A puzzle for new collectors. What was sawdust used for at U.S. Mints? 0

[RWB]

Who can explain the use of sawdust at U.S. Mints? Why would the Philadelphia Mint ship 30 barrels of the stuff all the way across country?

 

Colonel D. H. Rucker,

Deputy Quarter Master General

U.S. Army

Philadelphia, Pa

   August 16, 1880

   Sir:

            I have requested the Superintendent of the U.S. Mint at Philadelphia to cause to be delivered to you thirty (30) barrels of sawdust for shipment to the U.S. Mint at San Francisco, Cal. I will thank you to receive and forward the same as provided in General Order No. 66, dated July 24, 1876.

Very respectfully,

Robert E. Preston, Acting Director

 

[RG104 E-235 Vol 23]

Edited December 16, 2022 by RWB

[GoldFinger1969]

Hmmm...I'm gonna say it's to coat the floors to make it less slick for people walking around ?  Maybe to help move machinery around ?

Edited December 16, 2022 by GoldFinger1969

[l.cutler]

Tumbling planchets to clean them up?

[EagleRJO]

I would think it had something to do with packaging and protection of coins.

[zadok]

...dry wet blanks (planchets)....

[RonnieR131]

 All I can think of is humorous reasons. San Fran should have plenty of sawdust, so it must be sawdust from trees around the Pa. area that are special, so I'll go with zadoks idea, to dry wet blanks or similar. MS gold has too many marks on them to have been protected.

[Sandon]

   The sawdust may have been used to absorb spills of oil and other liquids on the mint's floors so that they could be more easily cleaned up.

[Mr.Bill347]

Annealing and upsetting - After 1836

After going through adjustments and various other operations, [the blank] was very hard and before it could be stamped, it was necessary to anneal or soften the material, otherwise it would be very destructive to the dies when the piece was struck on the coining presses. The blanks were placed in a charcoal fired (later gas was used) annealing furnace, where they remain in the retort until they become cherry red, then they were dropped from the furnace into water to keep them from oxidizing. After coming out of the water, they were cleaned in a weak acid solution and dried out in sawdust, then in an oven (later a centrifugal drying machine was used.) They were then sent to the upsetting (or "milling") machines where the edge was turned up and they were made perfectly round.

[Zebo]

Pickling the  Annealed Planchets

why was sawdust sent from Philly? Basswood?

Basswood is native to Eastern North America. Basswood is light, soft, and low-density wood.

Edited December 17, 2022 by Zebo
Description of Basswood added

[zadok]

On 12/16/2022 at 8:21 PM, Mr.Bill347 said:

Annealing and upsetting - After 1836

After going through adjustments and various other operations, [the blank] was very hard and before it could be stamped, it was necessary to anneal or soften the material, otherwise it would be very destructive to the dies when the piece was struck on the coining presses. The blanks were placed in a charcoal fired (later gas was used) annealing furnace, where they remain in the retort until they become cherry red, then they were dropped from the furnace into water to keep them from oxidizing. After coming out of the water, they were cleaned in a weak acid solution and dried out in sawdust, then in an oven (later a centrifugal drying machine was used.) They were then sent to the upsetting (or "milling") machines where the edge was turned up and they were made perfectly round.

...to summarize...dry the blanks....

[VKurtB]

Two things:

1) Shipping of dies, all of which were made in Philadelphia. 

2) Cat litter had not been invented yet. Jus’ sayin’.

[J P M]

Spoiler

Cat litter I love it. I was going to say to make it easier to clean up all the government bull

Yes, Shipping of dies

[EagleRJO]

On 12/17/2022 at 8:26 AM, J P M said:

Yes, Shipping of dies

So packaging.

[RWB]

Zebo got it! Zadok got part of the use, and Mr.Bill347 offered some good details.

Sawdust was used in drying planchets following annealing and quenching in weak acid, or after final whitening of silver planchets, then washed with clean water.

