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One is basically used for a quick oil for the dry valve, but you seem to need a 2. 3 may be to much for what you're looking for.

I used to use Hetmans exclusively but have switched to ultrapure lamp oil with a dab of fully synthetic motor added. It's a hellofalot cheaper and works just as good. I keep four bottles of mix on the shelf. 100% synthetic motor oil for linkages and rotor bearings, 50% synthetic motor oil for keys and slides, 10% synthetic motor oil for worn pistons, and 5% synthetic motor oil for tight pistons. Of course the balance on the above percentages is the ultrapure lamp oil. Not very scientific, but being in the repair business, I go through quite a lot of oil. The ultrapure lamp oil is $1 a QUART at Dollar Stores nationwide! You can experiment with different blends to get the one that is just right for you.

TubaTinker wrote:I used to use Hetmans exclusively but have switched to ultrapure lamp oil with a dab of fully synthetic motor added. It's a hellofalot cheaper and works just as good. I keep four bottles of mix on the shelf. ...

I use Hetman's because it's a hellofalot cheaper. I keep one 4oz bottle in my gig bag. It has been there for a year and is still half full.

and just fyi.. hetmans has returned to the old style bottle, none of that "dropper" junk anymore

hydeuphonium wrote:and just fyi.. hetmans has returned to the old style bottle, none of that "dropper" junk anymore

Yes! Hurray! We noticed that with our last section order.

Elephant,

I think you may still get good results with Hetman #1 (Light Piston Oil). Even though your tolerances aren't as tight as before, they may be acting tighter in warmer temps. FWIW, I gave a bottle of #1 to a euphonium player whose Besson euph is 50 years old... had valves lapped a couple of times. He says it works great for him.

the elephant wrote:Which Hetman piston oil will work well on my YFB621?

I would start with Hetman "Light Piston", #1. I use "Piston" (#2) on the York master and "Classic Piston" (#3) on the Holton.

When I played my 621 outdoors, I could not get anything to work well, until I started using Ali-syn. That worked quite well, but I'm thinking of switching the Yamaha to Hetman's Light which can be mixed with conventional oil in a pinch.

Rick "whose 621 valves have also been carefully lapped" Denney

I vote for the #1 light as well.