doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com color case hardening

so is that it, the process is complete? or is there one more step, like some kind of clear coating to protect your new colors from fading?

and turnbull does very pleasing work...

art in its truest form...

Hereford

Care to share what if any blocking you are doing on a LC Smith receiver assembly and how? looks like you are doing the assembly in one drop as opposed to the parts being separated in the Charcoal mix?

Have you done box locks and what kind of blocking do you do there?

Thanks for sharing your experiences with us.

Travis

Mike

Regarding water temp, air entrainment and circulation I kind of get the water temp component but is the air bubbling more for just water circulation or actually getting more small air particles in the water?

I would think water circulation is more important than air for the purposes of minimizing steam pockets along the quench.

I was thinking of a pretty simple recirculation set up where the water is pushed in from the bottom side of the tank at an tangential angle to the sides of the round tank and out the top at an angle so as to encourage a swirling movement to the water and then though a ice bath back into the quench tank. I would think this movement should be present through the quench drop in order to introduce a consistent as possible water temp to the part throughout the drop. If this is a sound idea, then would air introduction even be needed and if so why?

Am I over thinking this or more so am I just plain wrong

Thanks for your valued input.

Travis

Travis

I believe you�re over thinking it� the set-up at least.
Everything I�ve read; and I�ve got a pretty substantial library of pre 1920s books on the heat treatment of steel, all note that for case hardening with colors you need to introduce air.

As stated, before I believe that the air �enhances� the colors, and provides water circulation.

Now� with that said, I�ve seen pictures of both Winchester�s and Marlins Pre 1920s Case hardening processes. They quenched parts in a large tank, about midway between waist and chest height. They had a fountain of water coming out of the center, my guess a 4-6-inch main water line.

They did things a lot differently than we can, they case hardened in mass, Marlin did about half a dozen receivers at a time, reading old notes from the Winchester plant, they case hardened 250 hammers at a time., that should give an idea of volume.

As to the recirculation set-up that you brought up, I�ve tried it�. Using a pump off a 33,000-gallon pool. The biggest issue is the charcoal plugging up filters and the pump. It�s really hard to filter that much charcoal out of the water without clogging things up. You would have to use a two-station filtration system, similar to a septic system, where a second tank would catch most of the char.

Cooling the water would be another issue, the pump I have puts out 15-20 GPM, not enough surface area to cool that kind of flow with just an ice bath.

Respectfullly

Mike

Could you make heads or tails if this system was running during the quench, did it appear to create significant aggitation to the water?

Many tutorials recommend aeration for varying lengths of time, but then to shut it off prior to quenching. Then temperature of the water would likely be uniform, but I wonder if only so much air can dissolve in the water. It's curious to me that the water temperature that you settled on may be able to carry more dissolved air in it than at warmer temps.

The reason I think it might matter is because I suspect there might be vapor jackets that form and collapse around the hot parts, but not necessarily steam? The O2 that forms the oxides that eventually show as colors must come from somewhere, but too much doesn't seem to help. A prequench aeration likely has other benefits, too.

Just rambling around. I can't easily get to my little hobby setup right now, but it does make me want to play with it some more. Take care.

Craig, indeed, "only so much air can dissolve in the water"

And with respect to oxygen, there can be much more dissolved gas in cooler water. Warming reduces solubility. Ask a trout.

The set up I have used has a copper pipe with 2 full coils spiraling in. Put it in the bottom of the barrel. Run the air compressor high enough the water id rolling but not splashing out. When ready to quench, turn off the air and dump when the bubbles stop but the water is still moving. And don't forget the camel urine.

Right now all I've done is side lock guns and they are all dropped assembled. I have a small bushing that the side lock screw goes through to act as a spacer as well as the rear tang screw. There is nearly always a small amount of warpage where the side plates attach to the receiver. No big deal and easily fixed. I aerate my quench water from when I start the bake until I quench which is roughly 2 hrs. I've tried both with the aeration running and not running at quench time and have not noticed any difference. I've tried distilled, well, and tap water and have had no change either. Currently running tap that has been in the barrel for 2 years and I just add to it. Next variable I need to try is temp. I've used ice water one run and didn't notice much difference but am wanting to try it again a few times to find a sweet spot.

Just a lesson learned long distance. don't use hardenable screws (Allen screws) for blocking.
Part will shrink slightly from casehardening. Can't get them out or drill them out.
Chuck