Test for leaks in counterflow chiller?

I recently made a counterflow chiller out of some spare copper pipe I had laying around. It was in pretty bad condition to begin with, and I kinked it a good bit as I formed it. The outer part where the tap water flows doesn't appear to have any leaks, but I'm afraid I may have kinked the inner copper enough to tear a hole.

Any bright ideas on testing this thing for leaks? I thought about running a recirc loop through it from my HLT and testing for volume loss, but I don't think this would reveal any very small leaks without taking a very long time, and I don't want to leave my pump running for more than a few hours.

 

What you can do is run a strong solution of food dyed water through your copper line, while running a slow flow of water through your outer hose. If you see any evidence of dye in the discharge from the outer hose, you have a leak.

 

Good thought. I don't even have to be running the water through the outer hose, I can just flush it after a few hours.

 

Or if you can block of the "wort" outlet of the CFC and attach a garden hose to the "wort" in, turn the hose on full bore and check if any water comes out the cooling side (leave it pressurised for a couple of hours).

 

Might even be better that way. More time for a small leak to show itself.

 

Do you have a pressure gauge? Use some tubing to connect the gauge to one side, pressurize the wort line (with air/water/co2), and then let it sit and see if the pressure drops.

 

More good thoughts. I'm trying the food dye right now. The garden hose pressure idea is probably better, but oh well. Pressurized air would be good too, but I don't think I have the equipment for that. Could probably use pressurized CO2...