Glass bead or Black diamond

[Furnace1]

Just a question about removing scale. I have been brushing my work before and after forging but with scrolls and other areas that I can't reach I'm using a small sandblast cabinet to remove the rest. The thing is I don't like the surface of the metal when I use black diamond blasting media.I had some walnut shell stuff as well but that didn't work. I was thinking if the glass bead type would do any better without that surface finish I'm getting or is there something else anybody would recommend?
Thanks for any help....Scott

[peacock]

Soak it in vinegar over nite, wash of the scale with hot water and a brush. As soon as it's dry treat to prevent rust.

[pkrankow]

Soak overnight in vinegar. Wash with ammonia and water immediately to neutralize the vinegar, then use stiff brush and water.
Phil

[Naz]

Soak overnight in vinegar. Wash with ammonia and water immediately to neutralize the vinegar, then use stiff brush and water.
Phil

Phil, when you wash with ammonia and water do you make a "bath" of the 2 mixed together ? And what are the proportions ?
I would like to try this method but I heard ammoniac is really dangerous for the health.
Thanks !
Naz.

[pkrankow]

Household ammonia from the grocery store, its about a dollar for a 1/2 gallon. Mix about 1/4 cup ammonia per gallon of water and either dip or generously spray onto the metal immediately after removing from the vinegar bath. The PH is more basic than baking soda, and it is already liquid so it gets into tight spaces easier.

Phil

[Frosty]

Ammoniac is something else and contains flourine. Yes it's BAD for you.

I use baking soda and water solution to neutralize the acids I descale with. Vinegar works well but dilute sulphuric is faster and cheaper. Remember ALWAYS wear appropriate PPE and acid into water NEVER water into acid!

Frosty the Lucky.

[Dragons lair]

Just a thought on this. Last few years we have had a lot of members having young ones hanging out or working in the smithy. For those folks I would caution the use of acids.
Ken

[HWooldridge]

Just a question about removing scale. I have been brushing my work before and after forging but with scrolls and other areas that I can't reach I'm using a small sandblast cabinet to remove the rest. The thing is I don't like the surface of the metal when I use black diamond blasting media.I had some walnut shell stuff as well but that didn't work. I was thinking if the glass bead type would do any better without that surface finish I'm getting or is there something else anybody would recommend?
Thanks for any help....Scott

I use plain old #4 blasting sand and then wire brush for hi-lites. Sand is quite cheap ($5 per hundred locally) and will leave a natural finish that can easily be blackened with any commercial bluing/blackening chemical - or painted, if you have to go that route.

[MattBower]

Sal ammoniac is ammonium chloride. I assume it liberates chlorine when it's used as a flux, so yeah, inhaling the fumes isn't the best idea. Fluorspar contains fluorine, which is even worse. It's used in some flux recipes, but be careful. (Fluorine is also present in many electrical welding electrodes, so be careful with those, too.)

Household ammonia fumes aren't great for you, either.

[pkrankow]

Ammoniac is something else and contains flourine. Yes it's BAD for you.

I use baking soda and water solution to neutralize the acids I descale with. Vinegar works well but dilute sulphuric is faster and cheaper. Remember ALWAYS wear appropriate PPE and acid into water NEVER water into acid!

Frosty the Lucky.

I tried baking soda at first for neutralizing after a vinegar or acid bath, but I had rusting of parts by the next day. I tried ammonia based on someone suggesting Windex glass cleaner, and even without oiling my parts were still rust free after drying and sitting overnight. I find ammonia easier to mix and apply.

I have use muriatic acid with excellent results FAST, but have concerns of children and pets like Dragons Lair mentioned. I never considered sulfuric acid before.

I did some looking on the chemistry, and ammonia and vinegar produces some chlorine gas. Use adequate ventilation.

Phil

[Furnace1]

Well, thanks for all of the input on this. I have heard of some of the options mentioned but I don't think I like all of the chemical drawbacks that have been noted. I do prefer to have a piece finished from forging ready to have the final finish applied right away. Normally, I brush off as much scale as possible and while hot, dip in oil and back into the heat doing this a few times. This gives me the black finish I prefer but just not getting all of the scale off as mentioned. I have seen a few flakes come off later and that's what I'm trying to prevent. I like the sandblast option because I can do all of my work at one time while not far from the heating and oil process and have everything finished except for the waxing afterwards. Having pieces soaking overnight would probably result in them being there over several days until I have time again to work on them. I would think rust would be a factor and wind up setting me backwards in the finishing process? I have always appreciated the way I can go out into my forge and within a few hours completely finished a piece in that short amount of time I have. However, I do strive to make my work as best as I know how to do so I will try some of the suggestions mention and make adjustments as I go.
As with any endeavor, we are sponges for knowledge......please keep any suggestions coming....thanks again....Scott

[arftist]

Since you asked, one more suggestion, we used a blast media called broken glass IIRC. It was like a very fine sand. I am not saying it would work, just another posibility.

[John B]

If you are having problems with scale after you have wire brushed, you could always go down the "run a file or scraper over the area concerned" route.

Use different section files and scrapers if you have to, to get into these areas, you can do this hot or cold,

Another alternative is to "rumble" the pieces, I have an old cement mixer with the internal baffles removed,

you can use all sorts of stuff as an abrasive media depending on the finish you want, sand, grit, pebbles, metal cut off bits, old nuts, bolts, screws, etc

I use mine with a cover on, Two discs of wood, one that fits the mouth of the drum, and one that is larger than the drum, these are screwed together and held in place by two or three "spring" clips I made to suit

I just plug it in and turn it on, leave it running happily and come back and check on the finish periodically, you will soon get a feel for how long to leave it running,

When you have got the finish required, remove and clean off the dust, brush or airline will work, then finish as required.

[j.w.s.]

Just a thought on this. Last few years we have had a lot of members having young ones hanging out or working in the smithy. For those folks I would caution the use of acids.
Ken

Young ones hanging out or working in the smithy? Give them some dental picks and emery boards, their little fingers should be the perfect size to get into those small nooks and crannies.. :)