What kind of finish would be safe to use on a coin cabinet?

CoinAddict

I am building a coin cabinet but am not sure what kind of finish to use on the inside of the drawers. I am thinking of using Varathane but I am not to sure if it would eventually hurt the coins that are being stored in it over time. Do any of you know of a finish that would not harm the coins during storage over a long period of time. All help would be appreciated in this matter. Thanks.

airplanenut

Sulfur

CoinAddict

Very funny , Jeremy.

100proof1957

Man O War Spar Varnish ?

Or hows about raw aromatic cedar,or does that out gas to much ?

Flash

My guess would be to find out whatever sort of finish was used on the original coin cabinets that were in use 100+ years ago and use that. Whatever "damage" was done to the coins stored in them seems to have made them worth a premium today.

100proof1957

Didnt they use turpentine back then ?

AuldFartte

Varnish would be a bad idea, IMO. I got a small box on ebay to store slabbed coins, and it was varnished or laquered. I put some coins (in 2x2's and envelopes), forgot about 'em for about 3 weeks, and when I finally took the coins out, all of the copper was GREEN!!!

The silver coins were "hazed". The chemical smell was pretty bad.

Flash

<< <i>Didnt they use turpentine back then? >>



I believe that turpentine is a solvent.

ldhair

All you need to do is to seal off the grain of the wood.
What type of wood are you using for the drawers?
Anything you use that puts a thick coat on the wood will be a problem.

CoinAddict

The drawers have been built out of oak and the outside of the cabinet is walnut.

GaCoinGuy

tung oil, maybe? Or perhaps just a good burnishing with beeswax?

JrGMan2004

How bout just a felt lining? Or something else similar?

100proof1957

Leave the inside of the drawers raw or clear stain ?

CoinAddict

I am going to use tung oil on the outside of the cabinet. Do you think I should use it everywhere? I already use the varathane on the smaller drawers so it would not be so hard to get them finished but I could sand it all off if you think the tung oil would be safer to use. The bottom of some of the drawers are lined with silver cloth but some of the others are not going to be.

cacheman

The choice of the wood is as important, if not more important, as the finish as a lot of woods will outgas too. You'll want to use mahogany, walnut, cherry or oak. My cabinets are unfinished on the interior and have felt linings (velvet will tone your coins).

100proof1957

Cacheman,

Looks like Red Oak to me !

CoinAddict

The drawers are made of red oak. Here are some pics of them. The inside of all of the drawers have been varathaned but I could sand them all back down to the wood if that is what all of you think I should.

ldhair

Oak has soda straw grain.
Left raw it will dry quickly and will put out nothing that will harm your coins.

What you put in the drawer with the coins can be.
Paper, vinal, glue under felt and the felt are some things to consider.

sliderider

Wasn't there a discussion not long ago about the wood boxes that PCGS is selling and the possibility of harmful chemicals from the wood leeching into coins stored in them? Wouldn't the same thing happen in a wooden coin cabinet?

cacheman

"Looks like Red Oak to me ! "

Yes, red oak. Also, the felt isn't glued into the drawers but is pushed into a recess around the perimeter of the drawer to hold it in place...

Askari

I thought felt would outgas as well?

Askari

Here is how Peter Nichols builds his custom cabinets.

cacheman

...and you'll note that Peter also uses felt for a liner.

CoinAddict

That website did not really tell what kind of finish he uses. All it says is that he uses a process that has seven steps. It was a nice try though.
As for the material in the bottom of the drawers. I am using silverware cloth which should not cause any harm. It is the material that is used in the drawers with silverware so it should not cause toning or any problems to the coins.

mrearlygold

I made an inquiry to Peter last year and he told me he was booked up for 6 months or longer.

Anyone know anyone here who makes these?

Rgrds
Tom

100proof1957

For those of you that dont Habla metric
one MM =.0394 inches
eight MM is about 5/16 "
sixteen MM is about 5/8 "

lordmarcovan

Mackerel?

Flounder? Halibut?




Oh. Sorry.

I thought for a minute you'd said "What kind of fish would be safe to use on a coin cabinet?".

