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Posted: 10/24/2005 8:56:09 AM EDT
Building my first AK. I intend it to be a beater (often used  ) gun. It's a Romy and for now I just need some kind of finish on the receiver.So I have two questions. Is the (cold blue) finish really awfull, or just kinda awfull  ?If it turns out "really awfull", can I just finish over the top of it (i.e. durakote, gunkote etc...) ? Thanks in advance |
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Cold blues are good for touching up worn edges, but not an entire receiver. You would have 10 different streaky colors and would rub off any way. I don't know why more people just don't go the permanent route and manganese phosphate them suckers (military black parkerize). You know, like what was done on our AR-15 barrels. Very simple to do with a phosphoric acid, distilled water and manganese dioxide mix heated to just below boiling. Jasco brand prep and prime liquid rust converter is the source for the phosphoric acid, at Lowes or Home Depot. Manganese dioxide is sold through ceramic/pottery supply places. I do this on the gas barbeque grill. If you can boil eggs, you can do this. In the near future, I'm going to bend up a few more receivers, and post some pics of home parkerizing as I do them. So stay tuned for that. |
I have never boiled eggs in acid. J/kI have a question for you though. Does the receiver have to be submerged in the solution? Or do you paint it on? |
Submerged, longer is better to a certain extent, last time I did phosphating I left it in for an hour and got it nice and thick |
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That is the way I do it also. Then I spray molyresin flat black over it. But you could just leave it parked without the MR. I have also used Oxphoblue. It works very well on Ewbanks receivers because they are spring steel. Turns them BLACK. It does not work nearly as well on the 4130 (chrome moly) steels. When I made my home brew park solution I couldnt find any manganese dioxide for sale, so I cut up a couple of alkaline D cells with a hacksaw and used the stuff on the inside (manganess dioxide and zinc powder). Be careful when cutting up the cells. The alkaline (liquid), that some people (incorrectly) call acid, stings if you get it on bare skin. And it tends to squirt out when you first break into the cell. If you get some on you, just wash it off. Safety glasses are a good idea. Dont know what the perfect formula is, but I used about a cup of Jasco to a gallon of water and the guts from 2 dry cells. Put it in a stainless steel wall board mud pan with seams sealed with high temp RTV. Heated to 185F. Added a biscuit of steel wool. Removed the steel wool after a while. Then cooked the receiver in the 185F solution until it quit fizzing. It turned the receiver black. It obviously doesnt require a great degree of precision. A more direct route (especially for your first time) is to just buy pre-made Parkerizing solution and follow the instructions. I started out with stuff marketed by Duracoat and sold by Midwayusa.com. Worked well and is relatively cheap. |
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Ok, figured soem of y'all might want links to others sites with Parkerizing info yarchive.net/metal/parkerizing.html www.webshooters.org/diy_home_parkerizing.htm This is the one I found originally when I started out doing this. I buy my Phosphouric acid from a chemical suplly house in chemical grade (buy it in 4 gallon jugs) I get my Manganese powder in Chemical grade (purest I ahve found so far as far as grades go) from a Pharmacy up here (Shopper's Drug Mart) they order it in special for me in $25 batches which is the smallest special order I can have brought in, it is enough to last for some time) I only do the Manganese phosphating, I dislike the Zinc Oxide phosphating, it feels bad on my skin for lack of a better term |
Jasco Prime and Prep contains 75% (40% by weight) phosphoric Acid. Alkaline dry cells (commonly called batteries) contain a mixture of compacted manganese dioxide powder, zinc granules and alkaline electrolyte. The manganese dioxide is the black stuff. It needs to be broken up. The Zinc is the metallic looking grit in the middle. There is also a cloth membrane in there. Scrape out and break up the guts and pitch the shell and cloth membrane. Manganese dioxide and zinc are both good Parkerizing additives. Alkaline is basically the opposite of acid. When you mix the guts from a D cell with the Jasco two things happen. First, the alkaline neutralizes some of the phosphoric acid. Second, the manganese dioxide and the zinc go into solution and become available for plating out on the receiver. When you cook the receiver, the phosphoric acid etches the surface and creates crystals. This creates a surface that is great for holding paint or oil. The zinc plates out on the surface and provides corrosion protection. The manganese dioxide also plates out on the surface and blackens it. |
