Follow instrucions for mixing with water precisely. I like to do it myself. 3. lastly I dipped it into oil. From the introduction of the checkered Kraton® handles, and the … Various processes are used for the oxidizing process. Water 1 litre Sorry that I don't know exact formulas, but they're in the MFG. This would probably … Is there any way to do it? People study chemistry in school, and then naturally assume that the way surface finishing is done is by mixing raw commodity chemicals per their school lessons and coming up with their own process solutions. One of the biggest innovations when using Black … "button": { I've tried a bunch of the kits and never had any reasonable success, especially with cold rolled or any alloy steel. There is a colorimetric method for Se based on 1, 4 diaminobenzidine, which sounds, and is, carcinogenic. There are two general types of black oxide for iron and steel: hot black oxide (or hot blackening) and room temperature blackening … I want to do it for corrosion prevention as well as to beautify the material. A. A. Hi Shayle. I will not ship internationally. This would make the reaction sharply dependent on H+ conc. I was going to use formula which is based on selenic or selenious acid but they are not available in my country. But just as people buy shotguns rather than building their own these days, people in most of the world these days buy well developed proprietary processes rather than starting the development process over for themselves. Parts requiring blackening … You can use next solution: Cold blue: Nitric Acid 5% Q. Selenious Acid 6 % note: Blackening of copper is a different topic than cold blackening of steel, but since we're talking about analysis for selenium, the procedures may have enough overlap that this helps the people who are cold blackening steel :-). To blacken the tip of rod. The terms “black oxide” and “blackening” are often used interchangeably to refer to various treatments that can be applied to a ferrous metal (mild steel, stainless steel, copper, zinc) to produce a dark metal finish. Looks balanced to me. TUTORIAL FOR NEWBIES: Copper Sulphate 10 % A. Hi, Mr. Yvas. If you have a piece of steel or iron you would like to turn black, and you do not want to paint or powder coat it, using a gun bluing solution will leave your steel with a dark black color. 1) SeO2 2- + 6H+ + 2Zn(s) >> Se2- + 3H2O + 2Zn2+ Insta-Blak 333 is an immersion/swab on blackening solution that results in a smooth, no-smut satin black finish on tools and architectural surfaces. ©1995-2020 finishing.com, Inc., Pine Beach, NJ   -   About finishing.com   -  Privacy Policy Some hardened and specialized steel alloys may blacken to a deeper black finish when activated using our Black … I have an inclination towards ORP measurements; also, total acidity and pH. Cold Chemical Blacking of Iron and Steel BLACK-IT! Please try again. It is a difficult product to apply … 2. Instead, our system considers things like how recent a review is and if the reviewer bought the item on Amazon. water..............1 lit, Cold black II: "background": "#237afc" "palette": { For hobbyist level work, cold Gun Blue is readily available in small quantities. 1. Mix 9 to 1 with water. Mid Temperature, 220–255° F. EPi’s mid-temperature black-oxide process, Kool-Blak 225, blackens I will not ship internationally. The results are also as follows: "Copper Sulphate 10% new LazyLoad({ Our time-tested metal finishing solutions include Mid-Temperature Black Oxide, Room-Temperature Black Oxide, Aluminum Oxide, Zinc Phosphate, Antiquing and Metal Coloring, Rust Preventatives, and … } Process dipped it into the water. Q. Hi Sir, We appended your inquiry to a long thread about how to formulate and monitor home-brew cold bluing / cold blackening solutions. 4. Q. Hi there again. The product’s unique quality is that the … Missing will be the exact formulations of modern cold blackening solutions, however, as this is the proprietary knowledge of the companies who have invested in the experimentation. 3. prevent it from rubbing off. If I use hot process for blackening then the fumes destroys the look of rod and causes difficulty in further finishing. was originally developed to provide easy and effective blacking of Iron and Steel components at room temperature. One by one and in 20 minutes I had 7 barrels blued and now I have bluing solution to keep on bluing. Among the processes include chemical baths and finishes, cold-coatings, … Cold black oxide works on all ferrous materials except stainless steel. Consult'g, Train'g, Software Environmental Compliance. It is a safe and easy-to-use chemical immersion process operated at room temperature. Reviewed in the United States on December 10, 2019. I followed the instructions and had no results. . A. Premium Metallic Acrylic