Parkerizing Versus Bluing

Q – What is the difference between Parkerizing and Bluing (also spelled blueing)?

Parkerizing is a metal etching or phosphating process, which enhances the cosmetic appearance of metal. It provides a very durable finish that has extraordinary oil retention properties.  PJ’s Gun and Metal Care Products carries the Radocy Parkerizing solution which produces a medium to dark gray finish (for more details see Parkerizing section below).  Parkerizing generally provides a more durable finish than bluing because it allows for better oil retention and therefore is more abrasion resistant.

Bluing (Blueing) is a controlled rusting process.  It was originally used to camouflage a bright surface and to protect against rust. Special rusting mixtures are applied and allowed to rust, then they are brushed off and the steps are repeated until the desired colour is reached.  In Europe this centuries old technique was first called russetting and then browning.  Later on, a modified browning solution was introduced that resulted in a blackish-blue finish and as a result the name bluing came in to vogue.

There are various types of bluing such as Express Rust Bluing/Browning, Slow Rust Bluing/Browning, Hot Bluing, and Cold/Chemical Bluing. 

PJ’s Gun and Metal Care Products offers Radocy Rust Blue. This rust bluing method involves boiling water to bring the metal up to temperature (not be confused with Hot Tank Bluing that involves immersion in bluing salts).

Parkerizing

Q - What finish is produced by the Radocy Parkerizing solution?

The Radocy Parkerizing provides a highly durable finish, based on a one-step formula that produces an original gray military colour.  It is generally used by the military on their service guns for a non-reflective (i.e. dull not shiney) finish.  It provides extreme oil retention.  Parkerizing deposits a coating on steel to provide corrosion protection and this formula contains Zinc Dihydrogen Phosphate, not maganese.

Depending on the metal components in the various parts of a firearm there may be some variation in the colour achieved. The finish is usually quite uniform but there can be some variation between the barrel and other metal parts.  The chemical analysis of the metal involved (i.e. more or less chrome, or iron, etc.) will determine the colour. When oiled it naturally takes on a slightly darker appearance but if you use the formula as instructed on the bottle, the Parkerizing colour will be a shade of gray, not black. 

We don’t recommend or warrant making changes to the instructions provided with the Radocy Parkerizing solution, however some users have experimented with the formula.  If you are interested, you can read about one user’s experience below under the Question “I am looking for a dark rather than medium gray Parkerizing finish; any ideas re how I can achieve this with the Radocy solution?”.

Q - Some suppliers offer different Parkerizing colors (e.g. greenish); is this also available?

At this time we offer only the standard US military gray colour (medium to dark gray).

No sealer is required, other than oil. Once the Radocy Parkerizing solution has been used as outlined below, the piece must be well rinsed, well dried and then oiled.  We highly recommend the Radocy Xtra lightweight Penetrating Oil.

Q – Is the Radocy solution in the form of a concentrate? How much do I need to Parkerize a firearm?

Yes, the Radocy solution is in the form of a concentrate.  Follow the directions to mix 4 oz. per American gallon of water (preferably distilled water) to produce the standard military specification finish. The tank size is relative to what area you can cover and therefore how much solution you need to make. Generally for a 2 gallon tank, 8 oz. of Parkerizing needs to be mixed with water to Parkerize a whole gun.  For smaller parts or handguns, Parkerizing can be done on a stovetop with a 2 quart stainless steel or ceramic-coated pot to minimize the amount of solution needed.

No you cannot Parkerize aluminum or stainless steel.

Regarding nodular iron, neither our supplier, Radocy, nor PJ’s Gun and Metal Care Products has any experience with Parkerizing nodular iron, however, there are many success stories re bluing it using the Radocy Rust Blue, although it may have a slight pinkish hue/reddish tinge. 

Re-use of the solution is at your own risk. If you attempt to recover the solution, you must filter out all slag (metal debris particles) to avoid contamination, which can cause streaking on the metal finish (requiring you to have to sand/bead blast again). Store any recovered solution in a glass jar.

Q – Is there a shelf life for the Parkerizing solution?

There is no shelf life however as with any cleaning or refinishing solution it should be used within a reasonable realistic timeframe for best results and must be kept from freezing.

Q – I’ve never refinished a firearm before – is it difficult to Parkerize and what is involved?

There really is no trick – the directions are straightforward.  

Note: Prior to Parkerizing, the metal must be cleaned and degreased so the finish properly adheres.  If you are re-Parkerizing a firearm, the finish should be stripped off by an experienced person. To avoid problems, we do not recommend working with muriatic acid or any other acidic compound to remove the previous Parkerized coating.

