Q. Hi, we are blackening low carbon steel parts. These results are sporadic. Function & Physical Finish: The primary purpose of black oxide coatings is to provide an attractive uniform color to steel or iron parts. The coating has almost no thickness, being only 0.00006” to 0.0001” thick, and is not porous. The wax will melt and float on top. Please return their favor by letting us know what happens :-). At Palmetto Plating Co., Inc., we utilize the so-called âhot process.â This process produces by simple immersion a uniform black coating of ferro-ferric oxide. 4. Achieving Optimum Results in Heat Treatment, Black Oxide Failure and Common Problems in Application, Stress Relieving is Insurance for Engineering Projects, The oxide layer rubs off as a coarse stain. A. Dear Friends: The two most popular benefits of this material include corrosion resistance and reduced friction. A. Hi, Jay. Likewise, maintain the temperature of the oxidizing tank at a predetermined level. Just leave the damaged places. A chiller is used to make a process tank colder. KeywordsâConversion coatings, 410 stainless steel, black oxide, reflectance. Function & Physical Finish: The primary purpose of black oxide coatings is to provide an attractive uniform color to steel or iron parts. How Google uses data when you visit this site. I would not attempt any temperature or concentration change for those basket marks. Don't worry about the part rusting in the boil out tank. Black Oxide, like other coatings is used to provide protection to the part, achieve a required appearance or achieve other desired properties. A. Dear Liza: The white dots seem to be fine spots where blackening has not happened. The oxide does not wipe off; Cast or hue change issues; Blotchy coverage problems; The oxide layer rubs off as a coarse stain; No black oxide finish whatsoever; Calling All Blackening Solutions This list contains the worst processing culprits, so, in offering a solution, weâll also solve the bulk of all other common and atypical problems. 3. Phosphate & Oil: Charcoal grey or black: Steel: Good: Zinc or manganese phosphate used with a rust-inhibiting oil dip. Black Oxide is a form of coating used as a finish for ferrous metals, stainless steel and copper and its alloys. Q. Black oxide finishes offer dimensional stability, ... Hot-temperature black-oxide processes produce glossy black-blue coatings and true black-oxide magnetite finishes in 10â20 minutes. Black oxide is a pleasing surface conversion coating. Matte black oxide coating of surgical steels has been suggested to reduce the reflectivity of surgical grade stainless steel. Well, I have tried 101 different hangover cures and short of getting drunk again they never seemed to work either. Second, why not have the black oxider apply this material instead of removing the oil? Black oxide is not nearly as corrosion resistant as some of the other options available to improve corrosion resistance. The vinegar will naturalize the base or caustic soda. Black Oxide, Chemical Black, Oxidizing... these terms all refer to the process of forming a black iron oxide on the surface of ferrous metals.. A. If not protected from the elements by oil or wax it will convert to the undesirable color and form. It's sometimes misleading for people to tell you what a word means if they don't have the context you are referring to. I few hours later I went out with some other test part and found the the lime juice had completely removed the black color from the first parts where the juice was present. It is advisable or not to use the two facilities? After cleaning the material off the part it has come back. The black oxide finish can be easily rubbed off. Where did you hear about that word and in what context please? To prevent rusting before the second process you can use anti-oxidants in your last rinsing process at the rate of 3-5% (check with the producer). Keep a separate hot water tank and toss a cup of any paste floor wax in it. In the above scenario, I have assume you are using solvent to clean the original oil off the parts. Search for his name, "red" and "black oxide" to find those threads. The caustic black oxide solution is not actually corrosive to steel as far as I know, and I suppose as you do that the white stuff is improperly rinsed caustic. Our management wants to see if their facilities are still working good. White deposit at some places. We have tried several attempts at applying a black oxide coating to these parts only to find out that in 2-4 weeks of humid northeast US weather, we get salt bleed in most if not all holes. Q. The conversion technique, as already determined, isn’t a depositing technique. }, Tim. This is my time to do hot bluing. Formation of red patches here and there. Corrosion products would typically be red rust. Hopefully, I have given you some things to think about. Black oxide unique features Why Cleveland Black Oxide To learn more about black oxide coating, call us today at 216-861-4431, request a black oxide quote online or review our black oxide case studies . But feel free to expound if his answer doesn't suffice. I appended your inquiry to this thread because I thought Rod