Bulgarian 74 coating question, black oxide? --- LOTS of good parking info inside!

I have a Bulgarian AK 74 kit with a virgin barrel that I am working on right now. It's my first build. I bought one of the really cheap 74 receivers from NDS to build on.

Here's my question:

I'm trying to decide on a coating/finish for the metal. I'm not crazy that it all be matching, but I do want it to look good and be somewhat durable. The receiver came finished in black oxide. Is black oxide just the same as bluing? There's a pretty reputable shop around here that does bluing. I'm also not opposed to blasting the whole thing and doing another finish. I don't really want to cold blue the whole thing. I also know that parkerizing is a good option, but the kits from brownells are a little pricey in relationship to the overall budget of this build.

What's my best option? I have a can of grill paint, don't make me use it.

Personally I like Gun Kote and or Dura Cote... I got a sandblasting cabinet and blast them then paint them then let the paint bake in the sun for about a week you can also use a stove... I just recently learned to park but dont have a tank long enough to do the reciever and barrel together...

NDS receivers do not have black oxide coating. They are that color from the heat treat.

http://www.nodakspud.com/page2.htm

Go down and read under "Really low priced AK74 receivers"

It says: "Beautiful black oxide finish"

I aluminum oxide blasted the 2 74's I built and Gunkote'd them Satin black. I bought a small can of their AK black but it turned out to be pretty flat and I didn't like the look. My Bulgy stuff had a nice semi gloss finish which I wanted to replicate and the Satin black did just that.

Oh and the coating is tough as hell if you bake it correctly. I really don't treat my AK's with the love that my AR's get and they still look like I built them yesterday.

"Black oxide" = parkerizing. Specifically, manganese phosphate parkerizing.

It is very simple to do and FAR less toxic than blueing. It is easy to do at home. It is also and excellent primer for painting it you decide to paint later or if you don't like the results.

For a tutorial, google "Blind Hog 1911" and look at the tutorial on parkerizing.

You'll need to copy and paste this link: http://www.calguns.net/calgunforum/showthread.php?t=376334 He has a million pics up, pretty much every step along the way.

A member on Calgunforum "rust blued" a Yugo. Looks like a lot of work, but not particularly difficult, just a lot of repetition. Good part of that is, all the repetition also lets you fine tune the color, as each time you card it, it gets a little darker.

He did up a Yugo underfolder and I think it turned out tremendous. Almost had a slightly "worn" look in a new finish, but was consistent and even.

I plan to attempt this process on my next build.

I like the sound of that. I'm sure there will be future projects, so this sounds like a pretty practical option for the first time around.

no, black oxide = black oxide. it is completely different than phosphating or parkerizing.

Parkerizing is the best option. Duracoat comes in second place (in my opinion). We got our new sandblasting cabinet working this weekend and I will be returning to do my Bulgarian AK 74 as soon as I can. We purchased a stainless steel tank last year so parkerizing is the way I'll be going. I also have a ton of other AKs that will be going through the tank (I did sandblast a dust cover I had Duracoated and it came off like butter!).

I purchase my magnesium phosphate solution from Palmetto Enterprises.
His prices are good. You will need some stainless steel pans to 'cook' your parts in, which I purchased used from a local restaurant supply house.
Give it a try, you will like the results. Here are my latest builds that I 'parked'. BTW - you will need to prep your rifles by degreasing and sandblasting.

Any suggestions on a good parkerizing tutorial?

I also purchase my black oxide/manganese phosphate from Palmetto. For a tutorial on how to do manganese phosphate black oxide parkerizing using this exact solution, check out this website's pictorial and description:

http://www.blindhogg.com/parkerizing.html

-prep is EVERYTHING. You want to thoroughly degrease with something like "green" brake cleaner - then do it again.

Once you are 100% sure it is greas free, repeat the process. Can't be too thorough here. Wear gloves.

