Thread: Through hardening small parts made from silver steel

As a suggestion for anti-scale compound, I've heard of folks using borax (here in the States, 20 mule team brand) mixed with alcohol. Brush it on and let is dry. I don't know how well it works as I've never used it.
Warm oil cools faster than cold oil so pre-heat your quenching oil to "warm to the touch".

ron

Originally Posted by son_of_bluegras

As a suggestion for anti-scale compound, I've heard of folks using borax (here in the States, 20 mule team brand) mixed with alcohol. Brush it on and let is dry. I don't know how well it works as I've never used it.
Warm oil cools faster than cold oil so pre-heat your quenching oil to "warm to the touch".
ron

Ron & Andrew
I use borax when making small jewellers tools.
It works VERY well.
Here is a 12mm long piece of 6mm round silver steel I quickly cut and played with.
Warmed it up and dipped half of it in powdered borax which melts onto the surface into a paste. Then held it in tweezers above a glass of water and heated it to cherry red and dropped it from about 50mm to the water.
The black scaling is eaten into the surface, and the protected area has not been "etched". The mottled look on the bright side is just a stain on the surface.
I've used this process for about 35 years to save time stoning away the scale that would otherwise be on my engraving and diamond setting tools after hardening them before tempering.

I would suggest you put each of the small pieces on a steel wire and warm them up, cover them with molten borax by heating them up and immersing them in the borax powder over and over until a good even coating is on them. Then do the heating up to red.....etc.

Regards,
Peter

Originally Posted by lightwood

I would suggest you put each of the small pieces on a steel wire and warm them up, cover them with molten borax by heating them up and immersing them in the borax powder over and over until a good even coating is on them. Then do the heating up to red.....etc.

Hi Peter, Very nice,

I must give that a try... I think the Rosemill PBC stuff I've got is most like borax based, they sell a range of other borax based materials... PBC Anti-Scaling Compound

Ray

Thanks for all the replies guys. Unfortunately i messed up my estimations on piston-to-valve clearance, the stock pistons wont clear the 2mm OS valves at my compression height :s
So the head isnt going on this weekend.

I will pull the (nearly new) bottom end out/apart, and either relieve the cast pistons on the CNC, or fit the forged flat tops ive got stashed away (which were made to suit huge valves and cost the GDP of a small nation). 14:1CR in a road car... why not?

Either way this buys me enough time to get the shims hardened professionally, which ill feel much more confident about. Thanks again for all the help and suggestions.