ozzyo Posted May 17, 2012 Share Posted May 17, 2012 (edited) Hello all, in a thread there has been a bit of a discussion about metal blackening, so i thought I'd try some out. The contenders. The targets, brass, nickel silver and steel (this is silver steel as I did not have any steel in the same size). Before anything happened to them they were mounted in the lathe and polished with medium and fine Garryflex blocks at about 750 rpm. The targets cleaned in IPA and then Carr's metal black for brass applied. The targets were then polished up in the lathe again. Then cleaned in acetone and then Carr's metal black for brass applied. The targets were then polished up in the lathe again. Then cleaned in Carr's acid dip and then Carr's metal black for brass applied. The targets were then polished up in the lathe again. Then cleaned in IPA and then Birchwood Cassey brass black applied. The targets were then polished up in the lathe again and then cleaned with denatured alcohol (meths). Then the correct solution for each metal used. On this one I think that I'll let you make your own minds up. I know what I'll be using. This is why I said what I said in another thread. OzzyO. PS. I'm not to sure if this should be in this section or in questions, hints and tips. If it's in the wrong section please move it. Edit; To add these. I'm also going to do them in there own post as I know a lot of people don't go back on the post once they have read them. Edited May 18, 2012 by ozzyo 5 Link to post Share on other sites More sharing options...
3 link Posted May 17, 2012 Share Posted May 17, 2012 Hello Matey, I am glad you have brought this topic up as brass has always been a pig to blacken for me, I have just brought some blackening from hobby holidays at the Reading show and he reckons this is the strongest stuff on the market, so when I get time I will let you know the results. Any idea what metal the R-T-R loco wheel rims are : - Lionheart and San Cheng in particular, as they do not seem to take to any form of blackening the only thing that has had any success is a black permanent marker pen. ATB, Martyn. 1 Link to post Share on other sites More sharing options...
N15class Posted May 17, 2012 Share Posted May 17, 2012 (edited) OzzyO I see the carrs one you are using is for brass, which I found has no effect on anything but brass. I use 3 at the moment from carrs, brass, nickel silver and steel all work well when used on the right metals. I think that a test using the correct carrs product with correct cleaning neads to be done, as the test was very biased to the Birtchwood product. The results were good for them though. Below is an etched brass fall plate I did today. Tends to be brown rather than black but the coverage is good. Edited May 17, 2012 by N15class Link to post Share on other sites More sharing options...
N15class Posted May 17, 2012 Share Posted May 17, 2012 (edited) Any idea what metal the R-T-R loco wheel rims are : - Lionheart and San Cheng in particular, as they do not seem to take to any form of blackening the only thing that has had any success is a black permanent marker pen. ATB, Martyn. Have the wheels been chrome plated or anything? Edited May 17, 2012 by N15class Link to post Share on other sites More sharing options...
3 link Posted May 17, 2012 Share Posted May 17, 2012 Have the wheels been chrome plated or anything? Well they are very shiny, so I would think chrome plated or maybe stainless steel, I am not sure to be honest. Martyn. Link to post Share on other sites More sharing options...
buffalo Posted May 17, 2012 Share Posted May 17, 2012 (edited) Hi Ozzyo, I wonder if your Carr's brass black is past it's best? The bottle looks rather ancient compared with my current stock of Carr's products which is about five years old: The brass stuff is almost exhausted and is a bit cloudy because I've sometimes just dipped things in the bottle rather than my usual method of application with a cotton wool bud. I wonder if you's is just past its best? Here's a quick test, not as controlled as yours. I just wiped the end of the brass rod with 600 grit wet & dry, wiped it off with IPA, dipped it in the bottle and burnished with the bud, then repeated the process. It still seems to work well enough: One problem I find with any of these blackeners is if there is the slightest trace of solder on the metal, it will not be blackened and shows up after treatment. So, for example, on laminated rods it's often possible to see the joins between layers after treatment. btw. the three Carr's bottles all have the EINECS code for Selenium, 231-957-4*, though that doesn't say exactly which Selenium compound they are. The Birchwood Casey bottle says Selenium Dioxide and warns us that it is dangerous for Californians. I wonder if their product labelling is actually legal over here? Nick * type the code into google or search at one of several chemical info sites such as http://www.chemindus.../apps/chemicals Edited May 17, 2012 by buffalo Link to post Share on other sites More sharing options...