MFH

Cacheman:

Did you make those cabinets ? Or, are they available thru a retail source ? I noticed that each cabinet is twelve drawers high, and they are stackable. Do you have dimensions ?

Thanks !



Coinaddict:

Looking forward to the finished product !

CoinAddict

Actullay my cabinet is all built. All I need to do is finish it and add the knobs. Other then that everything is ready. I will post a thread with the progress when it is finished.

Askari

<< <i>...and you'll note that Peter also uses felt for a liner. >>

I know, but I'm wondering if it might not be a special type of felt -- archival grade or some such.


Kyle, you might ask Peter your question. Perhaps it's proprietary, I don't know. There's also a woman who writes on the topic of conservation for Coin World. I can't remember her name offhand, but she could be a very useful person to consult with.


Mike, I've not seen any offered retail except for some small ones. It seems to be typically a custom job -- and not one I'd likely trust the local cabinetmaker to execute.

CoinAddict

I just sent him this email.
Hey Peter,
I am in the currently in the process of building myself a coin cabinet and would like to have some input from a cabinet maker. I would like to know of a varnish or finish that would not do any harm to my coins. I was going to use Varathane for the insides of the drawers but some of my friends on the Collectors Universe forums were a little worried that that finish might let off gases that would eventually harm my coins. If you do not mind me asking, What kind of finish do you use for the inside of the cabinets you build? All help in this matter is appreciated.
Thanks,
Kyle

We will see how he responds.

mrcommem

My coin cabinet is for raw coins is a Peter Nichols. It is made of Mahogany, has no finish on the drawers' interiors, only felt. The outside has a lacquer finish of some type. I use Kointains on the raw coins to protect them. I haven't noticed any toning on any the coins either with or without Kointains.

MFH

How do I find Peter Nichols, and does he post here ?

MrSpud

In the thread talking about the PCGS wood boxes, Magicbilly mentioned using acrylic Gesso with Calcium Carbonate in it to seal the inside of wood boxes that coins will go into. The Calcium Carbonate is supposed to neutralize and acidic gasses (kinda like the Calcium Carbone in TUMS tablets neutralizing stomach acids). I've been on the lookout for some of this type of Gesso to seal the inside of a little treasure chest my wife has. Only the only type I have found so far is Bob Ross Acrylic Gesso and the label doesn't mention Calcium Carbonate. I saw some types on the net that specifically mention they contain the Calcium Carbonate, I'mm keeping a lookout for these at craft and hobby stores.

After reading the book Coin Chemistry, where the author goes on and on saying how great using bags impregnated with copper to store coins (the copper supposedly absorbs the tarnishing gasses), I'm also thinking of figuring out a way to blend in some copper filings into the Gesso before I use it. I don't know if it'll work though. The author of the book also mentioned that a good way to protect coins is to put a couple of uncirculated copper cents into a ziploc bag along with a slab or a coin in a holder. If the cents start to turn brown it is supposed to be time to change them. The author did experiments with coins in various slabs and holders including Kointains and found that all of them slowed down tarnishing to some extent but that none of them prevented it (Kointains did the best though, slabs didn't do as good as the Kointains). The author also theorized that most old proofs became tarnished and lost their mirror finishes because they were stored in wood or other containers that either didn't protect the coins from atmospheric gasses or, worse even, caused the coins in them to tarnish excessively. The author also said that some coins escapsed this fate, supposedly from being stored in tins or ceramic containers that were more protective.

Askari

<< <i>How do I find Peter Nichols, and does he post here ? >>

Check my link to his website. As far as I know, no, he doesn't post here ... but you never know, with there being so many folks with accounts here.

nederveit

Very, very cool setup (and pictures) cacheman

Robgetty

As soon as I finish 2 more projects for my wife, a coin cabinet is the next thing on
my list. I hadn't given the finish a lot of thought; guess that I should have!

