Kevin R. Cashen
Super Moderator
I hope I can help with the quench oils at least. In my experience, for what we do, an 11 Second oil is right on the borderline between a medium speed oil and a fast oil, a 28 second oil would definitely be a medium speed oil that would have rather limited applications (only very deep hardening alloys, just shy of air hardening). Fast oils are an odd beast in industry since industries answer has typically been to just develop or switch to an alloy capable of slower quenches rather than dealing with quench speeds approaching water. We bladesmiths however prefer our steels simple and old fashioned so we tend to go in the opposite direction and yearn for quenchants that approach water speeds for those steels. To us these rare fast quenchants that won't blow our blades apart are the Holy Grail.
I can't help much with the olive oil, except to say that it makes an excellent salad dressing or spiced dip for bread. But then it is a cooking oil, that is what it is for and so there are plenty of specific qualities that a entirely verifiable for that use, but there are no hard numbers to offer about it as a quench oil, just as there are no numbers to offer about salad dressing being used for and engine lubricant. Too often we look at features for a quenchant that appeals to us instead of paying attention to what the steel needs. You didn't do too badly though, at least you didn't give most common reason I hear for using olive oil, which is how pretty it makes the shop smell. One must never forget the metallurgical significance of the steels aroma in a quality knife. I am sorry if that sounds sarcastic, it is meant to lighten up a dry heavy topic, but I still cannot believe that people have given that reason and expect to be taken seriously.
Hamons really are no more of a mystery than a bit of trial an error to get everything adjusted just right for you own specific conditions. Quenchant, quench temperature, clay mix and its application, steel selection and its heating before quench are just a few of the variables to getting what you want. If you do get what you want it is important to lock in all the variables and stick precisely with that routine for what you want. This is where a good well designed quenchant is most valuable. If you use an alternative oil that is not formulated for consistent results frustration must follow in reproducing hamon effects as that oil changes chemically with every use, a good quench oil is specifically designed not to do that. Beware taking advice from water quenchers if you are using oil for hamons and vice versa. The clay application must be adjusted for the speed of the quench, closer to the edge with water and little further back with oil, and I would also recommend forgoing the thin clay wash with oil. The clay can be good old furnace cement, many will tell you to use Satanite, but I have done testing that showed readily available furnace cement much better for many applications. Satanite has the consistency of traditional Japanese clays and that is why I think it is so popular, but some of the best effects from oil I have seen were shaped with furnace cement. You will not get much sori with oil so do all of you shaping before the quench instead of leaving it straight and allowing the water quench to induce curvature, this has do with very subtle timing differences in the phases of steel that there are a few 1000th of a second difference from water to oil.