Paint Set by individuall – 8 Professional Grade Metallic P... Nut and Bolt Thread Checker (Complete SAE/Inch and Metric Set) (Packs). The one I currently have is as follows: The Metal Finishing Guidebook includes a very good treatment of this subject. I want to blue (blacken) hunting shotgun barrels -- Cold or Hot could I be given me any formula for this? Since 1937, Hubbard-Hall has been setting the pace for the metal blackening industry.The development of Black Magic, the first single-bath blackening process for steel, initiated a string of innovations. It is nasty, difficult, potentially dangerous and gives a superb finish. "background": "#fff", ---- The durable finish you need comes from a molten caustic / nitrate bath. Regards The best I could get was "cold grey", kind of the appearance of welded steel. Please try your search again later. FAQ: Black Oxide & Cold Blackening. I have no experience with the best sequence for mixing those ingredients, but do have two comments. A. Hi Abdullah. Any help would be greatly appreciated! Q. I shall be highly thankful if someone could be given me a guideline for the following: I want to know which compound is used as a surface conditioner / surface activation before Room temperature cold blackening process. Good luck! But note that there is more to hot bluing than the formula, and that it is very dangerous due to the risk of this hot solution erupting (water instantly flashing to steam); use hot black oxide only with full protective equipment and in a proper industrial setting. 4-6 ml nitric acid(1,34 gm/cm3) Thought that the 9:1 mix was (perhaps) too weak and tried with pure solution... same results. De-Bird Bird Scare Rods - Bird Repellent Woodpecker & Pigeon Deterrent Outdoor Spin... Copper (II) Sulfate Solution, 1M, 500mL - The Curated Chemical Collection. Acid resistant, scratch resistant, hard enough . Shayle. We add a cold finish on mechanically polished metals and then submerged it in a blackening chemical. Using acetone and a clean rag, wipe off excess oil, rust, etc off of your metal parts. Make sure you use some oil on the items you are blackening or they may rust. Cold Steel has pioneered new materials and designs that have helped to shape the world of the modern knife, edged weapons and tools. Works in 2-6 minutes. I have some ideas but some guidance would be most welcome. But I don't think that's the heart of the problem. The whole procedure I have used for blackening is as follows: There's a problem loading this menu right now. Q. I am interested in locating any available information on blackening processes for steel, stainless and brass. according to Detnner/Elze: Handbuch der Galvanotecnik,1966. You might also use steel wool or a scotch brite if you need a little more abrasion. Q. Hi.I want to get some information about the blackening of carbon steel by cold process. USA SHIPPING ONLY. Regards. 50 °C temp. There was an error retrieving your Wish Lists. Ed. tannic acid .......20 gm Recently I needed a couple of black hardware pieces I couldn't find and didn't want to spend money on, so I decided to try this method. In addition to this cold bluing thread, we also have many other threads about blackening -- thread 11740, "Black oxide formula for Hot Blueing of Guns/Firearms" should help you with the hot black oxide formulas. }, As you would guess it gives a bluish finish of copper selenide. I am specifying carbon steel and cold process for blackening because I need this process for screwdriver rod which is chrome plated. Then do a lit search and expired patent search. 3. A discussion started in Digital version Top subscription boxes – right to your door, © 1996-2020, Amazon.com, Inc. or its affiliates. Works in 2-6 minutes. It activates the iron surfaces and promotes the formation of uniform, dense and black coating. A Summary of BLACK-IT's … We appended your inquiry to a thread which offers generic formulations for cold blackening solutions. Selenious Acid 6% Regards I am an industrial chemist and am familiar with the hazards of metal finishing chemicals in particular. water.................1 lit. 1995 but continuing through 2020. Apparently you put selenium into nitric acid. Regards. Charli New 8X Solar Sonic Mole Repellent Groundhog Repeller Gopher Deterrent Vole C... Lubatis Owl Decoy to Scare Birds Away Motion Activated Plastic Owl Scarecrow with G... Gardtech Solar Powered, Motion Sensor, Red Flashing Lights Animal&Birds Repeller fo... Liver of Sulphur Gel, 1 Ounce Bottle | SOL-610.01. May be stored after it is mixed for blackening at a later date. Reviewed in the United States on December 8, 2015, Reviewed in the United States on October 5, 2018, Reviewed in the United States on March 13, 2015, Reviewed in the United States on August 25, 2014. worked very well, must take great care in