Blackening Fluids and Brass Parts - Advice

[Kingsman]

I've tried different blackening fluids including AK Interactive and Wilder with mixed results, and I'm looking for a bit of advice.  Am I doing something wrong?

 

I can't get brass gun barrels to blacken at all.  The best I get is a loose sooty deposit which needs to be cleaned off leaving just a few small black spots, thus negating the whole process.  Some brass etch does discolour to nearly black, but some (e.g. Airwaves) is completely impervious.  Some sheets darken only partly, leaving parts still bright.  Sometimes there is a sooty deposit, sometimes not.

 

I can get aluminium barrels to darken a little, but I would call it "greying" not blackening.  The AK Interactive blackening fluid (the one not for brass) eats aluminium alarmingly quickly, leaving a pitted surface.  It almost completely ate through some 0.2mm aluminium sheet in seconds, and took days for the resulting brown sludge to settle out.

 

I've read that washing brass parts in vinegar first helps.  Doesn't seem to make any difference.  Likewise, light scouring with a fine abrasive.

[Bigdave22014]

I've never used those products so not sure about your problems.

I have in the past used Carr's products and Gun Blue successfully. The best tip I can give you is to make sure they are thoroughly clean and grease free. Carr's produce an Acid dip for this.

Never used it on Aluminium but brass and nickel silver worked fine.

Btw, gun blue is exactly that. It is used for "blueing" firearms, can't remember where I got it though, think it was the big Model Railway show at Warley.

Hope this helps.

[PhoenixII]

Gun blue can always be had from a Gunsmith..........IF you can find one.

Shouldn't be too difficult around the Bristol / Gloucester / Somerset area.

 

Paul

[Kingsman]

More difficult that you think.  AFAIK the last gun shop in Bristol closed a few years back.  I had to go to Swindon even just to get some ballistic specs and ear defenders for a work shoot back in 2012!

 

I hadn't thought of real gun blue.  I suppose engineer's blue would be much the same thing. 

 

I imagine the vinegar bath one supplier mentioned was in lieu of an acid bath, on the basis that everyone can get vinegar and it's safe.  Might as well try lemon juice while we're at it!  Acid products are about to get a lot more difficult to get hold of, and rightly so.  It isn't the sort of thing that needs to be on general public sale.