Can anyone send me to a site, or some book or source where I can get a fast track on how to color metal by heating and chemicals? Mainly heating? It will be for decorative outdoor items.
Can anyone send me to a site, or some book or source where I can get a fast track on how to color metal by heating and chemicals? Mainly heating? It will be for decorative outdoor items.
Google "Patina". Tons of good info out there.
This is supposed to be a bible but I do not own it personally:I have this one which is somewhat unorthodox but I like it:
Might help if you said what kind of metal and what color you want it.
All. Mainly steel.
visit my blog atA fool shows his annoyance at once, but a prudent man overlooks an insult.
The local library has this one, covers just about ALL art metals. Depending on where you are, the chemicals may or may not be available, they tend to be poisonous, explosive or both. Kind of spendy, check the library FIRST. The problem with outdoor display is that the chemical coloring tends to fade or change, a good coat of epoxy paint might be better. Definitely better if it's steel, that eventually changes to rust-orange no matter what the original color was.
On Tue, 29 Jun 2010 16:27:20 -0700, "Steve B" wrote the following:
Text of patinas.html follows. Book suggestions included.
"Patina" -- "A surface appearance of something grown beautiful esp. with age or use."
Usually used in reference to copper, but also applicable to bronze, steel, and other materials.
This is a very broad topic that depends greatly on the material being treated, purity of the treatment, environment, and eye of the beholder. There must be hundreds or thousands of ways to do this, and some of them may be old wives' tales. I have no way to verify these! For the most part these are quotes from postings. For the most part it seems to rely on ammonia or other nitrogen compounds. Note that ammonia can cause brass to stress fracture (e.g. don't clean firearm cartridges with it!).
Cleaning the work is often stressed, and you can't usually get the patina quickly. It takes time to simulate age!
"It is common practice to treat copper roofs with ammonium sulphate to form the green color quickly; it is not exactly an oxide, and simple weathering sometimes does not do the trick." (From: John Whitmore, firstname.lastname@example.org).
"Unless you want to waste a lot of time experimenting and then still possibly not get a coating that will stay green, use a commercial patina made for that purpose. We use it in stained glass work. I'm sure it is available from anywhere that sells sculpture or architectural supplies." (From: John De Armond, email@example.com).
"Currently I patinate the brass with "Verde-It" (a chloride acid) and a blacking acid (selenium-based). Can anyone recommend other surface treatments? I also shine with anti-oxidants "Nevr-Dull" and "Peek". How long will these last? Can I do better? (I got tired of lacquering wires...)" (From: Matt Brand, firstname.lastname@example.org)[Electroplating a patina] "...the method consists of treating the copper anodically in a solution of:
Solution is held at about 95 degrees C, current density of about 0.04 A/(dm squared) for fifteen minutes. Initially deposit is CuS04.Cu(OH)2, but increases in basicity on exposure until the composition of the patina is reached. This is from H. Silman, et. al., Protective and Decorative Coatings for Metals, Finishing Publications..." (From: Rob Pauley, email@example.com).
"Here are a couple of green patinas to try:
Mix all in a plastic container that will be only for the patina mix and not used for other things. Warm or hot water will help the solids dissolve better. Spray the patina on the clean oil free copper and let set for 2 or 3 hours to dry then repeat 3 or so more times until you get what you want. You can also soak sawdust with the patina and pack it around the copper piece and seal it in a plastic bag for a day or
"You can get cupric nitrate at chemical supply houses. It works vary fast. I got a nice effect by dissolving about 2 tablespoons of the cupric nitrate crystals in a plastic spray bottle (with about 1 quart water). This was one of those sprayers that "Fantastic" cleaner comes in. Pre-heating the copper alters the mottling and texture too. Experiment on copper scraps with different strengths of solution and amount of patina solution applied." (From: Daniel Wold, firstname.lastname@example.org)
"To colour Copper or Brass Green:
Add distilled water to make 1 litre. Brush onto a clean surface. This is from an old text book, I haven't tried this one, but others in the book have worked well for me." (From: Steve Rayner, snipped-for-privacy@freenet.Victoria.BC.CA)
"The most common is to wash with a mild solution of salammoniac dissolved in water. Just brush (or preferably spray) it on & allow to air dry. Repeat as necessary to achieve the desired results. If you want an old roofers trick, and one that is much more effective I might add, piss on it! It is still common practice for the roofing crew to all pee in a communal bucket and pour it over the roof at the end of each day to force a patina." (From: Gary Hubert, email@example.com)
"Well, one thing that works well for me is dormant spray, the lime/sulfur kind. You can get it at your gardening supply store. Produces some really colorful patinas depending on strength of solution and how long you dip the metal." (From: firstname.lastname@example.org)
"Personally I use a solution of lime/sulfur dormant spray (very weak) and let it sit for up to three months in solution. Or if your area has hard water (lots of minerals) just drop it in the toilet tank and let it sit until it looks good (this is a technique used by antiquities forgers). A good solid patina takes time." (From: Carl Mork, email@example.com)
"NOTE: no patina is truly "tough". None of them can resist scratching. All you can expect is that light surface contact won't 'knock' bits off. You should plan to treat any patina with lacquer or plain wood wax. Three methods come to mind:
(From: Mike Schechter, Mike firstname.lastname@example.org)
"From - 'Creative Gold and Silversmithing' by Sharr Choate Colouring Copper Green "A patina is produced on the metal by brushing the surface with a solution consisting of 1 gram each of copper nitrate, ammonia chloride, calcium chloride, and 1 ounce of water. When the colour is reached the article is set aside to dry. A patina can also be produced by pouring a hot solution consisting of 1 1/2 grams of copper nitrate and 6 ounces of water onto the metal and allowing it to dry." (Quoted by email@example.com)
"The best 'cookbook' I have with patina formula is: METHODS FOR MODERN SCULPTORS [see reference section, below] For pre-mixed patina and coloring solutions in small amounts, the JAX brand handled by Merritt's Antiques at 610-689-9541 are OK. They have several at $7.50/pint. For my own work, I brew my own. Depending on what color or effect I want, I use cupric nitrate, ammonium chloride and burned oils, alone or in combination. For those who want to experiment with small pieces, get some "gun bluing" at the local sporting goods store and try different times and dilutions." (from: firstname.lastname@example.org)
"This [METHODS FOR MODERN SCULPTORS] is an OK book. Starting from absolute scratch, I have been able to get the simplest recipes to work. However, *there is no substitute for watching somebody do it*. My advice to amateurs is, read the book first, then spy on your local foundry, and see what the motion is like for heating an area evenly with a torch, how to use a stipple brush, the way a cupric nitrate solution should sizzle, how to keep drips away, what to do when you've flamed the end of your brush and there are bits of charred bristle everywhere. A thousand things that will never be in the book." (From: email@example.com)
"Regarding the hot oil patina: I preheat the metal, same as with the aqueous solutions. Use the *minimum* amount of oil. Sometimes I cut it with mineral spirits. Mostly, I stick with either Linseed or Tung oils." (From: firstname.lastname@example.org)
"Copper (II) sulfide solution will react with the copper, but will produce a greener tint. It does interesting things to other metals, too. Copper sulfide comes as a solution, or translucent-blue pebbles (like rock salt) or a fine blue powder. The latter two can be dissolved in hot water to produce the solution." (From: Derek Streeter, email@example.com)
"I believe you mean copper sulphate. Copper sulphide is a black, insoluble material responsible for the color of some patinas along with the oxide. I have used copper sulphate, and it fits the description of the compound that you are describing. Have fun." (From: firstname.lastname@example.org)
"As for coloring metal - this is not my field, but I know a tiny bit about it. In my opinion, it is best to color metal by changing the color of the metal itself (rather than by painting it). There are several books on the subject; "The Art of Patinas" and "The Coloring, Bronzing and Patinization of Metals" [see reference section, below] are two that come to mind. These processes involve oxidizing or chemically reacting the surface of the metal to make it change color - usually, this also protects the metal from further reaction to the elements. If you wish to obtain some references on this subject, I can recommend [Craft Books]. They have, at least, the book on Coloring, Bronzing and Patination." (From: email@example.com)
"Clean and degrease the metal and dunk it in liquid flours of sulfur. Brass doesn't put on a patina like bronze (brass being around 1/3 zinc). At least that's my experience." (From: firstname.lastname@example.org)
"A salt water or vinegar solution sprayed on the metal and sealed with an open container of ammonia will produce a blue patina. I have enclosed it in tupperware and garbage bags according to the size of the piece. The fumes will react with the solution." (From: email@example.com)
"A permanent Patina for Copper (quoting from Henley's book): Green -
Mix and dissolve. Apply to object to be treated, with a camel's-hair pencil. Repeat the operation until the desired shade of green is reached. First off you may be wondering where to get these chemicals:
Henley's says to use a camels hair brush, I've used one of those small, triangular makeup sponges with success. Keep in mind that the patina (verdigris) will appear as the solution dries on the copper surface. Several applications will probably necessary to get the depth of color you want. Heating the copper helps also, but isn't necessary. Note! Don't soak the copper in the solution, it won't turn green and the acetic acid will eventually start to eat away the copper!
Also, the copper sould be CLEAN when you do this. Steel wool and and then wipe it with Hydrochloric acid (Muratic acid at your hardware store - and be careful - rubber gloves, protect the eyes and get some ventilation). I usually wipe off whatever remains of the HCL when I'm done with a little distilled water." (From: Eric Kasten, firstname.lastname@example.org)[Brown/black on bronze] "Liver of sulfur is, as obtained by me from Bryant Labs, Potash Sulfurated (Lumps). I think that means "lumps of sulfurated potash". It turns copper alloys brown, more or less attractively varying with the exact alloy. By using a very concentrated solution and/or several applications a dark brown can be produced, but nothing I'd call "black". Adding some ammonium sulfide (a _truly foul-smelling liquid also obtainable from Bryant) helps for that, it gives a bluer-toned brown by itself. Either works ok cold and very well hot." (From: email@example.com) [It has been reported that "liver of sulfur" is potassium sulfide, or a mixture of potassium sulfides. JK]
"Oppi Untracht has a few books out, one is called "Jewelry Concepts and Technology", published by Doubleday. Another is "Metal Techniques for Craftsmen (Persons)", also try Rio Grande Supply 800 443-6766, they have great tech support and supplies." (From: Denise M. Maier, firstname.lastname@example.org)[Rust finish on Ironwork} "Many metalworker/artists use muriatic acid to get the finish you are after. Use with plenty of ventilation! Do some background checking on how to mix acid with water (never pour water into acid; do only vice-versa), what dilution to use, how to neutralize surface after etching, how to handle, store, and dispose of the acid. You can get some at a masonry-supplies store (it is used to etch unwanted concrete grout off stone and brick). Be careful!" (From: Laurence R Swain, email@example.com)
Steve Rayner ( snipped-for-privacy@freenet.Victoria.BC.CA) posted the following on March 6 1996 as a way of bluing/blackening brass:
I just found this in an old Popular Mechanics book. The formula may be of use to some of you.
Heat to near boiling (200 F.), and immerse work piece in solution suspended by a brass wire. Add more lead acetate to deepen the colour, and speed up the reaction. I would suggest using a pyrex container, as the hypo will react with iron directly blackening the container.
An article by Rand Esser, firstname.lastname@example.org, was posted as part of a "newsletter" from ArtMetal. Rand has kindly allowed me to include the information here, with the following notice:
Copyright 1994 Rand Esser. May be reproduced without permission by not for profit groups for educational use only.
The introduction included:
Rand Esser, a Raleigh, North Carolina metalworker who specializes in lamps and furniture, demonstrated the application of various patinas on steel and brass. Rand uses chemicals to achieve different oxidized surfaces on metal, often layering patinas on top of each other to achieve unique and distinctive effects. The patinas are then sealed with hot wax.
The article follows:
PATINAS ON STEEL
By Rand Esser
The patinas demonstrated at the March 12 meeting were copper sulfate solution, Black Topaz, and Rusty Red.
I mix my own copper sulfate solution by mixing copper sulfate crystals with water, a little at a time, until the water will no longer dissolve the copper sulfate. Copper sulfate is available at Southern States stores.
Black Topaz and Rusty Red are sold by Sur-Fin Chemical Corporation. Sur-Fin will send you a finish kit including seven six ounce bottles of their finishes for $50 (they also sell patinas for other metals). Larger sizes from one to fifty-gallons are available.
These finishes result in a variety of effects depending on strength of the solution, reaction time, relative humidity, temperature, surface texture, and type of top coating.
The Rusty Red and copper sulfate solution create similar effects. The Rusty red seems to be a bit more red and the copper sulfate is a bit more orange. I prefer the copper sulfate solution. It is more beautiful and less expensive than the Rusty Red.
TIPS FOR PATINAS ON STEEL
The surface to be finished must be completely clean. Remove all scale by sandblasting or wire brushing. Different surface textures will create different results. Sand blasted surfaces tend to be more dull and require a shorter reaction time. Wire brushed surfaces will be shinier, but require a longer reaction time. I sandblast first to remove the scale and then wire brush to create a shiny surface.
Remove all grease, oil, and, dirt with mineral spirits. Surface must be white glove clean for best results. Different concentrations of the finish solutions give different results. Sur-Fin recommends diluting the Black Topaz 1:10 with water. I have used the Black Topaz at 1:5 with a very brown /black result. Different reaction times give different results. I usually leave the solutions on for just a few minutes. The Black Topaz ranges from a jet black with a short reaction time to bluish, greenish, black with longer reaction times to brown/black with very long reaction times. The Rusty Red and copper sulfate solutions range from a light copper plating effect to light rust to a dark crusty rust depending upon reaction time.
Some interesting effects can be created by using two or more finishes on the same piece. The Rusty Red and copper sulfate solution will work on top of the Black Topaz finish. The Black Topaz does not seem to work on top of the others. I often begin with the Black Topaz and drizzle, drip, or brush a pattern on specific areas of the surface, leaving other areas bare. I then allow the Black Topaz solution to react until it is dry. Then I come back and coat the entire piece with the Black Topaz solution and quickly rinse the piece in water to stop the reaction. The areas treated first will have a different tone than the areas treated later. I then come back over the piece with the Rusty Red and/or copper sulfate solution and brush, drip, drop or drizzle it in specific areas to create coppery or rusty highlights. The entire piece is then thoroughly rinsed with water to stop the reaction.
Once you have stopped the reaction by rinsing with water, allow the piece to air dry or speed up the process by heating it with a torch. At this point the piece is not very pretty. You will not know what the piece will ultimately look like until you apply a top coat.
I usually heat the piece with a torch until it is barely hot and then apply wax with a lint free cloth. I have heard that linseed oil also works well. At this point the patina will reveal itself in its final state. By applying more wax and rubbing I can usually remove some of the more rusty spots revealing coppery areas. Additional coatings of wax will create a shinier finish with more depth.
It takes time and experimentation to get good results with these chemicals. Your finishes are likely to look different from mine due to the many variables involved. I am continually experimenting with different finishes on metals, steel in particular. I would like to compile a data base of information on this subject to share with other metalworkers.
If you have information that you would like to share please let me know.
Rand Esser302 Glascock Street Raleigh, North Carolina 27604
or send e-mail to: email@example.com
Vendor Addresses for Pre-Mixed Patinas:
Sur-Fin Chemical Corp. 1530 Spence St. Los Angeles, CA 90023 (213)262-8108 Chemicals for mixing your own patinas. Bryant Laboratory 1101 Fifth St. Berkeley, CA 94710 800 367-3141 Supplier of Brass, Copper, sheet, plate, bar, etc. Metal Supply Co. 4001 G St. Philadelphia, PA 19124 800-638-2521 [end of Rand's article]
On March 29, 1996, Charles Lewton-Brain ( firstname.lastname@example.org) posted some advice on cleaning, and patinas on steel.
It is really impportant to have a clean surface for goodresults: This may be Fantastick scrubbings, or more:
Cleaning Metal Surfaces, copyright Lewton-Brain 1985-91.
For all metal coloring and electroplating a clean metal surface is essential. The cleaning process must remove mineral oils, organic oils and greases as well as traces of chemicals on the surface. It must remove oxidation which might interfere with the metal coloration or plating adhesion and it should possible activate or roughen the metal surface to better receive the treatment.
Cleaning may be accomplished using mechanical (abrasive), chemical (heating, solvents, pickling with acids) and electrolytic (electrocleaning, electrostripping) means. Examples of easily achieved clean surfaces include sandblasted ones and ones scrubbed well twice with rinsings using Fantastic. A pumice rub followed by scrubbing with dishwashing liquid and ammonia on a toothbrush does pretty well. Repeated scrubs with Fantastic work. Best of all is electrocleaning.
A simple procedure is:
NB: electrocleaning can be used after step 1.3. While steps 1.0-1.3 produce a quite clean surface by themselves if one is electrocleaning it is not a bad idea to pre-clean using steps 1.0-1.3 so as to make the electrocleaning solution last longer and lower it's work load in cleaning the metal surface.
A much better and surer procedure is:
After cleaning, the metal should be placed in running or circulating water (preferably distilled) to avoid oxidation until it is plated or coloured. One can of course plate or colour immediately after cleaning. In all cleaning methods the piece must either be wired to suspend it in the solution or held with tweezers. It must afterwards be very well rinsed to remove all traces of cleaning chemicals. Do not touch the surface once it is free of grease.
Sand blasting may be substituted for steps 1.0 and 2.0 above, a sand blasted surface is clean but can be damaged easily as well as being matte in appearance.
Sample Electrocleaning solution:
PATINA ON STEEL:
A method of patinating steel, copyright Lewton-Brain 1990
Warning: This procedure should be undertaken with appropriate precautions; goggles, gloves, protective clothing, adequate ventilation.
As part of a large scale patination project in which I patinated a steel roof surface 24 by 48 feet on both sides I performed some 40 experiments to find out how to patinate the steel which was a requirement for structural reasons. In doing so I also experimented with paint, buying over $350.00 worth of spray paint, eventually finding one single color which for all intents and purposes is green patina. When placed in recesses and the high areas are rubbed off it is indistinguishable from a cupric nitrate patina. It is a car paint: GM 42, 1980 Chevrolet Medium Green. While this is ideal for smaller surfaces my paint experiments did not produce the surface effects I required on the large scale work. I reasoned that if I could plate the steel with copper and then convert the copper to patina in a fume not only would the job be easier but it would also be safer than dealing with solvents or corrosive patination techniques (such as a cupric nitrate patination) over large surface areas. I was dealing with 4 x 8 foot sheet steel to be equally patinated on both sides simultaneously. Other types of objects might be easier to deal with. 'Tents' of polyethylene plastic sheeting stapled to a framework of 'economy' studs were built. The construction of such a tent requires that it be sealed (draped onto the floor from the frame and then weighted down). The object inside is positioned on supports of some kind so that it is suspended off the floor in the air inside the tent. Then pans of household ammonia are placed underneath the object. The fumes attack copper or copper based alloy surfaces. Under normal conditions one can activate a copper containing surface with a dilute salt solution to speed up the procedure and obtain a blue patination but this proved too corrosive for dealing with steel. The final procedure chosen was as follows:1) The steel was cleaned well. Sandblasting would be ideal but was impractical for the project. Solvents were also out for safety reasons on such large surfaces without good ventilation. We ended up using Fantastic cleaner. Two scrubbings with Fantastic on large sponges and good rinsings in between and after were adequate most of the time. The surfaces were then left damp with the rinse water. Only the edges were handled to avoid contamination of the cleaned surfaces.
2) A contact plating solution for copper plating was prepared (see below) and this was applied to the steel using paint rollers (goggles/gloves!). Brushes work also but the paint roller is a bit more gentle. Plating occurs instantly. Several passes may be made over the same area, without pressing hard, which can remove the delicate plating. The surface was then rinsed very well. If areas of the plating lifted grease residues were the cause and a further local Fantastic sponging and good rinsing sufficed to allow plating to take place. After final rinsing the steel (held by the edges) was taken to the tent. One moves fast to retain the surface moisture.3) The steel was then placed in the tent and pans of ammonia enclosed under it. The tent was sealed. The centers of the thin sheet sagged causing pooling, therefore we built a wooden support with a single nail pointing upwards to support the sheet. More stable objects would not need support, though pooling may be factor to consider depending upon the surface relief. The time required to convert the copper plating was optimal at about 1-1 and a half hours.
4) The steel was removed and gently rinsed as scrubbing or hard spraying can remove the delicate patina surface. It will be a mixture of blues, greens and hints of brownish red where pooling has occurred and the surface dried. In my case I chose to re-introduce pink spatter marks to the surface by spattering droplets of the contact plating solution onto the patina surface where they instantly went pinkish-brown. The steel was then dried with fans and immediately sealed using clear automobile enamel paint. I then went back with stencils and gold spray paint to further modify the surface.