Here is what you need to know about using the Radocy solution to Parkerize a firearm.

Parkerizing is a 15 - 20 minute job plus preparation time. You need a suitable stainless steel tub large enough to put the parts in (use a vessel that is not common hot or cold rolled steel as the steel will phosphate).  For small parts, you can use a ceramic-coated or stainless cooking pot but for larger pieces a true tank is needed (like the big ones sold by Brownell).

Follow the manufacturer’s instructions on the bottle.  Basically they are as follows:

1. Prepare metal parts depending on the finish desired (sand/bead blast, buff or polish). Partially fill barrels with water and plug (cork) both ends to prevent solution from entering the inside of the barrel and destroying the bore/rifling.
2. Wear cotton gloves to avoid finger marks and degrease parts with a tool-and-parts degreasing solution.
3. Heat water and when correct temperature has been reached, add the parts.
4. Submerge parts for up to 15 minutes until desired colour is achieved, then remove.
5. Rinse parts with clean water and dry well.
6. Apply a good lubricating, penetrating rust-preventive oil, like the Radocy Xtra lightweight Penetrating oil, to the parts.

Q- Before Parkerizing, why do I have to partially fill the barrel with water before plugging both ends?

When The barrel heats up in the solution, it can cause the creation of a gas in the barrel and the pressure from the gas can release the plugs. You don't want Parkerizing in the barrel because it ETCHES (not oxidizes) the metal. The Parkerizing finish is not appropriate for the inside of the chamber, which should remain smooth.

NOTE: Don't fill the barrel completely; just a quarter/half cup is needed.

Q- Can I Parkerize only the receiver of a firearm and not the barrel? My plan was to mask off the chamber face and the first part of the barrel, so I don’t Parkerize it, and to just suspend the receiver in the pot.

Trying to mask off the area with duct tape or even the type of water resistant tape used in heat-treating plants is not recommended.  Even if you suspend the piece, the vapors can still seep in and impact the finish on the barrel.  Do not risk it – have your gunsmith take off the barrel to avoid any problems.

Q- I have an antique Harley motorcycle with a lot of parkerized metal that I would like to protect, especially since occasionally I get caught in the rain.  The parkerized finish is not Radocy which I understand is very durable.  It develops rust that cleans up fairly easily but it keeps coming back. I have been using WD-40 but it doesn't seem to last. Do you have a product that would be better?

The Radocy Parkerizing will do a first-class job should you decide to reparkerize your motorcycle. Just wipe down the parts afterwards (and periodically) with Radocy's Penetrating finishing oil and you should have NO RUST, just a nice durable matte gray finish.

Q- Is is possible to use a PVC or plastic tub to hold the Radocy Parkerizing solution instead of a stainless steel vat?

Yes it is but you must wait for the boiled water to be around 200 degrees before adding the Parerizing concentrate. Be ready to work fast and get everything done in about 15 minutes as the water will cool off quickly. Have all your parts "ready" to be parkerized beforehand (i.e. cleaned and degreased).

To make the PVC vessel, cap both ends of the tube and scallop out a hole in the center. Support the vessel on 2"x4" wood pieces notched with a "V" cut to make a stand. You can also make a vertical tube capped at one end; wrap it with insulation to reduce heat loss and set up wiring so the piece can hang in the solution.

Q – I am looking for a dark rather than medium gray Parkerizing finish; have you any ideas re how I can achieve this with the Radocy solution?

Depending on the steel, you may get a variation on the gray colour (shades of gray) but usually the finish is medium to dark if you do not deviate from the formula directions.

However, some of our customers have been experimenting - below is the first hand account of one user’s experience (photos sent to us reflected an almost black finish)….

Note: We cannot recommend any of these procedures nor be responsible for the outcome of any experiment, however for general interest, we are willing to share what we have been told by users of our products.

First User Report

Initial Contact

8/24/04  “Just wanted to let you know I did my first parkerizing job with your solution and it worked perfectly! I did pretty well every small part on my Garand and it turned out wonderful. I wanted a really dark gray, almost  black color and that's what I got. Very happy with the results. Having graduated from WECSOG (Wyle E. Coyote School Of Gunsmithing), I had to make due with some items at hand as this was a stovetop operation.

I had a $20 stainless pot, some muriatic acid , some wooden paint stick stirrers I used to pluck the parts out like chopsticks, and a quart of 20w50 motor oil. As I don't have a sandblaster, a 50/50 mix of muriatic acid and water was used to strip the finish of the parts. There wasn't much finish left anyways, so 2 to 3 minutes in the bath and light scrubbing with a toothbrush did the trick. Out of the acid and into a pot of clean, cold water to neutralize it. Then into the park bath.

