jazz Posted June 20, 2011 Share Posted June 20, 2011 Hi gang. I've been looking at metal blacking and find there are very mixed views about which product works and which dosn't. So, what do I intend to blacken - Steel wheel rims/ buffer heads, brass and nickle silver parts. I have heard you can use cotton buds to just blacken the wheel rims. I this a fact, as I do not fancy totally blackened wheels. As I have always relied on painting these parts, which product do you guys use and which would be the easiest to to use. Thanks guys. Link to post Share on other sites More sharing options...
smokebox Posted June 20, 2011 Share Posted June 20, 2011 Felt tip pen. The ones for use with overhead projectors or CD labels Link to post Share on other sites More sharing options...
James Posted June 20, 2011 Share Posted June 20, 2011 I use Birchwood Casey Gun Blue applied with cotton buds for blackening items like wheel tyres - then a damp sheet of decent (Bounty or whatever the name is now) kitchen roll to wipe the surface to stop the reaction. Works very well. For buffer heads, either applied in the same way or briiefly 'dunked' in the fluid and then in water to stop the reaction. Providing the metal is degreased and cleaned beforehand I've found BC's blackening fluids to be vgery user friendly. Link to post Share on other sites More sharing options...
Buckjumper Posted June 20, 2011 Share Posted June 20, 2011 Ken This is Bob Alderman's (The Guild's TIO) method, as posted to the 7mm Yahoo e-Group. Personally I only use Birchwood Casey Super Blue. Chemically Blackening Components – my approach. Bob Alderman. Steel parts. Blackener – either Birchwood Casey Gun Blue or Carr’s Metal Black for Steel. Buffers. 1. Polish the head to remove any tool marks and the parting–off pip in the centre. I use the modelling drill and some emery paper 120 grit. Use the drill at mid speed. This process will also remove any oils or grease left from the manufacturing process. 2. Take a cotton bud and apply the blackener. Only apply it to the head, front and back and the shank immediately behind the head. Avoid the area where the spring sits. The blackening is nearly instantaneous. Rub the bud over all the areas to ensure it is an even colour. 3. Rinse in hot water and allow to dry. 4. There may be a whitish residue left after this. The next stage will see to that. 5. When dry burnish the head with a brass wire brush. The black will shine a little after this. 6. I have found that the rear of the head and the shank may turn rusty after a time. Let it, it looks realistic! 7. Assemble with a little oil on the spring inside the body. Wheels. 1. Do any necessary truing and remove any plastic moulding pips. 2. I polish the rim with a Blue Garryflex bock (a block with an abrasive in a rubber matrix). Again I mount the wheel on an axle and spin it at mid speed in the modelling drill. The block is pressed into the tyre. It conforms to the shape. The tyre becomes shiny. 3. When the set has been prepared I apply the blackener with a cotton bud. Around the tread, then the outside of the rim and the back of the flange. Again blackening is nearly instantaneous. 4. Rinse in hot water and allow to dry. 5. There may be a whitish residue left after this. The next stage will see to that. 6. Burnish the tyre with a brass wire brush. Again the steel will shine after this. Axles. 1. Again polish them to remove any oil residues. For Slater’s do the necessary retouching of the square ends to make an easy fit on the wheels. 2. Apply the blackener with a cotton bud ensuring an even coating. I DO NOT blacken the square ends on Slater’s axles. 3. Rinse in hot water and allow to dry. Burnish with a brass wire brush. Again the steel will shine after this. 4. If Slater’s axles then you MUST ensure the screw hole is dry. I insert a hot soldering iron into the hole and wait until the axle is too hot to hold! Do both ends. When cool insert a drop of thin oil into the hole. This will ensure the future removal of the wheel retaining screw. Brass and nickel silver parts. Blackener – either Birchwood Casey Gun Blue or Carr’s Metal Black for Steel or Carr’s blackener for these materials. 1. Prepare the component. Remove etching cusps and lightly abrade with fine emery or a Brown Garryflex block. Note solder will not work on a blackened surface! 2. Clean the surface with Carr’s Surface Conditioner (C1056/C1057). It changes colour, slightly yellow and the surface goes matt. 3. Rinse in hot water and allow to dry. 4. Apply the blackener. Either immerse in the solution or apply with a cotton bud. If immersing then hanging the parts on a fine wire aids retrieval. Do not leave parts in the blackener too long. If using a cotton bud gentle continuous rubbing may be needed. Replenish the bud every so often. 6. If the solution is too strong the surface will blacken and flake. Diluting the blackener will prevent this. 7. Rinse in hot water and allow to dry. Edit - updated Link to post Share on other sites More sharing options...
craigwelsh Posted June 20, 2011 Share Posted June 20, 2011 I've used Birchwood Casey brass black on NS and brass though it seems to work better on NS, probably better to go for the gun blue one than this though. It also doesn't look as good on any solder left around. Link to post Share on other sites More sharing options...
jazz Posted June 21, 2011 Author Share Posted June 21, 2011 Thank you to all. A big thanks to Adrian for the time spent on very detailed and very useful instructions. I will now have the confidence to proceed with blackening. Best wishes Ken Link to post Share on other sites More sharing options...
bertiedog Posted June 21, 2011 Share Posted June 21, 2011 Can I just add that residual solder stops all blackening, even a trace, but there are acid removers from Carrs which act on traditional lead tin solder. They oxide the solder, turning it black and make it removable. Not a quick process. Stephen. Link to post Share on other sites More sharing options...
Buckjumper Posted June 21, 2011 Share Posted June 21, 2011 Thank you to all. A big thanks to Adrian for the time spent on very detailed and very useful instructions. I will now have the confidence to proceed with blackening. Best wishes Ken No problem, but as I say, they were Bob Alderman's notes, a copy of which I have in my files - it was a simple copy and paste job Link to post Share on other sites More sharing options...
Buckjumper Posted June 21, 2011 Share Posted June 21, 2011 Can I just add that residual solder stops all blackening, even a trace, but there are acid removers from Carrs which act on traditional lead tin solder. They oxide the solder, turning it black and make it removable. Not a quick process. Stephen's point is well made. After a soldering session and the obligatory washing away of flux residue, following a tip from Malc Mitchell, I tend to immerse the work in a bath of Viakal so the metal is clean for the next day's session. As well as brightening and cleaning the brass it blackens any traces of solder. In an ideal world we should be using as little solder as possible anyway - nothing is gained by using lots of the stuff and certainly has nothing to do with the strength of a joint - it just means more time and effort expended cleaning up! Link to post Share on other sites More sharing options...
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