Metallographic etchants for brass and bronze alloys. Sulphuric acid is a strong acid, but reacts with steel slower. Acid etch inspection citric acid passivation xri testing. Etching copper or brass with ferric chloride stepbystep duration. How to acid etch metalcopper and brass blanks for jewelry. A strong acid is used to cut the metal, leaving behind a detailed picture. Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio incised in the metal. Typical solutions are 1 part fecl 3 to 1 part water and 1 part nitric to 3 parts water.
Certain nonacids that form acid in water, such as ferric chloride fecl3 or copper sulfate cuso4, can also be used as etching chemicals. Especially, boiling the glass in a 70% nitric acid solution for 30 min is more effective in the reduction of sodium, calcium, and aluminum atoms at the surface of the glass than other etching methods with nitric acid. Etching of brass and bronze alloys for metallographic and metallography. Lift it from the acid and rinse it under cool running water. For etching alphabeta brass, bonze, tin, cast iron phosphides, ferrite, martensite, retained austenite, zinc and steel temper embrittlement. Etching silver with nitric acid jewelry discussion. He made an example of what this acid would do to me if i should ever get into it by dissolving a silver dime in it. Ferric chloride is a traditional homeuse circuit board etchant.
Sep 04, 2019 acid etching metals allows you to create beautiful designs in relief. Alpha brass an alloy of copper and zinc with no more than 38% zinc, usually. Processes include ultrasonic cleaning, vapor degreasing, nitric acid passivation, citric acid passivation, prepenetrant etch, humidity testing, and copper sulfate testing. Ammonium persulfate mix one part ammonium persulfate to nine parts. Protect the areas you want to keep brasscoloured with an insoluble coating, such as an oilbased paint. I was wondering if there is a reverseplating technique that would strip metal off instead of depositing metal onto a piece of red brass. Kellers etch, which is made up of distilled water, nitric acid, hydrochloric acid, and hydrofluoric acid, is. Electroetching brass rather than etching with nitric acid. If you can stamp it, draw it, or write it, you can etch it. The acid etching process on stainless steel and other metals. If you want the etching to be deeper, return the metal to the acid and check on it again in about 10 minutes.
The copperplate is first coated with an acidresistant substance, called the etching ground, through which the design is drawn with a sharp tool. While hand etching with a needle is popular in artistic and custom applications, chemical etching or machining is the most common industrial etching method, particularly acid etching and photofabrication. Some chemicals such as the ferric chloride we use for etching copper and brass are relatively safe, but they are still chemicals and need to be treated with care. Glass slides were chemically etched with nitric acid using five different methods. The ground is usually a compound of beeswax, bitumen, and resin. Edinburgh etch nontoxic printmaking, safe painting. The etching process is known as biting see also spit. Effects of chemical etching with nitric acid on glass. Acid etching is used both in industrial applications and by artists to create detailed designs on metal or glass. To avoid order delays and extra shipping charges, please read and follow the shipping restrictions listed with chemicals such as ferric chloride.
Various types of metal require different etchants, or reagents. Its easy enough to come by, and the ferric by itself is no big environmental problem. Acid etching is accomplished by covering the brass surface. Very hot concentrated phosphoric acid can also be used for etching of sinx silicon nitride.
Fecl3g hcl ml h2o ml 5 50 100 20 5 100 25 25 100 1 20 100 8 25 100 5 10 100. Xri testing offers a wide variety of acid etch inspection cleaning and chemical processes controlled under our as9100 and nadcap certifications. Etching, a method of making prints from a metal plate, usually copper, into which the design has been incised by acid. I was wondering if there is a reverseplating technique. White vinegar a dilution of glacial acetic acid will etch slowly and is safer to the hands.
