing flux on the OD end of the pipe/tube (not the ID of the fitting, too easy to get flux pushed inside the pipe/tube), insert into the fitting and give a litttle twist to spread/smear the flux a bit, apply heat and when flux turns liquid and 'clear' then apply the brazing filler.  It is mostly boric acid with some potassium fluoride and potassium bifluoride (overheating can decompose the flux and produce hydrogen fluoride, which is nasty stuff.  Don't overheat the flux!)  The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by ironmangqI think the only time I have seen hard solder used in the field is on high pressure AC fittings going to evaporator coils. Any hydronic stuff just used regular solder.
Reply:I also suggests trickling in nitrogen. This will eliminate oxygen during the brazing and keep the interior of pipe and fittings clean. Makes a much more professional job eliminated these brazing contaminates from entering and blocking the metering devices of each fan coil unit, also keeps the same contaminates from making there way to the compressors and making the lubricants contaminated. The better you perform these steps the better the equipment will operate. Sent from my iPhone using Tapatalk
Reply:I tried water in the white flux and it does work. Also tried 90% alcohol and acetone. The acetone seemed to work best.
Reply:I would not consider acetone at all. First, it's highly explosive, you may possibly get some into the system and cause problem with the system, and last is you and others safety. This torch, combustibles, and human factor are reasons to leave acetone at home. The standard for the industry is clean pipe and fittings with sand cloth or scotch brite pads, put fittings together, wipe with a small brush a small amount of brazing flux where the joint line is, brazing with O/A and cleaning and cooling the joint with damp clean towel. I can't impress on you enough not to use any substance like acetone: lacquer, mineral spirits, kerosene. Sent from my iPhone using Tapatalk
Reply:Originally Posted by papasmirfI would not consider acetone at all. First, it's highly explosive, you may possibly get some into the system and cause problem with the system, and last is you and others safety. This torch, combustibles, and human factor are reasons to leave acetone at home. The standard for the industry is clean pipe and fittings with sand cloth or scotch brite pads, put fittings together, wipe with a small brush a small amount of brazing flux where the joint line is, brazing with O/A and cleaning and cooling the joint with damp clean towel. I can't impress on you enough not to use any substance like acetone: lacquer, mineral spirits, kerosene. Sent from my iPhone using Tapatalk