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RobT · 8th May 2023, 07:32 PM

Ian,
Thanks for the data sheet. I did a screen grab and it’s now part of my data base (the wide range of phosphoric acid percent is a bit odd though). I don’t know at what percent phosphoric acid is considered strongly corrosive and I don’t know how (or whether or not) the phosphoric acid is buffered in the Evapo-rust solution. I do know, however, that I have gotten Evapo-rust all over my hands a number of times while working with it and have suffered no discomfort or ill effects to my skin whatsoever. When I finished working with the product, I simply washed my hands with soap and water. Whatever the strength of Evapo-rust is, it takes about 24 hours to etch a blade and that etch can be easily polished out. By the way, If a blade is left suspended in the solution for 24 hours, absolutely all the red rust will be gone but Evapo-rust struggles with black rust and is minimally effective.

Interested Party,
You make an excellent point about the base of the blade being covered by the sheath and thus being unable to contact the skin. I did note however that, in the 13 examples you posted, only 2 appeared to have a guard shorter than the base of the blade. All the rest had guards that were either wider or at least equal to the base of the blade so perhaps your surmise of discomfort to the hand during use is correct. As for the guard being a possible irritant, I checked my older examples that appear to have been made with concealed carry in mind and found every guard to be rounded smooth on all edges.
I would be willing to bet the ranch that, for a skilled Philippine smith, shaping such an obviously fine blade as yours around a mandrel would be quicker than stock removal.
If I were trying to remove a blade with heat, I would try a heat gun rather than a torch. If that didn’t work, I would give up. If you decide to press ahead, good luck with whatever method you choose to use.

Sincerely,
RobT

8th May 2023, 07:32 PM	#13
RobT Member Join Date: Mar 2005 Posts: 528	Additional Comments Ian, Thanks for the data sheet. I did a screen grab and it’s now part of my data base (the wide range of phosphoric acid percent is a bit odd though). I don’t know at what percent phosphoric acid is considered strongly corrosive and I don’t know how (or whether or not) the phosphoric acid is buffered in the Evapo-rust solution. I do know, however, that I have gotten Evapo-rust all over my hands a number of times while working with it and have suffered no discomfort or ill effects to my skin whatsoever. When I finished working with the product, I simply washed my hands with soap and water. Whatever the strength of Evapo-rust is, it takes about 24 hours to etch a blade and that etch can be easily polished out. By the way, If a blade is left suspended in the solution for 24 hours, absolutely all the red rust will be gone but Evapo-rust struggles with black rust and is minimally effective. Interested Party, You make an excellent point about the base of the blade being covered by the sheath and thus being unable to contact the skin. I did note however that, in the 13 examples you posted, only 2 appeared to have a guard shorter than the base of the blade. All the rest had guards that were either wider or at least equal to the base of the blade so perhaps your surmise of discomfort to the hand during use is correct. As for the guard being a possible irritant, I checked my older examples that appear to have been made with concealed carry in mind and found every guard to be rounded smooth on all edges. I would be willing to bet the ranch that, for a skilled Philippine smith, shaping such an obviously fine blade as yours around a mandrel would be quicker than stock removal. If I were trying to remove a blade with heat, I would try a heat gun rather than a torch. If that didn’t work, I would give up. If you decide to press ahead, good luck with whatever method you choose to use. Sincerely, RobT