To illustrate that Mike and I think that Gun Blueing or Black Oxide is not the Be All - End All for cannon surface treatment, we will state unequivocally that for our favorite, drag-it-to-the-range every time cannon, black paint (satin) or flat black is our choice for a good looking, easy to repair finish on machined steel. The two reasons that we use gun blue or black oxide (same thing) on our Seacoast Collection cannon is that our business is one of details. If we cover up the fine details we create with any kind of paint, we will not sell these cannon at the price we have chosen in our business model. Secondarily, Double D. is right, we can't find any durable paint which will create a true scale surface thickness, much less stand the shipment and reshipment that some of these cannons endure going from one Civil War Show to the next for display purposes.
Rather than blather on and on, I have posted a few photos of the markings that are found on the 7"Brooke.
Tracy
These particular markings are of the Preponderance (extra weight at the rear of this cannon to keep the tube in contact with the elevation screw end). On this cannon tube the preponderance weight is 1,740 Lbs. The 1/2" high markings on the original tube are (PREP. 1740). Our stamped characters are very small at only .083" tall. Could you see these under ANY PAINT? No. Although these are in-process photos of unblued steel, I can say with 100% certainty that they are as crisp and visible on black oxided steel.
The weight marking of 21,290 Lbs. is stamped (21290), on the original tube. Scale size for this marking is also .083" high. The super glue from fixture holding was wiped off with acetone . The vent liner is shown 7.5 degrees to the right of the center line as on the original. We used a stainless steel socket head cap screw which replicates the original steel vent liner and will stay shiny if the cannon is fired. After screwing down tightly, the head was cut off and, with the surrounding area protected with a .005" shim stock piece, the end was filed and stoned down to the shim. The vent hole is .079" dia. which is as close to scale as we can get and still fit commonly available 1/16" fuse. The 1mm fuse we have used for our bb cannons is too brittle for regular use.
The methods we use to create these markings vary. Sometimes we use hydraulics for the large trunnion face markings, but mostly we use the old fashioned hammer and hand stamps as shown in this photo. To make the markings as perfect as we can on this one, an angled aluminum block was machined to fit the breech strap recess and allow the stamp to have a solid rest at the correct angle to impact the segment of a spheroid surface at the rear of the cascable squarely. Left and right squareness and spacing was laid out on the aluminum block with small machinist squares, 6" steel rule and executed with an ultra fine tip fiber pen. Notice the heavy 24 oz. hammer. For fine work, we ALWAYS use light blows from heavy hammers. You have more control that way.
