SpudFiles

I have done lots of copper soldering. Here's some tips.
Clean your copper at the joints really well. They make products for this, but I usually use some vinagar and a scrub brush. Make sure to dry the copper really well afterwords. Next, scratch up the inside of the fitting and the outside of the pipe a little with some sandpaper. Apply a liberal amout of flux and put your pieces together. Heat the joint evenly. Get it good and red hot. Use gloves as mentioned before. You can use propain but mapp is much hotter and does the job alot quicker. After the joint is heated all the way around, apply the solder by pressing it into the joint on one side of the pipe, while keeping the flame on the other side. The melted solder should flow toward the flame and fill the joint. You shouldn't have to move the stick of solder around too much. You can move the melted solder with the flame. Right after you get the solder all the way around the pipe, wipe the still hot joint with a warm, wet rag (wearing gloves). If done correctly, this will create a very strong, air tight joint. Pressurize your chamber a little (15 - 20 psi) and submerge the joints in a bucket of water to check the seal.

Copper soldering isn't easy. It takes alot of practice and patience. It used to just piss me off when I thought I had done a good job but when I pressurised the plumbing, water would instantly start spraying everywhere out of pin holes in the solders. I have it down now after a lot of practice, but I still get an unexpected shower every now and then.
I Wish you luck in your project, Dark pyro. I hope this info helped.


Cheers

I guess I must have been lucky. I just helped my dad install the water softener, I just watched him do the first side, and then I did the other side myself, it looked ugly, and dripped every where because i didnt get it hot enough, but there were no leaks
also, how would you pressurize your cannon if it is a combustion?

Dark pyro never mentioned combustion.

I know, I am asking, If someone wanted to make a combustion, how would they check for pressure? or if they had some other way of pressurizing the chamber, such as one of the cannons here (they put water down the chamber, close valve, heat to steam, and thats the pressure). well I guess if that was the case, you would know because there would be no pressure left and you could re solder. but for a combustion how would you check it?

no i did not
i am useing for pneumatic cannon not a combustion
tnxs heaps for the help everyone ill put it to good use

Check this out. They have them at home depot.
http://www.watts.com/pro/whatsnew/whatsnew_ezsweat.htm
Watch the video. Thats really cool. I am going to try these out next time.

cool, let us know how they work

yeah looks good let us know 8)

I just might get one of those and try making a piston gun. They look realtively easy to put together. I always hated sweating copper pipe the regular way because you need 2 people to do it sometimes.

dont listen to anyone who says that solder isn't strong enough. i used copper to make my first cannon and melted it with a blow torch to apply to the cannon parts. i have pumped it up to 160psi so far, (my pump wont go any higher), and nothing has happened. This is just my experience and i accept no responsibility for what you use this information for.

hope it helps,
Corkie

Sweating copper pipe is where u `sweat' the copper before soldering,its used in areas where u dont want to heat up other connections to much and maybe cause a weak solder in a previously solderd joint.usual copper soldering is where u heat the copper to near metling point and add the silver solder to bond it and is often a stronger join.

solder i would say is not suited for the job. what u need to do is to braze it . that is much stronger. the difference is that solder melts under 800 degrees and the stuff u use for braze melts above 800 degrees. i believe u can just use a steel hanger for that. although i dont think u can melt steel with a soldering iron

You, my good sir, have no idea what you are talking about do you?

I am locking for thread kicking and stupidity.