Here's a few pics of just some of the stuff I did. It turned out so well I think I'm going to get my smith to do the barreled receiver with the same solution so everything matches. Thanks again, I will definitely be ordering more of this stuff.”

8/24/04 “Thanks so much for your e-mail and the photos. When we have used the Parkerizing solution we get a medium gray finish - how did you get the black????? Was it black after using the muriatic acid??”

8/25/04 “I actually followed another fellow’s recipe that uses your solution. I had him do an M14 trigger group for me and it came out very dark, almost black. You might remember him, Barney Gotuaco, he goes by Hungry on the Canadian GunNutz site. He was the one that gave me information on where to buy the Radocy. He uses a bit more than the recommended amount of the solution in the water (1 1/2 to 2 times what is called for). I think this is what gives it the very dark look. Either that or the etching from the muriatic acid really helps the park cling to the pieces.  Next time I try it I'll use the recommended amount and see if it makes any difference, then we will know if it's the increased Radocy or the muriatic acid that give the black look.  I have a few Garand bayonettes and some other small parts that need a go so I'll let you know the results and get some more pics."

I like experimenting with these things to see what colors I can get. I keep a log book of the methods used and results so I can match stuff up later.  Do you mix the Radocy solution yourself or are you a distributor for them? I'm really amazed at this stuff. Not sure if Jeff Smith at Valley Guns in Petawawa uses it but I'm going to show him the results and see what he thinks..... Thanks again.

NOTE: Valley Gun Smithing Co. has used PJ's products for many years with excellent results. See our Links section for more information about this well-respected Ottawa Valley (Ontario) gun smithing business, which also operates a popular firearms auction web site.

11/23/04  “I'd have to say the combination of the muriatic acid and double dose of the solution (produced the black finish). The last parts I did I used the recommended amount of solution and did some parts stripped in muriatic acid and some parts that were just in the white, newly manufactured. The parts that were in the white turned out as expected, medium to light gray, typical USGI color of Parkerizing. The ones that I had stripped in the muriatic acid were a darker gray, not black but noticably darker than the "in the white" parts that didn't get a muriatic acid bath."

Second User Report

'Extra' Parkerizing Example #1
Click on photo to enlarge

"This a an old HP9 Norinco clone of the Rem 870. I have been using this as my 'truck gun' on the property to take with me when I'm on the wood lot or what have you. It's seen a lot of miles in the back of the pickup and makes a good critter gun.

I bought it new 2 years ago and the finish was getting quite beat up on it. So, I've re-done the barrel, tube mag and receiver with your Parkerizing solution. I gave it a "bit" of an extra coat by leaving it in the tank longer so I would have a really durable finish. I also used Barney's formula for mixing the solution to get a darker finish.  I've put it back together using Remington 870 Wingmaster wood furniture and a Rem 870 mag cap.

So far, it's only seen a few hundred kms/miles on the floor in the back of the truck since the new park finish. It's holding up very well".

'Extra' Parkerizing Example #2
Click on photo to enlarge

When we asked about the dark parkerized finish, we were told: "This 1911 gun was originally blued. I had beat up the finish pretty good using it as my backup gun in pistol competitions (service pistol). I put an extra heavy coat on the frame and slide for durability. I think the dark finish is a combination of Barney's mix AND leaving it in the tank. I used muriatic acid to clean the old finish off the frame and slide, and then tossed 'em in the tank (after cleaning of course). I think the frame was in about 10 minutes, the slide maybe a minute or two more. I think to get a normal coat of park on it, the parts probably shouldn't have been in in the tank more than about 7 minutes".

Rust Bluing

Q - What are the different types of finishes associated with bluing?

For a dull or non-reflective finish, the metal should be bead blasted before bluing. For an elegant beautiful blue or blue-black shiney finish, the metal must be highly polished before applying the bluing solution.

When using rust blue, keep in mind that each coat of acid applied is followed by a 'carding' operation to remove the oxidation caused by the acid. Carding involves the use of fine steel wool(0000) to wipe down metal (or a carding wheel can be used). The carding process in effect polishes the metal.

Q – How do I prepare a gun for re-bluing?

If the firearm’s blue finish has worn or has rusted but the underlying metal is okay, use a bluing remover or remove by hand with an emery cloth to prepare the surface for re-bluing. If out of commercial blue remover, try a 50/50 white vinegar to water solution applied with a domestic green or industrial red Scoth Brite* pad (if stubborn, try a 60/40 mix).

