best prep for chem blackening?

mattmaus · Post by **mattmaus** » Thu Nov 12, 2009 3:57 pm

I have a project.

Tomorrow I toddle off to my supplier for a couple jugs of gun-blue.

I swore like hell I would never do this again.

I hated the results. I had streaks.

I think part of it may have been my prep/cleaning work.

What's the best way to prep for this?

Right now I'm leaning towards brake cleaner (also good for killing hornets, and probably careless armorers).

knitebee · Post by **knitebee** » Thu Nov 12, 2009 4:59 pm

I've found the larger the cloth you use to apply it the more even the finish is. Using the little dobbers always leaves streaks. That being said though do what gun smiths do, once its applied they buff the piece with fine steel wool to even out the finish.

whonew · Post by **whonew** » Thu Nov 12, 2009 8:36 pm

Sandblasting with a fine glass media leaves the surface clean and even but you get a flat finish. A fine wire wheel is ok . I like to dip when possible but the steel wool idea does work ok . cheers

knitebee · Post by **knitebee** » Thu Nov 12, 2009 8:57 pm

Your local paint supply place should have a degreaser/cleaner tht is used for cleaning the surface before automotive painting. For the projects I've done, I've ran the pieces through the buffer then cleaned off the buffing residue with acetone.

mattmaus · Post by **mattmaus** » Fri Nov 13, 2009 4:12 pm

Well....

I thought I was gonna get the stuff today.

3 stores. No luck. Probably because the stores were closed. Permanent like.

I will miss Longs. It was the only place in the world I know of that I could get my prozac, a 5th of tequilla, a ski-mask, a handgun, appropriate ammo for it, and a scale model kit of a '68 mustang fastback all in one stop.

Lazarith · Post by **Lazarith** » Fri Nov 13, 2009 4:45 pm

Greased lightning is the ticket. Works great!! As far as streaking goes, I use a fine scotchbright pad between applications while runnung water over the helm. Takes several coats also.
Hope this helps.

Lazarith

ruthardus · Post by **ruthardus** » Mon Nov 16, 2009 12:02 pm

I do ALOT of chem blackening.
heres what I do.
1. "Black Magic" gun blue... AWESOME. deep black, you can do the whole thing and not have 2 rush.
2. Hoppes "Super blue" is just about as good, and cheaper. Walmart has it. like $8 for little bottle. Oh. I can do 4 helms with a little bottle.

I used to use denatured alcohol to strip and clean the surface.. and I had to do one heck of a job so I did not get streaks.
But, this last time my friend brought me over a case of carb/ brake cleaner...OH MAN!.. that stuff rocks. super powerful... blasts into all the small areas, just set it outside on paper and hose it down from several angles, even gets in the creases. Only takes a few minutes to dry off. the blue came out darker than ever before and very clean.
I apply with cotton swabs, and even a good clean 1" paint brush for controll and forcing chem into small areas.
After really hose it off, dunk it in water and wipe repeatedly for several minutes with soft rag to stop the acid reaction. dont skimp on this. rust/ oxidation will keep creaping in on small corner spots for a while if you dont. wipe it dry, hair dryer it to super dry.
oil it... repeatedly. I rub it down with 3-1 oil and fine steel wool for a slick polish. and your there.
I used to rely on WD40 alot, but I find WD40 can take he "blue" off over time and repeated uses. just a thicker oil on a warm helm draws the lube into all the small spaces.
enjoy!

mattmaus · Post by **mattmaus** » Mon Nov 16, 2009 12:13 pm

FWIW

I have parts that will not ble blackened too.

In the past I have used petrolium jelly as a 'resist'.

After the black parts are black, I push that off and use it to oil the black parts. Seemed to work good.

Makes sense that wd-40 doesn't work so good. It's not just oil, but solvents and stuff too.

mattmaus · Post by **mattmaus** » Mon Nov 16, 2009 1:28 pm

Stupid question of the hour that just now popped into my head.

I know that with my experiments with acid etching various stuff, ambient/air temp, and the temp of my etch can play a big part in it.

Warming Ferric chloride up to over 100 and I think he said close to 200 F before trying to etch with it got a friend much better results.

Does the temp affect the black at all?

It's freezin cold lately, and there's no way in hell I'm bringing this stinky assed shit into the house.

es02 · Post by **es02** » Mon Nov 16, 2009 9:33 pm

Black magic recommend kerosene for cleaning. I've found the higher the polish before you start the better the finish.

ruthardus · Post by **ruthardus** » Tue Nov 17, 2009 10:23 am

in college we used clear fingernail polish as a resist. works great! just mask out the area and aft3er your done wipe it off with fingernail polish remover and your good to go.

mattmaus · Post by **mattmaus** » Tue Nov 17, 2009 10:41 am

ruthardus wrote:in college we used clear fingernail polish as a resist. works great! just mask out the area and aft3er your done wipe it off with fingernail polish remover and your good to go.

That is an awesome idea!

Thank you!

Before when I used the petrolium jelly, it was on the advice of Sir Haroun who is a chemist mundanely.

I was working with brass and steel. The gun blue doesn't affect the brass as much, but... it will do some... stuff to it.

This is steel and steel, so... yeah. nail polish is probably a better bet.

best prep for chem blackening?

best prep for chem blackening?

even finish