TONEDDOLLARS

I used Varithane to finish off my coin cabinet. I have not had any trouble as of yet.

magikbilly

<< <i>In the thread talking about the PCGS wood boxes, Magicbilly mentioned using acrylic Gesso with Calcium Carbonate in it to seal the inside of wood boxes that coins will go into. The Calcium Carbonate is supposed to neutralize and acidic gasses (kinda like the Calcium Carbone in TUMS tablets neutralizing stomach acids). I've been on the lookout for some of this type of Gesso to seal the inside of a little treasure chest my wife has. Only the only type I have found so far is Bob Ross Acrylic Gesso and the label doesn't mention Calcium Carbonate. I saw some types on the net that specifically mention they contain the Calcium Carbonate, I'mm keeping a lookout for these at craft and hobby stores.

After reading the book Coin Chemistry, where the author goes on and on saying how great using bags impregnated with copper to store coins (the copper supposedly absorbs the tarnishing gasses), I'm also thinking of figuring out a way to blend in some copper filings into the Gesso before I use it. I don't know if it'll work though. The author of the book also mentioned that a good way to protect coins is to put a couple of uncirculated copper cents into a ziploc bag along with a slab or a coin in a holder. If the cents start to turn brown it is supposed to be time to change them. The author did experiments with coins in various slabs and holders including Kointains and found that all of them slowed down tarnishing to some extent but that none of them prevented it (Kointains did the best though, slabs didn't do as good as the Kointains). The author also theorized that most old proofs became tarnished and lost their mirror finishes because they were stored in wood or other containers that either didn't protect the coins from atmospheric gasses or, worse even, caused the coins in them to tarnish excessively. The author also said that some coins escapsed this fate, supposedly from being stored in tins or ceramic containers that were more protective. >>



Hi Mr. Spud,
Although clearly in the minority, I still would not store my coins in wood if you paid me. As others have noted in the thread you mentioned, is just a bad idea. Outgassing, hygroscopicity..acidity - all in a concentrated envirenment. And PCGS admits the slabs are not totally sealed. And then there are the stains/finishes. And you recall the vast amount of water wood, especially the red oak mentioned here, can hold. Don't know about the copper in the "gesso" thing - if the prescence of copper is benificial I don't think locking it in an acrylic resin surrounded by CaCo2 would help. Anyway, a brand of acrylic "gesso" with CaCo2 content is "acrylic gesso" by Fredrix/Tara. I think I misspelled it when I wrote you last. Other brands of "acrylic gesso" with CaCo2 - Holbein, Liquitex.. I will try and find some more for you. Bob Ross may contain it as an unlisted extender but I would go with the brands mentioned that have a decent CaCo2 content.

Best,
Billy

Link to previous post concerning the dangers of wood and coin storage - COINS AND WOOD

CoinAddict

Peter's response to my question was " The short and easy answer is nothing. I am in the
very fortunate position of having my work tested an examined by the
conservation departments of the leading museums in Europe. They all came
to conclusion that the natural mahogany must be completely untreated to
ensure no interaction with any coins placed in contact with them. In truth
I have renovated many early cabinets from three centuries and some have used
varnish of unknown types on the trays, but then conservation was not a great
issue in Victorian times. My advice, process and sand the tray but
leave them untreated."

In my reply thanking him I invited him to come and check out the forums..

Askari

magikbilly

<< <i>Peter's response to my question was " The short and easy answer is nothing. I am in the
very fortunate position of having my work tested an examined by the
conservation departments of the leading museums in Europe. They all came
to conclusion that the natural mahogany must be completely untreated to
ensure no interaction with any coins placed in contact with them. In truth
I have renovated many early cabinets from three centuries and some have used
varnish of unknown types on the trays, but then conservation was not a great
issue in Victorian times. My advice, process and sand the tray but
leave them untreated."

In my reply thanking him I invited him to come and check out the forums.. >>



Hi,

from the Art Conservation Center at the University of Denver's Judy Greenfield, Conservator of Objects - "Building a Better Case"

"True African mahogany is reported to be one of the least corrosive woods, but it's expensive and difficult to procure, and other mahoganies sold as substitutes are corrosive" (Hatchfield). Additionally, mahogany is resistant to termite attack. There is disagreement over the benefits of seasoned wood. Kiln-drying (seasoning) wood helps break down and drive off some inherent acids, though it may depress the wood's RH-buffering ability (Miles). But Werner cites the Department of Industry's statement that "[seasoning] wood...accelerates the production of free acetic acid and formic acid. Most of the acid, however, remains in the wood."