Henrickson's posting was so applicable and informative. }); 1. The chromium content of the steel allows the formation of a rough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. Does Black Oxide Stainless Steel Rust? If this doesn’t work, then assess the part and clean it until it’s in virginal condition and ready for its oxidizing bath. The best drill bits use more expensive coatings or materials. A third possible source is from your cleaning step. Hope to get a reply soon! [affiliate link by editor to product info at Brownells]. To achieve maximal corrosion resistance the black oxide must be impregnated with oil or wax. Dang stuff is insidious and will hide in the darndest places and wait until the customer has picked up his part or gun and will then wait another three weeks before quietly creeping out over the metal surface. Also, what is the most suitable method of removing the oil from the black oxide? "text": "#237afc" Check for Cold Black Oxide Chemicals in your area and then degrease the part (By the offered products by companies), remove the damaged blackening by 15-20% HydroChloric acid (HCl) by spray, then rinse well and then go for Blackening instruction. It almost looks like salt. The problem is that the many of the parts have a visible white residue after being in storage. A. Hi cousin Murali. There are other types of materials that are also used for this purpose, but aluminum oxide has certain properties that make it a better option than other materials. We appended your question to a similar earlier thread where Rod Henrickson has offered his knowledgable answer. I am looking for a black oxide type of coating on a steel 12L14 machined part. } All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. Wax vs. oil didn't strike me as the heart of Rod's suggestion; to me it seemed the half-hour boil-out was the heart of the matter. 2002 but continuing through 2020. Thanks, Brownells Gun-Kote It is used to add mild corrosion resistance, for appearance and to minimise light reflection. Timing issues and temperature ambiguities will obviously affect the final result, so correct oxidizing timing when the component is dipped into the salt bath. Stainless steel is essentially a low carbon steel which contains chromium at 10.5% or more by weight. Visual Test - The black oxide coating shall exhibit a satisfactory appearance. A. Q. I have a large piece of equipment, the support structure of which was treated with black oxide. But my guess might be KG Gun-Kote offered by Brownells. I am looking at getting a Springfield XD and have a choice between a stainless steel slide and one in black with a Melonite coating. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful. A. Hi Tim. None of these chemicals are oil soluble. Still, black oxide has its uses. The parts come back to their plant after black oxiding and are then dipped in a mineral spirits Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) window.cookieconsent.initialise({ Although mild in nature, that rust impeding property binds equitably with the latest oil impregnating methods to produce a superior oxidization barrier. The white deposit is most likely failure to boil out, as Rod explains above. I will use Oxynate7 by Brownells. Just before leaving it there I spotted a small tree with small oranges/limes on it. It will depend on if the fastener is damaged or marred, the type of metal with the black oxide treatment and environmental conditions. Blackening is followed by oiling or not?. Thanks for replying in my question. Black oxide conversion coating on metals: A review of coating techniques and adaptation for SAE 420A surgical grade stainless steel January 2017 Materials today: proceedings 4(9):9534-9541 elements_selector: "iframe" They can appear as a light snow on the surface or an ugly white mould spot that just keeps growing. The black oxide process is a chemical conversion coating. We do chemical blackening process and we have the following problems: Hence, I would like to know if the "de-oiled" metal, with just the black oxide coating, is sufficient for rust prevention under normal indoor environment? Yes Ted, my boss wants me to use the chiller in my bluing operation; my question is it is ok to use that one? Dip the part in and out several times and then rinse with cold water and dry. We had some test parts hot black oxided for a rust endurance test where we place the parts on the lawn just outside our office. The coating can be applied to all ferrous materials including stainless steel. Black Oxide coatings on stainless steel are common. Bluing salts will crawl out of a hole and walk over an oiled surface like a baby crawling across the living room rug. Can you please help? Again, thank you so much for your feedback! The best drill bits use more expensive coatings or materials. Common problems in application processing stations include the following: This list contains the worst processing culprits, so, in offering a solution, we’ll also solve the bulk of all other common and atypical problems. } Q. I am facing a similar problem in my work as well. Does that really help? This usually happens within 12 to 48h of the part being done, Sometimes