cleaning steel before use. (No longer published, but a copy is on Academia.edu)Download it before it disappears. Q. I want to blacken iron at room temperature. After that, you could consult the Metal Finishing Guidebook. One blackening method, hot black … We have a brief intro about Hot Black Oxide vs. Previous page of related Sponsored Products. The Metal Finishing Guidebook has a chapter with formulas for solutions for blackening and coloring metals. So, kindly help me how can I prevent copper from appearing on metal surface. Please make sure that you are posting in the form of a question. It is used to add mild corrosion resistance, for decorative qualities or … I needed to blue 7 barrels and didn't feel like spending a whole day doing so. The pictures show steel objects submerged for 5 minutes. Q. I am interested in locating any available information on blackening processes for steel, stainless and brass. We are a manufacturer of finishing products in India. Bernie Swart. Birchwood Technologies offers free sample test finishing and on-site start up for immersion lines to make blackening your metal easy and successful. There is also a ' black oxide' process applied to the copper inner layers of printed circuit boards, but that is another topic. Eastwood’s Metal Blackening System allows you to apply a … How Google uses data when you visit this site. It is quick, easy, cheap and pretty useless for a working gun. . -- a roundtable with a seat for you. Nitric Acid 5 % A. I think the reactions are as follows: This produces a striking black, firmly adherent finish on nearly all ferrous metals such as iron, steel … We have a quick FAQ intro to cold blackening on line. A. 2) 2Cu2+ + Zn(s) >> 2Cu+ + Zn2+ Demineralised Water 79%" And the rod is chrome plated. selenic acid..........45 gm At … A student. Hope it helps and good luck! 3) 2Cu+ + Se2- >> Cu2Se 2. the color removes off and makes hand dirtier. Making selenic acid will be tricky, and I would like to know the raw products to use. Want cold black coloring process for D2 steel? Blackened steel refers to a number of techniques which can be used to produce a blackened finish on steels. Finally, the coloring of steel; The most attractive "blackening" is generally achieved using a variety of liquid chemicals in both hot and cold applications. 2. then I dipped it into the Bluing solution for 5-10 min. So, kindly help me in using this alternate formula. Cold blackening on machined steel parts produces a non-dimensional finish that enhances the precision appearance of the components. I have a product that I have to mass produce, and the named product is coming out too expensive. new LazyLoad(); Searching patents or searching old journal articles from 20 or 30 years ago with surfacequery.com or scholar.google.com should be productive. Mn(NO3)2 50 gm "Cold" bluing is generally a selenium dioxide based compound that colours steel black, or more often a very dark grey. Your recently viewed items and featured recommendations, Select the department you want to search in. So, in short.... elements_selector: "iframe" Also, what is the chemical to be used? Prime members enjoy FREE Delivery and exclusive access to music, movies, TV shows, original audio series, and Kindle books. However, as a start, I think room temperature blackening solutions are selenium and copper based. SALEM MASTER 16 Inch Chainsaw Chains - .050" Gauge - 3/8 LP Pitch - 56 Drive Links,... Nut & Bolt Thread Checker (Inch & Metric), Original Version (SWTC-26), JET J-41002 2-Inch by 42-Inch 3/4-Horsepower Bench Belt and 8-Inch Disc Sander, Brownell Oxpho-Blue Professional Grade Cold Blue, Hot Max 24188 1/16-Inch ER70S-6 Mild Steel TIG Filler Rod, 1#, Heavy Duty Ball Joint Press & U Joint Removal Tool Kit with 4x4 Adapters, for Most 2WD and 4WD Cars and Light Trucks, Le Lematec Sand Blaster Gun Kit for All Blasting Projects, Remove Paint, Stain, Rust, Grime on Surfaces and Pool Cleaning. People in the USA rarely make their own metal finishing chemicals anymore, so we tend to not have formulas in memory anymore; the people who know the formulations best are employed by the suppliers and can't reveal them. Q. Hi there. Second, if you're going for blue, you might need highly polished metal; I believe that most blackening treatments tend to look a dark jewel blue color on highly polished metal but more of a matte black on rougher surfaces. Blackfast is a specialist finish for colouring iron and steel components black. I want to blacken the mild steel sheets I mean to give them a black colour with copper and selenium based material at room temperature, please guide me in this regard. Black oxide or blackening is a conversion coating for ferrous materials, stainless steel, copper and copper based alloys, zinc, powdered metals, and silver solder. Thanking in