I had wondered this before. I recently acquired a 1787 Fugio. It is a details coin but has nice eye appeal. Viewing it under a strong loupe I see the tiniest spot of green verdigris or efflorescence. My fear is that if it wasn’t mitigated when slabbed that it may spread. Do the TPG’s impart any sort of routine minor preservation to old copper pieces before they slab them?
Randy, I have never submitted a coin to a TPG, but I do understand that some (ANACS for example) do, or did, offer conservation services in addition to their grading (at additional cost, of course). But I don't believe they will take it upon themselves to conserve without being prompted to. I'm sure other will chime in with their experiences.
I always submit my coins through an intermediary who has contacts at the TPG facility, asking that all coins (usually 4 digit+ value) are assessed/viewed by the conservation subsidiary. I had hoped to avoid the "killer" DETAILS outcome. That hasn't worked, trashing some relatively very valuable coins. I now avoid that process, just buying sight seen properly graded problem free coins. I'd recommend you don't try having the TPG associates correct perceived deficiencies. I will say that they have corrected some problems, but less than the detail statement results. I actually have located some dealers who have altered my coins without discovery. The TPG affiliates is believed from past results, would have failed. You may locate an experienced individual here, who may for a fee correct your perceived problem. JMHO
I appreciate that. This is far from a four figure coin. However it is an important historical coin and I would hope it can still be appreciated in another 200 years.
They all do conservation, for a fee of course. If you know it's needed, add it to the invoice - don't assume they'll notice and slide it in for free (they won't but it will delay your order weeks while customer service reaches out to you to find out what you want done...)
Randy , soak it in acetone and let it air dry and store properly. The acetone will collect any moisture and remove it when it evaporates. Jim
Jim, after a ~24? hour soak, would you suggest placing the coin by its edge on a multilayered toilet paper for a minute, before flipping the coin to the opposite face when raising the edge of the absorbent sheet to effect a "blotting" action by a 180 degree inversion?
I would not soak it that long, as the evaporation rate is very rapid. Unless there is extensive cratering, I would figure 5-10 minutes soak with no open flames nearby and hold by the edge so both sides are open to air, and hold for 3-5 minutes, no blotting or contact should occur as even toilet paper has processing chemicals residue. at least IMO, Jim
If the spot is tiny, I would not crack it yet. The type of slab may give you an idea of how long it's been in the slab. I would keep an eye on the spot for a while. It maybe stable already.
So what you're asking is whether they did do any conservation before they slammed???? Call customer service and ask if they did anything I'll have records of it