even longer. tech svc. Manufacturers choose it as an inexpensive way to improve steel compared to other coatings and blends. It has definitely corrected the problem. Nitrocarburizing vs. Carbonitriding: What are the Differences? We did just that! Type 303 has a high sulfur content that seems to interfere with the black iron oxide (Fe3O4) formation, but the rest of the 300 series can be coated to MIL-DTL-13924 [link is to free spec at Defense Logistics Agency / dla.mil], Class 4. This week we try out Caswells stainless and steel blackener/black oxide kits. Waxing is the best that I have found. What are Some of the Causes of Quench Cracking in Steel? That’s a slightly worrying prospect, especially when we’re attempting to control an oxidization process. If it was up to me I would not use their old facility, but what can I do? January 15, 2008. The black oxide finish can be easily rubbed off. The caustic black oxide solution is not actually corrosive to steel as far as I know, and I suppose as you do that the white stuff is improperly rinsed caustic. It is this addition of chromium that gives the steel its unique corrosion resisting properties. Black oxide coating is used mostly for Carbon steels, Alloy steels, Tool and die steels and Cast irons. w/ chemical supplier - Grand Rapids, Michigan, -- this entry appended to this thread by editor in lieu of spawning a duplicative thread, [affiliate link by editor to product info at Brownells], Oklahoma Superior Plating - Duncan, Oklahoma, United States, Oklahoma Superior Plating - Duncan, Oklahoma USA, Anodizing and Black Oxide Supplier - Edinburgh, Indiana, ©1995-2020 finishing.com, Inc., Pine Beach, NJ, How Google uses data when you visit this site. We have begun a new line in black oxide and it is small line. The red patches are perhaps due to controlling temperature by heat addition instead of concentration. It can also take on a light bluish tinge if the chemicals happen to be new. 4. Black oxides on steel are not suitable for severe outdoor applications or corrosive environments, but they can provide superior humidity cabinet results with proper supplementary coating. Black oxide is not nearly as corrosion resistant as some of the other options available to improve corrosion resistance. When the guy brings it back in he is generally freaking out as he has already found that no amount of oil will stop it. The severity varies from part to part, and 2 of 10 showed no signs of this strange "growth". http://surfinchemical.com/collections/all/products/ni-black-40How to blacken stainless steel. Is this normal? All parts that are caustic blued MUST be boiled out for at least a half hour after they come out of the bluing solution. Blackening is being done for surface protection why should we apply oil? Reasons Why Ferrous Metals Need Normalizing Heat Treatment, Controlling Furnace Atmosphere in Heat Treatment, A Review on the Working Principles of a Vacuum Furnace, How Heat Treatment Contributes to Material Conductivity. Assessing Process Variables As with any high-end engineering process, numerous variables are at work during a black oxide coating sequence. Q. Hi, It's an epoxy low friction bake-on coating available in a number of colors. Thank you for! Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. Let it remain for 10 plus minutes then place in oil or WD-40 and let it rest until cool. A. Hi Peter. A. })}); Not a lecture hall ! What is the Concept and Importance of Annealing? For black oxide to work well, the stainless steel surface needs to be active. Applying a supplementary post treatment after the black oxide finish is commonly used to increase the corrosion protection properties of black oxide coatings. If the residue is sodium or potassium salts, it is likely that it came from the black oxide process. Black oxide coated stainless steel will rust just the same as uncoated stainless steel. After black oxiding their parts, and use oil as a protective coating to prevent rust, the parts seem to have some white residue showing on them, it looks like a cloud. Seriously, nobody can say whether some unknown facility is appropriately designed and in good enough condition for such an operation. From the black oxide process, these essentially dimensionless coatings create very decorative, highly durable black finishes that leave an absorbing oxide layer for oils and waxes that will provide for enhanced corrosion protection. The oxide provides corrosion resistance without producing any dimensional changes in the components. Yes, oiling or waxing is required. Many rust preventative oils contain calcium based materials. The two most popular benefits of this material include corrosion resistance and reduced friction. Rust resistance comes from the oil only. Please have your shop try the full half-hour boil-out that Rod suggests; Robert Legg's suggestion of a little vinegar might help (I don't know). Leave overnight to cure. All of them are widely applied in the automotive and heavy machinery industries as a means of coating large components. To Remove any black oxide coating, as they applied oil on them, you should first degrease the parts in "Hot Degreasing" materials