Possible acids include muriatic hydrochloric acid hcl, nitric acid hno3, or sulfuric acid h2so4. Alternatively try ferric chloride with hydrochloric acid in water there is a very wide range of these recommended. It was developed from armordecorating and printing etching processes developed during the renaissance as. Chemical milling or industrial etching is the subtractive manufacturing process of using baths of temperatureregulated etching chemicals to remove material to create an object with the desired shape. This process involves very little mechanical work, for it is an almost entirely chemical procedure. Nitric acid etch jewelry discussion ganoksin orchid. Two times faster than the caustic etching solution. Mar 05, 2020 the blue solution gradually fades as the etching progresses and turns colorless when its finished. Acid etching, otherwise known as chemical milling or chemical etching, is a chemical process used by many industrial metal parts manufacturers to etch, cut or engrave very delicate or precise lines into metal. We investigated the effects of chemical etching treatments on such properties as chemical composition, surface. A company called cronite is a possible source of resist and etching materials. A good resouce for additional etchants can be found with the etchant database provided by pace technologies. Etching metal with nitric acid for intaglio printing youtube.
Although since 1983, pennies are actually made of zinc surrounded by a paperthin copper foil to give them the traditional appearance of pennies. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. Jan 10, 2001 sodium, calcium, and aluminum atoms in the surface of the glass are effectively reduced by chemical etching with nitric acid. Easy online ordering for the ones who get it done along with 247.
Edinburgh etch nontoxicprint nontoxic printmaking, safe. Sep 16, 2010 alternatively try ferric chloride with hydrochloric acid in water there is a very wide range of these recommended. Kellers etch, which is made up of distilled water, nitric acid, hydrochloric acid, and hydrofluoric acid, is best for etching aluminum and titanium alloys. Etching titanium with hf and nitric acid solutions part 1 randy markle chemcut. It is mostly used on metals, though other materials are increasingly important. In this short video tutorial viewers will learn to use ferric chloride solution to etch brass, copper, and bronze. Sodium, calcium, and aluminum atoms in the surface of the glass are effectively reduced by chemical etching with nitric acid. The edinburgh etch method allows this noble metal amalgam to be etched as easily as a sheet of copper. Different solutions are useful for etching different metals. The process we refer to as acid etching is a wellknown, ancient and. There are two general methods used to engrave metal with acid.
Fill a bowl deep enough to fully submerge the brass item with a 32 percent hydrochloric or muriatic acid solution. I have used nitric acid in the past to etch 16 gauge red brass but the nitric fumes are horrific to deal with. Once the pieces are pulled off, the brass is ready for its acid bath. Nitric acid turns brilliant bluegreen after etching copper or brass, and a cloudy gray after etching zinc. The surface left on the surface of the stainless steel is usually matt in nature and will be texturally different from the unetched part of the stainless steel. Acid etching metals allows you to create beautiful designs in relief. The acid i used was a mixture of nitric and hydrochloric acids. Sep 08, 2016 nitric acid goes a long way, it just starts to slow down but it will etch a lot of copper, brass or silver, but beware it will give you a good burn to, have some baking soda and make a solution with water and a bunch of baking soda to rinse youre hands and pieces afterwards use gloves and plastic apron, of course nitric is a serious acid. For example, astm 30, made up of ammonia, hydrogen peroxide 3%, and di water, is used for etching copper.
Etching solutions for steel, stainless, aluminum and other. Reagent grade chemical, much stronger than household oven cleaners. Nitric acid goes a long way, it just starts to slow down but it will etch a lot of copper, brass or silver, but beware it will give you a good burn to, have some baking soda and make a solution with water and a bunch of baking soda to rinse youre hands and pieces afterwards use gloves and plastic apron, of course nitric is a serious acid. Nitric acid mixture of 5 10% nitric acid with the balance being alcohol. It can also be mixed with acetic acid vinegar, in a 1 to 1 ratio, or with hydrochloric acid. Etchants, acids, bases, other etchants, acetic acid. Etching metal with nitric acid for intaglio printing duration. This method of etching uses a prepared ferric chloride solution which also contains hydrochloric acid. However, once youve etched a board with it, youre left with a solution with a bunch of cop. For example, steel typically takes hydrogen chloride or nitric acid. Copper is a reddishbrown metal, widely used in plumbing and electrical wiring. A little bit of acetate could have been in contact with moisture from the air and then come in. I was wondering if there is a reverseplating technique that would strip metal off instead of depositing metal onto a. You can use this to make a twotone effect when etching brass plate.
