SpudFiles

is there any special method people use? as im afraid if i use some random method it wouldnt hold much pressure

just clean the surface, put some flux. then warm it with torch and put some solder into it. i suggest you to do a small test with 2 caps and piece of pipe and attach a scrader into it and the try how much pressure it can hold

Welding or soldering? I believe copper can be tig welded but it's quite difficult. If you mean soldering then its very easy just as jakethebeast said, clean, flux, and heat the pipe and joints enough so that the solder will sweat in, there are different types of pipe thicknesses and diameters, and types of solder to take into account when determining pressure it will hold.

oooh! ook ok thanks alot for the fast reply guys

jor2daje wrote:I believe copper can be tig welded but it's quite difficult

It isn't as difficult as you think. It is just like welding steel really. The welds tend to get very poreous though.

But theres a difference in soldering, you can soft and hard solder it.

Soft soldering is done with tin as a medium (standard solder, but of course without a flux core!) You have to get pure Tin thread for soldering with copper, as usual electrics solder contains flux, so you don't have to put it on seperately.

But you want to put the flux (which is usually liquid) on the pipe itself.

Get some plastic copper cleaning sponge and clean it off till it shines (grab it hard with the plastic sponge and twist like ~5 times)

As the Soldering point shines add the Flux, and connect the two pieces, the solder will only flow where the flux is. (So other part must be cleaned too)

Now just heat the part until the flux starts to move bubble or melt or whatever and just putt one end of the Tin to that little slit between the pieces, the capillary force through flux, will pull the Tin everywhere. You can easily see if its enough, when you can see the Tin on the other side of the pipe (You really only have to touch one side with the solder, but can smear it around if you like, just won't look that good)

Done.


Then there is the "Hard soldering" method which is more expensive, as the metal sticks you need for it are quite expensive, look for a store who sells them cheaper. You need some kind of silver alloy. (Mostly contains like 3-5% Silver)

The welded parts will look a bit uglier, but this method is more durable and far more heat resistant. (Usually I think tin soldering is enough)

You do it the same way: clean, flux, put together, heat (hotter than before) and just put the staff of metall at the welding spot, it will creep between the two parts.

Done ^^

The "hard" solder uses brazing temperatures. It requires a "carbonizing" flame to use the self fluxing properties to get a joint free of porous oxides. This is the brownish joints you see on the connections on refrigerators. It requires a welding torch to do it properly.

It is very strong and leaktight when done properly.

Soft solder comes on a roll. The hard solder comes as a stick much like brazing rods.



Plumbing solder, electrical solder, silver brazing solder

Some of my silver brazing

Be aware that although brazed joints are stronger...the temps required to braze are high enough to anneal the copper pipe...lowering the working pressure. Not a problem on the annealed tubing used to plumb a fridge, but an issue on drawn tube used in most spuddy applications.

IMHO, sweating with 95/5 Tin/Antimony is the best bet for high strength joints at high pressures.

Reading material for the op;


http://www.google.ca/url?sa=t&source=we ... wB3yLmPGBQ

This is true that brazing does anneal the copper. So would welding. Brazing is at a lower temperature than welding. Hard silver solder is often used in installations with hard drawn copper tubing. It is used because no flux is required so the inside of the pipe stays clean when a shield gas is used. The annealing does provide some flexibility at the joints to reduce cracking.