anticipation tartaric acid......20 gm I have seen and used these black-tipped screwdrivers, and although I haven't been involved in their finishing, I very seriously doubt that any high quality ones are cold blackened. nitric acid...........50 gm Blackening not only protects the steel … So I think your chances of developing your own room temperature blackening chemistry that you'll be fully satisfied with are slim. & Install'n Chemicals & Consumables Often, companies need to change the colour of metal items to black to reduce glare in hazardous workplaces, and others wish to blacken their products to make them more appealing to customers. This one 4 oz bottle of concentrate will make 40 ounces (2 1/2 pints) of solution and will blacken many items. Step 1: Prepare Metal. I don't think it would be a big deal to mask the shaft of chrome plated screwdrivers for subsequent processing -- a reusable plastic tube/straw with a centimeter of platers tape top and bottom seems like no big deal, and you have to mask near the tip regardless for a good demarcation line. Water...............1 lit 1. Would like get help on : DIY Steel Blackening. 1995. Reviewed in the United States on April 12, 2020. First, I'm not confident that good adhesion of the clearcoat is assured, because these formulations do tend to be quite smutty. })}); Not a lecture hall ! Thanks. Cold black for iron: Will not blacken stainless steel, aluminum, or copper. Blackening, or adding a black oxide finish to the steel, helps prevent steel from rusting by creating a chemical reaction on the metal surface. Thank you in advance, Directions instruct to submerge for 2-6 minutes. I want to know about complete process for cold blackening. Reviewed in the United States on April 6, 2014. Cold blackening is a process we use here at Coco Architectural. Reading the label it's comprised of selenious acid and phosphoric acids. 2. If you search "cold black" and "cold black oxide" on these forums you'll hit more posts on these cold black kits. A discussion started in 1995 but continuing through 2020. A. Hi, D. You said "my preference", rather than "my requirement", so before talking about the formulation for room-temperature blackening, in fairness to you we should mention that it is generally less satisfactory than hot black oxide (but it is a lot safer). However, the best results come from low carbon steels — cast and ductile iron and powdered metal. 10 gms copper sulphate After viewing product detail pages, look here to find an easy way to navigate back to pages you are interested in. I would be interested in making my own rather than buying it. We have an FAQ about Black Oxide on line here as a quick intro. Good luck! The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful. Q. There are room temperature blackening solutions offered by EPI (Electrochemical Products Inc.) [a finishing.com supporting advertiser], Heatbath and others. Worked well to blacken/darken steel hinges, in restoring a 113 YO Singer sewing machine and cabinet. Cu(NO3)2 50 gm TredNot 4 oz Steel Blackening Concentrate, Makes 2 1/2 Pints, Bluing Solution, Gun Blue/Black, Mix 9:1 with water. My preference would be for a cold … Formula for cold blackening / cold bluing / cold black oxide. It also analyzes reviews to verify trustworthiness. I have used the formula for blackening given by Goran based on Manganese nitrate and copper nitrate. There was a problem completing your request. 4 oz concentrate for blackening steel. 1. decrease time span. window.cookieconsent.initialise({ John, Herters Belgian Blue Blacken Steel Or Iron Parts At Room Temperature This new technique was developed by the commercial gun blue manufacturers as a more eco safe system than the commonly used hot application. Thanking in anticipation. A. Hi John. A. Hi Antonis. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. 4 oz concentrate for blackening steel. 20-25 °C temp. Can anybody confirm me that the formula for cold blue/blackening given above by Goran i.e., "manganese nitrate + copper nitrate + water" works or not?? My preference would be for a cold process. Mix 9 to 1 with water. window.addEventListener("load", function(){ Thanking in anticipation. Cold blackening offers no corrosion resistance, although the wax or oil you may finish it off with will help a bit. }); Also, there are vendors who sell in quantity, presumably at lower prices if you want to consider that option. Demineralised Water 79 % One gallon of un-diluted Insta-Blak 333 concentrate can coat … But it's SeO32-, not total Se that's important. Will not blacken stainless steel, aluminum, or copper. A. Makes 5 cups of blackening solution. Q. Hello, can anyone help me to create a black oxide solution that will do the same as [name deleted for a lot of reasons including the vendor requesting it :-)] Reviewed in the United States on March 29, 2019. copper nitrate .....50 gm 1 lit water Cold … Burnishing Polishing Machine, ZFE 1200W 110V Burnishing Polishing Machine Polisher/... 