You may want to use low heat (less than 200) for a long time to get the oil or grease out of all the cracks & tight spaces.

That's way easier than I thought it was. I guess I saw a $300+ parking kit from Brownells that scared me off before. Looks like parkerizing is the way to go. I work right down the street from a restaurant supply store. I'll have to check for a good stainless tray.

Thanks!

Here are a couple of additional suggestions:

- I choose to use distilled water & mix that with Palmetto solution (follow directions on bottle). A friend uses tap water. We have not noticed any difference in finish quality. Distilled is probably not needed at all.

-I pre-heat the metal by hanging it on thin bare wire in a partially-open oven (stainless safety wire - degreased. Bare coat-hanger wire will also work.). This way, the reaction begins immediately since the metal does not need to come up to temperature.

-KEEP METAL SUBMERGED THE ENTIRE TIME! If you raise the metal above the surface, it will dry almost instantly & probably won't give you an even, professional-looking finish.

-This is also why you want to AVOID boiling the solution - the finish won't be even and the reaction could stop entirely. You want it JUST UNDER boiling.

-some directions indicate keeping the metal in until all "bubbling" stops at the metal's surface. I usually just take it out at the 20 minute mark. A friend uses, IIRC, 8 minutes. Reaction happens fairly fast.

-along these lines, when you take it out of the solution, have a cool water bath RIGHT NEXT to the solution, so the metal has no chance to dry out. You have to be quick about it, but be careful because the metal is drippin with solution & it contains a acid (wear protective clothing).

-I "fix" the park/oxide with WD-40 - it is meant to displace water.

-I always plug barrels - even chrome ones. No need to expose any barrel to park chemicals - although some places (like Century) have been know to take short cuts & park right over rifling. Sure - the park layer inside a non-plated barrel will quickly "shoot out" & maybe AK's are not known for accuracy, - but it is NOT the right way to do things in my book.

I agree with CBR900, but I do my parking a little different.

I use distilled water as well with my Palmetto solution. I agree that tap water may not matter in most cases, but I've read it can affect the results based on the mineral content of the local tap water. Distilled water is cheap and I want consistent results, so I go with it.

I've parked cold metal and pre-heated metal. I agree that pre-heated metal seems to work a little quicker. However, I drop my parts in a pan of heated water (here I use tap water) rather than using an oven.

Prior to blasting the parts, I warm up some degreasing solution in a pan (e.g. Zep's or similar) and get them thoroughly free of grease. Once they are degreased, I blast the parts.

For my parkerizing set-up I use two HF portable double burner propane cook tops set on a table. I place my stainless steel park pan on one and my pre-heat rinse pan (also stainless) on the other. To the side of that I have a pan filled with WD-40.

I drop my DE-GREASED prepped parts in the water pan (heated to 200 deg.). Once they have warmed up, I transfer them to the parkerizing pan (also at 200 deg) and let them cook. As stated by CBR900, keep the metal completly submerged or your finish won't be even. I do turn over the barrel and receiver once while they are 'cooking'. After the parts have finished fizzing (I don't actually time mine, but it is no more than ~15 minutes) I transfer them back to the heated water. This helps desolve any solution left on the metal. If allowed to air dry, you will likely get white streaks and crusting. This is supposed to be iron and it's a pain to get off once dried. Ask me how I know.

After the parts have rinsed in the water, I transfer them to my pan of WD-40 (buy a gallon can) and submerge them to remove any water. I just pull the parts out and set them aside on old newpaper until I'm finished.

Make sure you watch and control the temp on your park solution. If you go over 200 deg. it will begin to get cloudy and look like it is filled with a fluffy material. This is called flocking and you are overcooking the solution and ruining it. You can reuse your solution, so don't dump it! Strain it through a coffee filter and save it in a clean plastic jug until you need it again. I also pre-mix additional solution before I start parkerizing. If you are doing more than one rifle you will need it as the solution will evaporate to some degree and you can just top it off.

