Thread: Question about cold water:

Being the son of a metallurgist, I know that steel contracts in cold water and expands in hot. Wouldn't that mean that while shaving you should be rinsing the blade with cold tap water to retain it's sharp edge?
I tried it today and unless I imangined it, I thought the blade almost "sang" while I shaved. (in all fairness, it was a great old Sheffield that I bought on the forum)
Jim

I don't think that'll really make much of a difference IMO.

The steel won't move that much with the temperature changes and the temperature changes between hot and cold water wouldn't be large enough to make much of a difference.

If the razor was singing it was more likely good stropping and a good shave!

Thanks, Stubear,
Appreciate your input.
Also love your Pratchett quote.
Jim

The steel does expand and contract, but it does so minimally and all parts of the blade do it equally so proportionally there is no change.

Hmm... Maybe microscopic gaps do open in the edge when it's hot and close when its cold.
If you had a means to alternately make the blade hot and cold very rapidly the edge would become a microscopic sickle mower.

I think that would be the basis for the Gillette electric straight razor.

Since Gillette doesn't make an electric straight razor, I can only conclude that the expansion and contraction of the steel is too small to make a difference.

Originally Posted by Jimharper

I know that steel contracts in cold water and expands in hot. Wouldn't that mean that while shaving you should be rinsing the blade with cold tap water to retain it's sharp edge?

Somewhere in SRP, it seems to me I remember reading an instruction sheet written by a razor manufacturer around the turn of the century (1800's to 1900's) that addressed this same thing saying it is better to use hot water because the expanding steel closes up the gaps of the wire edge. I'll have to see if I can find it somewhere and post it. Unless someone else knows right where it is. It also said, when you are finished shaving, the hot steel dries better when you wipe it off because the heat helps to dissapate moisture from the metal.

Thanks kcarlisle,
I heard this hot/cold question in the movie Miller's Crossing set in the 1920's
Appreciate you pointing out that it may have been a popular theory years go.
Most guys here seem to agree it doesn't matter much.
Jim