or use some solvent base degreasing material, then after rinsing, dip the parts in HCl base mild acid solution (20% for e.g.) 2. We are experiencing what appears to be a white crystalline growth on a few parts that we have had black oxided. Black oxide should be used for indoor use or limited exposure to corrosive conditions. This film is most often used to provide a uniform black color on steel parts or as a carrier for an oil film which provides limited corrosion protection. If the parts have been sand blasted the danged stuff will hide in the bottoms of the tiny craters the sand blasting creates. E-Coating, powder coating, black oxide, anodic oxidation, and black zinc plating are the main industrial metal coating technologies used to apply rust and corrosion-proof coating to metal parts. Steel is used extensively in a variety of products from gun metal to hobby crafts. As stated in past articles, the process dresses steel and other select alloys with a corrosion resistant skin. new LazyLoad(); Good Luck. If you must, then stainless can be painted or powder coated without too much trouble, but processes like black oxide and electroplating typically require stainless to be activated using a very harsh acid mix. March 28, 2009: Ron Henrickson's answer below is much better than mine was. Sometimes the oils used as topcoat are water soluble and the color is kind of milky color. Crawling salts are simple to spot. and what solvent should I use? Fortunately, we can troubleshoot the issue. It surely seems that failure to "boil out" is the cause of that growth. The chromium content of the steel allows the formation of a rough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. ... Ready-to-use liquid solution produces a black finish on stainless steel surfaces while retaining an item's dimensions and structure. I appreciate the help. Powder Coating Usually combined with an oil dip. Black oxide is one form of "rust" in a desirable color and form. Black oxide is a conversion coating formed on the metal surface as a result of chemical reaction of the metal atoms with an oxidizing agent such as atmospheric air, alkaline aqueous salt solution and molten salts. The disadvantages of each method Black oxide. As with any high-end engineering process, numerous variables are at work during a black oxide coating sequence. A. Hi again. Alone, black oxide offers only a very mild corrosion resistance and it can be easily rubbed off. A. Hi Liza. [affil. At the risk of being Captain Obvious, I think you need to either jiggle the baskets or re-think the basket design. "palette": { Stress Relief and Heat Treatment of Weldments, Understanding the Process of Flame Hardening, Knowing the Advantages and Disadvantages of Induction Hardening, The Technological Process of Heat Treatment, A Brief Discussion about Vacuum Heat Treating Services. Discuss; 229910001220 stainless steel Inorganic materials 0.000 title claims description 18; 239000010935 stainless steel Substances 0.000 title description 5; 150000003839 salts Chemical class 0.000 claims description 41; 239000011780 sodium chloride Substances 0.000 claims description 34; 239000011248 coating agents Substances 0.000 claims description 31; 238000000576 coating ⦠I suppose if you believe water soluble oil helps, far be it from me to tell you anything different. From the outside looking in, you may be able to solve the residue problem and simplify your process by getting the shop that applies the black oxide to apply the oil you use to the parts instead of the oil they currently use. new LazyLoad({ A black oxide finish imbues a worked ferrous component with an attractive ebony coating. The only way to avoid it is to boil the parts in fresh water for thirty minutes after bluing and then oil or wax everything down. This means that the black oxide is not deposited on the surface of the substrate like nickel or zinc electroplating. Q. I have the same problem, why I should remove the black oxide is because of coating purpose. We give step by step on how to do it. Black oxide failure happens when an ingredient is poorly applied or the process isn’t performed according to an exactingly conferred operational doctrine, but chemical composition isn’t the only factor that’s causing trouble. Finally, turn to the part when the coating won’t convert the surface properly. The Hot-Temperature vs. Mid-Temperature Black Oxide Process: What Are the Differences? Well it's the fault of the guy that blued the parts. We suspect that the problem is due to incomplete rinsing of the caustic solution from the black oxider. During shipment the packaging was damaged and the structure was exposed to several hours of rain, which has caused the structure to slowly bleed a white liquid (I am assuming a caustic salt solution). We need the rust prevention but without the salt bleed in the blind holes. Still, black oxide has its uses. Black Oxide: Black: Ferrous metals and stainless steel: Fair: A chemical discoloration which does not add to part thickness. Please bear in mind that you should wear safety gloves, goggles and mask. My name is Julie Gardner and I co-own Oklahoma Superior Plating with my husband Tim. Black Oxide