You can safely neutralize it with baking soda and pour it down the drain, or in the ground. Sulfuric acid should be used only in concentrations from 10 to 25 percent. In modern manufacturing, other chemicals may be used on other types of material. If you are satisfied with the etching s depth, remove the metal from the acid and proceed to the next step. The mordants most commonly used for etching copper, zinc, steel, and other metal plates are ferric chloride most safe, nitric acid and the dutch mordant. Verdigris can occur when the copper is in contact with acetic acid. Aluminum etchants include hydrofluoric acid, kellers etch, and homemade. S w m m hot rolled, 5inch plate cast hotrolled rod, % inch in diameter colddrawn rod, jf inch. These will have varying affects depending on the alloy. Now that i have retired i have decided to try my hand at etching silver items. Safety considerations for etching metal with chemicals.
Pdf effects of chemical etching with nitric acid on. But the copper metal will only react if you use concentrated nitric acid, or hot dilute nitric acid. Nitric acid is commonly mixed in a ratio of 1 part nitric acid to 3 parts water. Protect the areas you want to keep brass coloured with an insoluble coating, such as an oilbased paint. Mar 18, 2019 the process of acid etching works equally well on the surface of stainless steel plates, profiles and sheets and other metals such as aluminium and brass are also suitable for acid etching. Brass can be etched in the same solution as the one described for the edinburgh etch for copper. Jul 04, 2011 electro etching brass rather than etching with nitric acid. This etchant is not a pure acid, but etches copper and copper alloys like brass and bronze. Using acids can be a dangerous operation because of the corrosive nature of it. The strength of the acid determines the speed of the etching process. Why doesnt the reaction between brass and nitric acid form. Fifty years ago i watched my dad etch sterling 925 and coin 90% silver using nitric acid that he bought at the local drug store. Mix it with water at a rate of 1 part acid per 3 parts water. Pdf effects of chemical etching with nitric acid on glass.
If using the ferric chloride bath face the plate upside down on small pieces of. Acid etching is accomplished by covering the brass surface to be etched with an acid resistant waxy ground. The metal is polished, any irregularities in the cut are burnished, and the etching is finished. Phosphoric acid h 3 po 4 85% this acid is an ingredient to many etching solutions, such as solutions for etching of al aluminum, gaas gallium arsenide, inp indium phosphide, ag silver or zno zinc oxide. Because brass is composed primarily of copper, it can be etching using the same acids that etch copper. You can store and reuse etching acid, but it becomes less potent with time as etched metal fills the solution. Why doesnt the reaction between brass and nitric acid. Copper, brass and nickel silver can be etched with ferric chloride. Copper, brass and bronze advanced etching ganoksin jewelry.
Dec 28, 2011 some chemicals such as the ferric chloride we use for etching copper and brass are relatively safe, but they are still chemicals and need to be treated with care. It is available from electronics supply shops, such as radio shack or from chemical suppliers. Acids capable of etching copper to not etch steel, iron, or silver, though, so youll be disappointed if you try. In case you are wondering, ferric chloride is much, much safer than ferric nitrate and nitric acid, two mordants which are used to etch silver. Etching titanium with hf and nitric acid solutions part 1. The most common etchants for brass and bronze alloys contain either ammonium hydroxide, nitric acid or ferric chloride, however, there are hundreds of more specific etchants. Edinburgh etch for brass brass is a superbly suitable material for intaglio etching and printing. The most popular metals for diy metal etching are copper, brass, and nickel silver.