As anyone who forges knows, scale is something you can't do much about. You can try all you want but you will still end up with scale on your project that needs to be dealt with. This scale is incredibly hard, and eats belts faster than anything I have ever seen. I cooked a 60 grit zirc to the point of being useless the other day while trying to surface grind the flats on one of my kith projects. Now zirc belts may not be the most durable or best choice for that, and not as expensive as ceramics, but I didn't want to wreck a new ceramic either. The old standard I had always heard was to soak it in vinegar, but that takes forever and I am impatient. Another option is an angle grinder with discs or flap wheels, which is ok on larger rough forged pieces, but too aggressive for knives with forged bevels and smaller projects, or tighter inside curves. So last night I decided to try something different. I picked up a jar of a product called PH-. It is a granular product for treating hot tubs and pools to balance the ph levels. In the volumes we use, a 1kg jug would last a lifetime. From my calculating, just 2 or so grams should lower the ph in a 5 gallon pail of water to the equivalent of vinegar. As I said I am impatient so I used more (read: didn't even measure but it was considerably more than two grams lol). I soaked a few pieces last night for about two hours, using heavily scaled pieces, which were write offs from an attempted weld. After two hours they came out and were rinsed and neutralized with baking soda. I then gave them a quick scrub with some steel wool and had shiny steel in most spots without noticeable etching of good steel. I now have some good projects soaking and will see how that goes. I may even try it as a patina, because it seems to give a lighter more even grey than ferric without etching as bad. So far it is looking like a win win. Faster than vinegar, seems to cause less rusting, and a lot cheaper than 5 gallons of vinegar. I should be able to make about 100 gallons of this descaler for a total investment of about 15 bucks. And that includes the pail and lid I had to pay 9 bucks for.
Well thanks for experimenting. I think I've got a project on the go that I would like to make use of it on.
That hot tub stuff is the real deal. Soak it, rub it down with steel wool and repeat. I never have the patience to leave it very long. A couple minutes in and then out and steel wool. LAther, rinse, repeat as they say.
