hello all, having hell of a time trying to solder some brass pipe to copper
pipe, I have flared the copper so it has about 13 mm1/2 inch sleeve onto the
brass pipe. Its an old car radiator I am hoping to adapt to cooling a
stationary engine set-up. With 10 mm pipe running external round the engine,
I want to drop it down to normal 13mm/1/2 inch then to 10 mm bore bendy
copper tubing. I'm sure it must be easy,,, if you know how, unfortunately I
don't. I can fix the copper to copper no problem. I am using normal plumbing
lead free solder/flux with a small propane blow torch. I have tinned both
pieces but when I try to mate them together the solder sort of reacts funny
spits a bit and goes all lumpy with no shine left. Any one got a pointer for
fixing these together? Thanks very muchly.

OK, are your surfaces totally clean and dry? It sounds like you have
some kind of contaminant in there somewhere. What you might have to do
is heat the area you want to solder, and then brush some flux on it.
This will clean the surfaces. As a Plumber, I can tell you that it can
sometimes be quirky. You meantioned you've tinned the parts, are they
shiny and all silver colored? Before you started heating to solder them
together, did you add fresh solder to the joint? It's not complicated
really, but I always found that there were a few things that had to
work together, and that could sometimes make it complicated.

Good luck, and let us know how it works out for you.

I've had great success with Solder-it - a syringe paste applicator.
May have Lead, but DOES have 6 pct or so Silver, very strong,
excellent flux. Most hardware stores /mark


wrote:
OK, are your surfaces totally clean and dry? It sounds like you have
some kind of contaminant in there somewhere. What you might have to do
is heat the area you want to solder, and then brush some flux on it.
This will clean the surfaces. As a Plumber, I can tell you that it can
sometimes be quirky. You meantioned you've tinned the parts, are they
shiny and all silver colored? Before you started heating to solder them
together, did you add fresh solder to the joint? It's not complicated
really, but I always found that there were a few things that had to
work together, and that could sometimes make it complicated.

Good luck, and let us know how it works out for you.

wrote:
hello all, having hell of a time trying to solder some brass pipe to
copper pipe, I have flared the copper so it has about 13 mm1/2 inch
sleeve onto the brass pipe. Its an old car radiator I am hoping to
adapt to cooling a stationary engine set-up. With 10 mm pipe running
external round the engine, I want to drop it down to normal 13mm/1/2
inch then to 10 mm bore bendy copper tubing. I'm sure it must be
easy,,, if you know how, unfortunately I don't. I can fix the copper
to copper no problem. I am using normal plumbing lead free
solder/flux with a small propane blow torch. I have tinned both
pieces but when I try to mate them together the solder sort of reacts
funny spits a bit and goes all lumpy with no shine left. Any one got
a pointer for fixing these together? Thanks very muchly.

Clean everything up good - get all the old soldier off as best you can.
Flux the joint and heat until the soldier wicks in.
In my experience that 'lead free' soldier doesn't like being heated multiple
times and gets downright nasty if overheated.

Ken.

You are using a hot enough torch, right? 99% of the soldering problems I've had
were due to not enough heat. Most of them went away immediately when I got a
proper O/A torch.

GWE

Ken Davey wrote:
wrote:

hello all, having hell of a time trying to solder some brass pipe to
copper pipe, I have flared the copper so it has about 13 mm1/2 inch
sleeve onto the brass pipe. Its an old car radiator I am hoping to
adapt to cooling a stationary engine set-up. With 10 mm pipe running
external round the engine, I want to drop it down to normal 13mm/1/2
inch then to 10 mm bore bendy copper tubing. I'm sure it must be
easy,,, if you know how, unfortunately I don't. I can fix the copper
to copper no problem. I am using normal plumbing lead free
solder/flux with a small propane blow torch. I have tinned both
pieces but when I try to mate them together the solder sort of reacts
funny spits a bit and goes all lumpy with no shine left. Any one got
a pointer for fixing these together? Thanks very muchly.


Clean everything up good - get all the old soldier off as best you can.
Flux the joint and heat until the soldier wicks in.
In my experience that 'lead free' soldier doesn't like being heated multiple
times and gets downright nasty if overheated.

Ken.

You're overheating the joint and the lumpiness is from the solder going bad
from the heat.
Keep the heat down on the joint by not heating it but rather the metal near
it. You may want to go to a soldering iron rather than the torch on thin
sheetmetal pipes. There is no reason why brass and copper can't be soldered
together as the brass is a copper alloy.

--
Why do penguins walk so far to get to their nesting grounds?

thanks for the tips chaps, a pall said to tin it with 'old fashioned
electronic solder, apparently full of lead and an old flux called rosin, or
some such, tinned both pieces using the 'dirty' solder and then used normal
lead free. fixed like a charm! cheers!