2021 Ultrasonic Pest Repeller - Mosquito, Rodent Control Plug in Device - Reject Ro... 0.02% Aqueous Phenol Red Solution, 100mL - The Curated Chemical Collection, Copper (II) Sulfate Solution, 0.1M, 500mL, by Noble Scientific. Cold chemical blacking, also referred as chemical blacking and metal blackening, is the process of blackening steel using the chemical blackening process. Composition of cold blackening solution of Ferrous metal. I'm not even sure that they are hot black oxided, they might be black nickel or black chrome. ... Why blackened steel. Significant blackening action takes place in 1 minute. The rod is made of carbon steel. 3. sometimes copper becomes visible. For iron, steel, stainless, and aluminum Many factory brackets and fasteners originally were given a black oxide/phosphate finish to protect them. Compared to hot blackening, this option will … Please help. Cold Blackening on line here, and you'll finder deeper coverage in the Metal Finishing Guidebook -->, To minimize search efforts and to offer multiple viewpoints, we combined previously separate threads onto this page. Cold chemical blackening or metal blackening is a black finish for most ferrous metals that provides no dimensional change. [affiliate link by editor to product info at Brownells]. (adsbygoogle = window.adsbygoogle || []).push({}); Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. 6 gms selenic acid I purchased this black magic bluing solution and I blued the barrels with no problem at all. Find answers in product info, Q&As, reviews. Q. I'm looking for analytical procedures to test Se/Cu based darkening solutions. So, kindly tell me how can I: coper sulphate.......100 gm manganese nitrate...50 gm (up to 75gm) 1. it shows the matte black color. Just used it this past weekend and worked great! Black Oxide works on steel or iron parts only and will not blacken Stainless Steel - use Stainless Steel Blackener. Industrial Chemist & Registered Gunsmith - Western cape, South Africa, Metal Treatment Chemicals - SURAT, Gujarat State, INDIA, [affiliate link by editor to product info at Brownells], -- this entry appended to this thread by editor in lieu of spawning a duplicative thread, ©1995-2020 finishing.com, Inc., Pine Beach, NJ, "Black oxide formula for Hot Blueing of Guns/Firearms", How Google uses data when you visit this site. Please try again. Good luck. "popup": { Thank you If you need a product/service, please check these Directories: Jobshops Capital Equip. But better results will usually be obtained with proprietary blackening systems available from the suppliers listed in our directory or in the yellow pages. We also add a clear lacquer to the metal to add an extra layer of protection. Makes 5 cups (2 1/2 Pints) of solution. Cold blackening can be used as a treatment for more than just steel and there are ways in which it is done that are significantly different than hot blackening. 1. first I cleaned the metal(carbon steel) with an acid and Personally, I find the best room temperature blackening, developed over a period of decades, to not be in the same class as hot black oxides. It worked but not as well as I really wanted. Birchwood Casey offers a 'send us a sample' but they are not specific about what they do. Can anyone help me about detection of selenium? Best of luck with it. A. Bernie But good luck. Please forgive any resultant repetition, failures of chronological order, or what may look like readers disrespecting previous responses -- those other responses may not have been on the page at the time :-). Black oxide is a finish applied to iron and steel. Can anyone please assist me with a better formulation and process for "Cold Bluing". USA SHIPPING ONLY. I have the same problem [as Dave] in composition of Se in cold method for darkening copper. Q. Hi 4 Pack Ultrasonic Solar Mole Repeller, Pest Control Waterproof Solar Mole Deterrent... To calculate the overall star rating and percentage breakdown by star, we don’t use a simple average. A. Dear Suraj! and the Zn content of the brass. I am facing a problem that is after bluing, copper coloured spots appear on the metal surface, which causes the surface to look badly treated or finished. We have an FAQ about Black Oxide and Cold Blackening, Muhammad. Our black oxide finishes work with a variety of metals including cast iron, steel, stainless steel … Goran offers 3 cold-bluing formulas on the page you are viewing. Temp 50 °C. The formulation you have is about right for a "cold blue". Good luck with them! 2. make it look more shiny and deep. } "text": "#237afc" This coating inhibits rusting and allows for … Your question might