As I stated earlier, I get my used stainless steel pans from a restaurant supply locally. Make sure you buy pans large enough to hold your barrel (~20 inches long).
Also buy a few stainless steel tongs (long ones are good) while you are there. You will also need at least one thermometer (stainless steel). Anything other than stainless steel will react with the parkerizing solution.

I used to plug my barrels as well, but no longer do this as it doesn't affect the chrome lining of the bore. I wouldn't do this on a non-lined bore. Personal preference here.

Good Luck!

We should start a tacked tutorial or something. Good stuff!

I did the parkerizing for quite some time when I worked at Barrett. Thouroughly degrease your parts. Sandblast with a good media, 120 grit aluminum oxide works great, we cut our media with 120 grit silicon carbide to really smooth out the finish.
Your park tank needs to be stainless, heated to about 195-200*, add in some 0000 steel wool to give the finish a really dark tint. If you want it blacker, add more steel wool. The 0000 steel wool is best, it dissolves faster after the tank is hot.

Leave parts in till the finish fizzing. That will depend on material type and heat treat. The harder on the RC scale, the longer it will take to park. And depends on material type, a hardened S7 part takes quite a while to park.

Have a rinse tank close, we used a hot rinse, seems to work better, gets in all the nooks and crannies quicker. Leave for a few seconds then take out and dry with a compressed air hose till dry. If your park tank is set up right, the surface of the part will have a slightly chalky look to it.

Dip in the oil of your choice. We used a very light preservative. Can't remember the name now.

Lots of great info in here. Thanks guys!

The oil we used was Du-Lite. Very thin, almost water consistency. Let your parked parts soak in the Du-Lite for about 3 minutes or so to really get into the pores of the metal.

I forgot about adding steel wool. I agree it darkens the final finish. Some park solutions recommend that you add steel wool as a prep step prior to cooking your parts.
One thing to add. If you use steel wool for this process, make sure you soak it with brake cleaner prior to putting into your solution. Steel wool actually has a light coat of oil on it to keep in from rusting in storage. If you don't you will be introducing this oil into your solution.

In addition to making sure to prime the solution with steel wool (which some in our group forgot one time) don't firget to rinse the barrel after sandblasting it or you will get a nasty reddish color instead.

I've never rinsed parts before going in the park tank. Just make sure to not touch the sterile blasted parts with your oily fingers or you will have rust where you touched the parts. Some people have naturally oily skin, if so, don't handle the parts.

If there is any residual sand on the parts, the boiling action of the parking will lift it away.

Those new to black park (or any parkerizing) might not realize that the actual color of the coating without oil. It is actually very porous. If you completely de-grease black parkerizing, it is much lighter in color - possibly grey or "chalky." Wiping the surface down with good protective oil brings out the black color we all know & love.

50 cal - thanks for the insider tips! Great stuff.

No problem. If anyone has any questions, don't hesitate to PM me. I try to check this thread when I think of it.

i have had great results with gunkote 4000 k phos treatment first then spray with gun kote 2400 series in the color you want, works great even with a cheap preval sprayer, all 3 products sprayer, kphos and 2400 color less than 50 bucks

I agree. If you notice in the picture that I posted earlier, my receivers look a flat gray and the barrels look almost black. I hadn't put any oil on the rifles, just assembeled them. The difference in the color is a result of the different metals. Different metals WILL result in different color tones from the same tank of parkerizing solutiion. Nothing I'm concerned with, but some may be. I use Manganese Phosphate to parkerize, which resutlts in a 'blacker' finish. Zinc Phosphate will result in a lighter grey finish. If you desire a uniform color for your rifle, you should apply a paint on finish after parkerizing.

You can also get a darker color, post parkerizing, by applying oil to all the metal surfaces and heating them up to let the oil soak into the finish. Some guys will apply oil and bake them in the oven at ~200 deg. to do this. You can also get the same results from using a heatgun or just from repeated applications over time.

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