The type of wood was important because it could not leave any residue on the planchets. Basswood fit this need, but was not native to the west. (See Zebo's post, above) The Philadelphia Mint owned a special circular saw used solely to cut basswood boards into sawdust. This was shipped to the other mints in barrels. Sawdust could be reused many times merely by drying it. (Dust from local saw mills was contaminated with resins and could not be used.)

[RWB]

PS: Sawdust was also used as packing around dies for shipment; however, this was contaminated by the oils and wax used to protect dies before use. Packing material was discarded.

[RonnieR131]

 Again, thanks for the question RWB, keeping us amused. Keep them coming occasionally as you usually do.

[RWB]

Extract of Philadelphia Mint machinery inventory September 24, 1885.

"One circular saw and screen for making saw dust for Coiner’s uses."

 

Extract of letter May 21, 1892 to the Philadelphia Mint.

"...expenditures for the quarter ended December 31, 1891, of eleven dollars and ninety
cents ($11.90), for sawdust furnished the Carson Mint, you are informed that this amount should
not appear in this statement. As the amount was to reimburse you for the basswood and labor in
converting the same into sawdust, you are informed that it should have been deposited in the
Treasury as proceeds of material sold."

[VKurtB]

On 12/17/2022 at 1:06 PM, RWB said:

Extract of Philadelphia Mint machinery inventory September 24, 1885.

"One circular saw and screen for making saw dust for Coiner’s uses."

 

 

Extract of letter May 21, 1892 to the Philadelphia Mint.

"...expenditures for the quarter ended December 31, 1891, of eleven dollars and ninety
cents ($11.90), for sawdust furnished the Carson Mint, you are informed that this amount should
not appear in this statement. As the amount was to reimburse you for the basswood and labor in
converting the same into sawdust, you are informed that it should have been deposited in the
Treasury as proceeds of material sold."

Is basswood native to the west? Is it still widely seen? I’m no botanist. 

[GoldFinger1969]

Why would you use sawdust to do that ? Why not clean, hospital-like linens or cloth or paper ?

What would they use today -- microfiber towels ?

[RWB]

On 12/17/2022 at 9:36 PM, GoldFinger1969 said:

Why would you use sawdust to do that ? Why not clean, hospital-like linens or cloth or paper ?

What would they use today -- microfiber towels ?

If you refer to drying planchets, the reasons were convenience, flexibility to absorb moisture from all parts of planchets, and absence of contamination.

(Back then, everything was cross contaminated. Making your own basswood sawdust ensured a pure, absorbent, nonabrasive, reusable product suitable for contact with silver and copper.

[B.C]

On 12/17/2022 at 7:06 AM, RWB said:

PS: Sawdust was also used as packing around dies for shipment; however, this was contaminated by the oils and wax used to protect dies before use. Packing material was discarded.

It was used to keep the ice for cocktails it was not discarded

[RWB]

On 12/20/2022 at 7:23 AM, B.C said:

It was used to keep the ice for cocktails it was not discarded

Yes --- but the mint building plans did not include an ice house. 

PS: The Philadelphia Mint actually used ice to chill water used to quench dies. The Melting & Refining Department used it to cool the tub of water into which liquid bullion was poured to granulate/flake metal for refining. Reason: Faster quenching of silver alloy reduced segregation (uneveness) of silver both in coining ingots and for assay samples.

Edited December 21, 2022 by RWB

[VKurtB]

I have some trees that need to be removed from my property. I’m going to add a few, too. I’m now putting a basswood on the list. 

[RWB]

On 12/17/2022 at 9:36 PM, GoldFinger1969 said:

Why not clean, hospital-like linens or cloth or paper ?

Hospitals are among the greatest store of pathogens anywhere. Technology to sanitize every surface every day exists, but most rely of alcohol, topical betadine and getting your money in their pockets and your germie body out the door, before your get really ill.