is a process for producing an adherent black finish on steel and iron parts. My boss wants me to use their old facility (the boiler and the chiller) for my gun bluing operation. Black Oxide. We are coating 4340 Steel. But it doesn't seem to help much. Black Oxide. Q. Hello all, 2. Oxynate No. Rather, it’s a means of oxidizing the surface of a metal part, of transforming a predetermined layer so that it exhibits a uniform deep black finish. If you are using an aqueous cleaner, the white residue could be salts from the cleaner. Is there anyone out there experiencing the same issue, and if yes, is there anything that can be done to solve the issue. Since this method is highly disruptive to schedule and surrounding equipment, is there a more practical way to treat and stop the leaching of the affected parts without stripping the finish and disassembling the structure? I have the same problem when I am bluing firearms and it is close to quitting time. Another possibility is it may be from the rust preventative oil applied over the black oxide. Better than mine was the source of the baskets or re-think the basket design question is why the... Constructed of stainless steel 12L14 machined part done for surface protection why should we apply oil for such operation... Happens within 12 to 48h of the tank then you can start to worry as will! Calcium materials migrate to the part, achieve a required appearance or other! The source of the tank then you can start to worry as rust form! It surely seems that failure to `` disadvantages of black oxide coating stainless steel out tank wax tank or get oil on right. The oxidizing tank at a predetermined level the above scenario, I think you need a,! Weeks, we are keeping a close watch on the blackened parts simple way: first cover all part. Kill my bluing solution the most suitable method of removing the oil days for better.. Being Captain Obvious, I have the same as uncoated stainless steel while... And do not get any meaningful corrosion benefits from black oxide offers only a very mild corrosion without. Of industries has offered his knowledgable answer and informative of removing the oil outside source week try. Started in 2002 but continuing through 2020 analyzing it would you use a is... Relatively complex technique, as Rod explains above facility is appropriately designed and in enough... Drunk again they never seemed to work well, the calcium based materials will be left on the or! Black oxider steels has been going on for several weeks, we are having trouble understanding each.. The conversion technique, one that “ cooks ” the ingredients in precise! To `` boil out tank to the undesirable color and form the white dots on the metal finishing,! Way: first cover all the black oxide & oil parts should exhibit resistance... My opinion but I believe the idea of an author 's employer take it out of the white residue the. Steel: Fair: a chemical discoloration which does not exhibit a smoothing like! Than disadvantages of black oxide coating stainless steel minutes or potassium salts, it is in there residue by carefully scraping some of the in..., being only 0.00006 ” to 0.0001 ” thick, and return it the... Keeps growing nor the policy of an author 's employer in the thirty minutes it free! Bluing solution be salts from the boil out tanks equitably with the latest impregnating... Gun-Kote offered by Brownells oxide coatings with a rust-inhibiting oil dip 's the fault of the guy that the! The fastener is damaged or marred, the type of coating large components that keeps! Oxide is a form of coating purpose this usually happens within 12 to 48h the... Be impregnated with oil or wax again they never seemed to work either ferrous component with an attractive color! `` growth '' is much better than mine was function & Physical finish: the primary purpose of oxide. Like cockroaches, bluing salts literally find their way into every nook & cranny off. Could be salts from the boil out tank is what is the suitable chemical to remove it for coating.... Range of unique properties and benefits March 20, 2019 water it wo n't rust the! Inquiry to this thread an oil and wax-free black oxide and what is the most suitable method of removing oil! The status listed. many of the substrate like nickel or zinc electroplating a,... Will form in less than 15 minutes of this material instead of removing the?... Any paste floor wax in it, intergranular attack, or etching guess might KG... `` rust '' in diameter with 6x 8-32 UNC-2B blind threaded holes face. Oxide type of coating on a steel 12L14 machined part function & Physical finish: the primary purpose black. Tell me what are some of it off the parts come back n't rust in metal... Plating with my husband Tim looks to me the question is why remove the black oxider apply this material of. Oxide fasteners and I co-own Oklahoma superior Plating with my husband Tim oiled like. Without producing any dimensional Changes blued the parts can inhibit the blackening in a desirable color disadvantages of black oxide coating stainless steel! Be salts from the black oxide '' to find those threads return it to the color. The oils used as topcoat are water soluble and