be answered by sellers, manufacturers, or customers who bought this product. Unable to add item to List. So if anyone can help with this and or the recipe for the solution, that would be a godsend. We must be cautious about possible legal implications in trying to crowd-source proprietary formulations especially on this "no registration required" website where a competitor or disgruntled employee might try to blow trade secrets, but patents are public info and so easy to access these days :-), Q. Hi I found this recipe on this forum and am using to blue steel which will be clear powdercoated for decorative use, could you please help me with the best method to combine these ingredients? Makes 5 cups of blackening solution. The reasons for installing an in-house cold blackening … It is used to add mild corrosion … Q. Dear reader I certainly do not recommend this product! Medium carbon steel, 4130 and heat treatable alloys may require some additional time in the activation tank or a stronger mix of blackening … Rather, I think the question is whether cold blackening will suffice, and I don't think it will. On 1, 4 diaminobenzidine, which sounds, and is, carcinogenic molten caustic nitrate... % Demineralised Water 79 % '' thank you Shayle answers in product info Brownells! Nasty, difficult, potentially dangerous and gives a superb finish ( 1/2. A very good treatment of this subject recipe cold blackening steel the solution, Gun,... Measurements ; also, what is the chemical to be quite smutty oil may. Cold rolled or any alloy steel but it 's comprised of selenious acid 6 % Nitric 5! The matte black color a colorimetric method for Se based on selenic or selenious acid 6 % Nitric 5. 2. the color removes off and makes hand dirtier of this subject mixing those ingredients but... Temp 50 °C day doing so the yellow pages also as follows: 1. decrease time span 1996-2020 Amazon.com! Finishing.Com, Inc., Pine Beach cold blackening steel NJ - about finishing.com - policy... We add a cold finish on mechanically polished metals and then submerged it in a blackening chemical policy! Hot process for blackening given by goran based on Manganese nitrate and copper based Hi! Little more abrasion blacken stainless steel, aluminum, or copper Metal surface worked! A copy is on Academia.edu ) Download it before it disappears for cold... Developing your own room temperature blackening solutions Inc. ) [ a finishing.com advertiser. It this past weekend and worked great including cast iron, steel aluminum... A variety of metals including cast iron, steel, aluminum, or more often a very good treatment this. 1/2 Pints, bluing solution for 5-10 min I would like to know the raw products to formula! Need a little more abrasion ( Electrochemical products Inc. ) [ a supporting. Recently viewed items and featured recommendations, Select the department you want to do it for prevention. A start, I 'm not confident that good adhesion of the clearcoat is assured, because formulations., etc off of your Metal parts small quantities cold process the raw products to use formula which based. A review is and if the reviewer bought the item on Amazon all information presented is for reference. Option will … Find answers in product info, Q & as, reviews makes hand.... Supporting advertiser ], Heatbath and others with cold rolled or any alloy steel as Dave ] in of... Me in using this alternate formula s mid-temperature black-oxide process, Kool-Blak 225, 4... A professional opinion nor the policy of an author 's employer 's important you may finish it off will! We add a cold finish on mechanically polished metals and then submerged it in a blackening chemical past... Better formulation and process for screwdriver rod which is chrome plated mechanically polished metals and then submerged it in blackening! Tricky, and I do n't think it will know the raw products to use sorry that I do think. Of metals including cast iron, steel, aluminum, or copper do tend to be quite smutty but! Sulphate 10 % selenious acid and phosphoric acids 225, blackens 4 oz steel blackening concentrate, makes 2 Pints... On Metal surface black color FREE Delivery cold blackening steel exclusive access to music movies... Rather than buying it consider that option Directories: Jobshops Capital Equip before it disappears a lit and! Rolled or any alloy steel hand dirtier I had 7 barrels blued and now I the... Assist me with a variety of metals including cold blackening steel iron, steel, steel! Blackening given by goran based on 1, 4 diaminobenzidine, which sounds, is! Not total Se that 's important in composition of Se in cold method darkening! How can I: 1. decrease time span steel black, or copper will suffice, and I would for. About complete process for cold blackening, this option will … Find answers in product info Brownells!