Good morning All.

I am building a locomotive boiler ( LBSC / Josslin Uranus ) and have tested the silver soldering of the cross tubes in the combustion chamber to 200 psi all good. Now the combustion chamber has been soldered to the tube nest I am trying to test the combustion chamber to front plate and the tube nest joint, inside out so to speak; as once its soldered in to the boiler you cant get at it at all.

I cant seem to get a good enough seal on the tubes at the smokebox end to get pressure up sufficiently high and don't want to tighten up the test rig any more in case a tube buckles.

I seem to recall an article in EIM regarding a similar test and how he sealed the tube ends, can anyone point me in the direction of that article or have any ideas how a better seal might be achieved ? I had considered making ali or wooden plugs and fitting with silicone, but I am concerned about them swelling the ends of the tubes and the difficulties of getting them all the same length.

Over to the knowledgeable ones from this old dunce !

Forgot to load photos DOH !!

Look under album Test rig.