M1 Thompsons Blued or Parked?

[jbassmaster18]

In WW2, did M1 or M1A1 Thompsons have a blued or Parkerized finish??

[buzz]

My understanding is that no Thompson left the factory with Parkerizing on it.

 

Apparently they were put into a typical bluing solution called Dulite (black oxide)

 

Without polishing the metal, the bluing solution comes out looking like very smooth black Parkerizing.

 

So the parts all have a slightly different sheen depending on the amount they were polished in manufacturing.

Edited April 12, 2015 by buzz

[LSU Tiger]

I agree with Buzz. I'll add to that, according to what I've read, frames and receivers were milled to final size and smoothed somewhat. Then, they were lightly sandblasted, roll marked, then degreased before finishing with Du-Lite. The final color was as Buzz mentioned, a smooth, but dull blue-black.

[Paladin601]

What Grit sand was used for the sandblasting?

[LSU Tiger]

What Grit sand was used for the sandblasting?

 

From the original finishes I've seen, it must have been a very fine sand.

[buzz]

My understanding is that some parts are burnished by the manufacturing process and they come out of the lathe or whatever with a light polish.

 

I would expect a part that was burnished like that to have a different look to it than something that was rapidly milled with big machining marks all over it.

 

The idea is that if a rough part was blasted and dulited it would look different than if a shiny part was blasted and dulited.

 

That's the way my savage 28 looks but that's just one data point

[Paladin601]

wonder what the method of burr removal, burnishing? they did not want a reflective surface, that is for sure.

[LSU Tiger]

From what I remember from Helmer's "The Gun That Made The Twenties Roar," Auto Ordnance in Bridgeport used wood barrels that contained abrasive and the parts were tumbled. Savage may have used a different method.

 

Buzz would probably know better, but I'd think the hardness of a given part could effect the depth or shade of the color. It may only show up on polished parts.

Edited April 15, 2015 by LSU Tiger

[buzz]

Thanks, but my knowledge of Thompsons in general is pretty sketchy.

[gijive]

Buzz is correct. The guns were DuLite (black oxide) finished. The color and texture all depends on the metal preparation. Many novice collectors and military buffs think the original matte finish on WWII Thompons is Parkerizing. The Parkerizing came in when the guns were arsenal refinished and rebuilt at the end of and post WWII.