White bread. And cut off the crusts. Otherwise once you’re done you’ll have to call the local radio home show on Sunday morning for help on how to find your sprinkler valves, dig them up, disconnect them, and dig out the hunks of wheat bread that don’t dissolve causing the valve to stick open oh so slightly, resulting in omnipresent wets spots on a part of your lawn.
I’d say “long story,” but that’s pretty much it. 
You may want to try these Pre-Soldered copper fittings.
Them there are the Yorkshire fittings, they are readily available in any DIY store in UK. Never understood why Home Depot, or the other big box DIY stores here don’t carry them.
My 200 pesos
I solder often. Here is my experience and what works for me.
YMMV.
Clean, new fittings are important. Solder is very thin and doesn’t cover large gaps very well. If you have large gaps, or older fittings that don’t fit well then brazing is preferred.
I strongly prefer sandpaper, and the “screen” kind is best. It comes in rolls about 1 1/4 wide. (its looks a little like window screen)
I sand the male fitting only, and only the female fitting if its older or been bouncing around in my bucket for a long time.
For the same reasons I usually flux only the male fitting, although for the reasons above I sometimes flux the female. Clean, new fittings get sanding/flux on the male only.
I prefer mapp gas, although I don’t see a huge difference vs propane. Both will work fine.
My solder of choice is Stay- Brite 8. My favorite flux is Stay Clean Paste Flux.
6)** How you heat the pipe is critical.** I disagree with heating the fitting first. If you think about it, at the fitting there is double wall thickness; the male pipe and the wall thickness of the female.
I start by heating the male, near the fitting. If you heat the male first the heat will travel into the fitting. Only after heating the male do you move your flame to the female fitting. Male first, then onto the female.
The solder will “chase” the heat. You apply the solder directly to the joint where the male meets the female. The solder will be “drawn in” to the fitting. That is happening because you A) preheated the male, and then B) moved your flame and heat onto the female fitting.
Never apply the solder with the flame directly. The solder is being drawn into the fitting by the heat of the pipe, not your flame. You may draw back your flame at the point of laying down the solder because the flame has already done its work; the pipe is already hot enough to accept solder. At any rate, at that point the flame is on, or near the female fitting. The idea is to use the heat/flame to draw the solder into the fitting.
If your pipe isn’t accepting solder there are a few possible reasons for it:
You didn’t apply flux, or enough of it. Just a slight layer will do. You don’t need to slop it on.
Uneven heat. You may have heated the fitting, but if the male pipe is still [relatively] cool, it won’t take. Try preheating the male before moving onto the fitting.
Overheating. If the flux turns grainy and blackish in areas, and you see the connection start to slightly smoke you overheated the connection. Ease off, cowboy.
Different size pipe naturally need varying levels of heat. You’ve been told that you can both underheat, and overheat the connection. As an example, I would guess (I’ve never timed it) that for a 1/2" connection I’d have my flame on the male for 5-10 seconds, and on the female another 5-10 seconds before laying down solder. 3/4" copper slightly longer.
By coincidence, I think you may live close to me.
If that’s true, I’ll gladly come give you a 15-30 minute tutorial and I’m sure by the time we’re done you’ll be competent, and depending how much you have to do you’d be pretty good after a couple hours of practice.
The offer is open any time.
I like boytyperanma’s approach. Draw the flame away slightly, near the far end of the female fitting.
Both will work fine. If you do one, do the male.
Doesn’t matter.
Once again, I think boytyperanma has a good approach. Move the flame around a little. The bigger the pipe the more important that is.
Very good advice, IMO
Appreciate it, raindog. May just do that. And thanks for the excellent advice above. (FYI, I live about 40 minutes north of Dayton.)
Did some more plumbing yesterday, and I’m getting a bit better at it. One potential problem is that I don’t know when to stop feeding the solder. Out of fear that the joint will leak, I have a tendency to use too much solder.
I get up to Sydney from time to time. That’s got to be close, I would imagine.
Its a common thing to lay down too much solder when you’re beginning. If you see big tear drops at the bottom of your horizontal connection you’re laying down too much. It’s deceptive because the solder “disappears” so quickly.
If you need phone advice, feel free to PM me and I’ll give you my phone number.
Good luck.
Clean the pipe end with sandpaper or emery paper-then wipe it clean with a paper towel-do NOT use your fingers-your skin will seposit an oil that will inhibit the solder wetting the pipe.
I agree though-the new tin/silver solder stinks-tin/lead flows much better, and gives a stronger joint.
You cannot, and should not, use lead solder in potable water lines.
I would guess that the worst solder you can buy would require 2500 lb of pressure to burst, and 30,000 lb to pull apart.
A house line is under 60 lb of pressure.
Any solder you buy will do the trick.
I’ve been told to keep a bucket of water with a wet rag on hand. After each connection is soldered, use the wet rag to immediately cool the pipe/fitting.
Yes? No? Doesn’t matter?
Funny story about sweating pipe. My buddy was teaching me how to do it at my house one day - we were replacing a line of galvanized. I’d never done it before, but I’m not a moron. He was way too far into the teacher/pupil scene, and was getting on my nerves a bit because he was really talking down to me as if he were Mr. Plummer himself.
Anyway, I was off doing my own thing for a minute and he was out of sight but within earshot. He was talking aloud, announcing every step he was taking for my benefit, even though I was already getting it pretty good. At one point, this is what I heard:
“Now you gotta be careful, 'cause this pipe gets really hot once you’ve put the flame to it. Never touch it with your bare hands, always use pliers…”
Then I hear, in succession:
Clang - sssssssss - Sonofabitch!!!
He had dropped his pliers, then went to hold the joint with his bare fingers. :D:D
I agree you should keep a bucket of water around.
When you heat and cool metal you are tempering it. The faster you cool it the harder the temper. Harder tempers are more prone to cracking. If there is no compelling reason to cool it, I let the pipe cool on its own.
If I need to handle the pipe soon after or have reason to want it cool quickly I will use a wet rag on it.
In the end I doubt it matters one way or the other. I’ve read no information showing good data either way. Considering the strength of the copper and the solder, annealed or hard tempered, I’m confident it can withstand the considerably low 30-100 pounds of pressure pipes are expected to handle.
Why would anyone be using soldered copper pipe nowadays, with all the available plastic, pex, etc. that is so much faster & easier to install?
Especially for something like a wet bar, which is a low pressure and low usage installation?
Local codes.
AFAIK, PEX is still not allowed in California, and various local jurisdictions also take a very dim view of PVC. Plumbing work in San Francisco can be breathtakingly expensive - not only is PEX and PVC of the menu, they have a charming way of requiring copper for drain lines. You don’t know what “expensive” is until you have to buy 30 feet of 1-1/2" copper for a kitchen remodel.
I think it’s likely that most plastics will be implicated in health concerns over the long term. And longevity issues too.