Hey Guys, can someone tell me how to solder brass tubing? I feel a little stupid for asking, but I can't make it work for some reason. Do I need some special solder, special flux, or what? My problem is I can't get the solder to seep down into the joints.
Please help. Thanks up front.
Zack
3 reasons why you can't get the solder to "run" 1 You didn't get the job hot enough. You could try a bigger wattage soldering iron or a small blowlamp 2 The wrong kind of flux. You really need a phosphoric acid based flux. The resin based fluxs will work, but see reason 1. Phophoric based fluxes can be had from the Model Railroading suppliers. 3 The brass isn't clean. Oxidisation on the metal can prevent any kind of flux and solder combo from working. Some brass even has varnish on it to prevent oxidisation which also prevents soldering. Clean the joint throughly with wire wool or a light abrasive.
I'm using a "plumbing kit" to solder the tubes. Is this maybe the wrong kind of solder?
I know it's plenty hot, I just tried it again and melted the tubing. I'm using a small torch not an iron to heat the piece. I went over all the parts with sandpaper to clean the parts and give the solder something to "grab", but it is still just bubbling up on top.
Most plumbing fluxes are the self cleaning sort but cleaning the joint still helps. Don't use sand or glass paper as they leave fragments use the wire wool or coarse wet and dry paper. If the joint is really tight fit it can stop the solder penetrating. Try "tinning" the parts first, clean, flux then give the part a light coating of solder and wipe it off while it still liquid. The part should have shiny silver coat all over. Flux it again and assemble the joint. Warm the job gently and dip the end of the solder in the flux and touch it to the joint. If the tempreture is right the solder should run in and capillery action will run it alround the joint. Most plumbing solder melts around 180-200 degrees C so it doesn't take a really hot flame. a soft blue flame should suffice. Don't forget that plumbing flux is designed to work with copper but it should solder brass no problem and remeber that it tends to be acidic so wash the job with a weak washing soda solution to neutralise it afterwards. Failing this its a specialist flux for brass. Solders tend to be much of a muchness so the type tends not to matter. Lower melting point types are easier to use though. HTH
Probably, try 63/37 or 60/40 tin/lead electronics solder and an iron, not a torch.
If it just sits in little globular balls you have what is known as dewetting and you're pretty much hosed for those pieces. This can happen when you overheat copper or brass and it's a bitch to correct.
I wrote an article for FSM on working with metal a couple of years ago. Covered soldering brass. I use resin core solder, found at places like radio shack and some hardware stores. The electronics solder is made in small diameters, and easy to heat with small iron.
You need to get heat conducted from iron to metal. Best way to do this is hold iron against brass tubine, and melt a bit of solder on the iron tip right where it is touching brass. The solder melts, then flows across the gap. You now have a gob of liquid solder conducting heat from iron into brass- heats much better than the small area of contact between iron tip and tubing. You can easily clean off extra gobs of solder on workpiece when you are done with needle files. Also, make sure the second piece of tubing is heated well. When first piece is hot enough, melt some solder down in joint and hold iron on first piece long enough so that solder between the two pieces of tubing are completely melted for several seconds.
Oh, and make sure to clean the tip of the iron just before using it. A wet sponge is best, but a rag will work in a pinch. You have to wipe it fast, so rag doesn't burn, but it will work. The tip of the iron should be shiny, silver colored.
Rosin core flux works fine on brass. Acid core is needed when joint is really corroded, but if the brass stock is un-used, it only needs a mild cleaning, and I find rosin core works fine. I like the rosin core electronics solder 'cause I can get it in 1/16 inch diameter. Hard to find acid core solder in that fine a diameter.
OK guys. I think I got it. I backed off the heat and used an Iron instead, changed to electrical solder, and it seems to work like a charm.
Thanks for all of the imput.
Zack
Anytime.
No problema
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