*Scotch Brite is a registered trademark of the 3M Corp.  

Five tips:

1. Pre-preparation is the most important step in the bluing process. All dents, rust pits and scratches should be removed by hand or machine for a perfect job; otherwise imperfections will be obvious.
2. Prior to bluing a gun, the metal must be degreased so the finish properly adheres. No bluing solution will work unless the metal is completely clean and degreased.  Use the RB-17 gel gun cleaner which is very aggressive and ensures the best 'prepped' surface.  This is especially important on old metal, which is often full of oil and dirt.
3. Use the right product for the job.
4. Keep the metal hot and clean throughout the entire operation.
5. To prevent future rust, after every bluing job be sure to neutralize the bluing action (because blue is an acid) by soaking the part in a solution of warm water and baking soda (1 tbsp soda per litre of water).

Q – Do I need to worry about a bluing solution pitting (i.e. cratering) the metal?

If used according to our instructions and not modified in any way, there is no need to be concerned about pitting of metal when bluing a firearm with our products.  Generally speaking, ambient air and water won’t cause pitting overnight.  However, some small 'cratering' may develop after a month or more because of natural oxidation if metal is exposed/left unprotected to the elements.

The Radocy Rust Blue is an Express solution that gives a beautiful blue-black finish. The metal must be degreased and thoroughly cleansed before going into a hot water tank. The process begins by heating the metal in boiling water then applying the well-shaken solution.  The metal is then re-heated to speed up the oxidation or rusting.  The rust is then brushed off with steel wool. The procedure is repeated until the correct colour is achieved.  This method is excellent for double barrel shotguns as it does not weaken the solder.

Note:  Slow rust bluing produces the same result as the Express approach but uses humidity and therefore is a time-consuming process.  In the wild world of bluing, both Slow and Express Rust Bluing generally give the most durable finish and offer the option of controlling how dark or light the finish is on the firearm.

Q- Is there any tip you can offer for successful rust bluing with the Radocy solution?

Follow the instructions exactly and remember that for the blue to perform, it is imperative that parts have been cleaned (degreased) and are kept hot.  A heavy receiver piece stays warm longer than a tang piece as the outer ends cool off first. So remember to return the item to the boiling water as often as needed to keep the metal hot and be sure to change the water if contaminated (degrease again).

No, but be sure it is stored in a cool dry place.  Do not freeze.

Cleaning/Oiling Firearms

This internationally acclaimed, non-toxic, biodegradable gel cleaner removes rust (with no harm to bluing) and accurizes the firing of a gun as it easily and quickly dissolves unwanted lead/copper/brass/plastic bore buildup.  It also erases black powder burns from the cylinder and removes old gun oil, hand stains, and worn varnish on stocks. Although it contains no acids, phosphates, or petroleum by-products, it is highly aggressive, completely deep cleaning rust from metal parts in seconds.

You need to persevere when using the RB-17 gel cleaner and you must keep the metal warm with a hair dryer or heat gun. For major bore build-up, dip the bore brush into the cleaner and run it up and down the barrel as many times as needed.  For general cleaning, apply with a clean soft toothbrush, then leave it for 2-3 hours to dissolve the debris. Be sure to wipe off the metal with a good rust preventative oil to neutralize the action.

Q – Is there a shelf life for the RB-17 gel cleaner?

No, the gel cleaner can be stored indefinitely but be sure to keep it from freezing.

Use any premium gun oil such as Radocy Penetrating gun oil or Clenzoil; both choices are excellent. 

Cut the RB-17 cleaner 50/50 with methyl hydrate (a form of alcohol - not the drinking kind) and use it in a spray pump bottle. 

Clenzoil

Q – I am looking for a product that will clean, lubricate, and preserve a firearm and have heard that Clenzoil will do all this – is this correct?

The Clenzoil Field and Range oil is an excellent product and exactly what you need. It is sold world-wide and has a huge fan club.  It effectively removes built-up oils, dirt and other contaminants, without buildup and ABSOLUTELY PREVENTS RUST!

Clenzoil NEVER gets gummy or sticky and NEVER evaporates.  It will protect firearms for many years with one application.  Since a little bit goes a long way, to avoid waste and ensure direct/correct application, we recommend you use a needle-nose bottle when applying the oil to small areas of the firearm.   

Q - Is there a shelf life for Clenzoil?

There is no shelf life and you do not have to worry about freezing affecting this product.   

Takedown Guides

Q – Can I obtain a Radocy Takedown Guide for a firearm not listed on your web site?

Our list of Takedown Guides changes on an ongoing basis as new guides are made available.

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