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OK. Here is some technical stuff on cold blue. All cold blues, regardless of who makes them, chemically react with the steel and put a selenium compound (I forget the name of) on the surface. Different brands have different additives and concentrations, but the basic formula is the same. The selenium coating is very thin, but harder than regular steel. It is black when viewed at a 90 angle (perpendicular) from the surface and translucent (brownish) when viewed at a smaller angle (sideways). So, it looks best on a polished or bead blasted surface, but not so great on a sanded (groovy) surface. By the same token, it doesn’t hide scratches well. It reacts better with carbon steel than with chrome moly steel. Spring steel (such as 1050) is carbon steel and gun barrel steel (4140) and aircraft steel (4130) are chrome moly. I presume that the chrome inhibits the chemical reaction. Be aware that SELENIUM IS HIDEOUSLY POISONOUS. They should put stronger warnings on the bottle. Be sure to wear rubber gloves if handling it. I usually just wad up a small piece of paper towel and clamp it in forceps. I use a piece of steel wool to buff the first coat. That makes it come out more even. Use a new wad each time you rewet so that you don’t contaminate the solution. You are done when a newly wetted wad no longer turns black. In my experience, cold blue provides almost no corrosion protection. However, if you rub it down with low gloss tung oil after you are done, and wipe off all excess, it looks great and it is very corrosion resistant. If you want to take it back off, just use a metal polish like Flitz and it will come right off. If you sand it off, be sure to wear a mask. By contrast, true blueing converts the surface to blue iron oxide (magnetite), is much thicker than cold blue and is largely unaffected by metal polishes like Flitz. I wrote this kind of fast and by memory. So if anyone has any technical corrections, feel free to let me have it. 
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well this small college town I just moved to isn't great for the manganaze oxide, so batteries it is. Not much luck on the Jasco either, but i did find a similar Phosphoric acid based product sold in qt. containers. So I think I'll give that a try. It's like a Mr. Wizards experiment all over.
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Yup, I called the local pottery place, and they refered me to the area supplier, no luck. I might try to grab some in Eugene if anyone's open on Sat. If not it's me and some batteries. |
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Quoted: Ok, figured soem of y'all might want links to others sites with Parkerizing info yarchive.net/metal/parkerizing.html www.webshooters.org/diy_home_parkerizing.htm] Great information, thanks alot. |
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I ran a quick test on a scrap of 4130 sheet using ozzy_the_nuke's home brew park formula with D cell guts and am quite pleased with the results. My test piece turned a very pleasing gray with a definite parkerized feel. Not black as in his description - course MANY variables could change color. The energizer bunny would be proud. The below pic demonstrates the color - top piece untreated bottom piece parked. http://65.172.200.34/park.jpg |
| Wow. Somebody actually had the courage to do it. (WTG Aceface) Little did you know that I just made it all up. J/K Actually, I got most of the info from fishing around on the forums at parkerizingtanks.com. Sorry I dont have better recollection of the formula I used. I went at it kind of like a Cajun cook. What you did looks good though. It will get a lot blacker if you oil it. I forgot to mention that step. If you are NOT going to paint it, you need to hit it with WD40 right away. |
For me finding some way to progect the bore would be the the EZ one. Corks - rubber plugs - what ever. Finding a 26 inch long simmering tray would be the biggest issue. Reminds me of where do you find the buns for an elephant ear sandwich? |
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Another finishing option is a product by VHT, it can be purchased at Autozone, The product is titled VHT Brake caliper,drum & Rotor. I use the gloss black (gives a good Maadi style flavor), prep the surface by sand blasting (this works best but you do not have to blast). Surface prep is key! Remove all wood and plastic, use Brakleen no residue brake cleaner (again Autobone or Advance Auto) (No I don't work for either joints!). After hosing down with brake cleaner, use your propane torch to gently evap all traces of cleaner and warm the part at the same time (not too hot!, just warm). Apply the paint in even strokes, one light coat first then follow up 45 mins later with another light coat. Wait 24 hours prior to reassembly. Says its good to 900F, chemical resistant and fairly good abrasion resitance qualities. $7.00 for VHT product $3.00 Brakleen no residue $5.50 6 pack of Yuenglings black and tan. Under $20.00 and you have an evening of fun! |
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Since I didn't find the Jasco compound. Here's what I found: http://www.ospho.com/index.html The guy at the family hardware store said it works the same as the Jasco, for what he's used it for. I'll be experimenting on a piece or 2 of metal before I throw my reciever in tho. |
What your looking for is a porduct with a high concentration of phosphoric acid. I used a product called "rust mort" that my local NAPA dealer sells. Label says contains 75% phosphoric acid. I do not know the concentration in the Jasco product. Be sure and pretreat your solution with steelwool - it appears to be an important step! Nice handle VWTim - got oval window? |
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