Author Topic: Breech-Plug Design - obturation (Read 636 times)

Cat Whisperer · « **on:** April 28, 2005, 01:44:55 PM »

Obturation means 'to close or block up' or to seal the breech.

The design should be such that it seals completely - to eliminate the possibility of corrosion in later years causing cracks in the tube.

How to do it?

One method is to have the breechplug fit with a 'crush-fit' that seals most completely and permanently.

Of recent I took apart a 20" long .50 caliber model cannon and removed the breech plug.

It was interesting to see the COPPER DISK used to seal the bore.

Threads were 1" max diameter and 8 TPI, the copper disk of 3/4" diameter and extended about .100" past the steel.

The cast balls are .498 and 12ga.

Breechplug

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Obdurating disk

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Blaster · « **Reply #1 on:** April 28, 2005, 03:47:02 PM »

Hey Cat....nice post and great pix. Now I'm wondering if you perhaps meant obTuration?? Please don't think that I'm trying to be a know-it-all.
:wink:

Cat Whisperer · « **Reply #2 on:** April 28, 2005, 04:09:18 PM »

Quote from: blaster

Hey Cat....nice post and great pix. Now I'm wondering if you perhaps meant obTuration?? Please don't think that I'm trying to be a know-it-all.
:wink:

Thanks, I looked both up in my 1947 Funk and Wagnalls. Obturate is the more correct term.

Cat Whisperer · « **Reply #3 on:** April 28, 2005, 04:35:55 PM »

Two more pix. Carbon build up was all over the copper and past the copper inside the cavity in the clearance area past the threads, but not into the threads.

Close up:

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Overall:

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CAV Trooper · « **Reply #4 on:** April 28, 2005, 05:34:42 PM »

I just love that tail (cat?) in the picture for size reference. Very novel and original.

I'd have just stayed with the old boring standard and used a can of Goex. :wink: