Forum Title: Failing copper joins during soldering
I am re-plumbing our 70 year old house with new copper pipe and fittings.The underfloor crawl space is about 16inches (40cms) so access is a challenge. I am a human ferret -- luckily only very slight build.When I started getting too many joint failures and soaked to the skin I changed my process to assembling manifolds in my workshop then making final connections under the floor. (Thankfully it is mid summer here)Some of the final connections are failing/leaking and in some instances are not even structurally sound. When I melt/pull the joins apart the failed joins are black on the pipe, not a sign of any solder. I am using (water soluble) flux for lead less-solder and using lead-less solder (roll of coreless lead-less solder) - using abrasive plumbers tape on outside of pipe and fittings brush prep in copper fittings. - liberal use of flux in fittings and and on pipe -- before assembling ready to solder. - using MAP Gas which I know is extremely hot and potentially overkill to melt solder. - because of access problems I cannot get the heat behind the fittings, only from one side because of close proximity to bearers, joists and flooring. - and I simply cannot move quick enough to new positions to try and spread more heat. Overhead soldering is not easy and potentially a risk for personal burns (none so far)This is my first experience with lead-less solder. I have plumbed out several houses before (using sticks of lead solder) but never tight access This current project has me baffled -- and overhead soldering is not easy. Here in OZ lead solder is still the national accepted standard. Q1: Is leaded solder easier to apply and more predictable than lead-less solder. ? I wonder if my problem might be too much heat in a short time with MAP gas on high or not enough solder available on top of the fitting when soldering over head - I cannot see the top of overhead fittings so I am never sure if the solder-wire is on the edge of the capillary gap or not - (I could do with a third arm at times, but alas I only have two hands ) - even soldering both ends of a copper fitting is a challenge because of cramped work space - I guess my question is would I be better of with a stick of solder rather than the thinner rolled solder. - I bend a hook in the end of the rolled lead-less solder to start the solder flow on top of the fitting/joint -- and heat the fitting to apply the solder. - I take the heat off the join while applying the solder - most of the joins by previous plumbers are covered in solder, not as neat as my joins, but frankly I don't care what the joins look like ... as long as they don't leak and are structurally sound Lead-less solder and flux are all new - (my leaded solder flux is about 12 years old - the greasy type of flux for lead soft solder) There are 3 joints in very awkward locations that are giving me grief. - in frustration I used 2 straight push-on (for copper) connectors - push-ons are 10 times the cost of soldered copper fittings. - the third fitting is presently isolated (the push-on caps for copper do have their use) She-who-must-be-obeyed is getting impatient for her refurbished laundry - the upgrade revealed a lot of water supply problems ... I assume by qualified plumbers. I would be very grateful for any help -- thank you
Post By: LOUISE HUGHES (Springfield, IL), 06/29/2016
you don't need a liberal amount of flux. Just a thin coat Soldering is like cooking. Easy on the heat. You only need about 350 F or so to melt solder. flux will burn before you get the pipe in the fitting up to temp. I use a torch with an adjustable flame. If you don't have, just throttle the trigger with finger pressure. Don't hold the flame in one spot. If it's just 1/2 and 3/4 you don't need a lot of heat. if you have water then you got a problem. There are a lot of videos on YT. Trick is finding the right one. The pipe inside the fitting takes a little longer to get to solder melting point than the fitting. To much heat and you burn the flux before the pipe gets to temp. Like cooking and egg. Cook it! Don't burn it.
Also, are you trying to solder as you go? Or piecing everything together and soldering all at once? Any water getting into the pipes? Could you be getting your hands on the pipe ends after they been fluxed?
Can you post a few pictures of some of your joints?