The steps in the procedure are then: Clean, rinse,plate, rinse, fume, rinse, dry and seal.
The conversion process
The copper on the surface is attacked by ammonia liquid, not as much by the fume which has a different chemical composition than the liquid. The water dampened surface slowly takes in ammonia fumes where they are converted to ammonia liquid in solution so that they can attack the copper. The purpose of the pans of ammonia below the object is to provide a constant vapor pressure which replenishes the ammonia on the surface at a constant rate as it is used up in converting the copper to patina. This system therefore ensures better overall constant dilution control than beginning with ammonia on the surface.
Resists: Resists may be used to prevent plating or to prevent the plating from being converted to patina by the fumes. Resists to plating may be a greasy material (litho-crayon, oil) or thinned rubber cement. Other resists require too much cleaning time and may need solvents for removal. Resists to patination may be a protective spray through stencils (Pam) or thinned rubber cement. Pattern control through resists is easy.
Time: Time is a factor in all fumings. Experiment with various times on sample pieces to have a palette of process marks (colors, tones, effects) to choose from.
Pooling: Where pooling occurs variations in color will result. Pooling can be encouraged and controlled by local application of greases before or during patination and by the position and shape of the object. Various liquid thicknesses cause surface variations.
Sealers: Sealers will each have a characteristic effect on the surface. I recommend making a palette of various sealing options over a patinated surface. Examples of sealers include waxes, oils, lacquers, transparent acrylics, enamels, varnishes and so on. They often have a tendency to darken the colors on the surface. I prefer clear auto enamel or Spray-Lac number 1473 professional Finish Clear Dead Flat lacquer. It is available from Star Chemical based in Hinsdale Illinois, Deerfield Beach, Florida and Dallas Texas. It is an industrial quality spray and requires good ventilation. It is very unobtrusive on a surface. With any spray the surface chosen can be glossy, like paint (in which case why not use paint?) or shortly after spraying can be matted down with a cloth pad for better surface control.
Other Chemicals: I mentioned dilute salt solutions earlier. Many chemicals will modify surfaces. (Remember never to mix bleach and ammonia). Experimentation and sample making will offer the user control choices. Suggestions for initial investigations include salt, vinegar, baking soda and local heating. There are a number of patination books available including one I sell on patinas for small studios.
Contact Plating Solution Recipe All safety warnings apply. Always add Acid to Water!! Goggles/Gloves!250 grams copper sulfate (CuSO4) Technical grade chemicals for this solution is fine. 42 cc sulfuric acid Distilled water to the 1000 ml level.
Put about 800cc water into plastic or glass container after marking the 1000cc level on it. Add the copper sulfate and stir to dissolve. Slowly pour a thin stream of acid into the swirling water. Heat is evolved-be aware of this. Rinse the acid container with distilled water and top up the mixture with it to the 1000 ml level. This solution can also be used as an electroforming solution for growing copper. Remember, acids are dangerous. A dust mask is suggested around chemicals. Work cleanly. Copper salts are toxic and irritant and should be handled with care. Dispose of properly.
Ron Young's books are very good for larger scale work. His Contemporary Patination makes up for the poor safety attitude in the Methods for Modern Sculptors book. The former is a working, useful studio guide to patination unlike the monumental Colouring, Bronzing and Patination of Metals put out in 1983 by Hughes and Rowe.
Ronald Young, Robert Fennell "Methods for Modern Sculptors"
Ronald Young "Contemporary Patination"
Source: Ronald Young Sculpt-Nouveau21 Redwood Drive San Rafael, California 94901, USA
If ordering books through the mail New World Books is to be recommended. They will obtain for one any book in print in North America for 10-30% off the list price, including Jewelry Concepts and Technology by Untracht for about $70.00. Their address is:
New World Books2 Cains Road, PO Box 89 Suffern, New York, 10901, USA
Cheap Thrills in the Tool Shop, goldsmithing tricks book by Charles Lewton-Brain. Also 'Patinas for Small Studios" 15.50 plus 3.00 shipping.
Source: Brain Press, Box 1624, Ste M, Calgary, Alberta, T2P 1N3, Canada (403) 263-3955, fax: (403) 283-9053, Email to email@example.com (offers 10% discount to internet users)[end of text by Charles Lewton-Brain]
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