Hillbillysmith Posted January 30, 2013 Share Posted January 30, 2013 I know the conventional equipment to use is ferric chloride for this but had anybody used hydroflouric and/or nitric acids??? I ask because this is easily accessible and readily available to me in quantity.... The movie i speak of is a pickling etchant for stainless and high nickel alloys.. Mind you, I'm working on a Damascus shotgun. -Hillbilly Quote Link to comment Share on other sites More sharing options...
dablacksmith Posted January 30, 2013 Share Posted January 30, 2013 a lot of different acids will work even some fairly mild ones tho getting the depth and color you want is a trial and error prosess... as far as a damascus shotgun goes i would go lightly on the etch ... you dont want it to weaken the barrel ...good luck! Quote Link to comment Share on other sites More sharing options...
thingmaker3 Posted January 30, 2013 Share Posted January 30, 2013 SAFETY WARNING: You do not ever want any hydrofloric acid on you. Not even a drop. It is far nastier to one's flesh and bone than most acids. Far nastier! This stuff absorbs into your skin very rapidly. It can cause nerve damage and bone problems. At my day job, we keep the stuff in double walled pipes with expensive sensors in the the outer pipe. We aslo have very strict protocols regarding any unidentified clear oderless liquid. Much much much safer to stick with the nitric acid. Now... if you meant hydrochloric acid, then yes, hydrochloric is a dandy etchant. If you don't know what you have, then it should obviously not be used. Quote Link to comment Share on other sites More sharing options...
Albert A Rasch Posted January 30, 2013 Share Posted January 30, 2013 I have a very good article on refinishing damascus barrels in my files. The long and the short of it that there is a very good reason for using Nitric Acid.I don't recall why, but there is! Give me a couple of hours to find it! Albert Quote Link to comment Share on other sites More sharing options...
Albert A Rasch Posted January 30, 2013 Share Posted January 30, 2013 Wow, I was all nervous trying to find the link! I knew I had the article saved, and I found it, but finding the newest posting was a bear! Ok, it took me longer to type this out than to actually find it, but you get the idea. https://docs.google.com/document/preview?id=18MIvJwHhLh87zYiUDOQ4RkZKw7b42sUhVKz_9HMDdv4&pli=1 Damascus Restoration. Using something like HCL will strip far too much of the iron if I read it correctly while typing this. i hope this helps you! Best regards, Albert Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 30, 2013 Author Share Posted January 30, 2013 Yes, i know about hydroflouric acid and yes that's what i speak of.... The acidic mixture contains BOTH hydroflouric AND nitric acids. We use it as a pickling solution for our stainless steel and inconel product to give a uniform finish among other reasons....... Thanks for the link. I'll read it when i get home and decide if I'll use this picking solution for it or not. -Hillbilly Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted January 30, 2013 Share Posted January 30, 2013 We do NOT use strong acids, water it down first, remember always ad acids. 1/5% ferric Chloride is normal, White vinegar is cut in half with water. not more than 10% strength HCL ,and 5% is even better its always easier to let stand in acid longer, we can not back up,. also a slower etch is a smoother etch. Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 30, 2013 Author Share Posted January 30, 2013 We do NOT use strong acids, water it down first, remember always ad acids. 1/5% ferric Chloride is normal, White vinegar is cut in half with water. not more than 10% strength HCL ,and 5% is even better its always easier to let stand in acid longer, we can not back up,. also a slower etch is a smoother etch. Ok, so how long do you usually let it set in the etchant if "slower is smoother"?? I was going to do multiple soaks to get the color results i desire with a 10-15 second maximum soak per dip followed by a distilled water rinse between each acid dip. -Hillbilly Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted January 30, 2013 Share Posted January 30, 2013 15 minutes at a time 2 to 4 times ( 30 to 60 minutes total ) for Ferric Chloride, the vinegar takes 7 to 8 hours, Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 30, 2013 Author Share Posted January 30, 2013 How well phosphoric acid work?? I'm just trying not to buy an etchant for this project. I already have 2 gaskins of phosphoric on hand. -Hillbilly Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted January 30, 2013 Share Posted January 30, 2013 Several things bother me with this post are"t You got the acids at work and are relying on folks on here to tell you of the dangers of wot you are wishing to use. At work should be aware of MSDS sheets that tell you of the dangers. That is part of youir question. The other is about etching a pattern welded shotgun barrel, again I feel you should not just jump into this without guidance. If you care at all about human safety you have to get this barrel (s) examined by a gunsmith to see wot etching would do to them and if there is any possibility that they will be fired afterwards. It has been a lot of years since shotguns were made with pattern welded barrels and most of the time the feeling is the old ones should not be fired anymore. And if so after gunsmith approval and with the poweder they were made for. Any of the acids remove metal. and that of course depends on acid strength in its diluted state and length of time and number of etchings. Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 31, 2013 Author Share Posted January 31, 2013 I am not worried about human safety because the gun will not be fired. I know more about guns than my own boots. Between load and charge weights, type of powder n primers, chamber pressure, size of shot, etc. i am neither worried about my personal safety during three use of the etchant(s) because I'm not an idiot and am fully aware of the potential risks involved with the use if acids..... All i wanted to know is how well these particular acids would work as an etchant on a Damascus shotgun barrel..... I now have my info. Thank you for the concern. -Hillbilly Quote Link to comment Share on other sites More sharing options...
