Tracking down very tiny regulator leak

[zolakk]

I'm dusting off my regulators after an over 1 year hiatus and I noticed that there must be a very tiny leak somewhere because after pressuring the set and then closing all shut-off valves including the one from the tank regulator they will lose pressure over a few days - for example in my pic the regulator on the right by the blue tape read 40 two days ago but the others have held steady (I'm guessing once it drops below 10 the others will follow suit). I've tried soapy water and star san on all parts but nothing bubbles and I'm not sure what else to try since I don't think I can submerge it in water, or is that just the actual gauges themselves I can't get wet?

 

[Bobby_M]

I'm dusting off my regulators after an over 1 year hiatus and I noticed that there must be a very tiny leak somewhere because after pressuring the set and then closing all shut-off valves including the one from the tank regulator they will lose pressure over a few days - for example in my pic the regulator on the right by the blue tape read 40 two days ago but the others have held steady (I'm guessing once it drops below 10 the others will follow suit). I've tried soapy water and star san on all parts but nothing bubbles and I'm not sure what else to try since I don't think I can submerge it in water, or is that just the actual gauges themselves I can't get wet?View attachment 611682

The one spot that is prone to leaks and hard to spot is the pressure reading coiled tube inside the gauge. The end is soldered shut and ive found a leak there twice.

 

[zolakk]

I never thought of that, but it would make sense considering no other connections have obvious signs of leaking. Any tips for checking that? I've not been able to find anything online aside from the soak the other connections and look for bubbles

 

[Bobby_M]

I never thought of that, but it would make sense considering no other connections have obvious signs of leaking. Any tips for checking that? I've not been able to find anything online aside from the soak the other connections and look for bubbles

Remove the front lens and the two screws on the back. That allows you to tip the case back. Spray soapy water and look for bubbles.

 

[zolakk]

Remove the front lens and the two screws on the back. That allows you to tip the case back. Spray soapy water and look for bubbles.

That did the trick, thanks! The gauge I had set to 40 in the pic had a very tiny leak right where the metal C part of the gauge mechanism was soldered to the base.