Unknown Copper Pin

[CarlS]

Good day all,

I was cleaning a cannon ball for a prominent member of this forum and when it came out of the electrolysis tank I noticed an oddity on the side near the mold seam when rust came off.  In fact it turned out to be right on the (faint) mold seam.  It appears to be the head of a copper pin driven into a hole.  Perhaps it was a casting flaw the manufactorers decided to fill?  I've seen this with lead but not sure I can recall seeing it done with copper.  It's way to small at 1/2 inch to be a side loader plug.  Any thoughts?  Anyone seen this before?

[Pete George]

  Because the spot is "right on the (faint) mold seam," I believe your guess is correct, it is a patch-job for a significant casting flaw.

For anybody who doesn't already know:
  The mold's filler-hole is always located on the mold's seam.  On occasion, contraction of the cooling metal -- or an air bubble trapped in the molten metal during the mold-filling process -- causes a sunken-in spot on the projectile at the mold's filler-hole.  If the casting-flaw is of a size large (or deep) enough to possibly result in fracturing when exposed to the explosive blast of the propellant-charge during firing, the shell-manufacturer would "patch" the flaw by filling it with an easily-malleable metal, such as lead ...or in this case, copper.  Because a malleable metal is used for the "patch," it could simply be hammered into the flaw, instead of having to use a more complicated repair process ...or having to scrap the whole newly-cast projectile.

Regards,
Pete

[John D. Bartleson Jr.]

It is amazing that we see all these odd ball items show up. Good thought Pete  I wouold have guessed someone drilled an inerting hole to wet the powder.
Regards,
John

[emike123]

I should think that pretty much makes that a several thousand dollar shell ;-)

I recently did my own electrolysis (yes, Carl, occasionally I do do it myself and even have something in the tank as I write this) on a 30pdr Read and it had a couple similar, period spots where lead had been used to fill big casting bubble holes.

[Dave the plumber]

        I have a 10 lb Parrott with a small lead filler hole.

[CarlS]

Mike:  I didn't get several thousand when I sold it?!?!?!?    I've seen your preservation work.  You do a great job cleaning them.

Dave: You reminded me that a friend of mine who is on this forum once found a 10 lber flat top Parrott bolt on one of our trips that had some lead filler on it like yours.  I had forgotten about that.  I seem to recall it was a decent size area that was filled. 

[emike123]

By the way folks, that is a 24pdr ball with a CS Bormann replacement fuse adapter so a bit different to begin with.

I do not really enjoy the mess of electrolysis but I do like its revealing process that shows hidden things like this, lathe marks, arsenal stamps, etc. 

[Dave the plumber]

     Carl,      I'm surprised a solid shot had lead filler.
     I figured it was for shells only, so as to keep them more 'robust' and 'strong' because of the thinner walls when leaving the tube, that the 30,000 psi of pressure would not crack the shell open.
     And of course, a weak spot in casting might lead to a premature detonation in the tube if a shell had a thin spot in the wall and was subject to that pressure. Hence I figured a shell would be plugged, not a bolt....

      Didn't I read that shells were subject to underwater air pressure testing looking for 'leaks' before leaving the foundry ??

[CarlS]

Dave,

Good question.  I figured the added lead was to help keep the projectile more balanced so that it would probably be more stable in flight.  An exploding projectile just has to be pretty close while a bolt needs to be right on for it to be effective.  Of course it may be as simple as quality of product and the foundry didn't want to deliver goods with holes in the side.

I'll see if I can get a picture of it from the owner.