Kenton Posted May 17, 2012 Share Posted May 17, 2012 (edited) I think you need a new pot of Carr's - it does goes off and yours doesn't seem to work very well. The pot looks like it has been around a few decades I actually prefer Carr's - it is a little less aggressive (and less toxic - slightly) I usually leave it on for "overnight" or until dry with brass which seems to work best when the part has been thoroughly cleaned. Apology to buffalo: the time taken from camera to PC and an upload glitch didn't help - nice to see same conclusion though. Not quite a fair test OzzyO Edited again because of the screwball RMWeb editor Edited May 17, 2012 by Kenton Link to post Share on other sites More sharing options...
buffalo Posted May 17, 2012 Share Posted May 17, 2012 ...Apology to buffalo:... No need, Kenton, I was also fighting the SQL errors and editing to retrieve lost images... Nick 1 Link to post Share on other sites More sharing options...
ozzyo Posted May 17, 2012 Author Share Posted May 17, 2012 (edited) Hello Martyn, I'm going to state charging you double for two questions in one post. Lets get the hard on out of the way first. Brass! To most modelers it's a yellow metal thats easy to work with that solders together quit well. Thats the easy part. Brass is available in 50+ different types, in it's simplest form brass is a composition of copper and zinc, so we now have an alloy. The different % of copper to zinc, willafect the property of the brass. The basic mix can have other metals added to it, this all affects the property of the brass. Some of the hardest of the copper alloys are nickel alloy bronze & the gun metals. So we have the basics of brass, if we take the same grade of brass depending on what we want says what happens next. This can be cast but not that common as it has length limits. The next one is hot rolling, this starts off as a billet of a given size for what is required it then goes through different size rollers, it may have to go back for reheating during all this. The out side of this is not a accurate as the next. The next type is drawing. I'm not sure at what size these start but I think that we all know that it goes down to at least 0.03mm.The starting size will depend on the finished size and the length that is required. It can be hot drawn or cold drawn. The hot drawn will be softer than the cold drawn, this is the sort that we use as handrail and such. Next we come to casting brass, this class probable has more types than the others. A casting can go from say a 6' diameter water stop feed valve for a power station, to the steam lance on a model loco. To be able to do this you need different types of brass. Most casting brass has silica added to help it flow. As the casting is cooling the silica migrates to the outside of the casting, that is the main reason that you can't solder a casting without filling it back to base metal. The wheels, more than likely a form of chrome plating. Remember back in the seventies when Triang brought out the silver seal range came out. I reckon that the San Cheng etc. will be using something along the same lines. OzzyO. Edit; To add these, I'm also going to posts them later on in another post. As I know a lot of people don't go back and re read the thread. Edited May 18, 2012 by ozzyo 1 Link to post Share on other sites More sharing options...
ozzyo Posted May 17, 2012 Author Share Posted May 17, 2012 Hello Kenton and Buffalo, it was no good when I bought it and it's still no good. It just sits on the shelf gathering dust. In photo six not including the bottles. The B/C worked on all three metal types to about the same extent. Martyn, what is the name of this super blackening solution? OzzyO. Link to post Share on other sites More sharing options...
buffalo Posted May 17, 2012 Share Posted May 17, 2012 ...The B/C worked on all three metal types to about the same extent... Agreed, if the gun blue bottle is to hand and the Carr's are in the cupboard, I often use it on brass and nickel silver. Nick Link to post Share on other sites More sharing options...
LaScala Posted May 17, 2012 Share Posted May 17, 2012 Have the wheels been chrome plated or anything? There's a lot to be said for laundry marker. Link to post Share on other sites More sharing options...
