case colors streak

[Alfred Greeson]

Bruce, thanks for sharing, beautiful guns. I have never seen any engraving like the little 20.

[Wild Skies]

Originally Posted by Dean Romig

It is the front to rear patch of lighter color on the floor plate (...snip...)
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In the Parker Pages article by Charlie Price which Mr. Bastiani referenced, Charlie's pics of guns retaining original colors, show a dark streak more often than those with a light streak and more on the order of the Remington Parker that Reggie B has shown in this thread. It appears they could be either way with either a light or dark streak, but nonetheless; with a streak.

[Dean Romig]

Originally Posted by Greg Baehman

In the Parker Pages article by Charlie Price which Mr. Bastiani referenced, Charlie's pics of guns retaining original colors, show a dark streak more often than those with a light streak and more on the order of the Remington Parker that Reggie B has shown in this thread. It appears they could be either way with either a light or dark streak, but nonetheless; with a streak.

Right Greg - I should have, instead of saying "light" streak, said a streak of a different hue.





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[edgarspencer]

Originally Posted by Brian Dudley

Odd... as I recall, nearly every parker I have had re-cased has had it.

Yes, it is dependent on the case hardening process. But more a function of how the trigger plate is machined. The channel in the plate for the unhooking slide results in a dramatically different thickenss of material up the middle of the plate. This is really the main reason for a difference in the appearance and patterning of the colors in that area.

And I will add that not all original examples are that pronounced. Every gun is different.

Brian is correct in that the inside of the floorplate is machined such that there are three areas of mass; the outside two the same and the center, much thinner. See my work of art below.

The outside square represents the packing box. Surrounding the part is the packing media, which is an organic mixture of the makers own recipe. The drawing shows a theoretical cross section.

There are three factors involved: Random, Variable, and Fixed.
The Fixed factor is the part being heat treated.
The variable factors are Time and Temperature
The Random factor, almost entirely human, is the location of the part, in relation to the inside walls of the packing box, location of any other parts also in the box, and the density of the packing material.

The entire part is held sufficiently long enough for the core of all sections to reach the same temperature.
The quench process is where the magic occurs because the three areas of mass are cooling (from the center outwards) and while the quench media is still working at cooling A & C, B has gotten as low as the quench media will allow. Everything started at the same temperature, was ultimately soaked at the same temp, and eventually back down to the same temp. However, the rates at which they rose, and cooled was controlled by their mass.

[Reggie B]

Edgar, we really should have known.

[Dean Romig]

Looks like a Picasso... Nice job Edgar.

Thanks for putting the entire process into layman's terms for us. Your experience in the field of metals is invaluable to us.





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[stumpstalker]

What a great thread you initiated, John.

And exemplary. It quickly brought in some valuable knowledge, original graphics, rare insights, and magnificent gun photos, all freely given, from some of the top mavens in the Parker gun community.

Best of luck to you as you move forward in collecting such fine pieces as you are now considering.

[Mike of the Mountain]

Originally Posted by Brian Dudley

Odd... as I recall, nearly every parker I have had re-cased has had it.

Yes, it is dependent on the case hardening process. But more a function of how the trigger plate is machined. The channel in the plate for the unhooking slide results in a dramatically different thickenss of material up the middle of the plate. This is really the main reason for a difference in the appearance and patterning of the colors in that area.

And I will add that not all original examples are that pronounced. Every gun is different.

Good call Brian. Makes sense that any difference in metal thickness would cause temperature fluctuations.