Bent Plancet

[BoomerEO-migration]

Can a bent planchet be straightened? Actually, I guess the term would be 'flattened."

 

The premise here is the "bend" is minor, and the coin would return to "grade able", i.e. "conserved."

 

Seems like this would be an acceptable conservation technique, if possible without noticeable (under 10x) distortion to the edge, obverse, or reverse.

 

Awaiting Expert Opinion,

 

BoomerEO

[HiHoAudio]

I'm certainly NOT an expert, but if you place the bent coin between two pieces of unused oak and then apply gentle pressure with a vise you may be able to flatten the coin. Perhaps try pine first.

 

Gold = easy peasy

 

Silver = maybe, maybe not

 

Copper/Brass = good luck!

[BoomerEO-migration]

HiHoAudio:

 

That's what I'm thinking. But since it seemed SOOO obvious, and no one talks about it, I wanted to see if anyone considered it Doctoring vice Conservation.

 

Boomer EO

[physics-fan3.14]

You can probably straighten it somewhat, but I doubt first that you can return it to perfectly straight, and second I doubt that you can do it without leaving some sort of telltale evidence. A straightened coin will almost always leave some sort of stretching somewhere. Unless it is a very valuable coin, I don't really see a need to straighten it.

[James_OldeTowne]

I have straightened a couple of coins that subsequently got certified with no problem. So long as there is no strange wear pattern, it can certainly be accomplished.

[BoomerEO-migration]

Thanks!

 

What was your technique? I tried HihoAudio's method on a worn Morgan but was not successful. The Morgan proved much stronger than I anticipated, even with a very "firm" tightening. The hardwood gave but the Morgan didn't! Surface changes were not evident under 10-30X though, thank goodness.

 

I think I need to clamp the largest area "flat" portion in the vise, then clamp the remaining portion between two flat pieces of wood using a couple "C" clamps, and then provide leverage on the free section to remove the bend.

 

BoomerEO

 

[Conder101]

The problem with a vise is it gives the wood time to absorb the energy and distort rather than helping to remove the bent. I would think a heavy impact would work better. The wood (Or heavy leather) cushions and spreads the blow out evenly over the whole surface of the coin instead of just the high points of the bend.

[BoomerEO-migration]

Thanks!

 

A rational, physics based answer.

[HiHoAudio]

Please don't expect rational answers from me. Once in awhile maybe...

[ragtag]

I like the leather idea. But wouldn't the leather just compress and the coin stay bent? I have a nice high grade Mercury dime that is bent. Thinking of taking it to a machine shop that has one of those hydraulic presses. Those type of vertical presses have something like one ton of clamping force.

[leprecoin]

Leave it on the train rail