RMweb Premium DLT Posted May 17, 2012 RMweb Premium Share Posted May 17, 2012 Hello all, in a thread there has been a bit of a discussion about metal blackening, so i thought I'd try some out. The contenders. OzzyO. PS. I'm not to sure if this should be in this section or in questions, hints and tips. If it's in the wrong section please move it. Hi Ozzy, That bottle of Carrs must be over twenty years old. I had some at the time and I agree with you, it was useless. As others have said, the current Carrs range is quite different, and its results are the same as with Birchwood Casey. The two look and behave similarly, and may well be a similar chemical solution. I'm no chemist, just a regular user, and I happily recommend either. Thanks for drawing attention to all the old and almost empty bottles of potions various that I have stuffed at the back of my cupboards! Cheers, Dave. Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 Hi Ozzy, That bottle of Carrs must be over twenty years old. I had some at the time and I agree with you, it was useless. Thanks for drawing attention to all the old and almost empty bottles of potions various that I have stuffed at the back of my cupboards! Cheers, Dave. Hello Dave, how's it go give a dog a bad name. OzzyO. Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 Hello all, as we started with metal blackening, I dug out one of my old engineering books (no date no copyright marking) and found these for yous. I'm sure that if you took the recipes to your local chemist he would help you out. Or call the bomb squad!!!!!!!!!!!!!!!! Page 316, brass Tin coating of. The granulated tin might be a bit of a problem and expensive to get, but the cream of tartar no problem, as it's used in baking. It would give a good surface for the paint, but would have to be done before the W/M parts were soldered on. Can you still get enamelled sauce pans? Go on who's going to be the first to give it a go? Let us know how you get on, with pictures. Please. 3Link, asked about brass, I gave a reply off the top of my head, so some of it may have been wrong as I have been out of engineering for over twenty years. So I got this lot out of the same book. This one will kill you. Have a look at the shop fire extinguisher. IIRC it's the second one. What would the H&S mob say about that lot???????????????????????????????? OzzyO. Link to post Share on other sites More sharing options...
Krusty Posted May 18, 2012 Share Posted May 18, 2012 As others have said, the current Carrs range is quite different, and its results are the same as with Birchwood Casey. The two look and behave similarly, and may well be a similar chemical solution. I have a vague recollection of Brian Lewis many moons ago saying that the Carrs blackeners were actually made by Birchwood Casey. Link to post Share on other sites More sharing options...
Horsetan Posted May 18, 2012 Share Posted May 18, 2012 I bought Birchwood-Casey gun blue because around here it's easier to get to a gunshop / shooting supplier than it is to find a model shop...... Link to post Share on other sites More sharing options...
Mike G Posted May 18, 2012 Share Posted May 18, 2012 Can you still get enamelled sauce pans? Go on who's going to be the first to give it a go? Let us know how you get on, with pictures. Please. OzzyO. Yes you can but they are really expensive - don't ask, no really don't! - better off looking in a second hand shop - (euch-a-vie! The thought of second hand pots...) and secondly...you are such a tease!! The concoctions in your list are frightening... Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 Hello all, I'm looking at the price of granulated tin at the moment, just waiting for the email to come back to me, so who know what may happen. The totally mad, OzzyO. Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 I bought Birchwood-Casey gun blue because around here it's easier to get to a gunshop / shooting supplier than it is to find a model shop...... Hello H/T, what sort of price? OzzyO. Link to post Share on other sites More sharing options...
Horsetan Posted May 18, 2012 Share Posted May 18, 2012 Hello H/T, what sort of price? Gunshop in East Barnet sold me a bottle of BC Gun Blue for a fiver. That was some years ago. I'd expect at least eight quid a bottle now. There's another gunshop in Park Street / Bricket Wood, but I haven't had a chance to visit it yet. Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 I've just noticed some thing in one of my messages. Link to post Share on other sites More sharing options...
buffalo Posted May 18, 2012 Share Posted May 18, 2012 ...This one will kill you. Have a look at the shop fire extinguisher. IIRC it's the second one... I also enjoyed the idea of asphalt as an etch resist. I'll bear that in mind next time they're resurfacing nearby. Nick Link to post Share on other sites More sharing options...
N15class Posted May 18, 2012 Share Posted May 18, 2012 (edited) I think th H&S boys are sat in a corner weeping with that list. I strikes me as strange you put these chemicals in a bottle with a trade name, rather than mix them yourself and every one seems happier. I remember some of the nasty things we had in our metal workshop when at school. No body died, a few had sore hands and arses for messing. You only ever did it the once because you learnt it hurt touch. I wonder how you would get on today, on every one they say to wash well with water, these days the water boards don't even like you putting dirty dish water down the drain!!!! Edited spelling Edited May 18, 2012 by N15class Link to post Share on other sites More sharing options...
ozzyo Posted May 18, 2012 Author Share Posted May 18, 2012 Can you use Pyrex on the top of a gas hob, if has liquid in it? OzzyO. Link to post Share on other sites More sharing options...
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