Albert A Rasch Posted January 31, 2013 Share Posted January 31, 2013 Hillbilly, I think, and again i'm just thinking, that Phosphoric acid will combine with the iron oxide and give you a different result than what you are looking for. I want to say that "French Grey" is the result. I know that phosphoric acid is used to remove rust ala Naval Jelly. Give me a sec...LOL! I found this: Phosphoric Acid etches steel and leaves a dull gray phospate coating behind. Many refer to this as French Grey. Phosphoric acid is used in the auto body business to stop surface rust on bare metal before painting it. It's commonly known as Conversion Coating. And an interesting thread: A much safer alternative to hydrochloric, sulphuric acid etc is boric acid, often sold as a pharmaceutical, I believe it forms part of many skin preparations. It is not expensive, about £5 for 500gms, and made up as a saturated solution, about 5-7% solution in distilled water at 70-80 C, it lightly etches steel to give a silk grey finish over an hour or two depending on temperature. It also removes rust and other oxide finishes very gently but completely. I have used it several times to remove the thin brown rust coating on lock plates and actions and although the finish is a bit drab for my taste, it may be what you are looking for. There doesn't appear to be any after rusting, a problem with many stronger acids. Used on Damascus barrels it will produce a differential etching of the steel and iron to prepare the barrels for browning. I prepare all my damascus barrels (thoroughly plugged of course!) and damascus snapcaps with this solution. After degreasing with 'whiting' I lay the items in 70-80C solution for anything from 30 min to 3 hours depending on the finish I require. The carbon in the steel remains on the etched surface and just needs wiping off before thorough rinsing and then straight into the browning process. It is pretty safe on one's skin although I always wear light gloves as it tends to dry one's skin out. here is the link, because the thread is pretty interesting: http://www.doublegunshop.com/forums/ubbthreads.php?ubb=printthread&Board=1&main=14958&type=thread&PHPSESSID=0bffbea8e40dd06d53422668850aaeb5 I hope this all helps and gives everyone ideas to experiment with! Regards, Albert Quote Link to comment Share on other sites More sharing options...
Hillbillysmith Posted January 31, 2013 Author Share Posted January 31, 2013 Thank you Albert, you have been the most help with this. Especially explaining the effects the acids have on the physical appearance of the Damascus as elk as the links. -Hillbilly Quote Link to comment Share on other sites More sharing options...
Albert A Rasch Posted January 31, 2013 Share Posted January 31, 2013 Roger Hillbilly, Always happy to help out! I've done a lot of reading over the years, and i find that many times one thing is interrelated with another. As you obviously know, there are tips and techniques from one trade that are applicable to another. So it's just a short mental hop from one idea and application to another! My latest mental gymnastics is Mokume Game. I really wish someone would coin an American name for that. like DMS Dissimilar Metal Sandwich or something... Anyway, I'm preparing to give that a try this next R&R with my son. But rather than use it for knife guards and such, I am contemplating firearm applications... But as i was saying, i enjoy the researching, and it adds to my store of accumulated knowledge so it's a help to me too! Thanks again! Albert Quote Link to comment Share on other sites More sharing options...
Albert A Rasch Posted January 31, 2013 Share Posted January 31, 2013 Ok, One last thing: maybe... I found this, and though slightly off the etching topic, it might be of some use too: Coloring Metals http://chestofbooks.com/reference/Henley-s-20th-Century-Formulas-Recipes-Processes-Vol2/Coloring-Metals.html#.UQoRemerp8E Etching Metalshttp://chestofbooks.com/reference/Henley-s-20th-Century-Formulas-Recipes-Processes-Vol2/Etching-Fluids.html#.UQoZZWerp8E Regards, Albert Quote Link to comment Share on other sites More sharing options...
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