Heat-stained brass technique

Imperial Knight Conversion: Pt. 19 — Annealed brass on engine exhausts.

There was a lot of interest in the technique I used to add some heat-staining (the phenomenon is called annealed metal, but known by many other names as well) on the brass heat-shrouding on my Imperial Knights exhaust stacks. I wasn’t really sold on whether I should do it at all, but after watching a bunch of YouTube videos and doing some research it was clear that brass absolutely does discolor at high heat. Not quite in the same way that steel does, but it’s noticeable. A couple of the videos I used were from firearm enthusiasts who refit their fired brass rifle cartridges, and they use blowtorches to anneal the metal jacket which makes it a bit softer. I had no idea. Anyway, I knew the effect I was shooting for (no pun intended) and I set out to replicate it. It’s worth mentioning that you could surely cut some of these steps down with some wet blending or something. I like the depth and subtle variation in color that I got with it and I’d do it this way again. I probably will, on the melta cannon.

First things first, though, you have to get your brass to the finish you want it before you start washing on the transparent inks and washes. I simply used the technique from my earlier post, but stopped before adding the patina stage.

Paints used for heat-staining washes.Here’s what you’ll need: to be fair, you don’t need exactly these colors. These are what I had on hand that made sense. You don’t want anything too red, though. Keep it to the cooler side of the color wheel. In my case it’s Lahmian Medium to thin everything, Seraphim Sepia, Agrax Earthshade, Warlock Purple, Xereus Purple, Runefang Steel and old Citadel Blue Wash.


First step: aged, worn brass. This is what I started with. Some seriously crusty, worn, dulled brass. The technique should really work no matter what sort of brass color underlies it. The trick is to shade and highlight it as normal because you won’t be able to after you do the rest of these steps. Remember, you can click on these pictures and zoom way in if you want to.

You may notice that the line dips down a bit in the middle. That’s intentional, because the pipes fit right up to the heat shroud on the sides, but not in the middle. That area would naturally be a little less hot. I’ll leave you with one last picture from the other side. I’m pretty pleased with the natural variation in color and size of the bands. I may go through and actually make the bottom more steel colored. In fact, I wonder if it would look better to do the steel coloration before the washing. Maybe I’ll try that on the melta cannon and hope it doesn’t look too dissimilar. The lighting also makes it look a little more dramatic than it is in real life. In fact, if you go up and look at the picture with the paints, you can see it in different lighting and it looks more like it would on the tabletop. It’s noticeable, but not at all over the top.

Heat-stained brass technique.

What do you think? Do you have a different technique you like to use?

Heat-stained brassEDIT: I’ve finished my Knight and I did a much better job on her Thermal Cannon. Same recipe, but I took my time and did even thinner layers of glazes for a smoother transition. I also scaled back on the amount, and I think it makes for a very nice transition. You can compare both in this photo.