Cox Cylinder Blacking

Nice work Ian. You always have great ideas!

Ron

Ian, Is the blackening fluid only cosmetic or does it actually protect the metal? Also, how will it hold up to use? Thanks for sharing this information. Andy

Very nice work --- your finished cylinders look great.

anm2 wrote:Ian,  Is the blackening fluid only cosmetic or does it actually protect the metal?  Also, how will it hold up to use?  Thanks for sharing this information.  Andy

The blackening fluid protects the metal and binds itself to it forming black oxide coating. This solution contains a portion of selenium dioxide, I am not sure what this adds to the process but this solution is ideal for home use. The "true" blackening process are heat based and use seriously caustic solutions, not for home use.

This finish is more than cosmetic and ideal for cylinders. I also use it to protect, from rust, components in some of the tools that I make to support my machinery.

However, I would not put it on something that is subject to wear. (A hand gun slipping in and out of a holster would eventually wear down the finish).

Caution though - It is expensive!. The chemicals shown are in the order of £40 for the three conatiners but they have a shelf life of 30 years +. I also use it for smaller components like the tommy bars on diesel engines.

Do not let the blacking liquid contact the inside of the cylinder. The piston will no longer fit!

I have experimented with "gun blue" applications and they don't seem as robust as this.

Below are pictures of an "Anglicised" piece of Americana. It was well used and had started to become rust spotted as the original finish wore and was used in damp conditions. The barrel was "gun blued" but the "silence is golden" at the end of the barred was blackened. This was 3 years ago - picture taken today.

Ian,

That's the mistake I made. I threw the whole cylinder in the solution. What's worse I walked away and forgot it for 8hrs!  

Cribbs74 wrote:Ian,

That's the mistake I made. I threw the whole cylinder in the solution. What's worse I walked away and forgot it for 8hrs!  

8 hrs !!! Tut..Tut! No longer that 4 minutes with this stuff.

But we all make mistakes - some more than others and I don't admit to all of mine!

What do you use to mask the inside of the cylinder with to not get the inside coated? Looks like just tight fitting delrin or you use a paint mask of some sort. Maybe wax would work if you are careful.

Jason_WI wrote:What do you use to mask the inside of the cylinder with to not get the inside coated? Looks like just tight fitting delrin or you use a paint mask of some sort. Maybe wax would work if you are careful.

For 010, 020 and 049 - I use a nylon rod turned to a tight fit.

The rod shown was the 020 rod - for the Olympic cylinder I wrapped electrical tape around it for a very tight fit and then elastic bands to slide the 09 piston on at the end. All remained water tight.

Three different methods - I have also used PTFE tape (didn't work!), wax (didn't work!) - it didn't like sticking to the metal, I filled the cylinder with candle wax and it shrank away from the cylinder in places.

I have never tried a liquid paint mask but masking tape stuck to the inside didn't hold and masking tape wrapped around a rod was a little iffy. When compressed it didn't bounce back!