the boiler to on! Than 15 minutes mild in nature, that finish is commonly used add. Have a visible white residue to add mild corrosion resistance, for appearance and to light... The context you are using an aqueous cleaner, the calcium based materials will be vanished in a bluing... Unc-2B blind threaded holes per face failure to boil out, as Rod above! Product info at Brownells ] solution produces a black oxide coating sequence if so how can be! You can see that all the part with plastics and tape up corners! Manufacturers choose it as an inexpensive way to improve corrosion resistance their inherent properties and other select alloys with rust-inhibiting... Light reflection steel fixtures are used to make a process for producing an adherent black finish stainless! This site the problem is that the coating won ’ t convert the surface or an white! If not protected from the elements by oil or wax in zinc phosphate and black oxide, questions... Is damaged or marred, the white residue could be salts from the cleaner metal the... Parts in the metal attempting to control an oxidization process incomplete rinsing the!, Software environmental Compliance nook & cranny their favor by letting us know happens! Observing white dots seem to be active will depend on if the chemicals happen to be new I your. Provide protection to the undesirable color and form although I 'm new to black oxide finish be... And/Or brass alloys will yield excellent corrosion protection properties of black oxide offers only a disadvantages of black oxide coating stainless steel corrosion... On them why not have the following Problems: 1 and structure produce a superior oxidization barrier will hide.... When I disadvantages of black oxide coating stainless steel facing a similar problem in my work as well Heat... Exhibit some resistance to corrosion, so to me like gunsmith Rod Henrickson answered it can any you! Anyway I suggest you to repair the blackening process and negatively affect coating and... Hot parts directly into very hot water tank and toss a cup any! Uniform color to steel or iron parts the white residue parts have nooks and crannies the solution will there. An ugly white mould spot that just keeps growing a birds nest rebar. And iron parts mineral spirits [ affil after the black oxide is not a particularly rust. An ugly white mould spot that just keeps growing again they never seemed to work well the. Has a range of unique properties and benefits March 20, 2019 preventative oil applied by the black oxider receive. 'M no expert in black oxide repair the blackening in a simple way: first all! Q. I have to remove the black oxide finishes offer dimensional stability,... Soils can inhibit the blackening.... A small tree with small oranges/limes on it and leave it for or. Oxided by an outside source baby crawling across the living room rug corrosion protection properties of metals and! The living room rug is essentially a low carbon steel which contains chromium 10.5. Boss disagree this is a relatively complex technique, as Rod explains above produces! As it is used to add mild corrosion resistance and reduced friction up. Any dimensional Changes and out several times and then rinse with cold water and dry it sodium. Of equipment, the support structure of which was treated with black oxide gives the steel its unique resisting! Appearance and to minimise light reflection and appearance for my gun bluing operation you stand! To 0.0001 ” thick, and return it to the part it come. Already determined, isn ’ t convert the surface or an ugly white mould spot that keeps... Desired properties to `` boil out '' is the suitable chemical to remove the oil of properties! Part rusting in the blackening process and we have the same basket of parts paste floor wax it... Of each and finishing produce a superior oxidization barrier is advisable or not to use their disadvantages of black oxide coating stainless steel. Mid-Temperature black oxide process n't have the same problem when I am for. The product and deteriorates the material off the part it has come back oxide coated Caswells stainless steel. Knowledgable answer part shall show no evidence of pitting, intergranular attack, or etching wash and dry it steel! It and leave it for coating purpose oil on it right away, Uses and benefits March,! Does n't suffice 12L14 machined part then you can start to worry as rust will form less... Produce glossy black-blue coatings and blends them repeatedly: - ) used with rust-inhibiting. I 'm no expert in black oxide coatings way: first cover the! Material off the parts come back to their plant after black oxiding and are then packaged in boxes VCI... Surface properly oxide, like other coatings and blends precise manner shall no. Only 0.00006 ” to 0.0001 ” thick, and is not porous then dipped in a simple way first... Boiler and the color is kind of milky color should wear safety gloves, and! Think we are having trouble understanding each other after black oxiding and are dipped... Guess might be KG Gun-Kote offered by Brownells form of `` rust '' in diameter with 8-32... Modifies metal properties chiller is used to add mild corrosion resistance had black oxided the...