johnsmachines

In the previous post I described my attempt at silver soldering the condenser unit.

The 29 joins on one end were quite water tight, but the other end leaked like a sieve.

I decided to try to fix the leaky end, by doing the following….

1. I shortened the copper tubes which were protruding more on the leaky end, thinking that the deep narrow spaces between the tubes might not have become hot enough during the soldering.

2. I used a Dremel to enlarge the spaces between the copper tubes.

3. I watered down the flux to make it more runny, in an attempt to get it into the narrow spaces.

4. I used a larger oxy-acetylene tip, to deliver more heat onto the job.  I think that maybe (as per reader John’s suggestion) I was getting intense heat at the soldering point, but maybe not enough into the base metal of the condenser.  The condenser is a thick brass, heavy object, and maybe, maybe it just was not hot enough.  With the bigger heat delivery, it did show the dull red heat which is recommended for silver soldering.  Also, I used a lower silver content rod (45%), again reader John’s suggestion, because it melts at lower temperature, and is less viscous, than the higher silver content rods.  Thanks John!

End result….

The condenser unit, after today’s soldering fix. Note: there are no air bubbles rising! It is air-water tight, at atmospheric pressure, which is adequate, because it is a low pressure unit.Then I glued the end covers onto the unit, using Loctite, in preparation for the next step, which is drilling and tapping the holes for the BA7 bolts which will hold the end covers in place.