- Joined
- Nov 16, 2012
- Messages
- 5,596
I don't know why iodized salt is discouraged for quench medium. It might (just a guess) cause a problem if the metal is to be blued afterward. -Just a guess. I do know however, that salt is intentionally iodized because it's a necessary dietary ingredient. Just like most water supplies have fluoride added to help teeth and milk is fortified with vitamin D, salt is commonly given some iodine to aid health.
Anyhow, on the issue of heat treating, I completely agree with George's suggestion to get some current books from the library and study up on the process. The fact sheets provided by most suppliers are often missing information and most don't seem to tell the whole story. Also, it wasn't until the 1970's and 80's whereby increased availability of the electron microsocpe really helped refine the procedures for heat treating. Metallurgists now have the ability to theorize and SEE what is actually happening. Prior to that, processes were established by trial and error. This doesn't just apply to exotic metals either. Many things have been learned such as the need to never let metal cool below 150 before the first temper -and that some metals require a second or third temper for best stability. Also, the critical temperatures are now known precisely. In times prior, books would say somthing like "Heat to 1400-1500 degrees"... -Close, but no cigar. Missing the mark by 20 degrees has a measurable effect as does improper soak times.
Of course this applies to precision heat treating and for some things, it's not critical.
Ray
Anyhow, on the issue of heat treating, I completely agree with George's suggestion to get some current books from the library and study up on the process. The fact sheets provided by most suppliers are often missing information and most don't seem to tell the whole story. Also, it wasn't until the 1970's and 80's whereby increased availability of the electron microsocpe really helped refine the procedures for heat treating. Metallurgists now have the ability to theorize and SEE what is actually happening. Prior to that, processes were established by trial and error. This doesn't just apply to exotic metals either. Many things have been learned such as the need to never let metal cool below 150 before the first temper -and that some metals require a second or third temper for best stability. Also, the critical temperatures are now known precisely. In times prior, books would say somthing like "Heat to 1400-1500 degrees"... -Close, but no cigar. Missing the mark by 20 degrees has a measurable effect as does improper soak times.
Of course this applies to precision heat treating and for some things, it's not critical.
Ray
I have thought of that,but you can also easily buy non iodized regular salt. My wife did-and it hardened up in the box!! Told her to NOT do that again!!!Beyond that,salt is salt,I GUESS. By the way,all this "Sea Salt" crap!! ALL salt started out as sea salt!!!!!
Sometimes it is not possible to separate fact from LORE. But,in my many years in a museum,I am reluctant to dismiss out of hand the lore part,as it sometimes turns out to be the truth for reasons we haven't thought of.
Salt in Mexico is apparently ground much finer than our salt,like popcorn salt. I'd like to find some,because it taste saltier than our salt,being ground finer. It presents more taste area to the tongue,and sticks to whatever you are shaking it on to,like French fries. Plus,you end up eating LESS salt as it its saltier. Of course,the scientists have recently proclaimed that SALT IS GOOD FOR YOU. Wish they's make up their minds!!!
