Sweating Copper/Brass

[JimBinMI]

Cowboy,

The panels were made for home heating, the folks that I bought them from had them mounted on their roof and heated water for use in the house and for some home heating. I have three more panels, 6 in all that I want to get added.
They connect to each other with 1" copper and I ran about 54' of the stuff to connect everything together. The pool uses 1 1/2" black piping.

A lot of people with pools around here have heaters. A new one is about $1,400 plus the propane (I don't have natural gas available) cost yearly. I paid $500 for the panels with aluminum frames and all the mounting hardware plus a storage tank and pump system that I haven't used.

JimBinMI

We boys and our toys!

 

[Bird]

JimBinMI, you may have the same kind of torch I use, but if you had any water at all in there, that could sure keep it from working right. And I agree with Cowboy; sure don't have to do much copper sweating since PVC got so popular.

We had an inground pool put in the backyard when the kids were younger and we lived in town. Thank goodness, I don't have to maintain one of those things anymore!/w3tcompact/icons/smile.gif

Well, our big neighborhood July 4 celebration and barbecue is always on Saturday on the 4th, or the Saturday before, so it's about time for us to go the neighbor's place. We put one goat, one pig, and a few briskets and chickens in the smokers yesterday evening, so they ought to be about ready to start eating./w3tcompact/icons/smile.gif/w3tcompact/icons/smile.gif

Bird

 

[RickM]

JimBinMI,
Is this brass valve a ball valve? If it is you will need to wrap a wet rag around the middle of it to avoid damaging the teflon seats when applying heat. From what has been posted I'm guessing that you do not have enough heat from your torch. That brass valve is an enormous heat sink. The rule of thumb is that a hand held propane torch is good for up to 3/4" copper sweating. You might get away with sweating 1" if it is only copper pipe and fittings. For sweating 1" copper and a brass valve I think you will need to have use of an acetylene torch. They do however make hand held torches that use MAPP gas and a special head that employs a "swirl tip" combustion for a hotter flame. Be sure to clean/polish the inside of the valve and outside of the pipe mating surfaces and use lots of paste flux and don't forget the wet rag if the valve has any "plastic" seats inside. Good luck. /w3tcompact/icons/smile.gif

 

[gordon]

Jim this is from a Master plumber me.
The propane torch may not produce enough heat but you still should be able to sweat it in with no problem.
With the valve your dealing with a much larger mass than a regular coupling so it will shed the heat much faster and also take longer to heat as well.
The key to a good sweat joint is making sure the valve and pipe are both cleaned with scrach cloth and fresh flux not the can you have had open for two years thats turned from brown to partial black.
When using 95/5 solder it takes a large amout of heat to get it to run and a short working time.
Now with the valve cleaned and fluxed apply the heat to the pipe for a couple of seconds then start heating the valve on top then sides then bottom and the solder will run right in capallary action is what happens.
Now if you have already done all that and the solder won't run your torch isn't getting the valve hot enough. I don't really care for the small propane torches but their good in a pinch. Go to the rental center and get a B-tank and you'll get more heat than a little bit. Use a number 4 tip and that should be fine for a one inch valve. Or you could use a turbo tip on the propane torch makes a great difference or go to mapp gas.
Good luck
The key clean joints clean and fresh flux and quick high heat.
Gordon

 

[JimBinMI]

RickM,

Yes, it is a ball valve with teflon seats, I didn't use a wet rag though. It's OK if the valve leaks a little, in case I damaged the seats. As I said earlier, I'm trying to restrict the flow of water from the panels so that the water can get more heat while in the panels.

Your answer is what I thought might be the problem, I was getting the copper hot enough to melt the solder with the flame removed, but the solder never really flowed into the connection. I used this same torch with propane to sweat over 50 feet of 1" when initially installing the panels so I know it works for the 1". Not sure if it's worth buying a new torch, even though the valve cost me just over $15!

The welding teacher that works in my building might be able to help me, just thought of him! I used lots of paste flux and cleaned all surfaces.

Thanks for the info Cowboy, Bird and Rick,

JimBinMI

We boys and our toys!

 

[JimBinMI]

Gordon,

Thanks, sounds like good sound advice! Yes, the flux I'm using is older and darker, I have a container that I haven't used yet, when I try it again, I'll use that and probably a hotter flame.

JimBinMI

We boys and our toys!

 

[RickM]

Jim,
There is another solution, but might be more costly./w3tcompact/icons/frown.gif A 1" ball valve with threaded connections and 2 adapters (1" m.i.p. X 1" compression). My guess is that your system runs at low pressure and if that's the case the compression fittings should be more than adequate. An added benefit of this method is that the connection can be taken apart and remade again with hand tools.

 

[gordon]

Good idea that might be the best way for you to go if you can't get a decent soldered joint.
Gordon

 

[Anonymous Poster]

Jim,
You may not need that valve at all. You said the goal was more heat. Reducing the flow of the water through the solar collectors will produce less heat not more. Sure the water discharging into the pool will be hotter, but since there is less of this hot water the BTU's added to the pool will not be greater. The BTU's will in fact be less because the rate of heat transfer in the collector is partly determined by the difference in temperature between the water and the hot surfaces heated by the sun. The bigger the temperature difference the more transfer. In addition higher water flow creates more turbulance in the pipe which increases heat transfer as well.
If your goal is to have a hotter stream of water discharging into the pool then slowing the flow will help. If your goal is to raise the temperature of the pool then slowing the flow will not help.
If you do want to slow the flow, how about soldering in a short section of smaller pipe, like half inch.

Andy

 

[TomG]

Hope you got it fixed by now. Whenever I've had trouble getting a good solder joint, it's been water dribbling down the pipe into the joint. Like other comments, it doesn't take much water before a joint just won't solder. Converting water to steam takes a lot of calories.

One other basic that may be obvious is that the hottest part of the flame is just a little further than the tip of the inner cone. A joint may not solder well if the joint is inside, or too far from, the inner cone. Also good idea to keep a fire extinguisher handy when using a torch in close quarters around any combustibles. You get concentrating on heating the joint and don't notice that you're also charring a wall stud.

When the valve is finally soldered and holding pressure, you may notice some droplets of water forming on the valve body (if it's cast brass). There can be enough so it looks like a leak if you just glance at it. Don't do anything radical for awhile. Freshly soldered cast brass can be porous enough to pass water through the wall. That's normal, and it stops in 20 minutes or so.