Carborundum is the paste to use as it does not bed into the valves or seats, I think I would be worried that diamond would do the opposite as its virtually indestructable.

I would use the double ended tin, it will last for years, Holts and chemico both do it, I'd go for chemico, If you have a branch of MPD near they will have it. Noel.

Metal polishes such as Brasso and Solvol Autosol aluminium polish are a good fine abrasive for smaller jobs. Brasso is a bit too fine sometimes but the Autosol works well. As does Mothers Aluminium Polish. Never tried it on small model IC valves though.

Timesaver Sampler Pack. 8 different grades. 4 each for ferrous metals and 4 each non-ferrous metals. Non embeding! I have used it for more than 25 years. Rick

Dougie – I have plenty of Silicon Carbide (Carborundum) powder in 280 (too coarse for piston/liner lapping actually) 320, 600 and 1000 grits.

Send me a PM if you want some.

'TimeSaver' is great but far too expensive when only small quantities are required.

Diamond is a definite no no if the surfaces are not hardened. It will embed itself into the material and no amount of solvent cleaning will release it all. You need a good ultra sonic cleaner to do the job properly.

Silicon Carbide is ideal – does a good job and is easily removed with a solvent such as cellulose thinner. I haven't done any valves but I have done the odd piston and liner.

I am disposing of some of my workshop – Silicon powder is no longer required nor some genuine Kasenite case hardening powder – if anyone else wants some then PM me.

Best Tug

Edited By Ramon Wilson on 21/02/2023 18:38:32

I bought mine years ago from McMaster-Carr. There was a discussion a while back and if I remember correctly, it was hard to find in Europe and expensive. Probably not worth it for one or two jobs. I have built numerous engines over the years and I would not be without it. Still have 50% of it left. A Google search should turn something up if you are still interested. Rick