05-24-2019, 01:06 PM
Join Date: Apr 2006
I rescued this little guide from the Stock Class Paintball forum.
I don't recall the original post date but I think it was before 2008.
Eric Six made a bunch of side tube PGPs, he then posted this guide about what he had learned about soldering.
Brass Soldering Basics |
By Eric A. “Six”
Soldering is a means of joining metals (Brass in this instance). Regardless of the type of solder you use the technique is essentially the same there is just a difference in melting temps.
Whenever you work with copper or brass, tin etc. do so in a well ventilated place. When you are filing it, grinding it, heating it etc. or in any way coming in contact with such stuff wear a mask. Why? Heavy metal poisoning; It takes a bit of exposure to do you harm - but the harm is irrevocable. It causes severe neurological problems; it can make you twitch, and make you Mad...Mad as a hatter in fact... Do some research on this subject.
Torch - get a torch designed to burn Mapp gas. This will provide more than enough heat to do any solder work you want. You can use a propane torch, but it takes much longer. Use Map gas though as it isn't much affected by cold like propane, and is very quick to heat things with the proper torch head.
Flux - with brass, copper or tin use a resin based flux. From all of the reading I have done this is the best stuff to use for copper, Brass, and bronze. I use a paste type flux that is common in any plumbing section in stores.
Solder – There is a number of solders on the market that come in various types with different melting points, strengths and physical properties. For constructing paintball guns silver solder is likely the best to use but in some areas it is hard to find and must be special ordered. I often use common 50/50 lead/tin solder that can be found at any plumbing supply store and I have not had problems with it. 50/50 lead/tin solder is intrinsically weaker than silver solder however I have used it for some time now and I’ve not had a gun spontaneously explode on me or fall apart – and I’ve put my guns through some pretty rough use.
Cleaning - Any surface that you plan to solder must be immaculately clean. On brass I used to prep with 220 grit wet dry sandpaper, then 400 grit. At the suggestion of Bret G. over at MCB I have since started using Brasso and steel wool. When all debris and gunk is removed from the surfaces with the sand paper / Brasso / steel wool, I then take some paper towels and some Windex and wipe them all down being careful not to even touch the surfaces that are to be joined. This helps to remove all impurities from the surface and ensures that you will have nothing to disrupt the capillary action of the solder in the joint. Once cleaned, I don't touch areas to be joined because of fear that oils from my hands may get on the clean surfaces. If there are impurities, the flux will not penetrate evenly, capillary action may be inhibited and the solder will not stick, join or penetrate effectively resulting in a weak joint.
Setup – Once you’ve got things milled, cleaned and are sure that everything is in order it’s time to setup to solder. Line up the pieces to be joined and secure them with clamps, wire, hose clamps or whatever you have available that will keep the items in place and not allow them to “shift” around when you are soldering them. Once you have the items immaculately cleaned and secured in place it’s time to solder.
Base Technique – Apply flux to the area to be joined. Light your torch and begin heating the area. BE SURE THAT THE FLAME OF THE TORCH DOES NOT TOUCH THE AREA DIRECTLY as this can cause carbon impurities that will affect / disrupt the capillary action of the flux/solder. Heat the area and apply solder to the area to be joined being careful not to touch the solder or joint area with the flame of the torch. If things are going right the solder should be “sucked” into the joint by the flux through capillary action.
I usually “spot solder” a section, let it cool and then spot solder another section further down the joint or on the other side of the joint after the initial joint has cooled. NOTE: Allow the brass / joint to cool by ambient temp. DON”T douse the joint in water as it will cause warping of the metal.
Mill / Fit; Clean; Secure; Flux; Heat; Solder - the technique doesn’t change. You use the same technique to join barrels to valve tubes; add feed-tubes; Receiver shrouds; Sights etc.
You can take advantage of the differences in melting temps of some solders to add greater ease and creativity with some items. For example: Using silver solder to secure a sight to a barrel collar and then using 50/50 lead/tin solder to secure the barrel collar to the end of the gun to use as a sight. The silver solder has a higher melt temp so it won’t fall apart when you solder the barrel collar to the barrel of the gun with 50/50 solder.
Final note, you can practice your soldering skills and technique on common copper pipe and tubing. It is inexpensive and there is little difference between soldering brass tubes or copper ones. Good luck!
Many thanks to Bret G. over at MCarterBrown.com for suggestions on soldering techniques and construction tips.