(Failing miserably at) Blueing a Denix

[ollyhills]

So I've been having the most miserable time when it comes to blueing—it just doesn't seem to be doing what I want it to do. I'm using Birchwood Casey Super Blue, and it's not doing much more than turning my Denix a slightly darker silver, after at least 5 or so applications. I've been struggling with steel too; while some of my parts have been probably about 90% of what I'm looking for, others aren't. I almost feel like each time I'm applying it the previous load is getting washed off and it's just stuck in this loop and going nowhere. Would I be better off with Aluminium Black? Am I missing something entirely (I'm following the instructions on the label)? I just want this stupid thing to turn black(ish) already

 

[thd9791]

I struggled with blueing solution too for a bit - and it IS hit or miss because it's a chemical reaction. Here's what I've learned:

1) Machined aluminum seems not porous enough to take on Aluminum Black quickly. Scuff it up with some sandpaper first.
2) Heat up your parts, hotter metal takes blueing/blackening better
3) Denix metal is pot metal, so zinc, etc. and responds better to Aluminum Black than it does to Super Blue which is for steel.
4) Oil up your Blueing finish afterwards to prevent air-corrosion, or at least a paste wax without too much solvent in it.
5) It can take 8-12 passes on some parts... heat, blue, water to neutralize, dry it off over the heat, repeat.
6) get near a window or have a fan because the fumes suck!
7) Brass black exists too - and permablue and superblue are both for steel I think...

 

[ollyhills]

Awesome, cheers man! I will say tho—I was all prepared for the stuff to be stinky and fumey and all that but... it’s not? Is it just me? Have I no sense of smell or taste or something?

but genuinely cheers for all that. I did notice getting stuff warmer earlier did do some help, but only to start. And I f i scuff up the metal, won’t that come through looking all crappy and dull?

and what kind of oil/wax should I be finishing it up with?

 

[James Kenobi 1138]

I agree the Aluminum Black works better but what I learned is the PermaBlue Gel works WAY better than the PermaBlue liquid.

 

[Mara Jade's Father]

Basically people tried this 20 odd years ago and I think it was determined bluing works for steel and not for the alloy type metal of a denix

Aluminum Black works. You will need to strip it down to the bare metal. by sanding the surface, the chemical will take better too. do a coat, wash off and repeat. Try to put it on thin because if the chemical reaction is too fast and too thick, it almost creates a black layer that chips off. If it does not look black in your first coat, don’t worry, just keep repeating.

 

[Bradberry00]

My best results are achieved by putting the part in a ziplock bag with a generous squirt of bluing/blackening solution. Massage it through the bag, remove it and rinse it with water, rub with fine steel wool and repeat until the desired finish is achieved. If you want more control a saturated cotton ball works to massage the solution into the metal. When I’m doing brass and want to creep up on the color I dilute the solution with a bit of water.