proper way to solder

I did do a search and saw some great information, so thanks. I am practicing on some extra fittings and pipe I have before I solder.

I also have 2 pieces of 26ga zinc plates to use as a fire shield, a wet rag, fire extinguisher, flux, lead free solder for plumbing.

However, I have a bunch of questions.

1) Will 220 grit sandpaper work to clean the fitting if I don't have emory cloth?
2) Should both pipes connected to a 90 degree elbow be sweated at the same time or should I do one connection, let it cool and then the other?
3) Using LP, should the flame still be on the joint when the solder is applied to the other side?
4) When doing a connection that is vertical, will the heated joint draw the solder up into itself? I still have a tough time envisioning solder flowing uphill.
5) Approximately how long should a copper joint be heated? The LP instructions say 30 seconds, but I read in several post, anywhere from 15 seconds up. I have the feeling I am overheating the joint. I see the flux burning off (smoke) and it is only about 10-15 seconds. I have the feeling that I am burning off the flux and it isn't helping to draw the solder into the joint.
6) I saw a post that said the person wiped a wet rag on the pipe to remove excess flux before applying the solder. I would think that would cause it to cool down and need some more heat, right or wrong?
7) And no, I want to do this myself and not call a plumber...I want to learn this for the future too.

You are ready to solder. It really is not very difficult and as long as you are careful not to burn down your house, you should not have any problems. It is good to keep a fire extinguisher handy. Since the water will be turned off, that is your last defense. (1)The sandpaper should work, but if you are doing more than a couple of joints, you can get waterproof sandpaper specifically for plumbing or a couple of different tools that contain wire brushes to clean the pipe. (2) You should sweat all joints at the same time. No need to let one cool before moving on. (3) As far as keeping the flame at the joint, you will get the feel for it. You just do not want to put the flame directly on the solder. Keep the solder on the opposite side. (4) Solder will run vertically into a joint. Once you do it, you will see, it just happens. (5) Don't worry about keeping track of the time, just heat the joint until it takes the solder. sometimes you could hav a litle water in the pipe which makes it take longer. If it is taking too long and the pipe turns black, take apart the joint, clean and re-flux it. I find I have less problems with heat when using MAPP gas which burns hotter. (6) You should use the wet rag after you are done soldering, but while the solder is still hot. You do not have to, but it looks a little better.

Good luck.

I will practice a little bit more and thanks for the response. I have solded electrical wires but that is a little different (flame vs hot metal tip).

I was under the impression that the wipe not only made it look good but avoided the possibility of having flux left under the glob. This could cause the acid flux to eat at the solder and eventually cause pinholes and maybe leaking. Is that correct?

solder

Wipe it to get the remaining solder paste off.......

Buy a foot of 1/2" copper pipe and a few fittings, and practice soldering in the garage or basement a few times. You'll get the idea and do a better job when it "counts". Look at it as a $5 training course.

I bought a 10' piece of L copper. I need about 3-4' for all the connections and I am using the remainder to practice a lot.

Another note,

Always solder your joints FARTHEST away from you BACK towards you .You don't want to lay a hand or forearm over a freshly soldered pipe .

There is an "old rule" (kind of) ,,1/2" joint--1/2" solder, 3/4" joint"--3/4" solder . That is if the pipe/fittings are clean,dry,fluxed and not OVERHEATED .

Let the joint cool of somewhat before wiping with a wet rag,otherwise you will "crystalize" the wet solder and weaken it .

Practice,,,,you will learn the difference .

New pre-soldered fittings

I worked with pre-soldered fittings today. Work like a charm. Just clean the pipes. Apply flux on the pipes only. Dry fit both pipes and start the flame. In no time you see the solder comming out and you are done. Tested at 100 psi. It works.

fittings

IF you only flux the pipe, unless the fitting has a heat activated flux on it, you have no guarantee that the fitting will not oxidize before the solder flows, and depending on the excess flux on the pipe to protect it would be risky.

I have been practicing and several of the sweated joints look good now. I just need to get time to do the real job now.

joints

Some of the worst solder joints I have ever encountered "looked good". External appearance has no relevence to the integrity of the joint. You have to take the joint apart and see if the inside of the fitting, and the outside of the tubing are completely coated with a layer of solder.

I did look at them through a magnifying lens and it looked like a solid ring of solder was between the ID and OD of the fitting and the pipes.

But you are suggesting that I reheat my test joints and see if they are covered with solder. I guess I can do that with the test pieces.

joints

As I said, many very poor joints had a perfect bead of solder at the face of the joint, and at least one that I know of, inside a cabinet, held for 20+ years until the owner dropped a can of peas on it and it came apart and flooded the kitchen.