So, even if you are lucky and your cabinet is actually made out of true African Mahogany it is still only a lesser evil. While Mahogany is much more stable than red oak, particularly dimensionally which I imagine would play a role in cabinet making, none of this this alters the fact that wood is factually not the best choice of material in which to store coins. I continue to quote from Art Conservation Center at the University of Denver, and this information is specifically in regard to display/storage cases - not so terribly removed from coin storage. And remember, display cases in museums are often temporary and yet these matters are considered.

"Although some woods are worse than others, all emit a variety of acids, aldehydes and other lignocellulosic degradation products." (Miles). Wood emits mostly acetic acid; formic acid is produced at 1/10th the amount of acetic acid(Blackshaw). Moisture hydrolyzes acetyl groups in the hemicellulose (a form of cellulose, the "building block" of wood) to produce acetic acid. Elevated temperatures appear to foster acetic acid production (Werner)." I don't know what to make of the claims about sanded mahogany - it is also agreed among conservators that all woods must have a barrier between the wood and the display case interior. "No wood can ever be completely sealed to stop emission of organic compounds, though sealants can impede emission." At least one case I saw made by Mr. Nichols appears to have the coins "exposed" to the inside finish, which IMHO should not be inside the case at all. You don't need physical contact for outgassing problems, and we know PCGS slabs are not "sealed" and plastic is gas permeable anyway. Also, the PCGS boxes are "cherry wood finish and are lined with black felt" - I don't have any idea what wood is used, what adhesives, what finish (oil or Varathane?) or what fabric. To me. once closed, the environment in a wood box is concentrated - and the wood just sits there outgassing with the adhesives and finish, waiting to absorb large qualtities of water...now if the box is in a safe.....

Someone mentioned Varathane - "Even after 18 months' drying time, oleoresinous (oil) paints corroded lead in an experiment cited by Miles. As oil products dry, they undergo oxidative degradation which yields volatile organic acids, aldehydes and carbon dioxide (Miles). Oleo-resinous products include oil-modified paints and varnishes, one-component polyurethane varnishes (e.g., Varathane), alkyd paints, epoxy ester paints, aluminum paints, silicone paints and most varnishes (Miles)."

The information just goes on and on...and on - ESPECIALLY about the harmful glues and adhesives that might be used in construction (perhaps more important than the wood and as important as the finish), the fabrics - fabric should not be used where humidity is not controlled (someone mentioned a tarnish retardant cloth - these can be bad - as can certain dyed felts etc.!)...all can be injurious, and usually are unless care is taken. All I am saying is that wood in not an ideal choice, or even second choice for long term coin storage. Yes, this data is about storage/display cases in museums, but most of the problems above seem are mainly influenced by humidity and temperature - variables found in every deposit box and safe. And those are concentrated environments, more than the cases in the above discussion.

Best,
Billy

PS - Despite recent posts to the contrary, oak is indeed the most acidic of woods and does in fact outgas. "The most acidic hardwoods include oak, beech, birch and ash. Oak is the most acidic. With a pH of 3.7 to 4.9, depending on the source (Miles, Stamm), it is capable of liberating up to five percent of its weight in acetic acid (Erhardt)." Brazillian Mahogany, as apparently used by Mr. Nichols, is apparently properly called Honduras Mahogany and IS NOT true African Mahogany and does not share the same "stability" as the African source above - "other mahoganies sold as substitutes are corrosive" (Hatchfield)". I have no idea what wood Mr. Nichols uses other than what he states on his website. As stated above about Mahogany though, regardless of seasoning or kiln drying "most of the acid, however, remains in the wood." I have no issue with Mr. Nichols fine and attractive cases, this is not an attack on his cases nor do I wish to engage in any further discussions about his work as I do not even know him.

Robgetty

OK. so we line our cherry coin cabinet with Intercept, and everyone is happy, right?

magikbilly

<< <i>OK. so we line our cherry coin cabinet with Intercept, and everyone is happy, right? >>



Hi,
well, thats just it - is it cherry, or cherry finished...

Best,
Billy