TromboneChat

I am wondering how the axial valves in modern Bach 42's are?...

I know some of the new ones have an Infinity valve.  I am asking about 42's made just a few years ago that seem to have a more traditional Thayer-type valve. 

Good, if set up right. They can always be worked on, and if necessary, re-cored to bring them back to spec.

42Ts (before 42AF) are some of my favorite trombones.

The 42T's were using OE Thayer valves before the switch to the Infinity Valve. In the early years they did not set them up right, but by the mid 2000's they were doing it right, so they should be good.

Eventually though, all things do wear out. Early Thayer valves that bach used were Teflon coated aluminum I believe. Later on they moved to Anodized aluminum. Works great but once the coating is compromised, the aluminum can corrode. Also unlike some other axial flow valve designs, the OE Thayer valves do not have a replaceable spindle bearing, so once that goes, you need to replace the whole valve.

So, before buying, definitely get a look at the valve core.  Also check the valve for end play and bearing slop.

The 42T's were using OE Thayer valves before the switch to the Infinity Valve. In the early years they did not set them up right, but by the mid 2000's they were doing it right, so they should be good.

Eventually though, all things do wear out. Early Thayer valves that bach used were Teflon coated aluminum I believe. Later on they moved to Anodized aluminum. Works great but once the coating is compromised, the aluminum can corrode. Also unlike some other axial flow valve designs, the OE Thayer valves do not have a replaceable spindle bearing, so once that goes, you need to replace the whole valve.

So, before buying, definitely get a look at the valve core.  Also check the valve for end play and bearing slop.