Finding a leak

[miketeachesclass]

I’ve got a 1980 globe stamp that I love. After its last cleaning, a hole developed, which was patched. I have a suspicion there’s another very small leak somewhere, as the resistance has changed.

Does anyone have a suggestion for a method to find a small, possibly pinhole leak?

Thanks!

[miketeachesclass]

I feel a little dumb saying this, but I did find a thread from 2016 that provided some useful info. I would take any additional suggestions though.

[Snake Charmer]

Easiest way is flushing the instrument. I use an adapter to connect the shower hose with the leadpipe and flush warm water through the horn. Important is to start with a dry horn, don't spray water on the outside while connecting/adjusting everything. If you have some light moving tuning slides secure them with rubber band or tape. Turn the water on (the bell pointing downwards into the shower tub) and look along the instrument for waterdrops. Press the valves while water is flowing (one at a time).
If you don't find a leak this way there is none, but anyway you have a clean horn (after emptying and lubricating)
In the last 30 years I detected pin holes, cracks, a split leadpipe, leaky tuning slide fit, bad solderings and failing waterkeys!
I takes roughly one hour to do this including cleaning up the shower. It's better not to wear too much clothing, when emptying out a bigger horn the chance is good to get wet at some point

[tokuno]

I would imagine that a compressor to the leadpipe, plastic wrap on the bell, and plumber's leak detect might work.

[miketeachesclass]

I will absolutely try this. Thank you.

Easiest way is flushing the instrument. I use an adapter to connect the shower hose with the leadpipe and flush warm water through the horn. Important is to start with a dry horn, don't spray water on the outside while connecting/adjusting everything. If you have some light moving tuning slides secure them with rubber band or tape. Turn the water on (the bell pointing downwards into the shower tub) and look along the instrument for waterdrops. Press the valves while water is flowing (one at a time).

If you don't find a leak this way there is none, but anyway you have a clean horn (after emptying and lubricating)
In the last 30 years I detected pin holes, cracks, a split leadpipe, leaky tuning slide fit, bad solderings and failing waterkeys!
I takes roughly one hour to do this including cleaning up the shower. It's better not to wear too much clothing, when emptying out a bigger horn the chance is good to get wet at some point