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wierdscience
08-21-2005, 12:35 AM
http://www.precisionbrand.com/news/news_detail.asp?n_newsid=33

matador
08-21-2005, 01:52 AM
I wonder if,being a gel,how you would put on an even coating?interesting idea,though.

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Hans

SJorgensen
08-21-2005, 02:08 AM
I think a gel would enhanse getting an even coating.

John Stevenson
08-21-2005, 06:38 AM
Not tried the gel, in fact didn't know it existed.
I have used the convention cold black with differing results. It seems to be based on the quality of the steel.
Alloy steels seeem to come out the better, normal bright mild steels are fine but I find that leaded steels and hot rolled come out patchy on a random basis. I'm talking machined all over here no scale or skin.

I recently bought some hot blacking salts that you can do at home in an oven at 140 degrees C but I haven't tried these as yet.

My problem is there is a professional hardening company 300 yards up the road from me and it's too easy to pop stuff in and have it ready the next day for a few pounds that the effort isn't worth it.

John S.

speedy
08-21-2005, 07:24 AM
I haven`t tried this:
From Engineering Workshop Practice vol 3, Blackening Steel:
make up the following two solutions (A) Sodium hyposulphate 4.5oz, water 40oz. (B) Lead acetate 1.25oz, water 40oz.
Clean the articles with caustic soda to get rid of all traces of grease, warm them, and brush over with a mixture consisting of equal parts of the two solutions. It is necessary to boil this mixture before use. After allowing to dry in a warm place, polish with boiled linseed oil.
Use all care

Might be far easier to just buy a bottle http://bbs.homeshopmachinist.net//biggrin.gif
Ken


[This message has been edited by speedy (edited 08-21-2005).]

Joel
08-21-2005, 04:36 PM
Haven’t tried that one yet, but I sure do like the Birchwood Casey perma blue paste.

http://www.thesportsauthority.com/sm-birchwood-casey-perma-blue-paste-gun-blue--pi-865279.html

CCWKen
08-21-2005, 07:22 PM
I haven't tried the paste but the liquid version of Precision Brand works pretty good. I've done some tooling but mostly nuts & bolts to match some old engines and car parts. It does work better if the part is warmed then diped into the solution.

As John mentions, the alloy has a lot to do with how well it blackens and the durability of the coating. Plated nuts and bolts will blacken great. W-1 will also take a deep black. The only problems I've had was with hot rolled too. It looked more brown than black and came out blotchy as John says.

Since I dip or brush, I don't see the real advantage of a gel. The blackening occurs instantaneously so trying to get a gel coat on evenly to begin with seems harder than a dip or sponge. I think the gel would be more inclined to streak.

JMO, Ken