Thursday, July 15, 2010
Leaks, leaks and more leaks
Its a moral tale... and the moral is: pressure test everything as you go along.
I'm guilty of rushing a few bit here in retrospect. I got a bit carried away with the excitement of nearly having the pump finished and didn't pressure it at the silver solder stage. Because once you start soft soldering you cant go back and fix your bad silver solder joints.
So for the pump barrel I pumped the system down as much as I could with the backing pump and painted some shellac on to the area that was leaking. That fixed that for now. How well it stand up to the 220 degress plus, I dont know.
This was in interesting discovery. I found a bad lead solder seam which looked ok and worked ok for the last few months. But now I found it was leaking. Naturally enough it was the last place I looked. I desoldered and resoldered everything else, assuming that one was good. Then in exasperation, I pressure tested it. And there it was...
Today I hooked it all up and pumped a but of water through the cooling sleeve. There was a leak there too. Actually two leaks:
One I thought I'd fixed, close to the bubbles in the top photo.
The other at the top of the sleeve. This one only became apperant when I was pumping the water through. I had tested it initally just with gravity and it was fine. But the small pressure of the pump pushed a bit of water above the inlet level and squirted out the top.
High temperature silicone!