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Cork Shelf Life

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Cork Shelf Life
I have a quantity of cork, tan and dark, that came from Jeff. It is all 15+ years old. This week, while hunting in MO, Mark Schupp mentioned a story about the highly regarded Wiley cork drying out an becoming unusable after too much time goes by, that it crumbles when you try and work it with a knife. So with 2 1/2 pickup truck loads of cork I wonder if I am saving useless cork. Does anybody have experience with working old tan or dark cork?

Eric



Last edited by:

Eric Patterson: Jan 7, 2021, 5:35 PM
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Re: Cork Shelf Life In reply to
Interested in the responses Eric. I've got both Wiley and some 20 year old MLB black cork that looks good and have a buyer for.


Pete


MOLON LABE [mo 'lon la 've]

Technology has it's place, hunting isn't it.

Life's a blink, never have to say ....... "I should have"!

"That human optimism & goodness that we put our faith in, is in no more danger than the stars in the jaws of the clouds." .................Victor Hugo
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Re: Cork Shelf Life In reply to
Jason Russell talked about the crumbly Wiley cork when we talked about cork I got from Debby. I think he impregnated the old cork with epoxy resin? To help stabilize it?
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Re: Cork Shelf Life In reply to
Dani wrote:
Jason Russell talked about the crumbly Wiley cork when we talked about cork I got from Debby. I think he impregnated the old cork with epoxy resin? To help stabilize it?



Dani, yes, Mark talked to Jason so he is the original source of that info. Leaves me wondering if dark cork goes bad and if storage conditions matter. Mine has been stored in hot dry conditions so might be unusable. I probably should test it by trying to cut it with a sharp knife or rasping.

Eric

Last edited by:

Eric Patterson: Jan 7, 2021, 6:45 PM
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Re: Cork Shelf Life In reply to
Good morning, Eric~


I have not made a lot of cork birds - but have used both black and white corks over 40+ years of carving. Here are some observations:


Wiley Cork: I have 10 Wiley Black Ducks that I made in the late 1980s - and hunted for about 10 seasons on Long Island. They were oiled and burned (charred, really) and never painted. Although I re-burned them a few years ago, the cork has shown no signs of deterioration.


Several years ago, Tom Russo (site member and old friend from Long Island) brought me a case of Wiley Cork. I do not know when Wiley went out of business, but I had no problem working the cork.






I oiled and burned the decoys I made from this batch.






Best look for Black Ducks I have found.....






I have a couple of sawn-out bodies and other pieces in the shop. I have seen no change in the material.


Black Cork (aka brown or refrigerator cork).


I have made only a few decoys with black cork. I have always sealed black cork with a soaking coat of Spar Varnish, then primed with flat oil paints, then top-coated with flat latex.









I have restored scores of LL Bean decoys and hunted over some Wildfowler Black Ducks that belonged to my Dad. Al McCormick made his decoys of black cork - from National Cork Co. in Keyport, NJ - but he sealed his with a slurry of cork dust and spar varnish to yield a hard shell.


Black cork seems to vary lots in quality - esp. grain size and tightness. I still have a few pieces of the National Cork - and a case of another of unknown origin - given to me by a friend. The latter case seems coarse-grained and quite crumbly. After sawing plan and profile views, I would shape with a rasp and coarse sandpaper, not knives.



Black cork - whether in the case or in decoy mode - dries out over time. I think gunning birds especially dry out because of the cycle of soaking and drying. My oldest Wildfowler birds have begun to crumble on the shelf - even though they have not seen the water for 35 years or so. If not well-sealed at manufacture - like LL Bean, Cabelas, etc that I have seen - the cork needs to be protected to prevent deterioration.


I have a pair of original paint (with plenty of hunting wear) Beans Coastal Black Ducks on a shelf in my shop. I regard them as antiques and they will never be hunted. Nevertheless, I painted a wet coat of Linseed Oil on them to protect the cork, the wood and the paint.


The black cork I have on hand is mostly for repairs. However, if I did make decoys from them, I would:


1. Use a bottom board (either solid softwood or AC plywood)
2. Use a tail insert (either solid softwood or AC plywood, or plastic).
3. Seal the cork thoroughly - with either Spar Varnish or a thin epoxy resin.


Not sure if this helps with your original question. I would just try each piece and see if it's too crumbly. I do not make many gunning birds, but my preference now is for hollowed Atlantic White Cedar (or White Pine).


All the best,


SJS







Steven Jay Sanford
Pencil Brook Farm
South Cambridge, NY
http://www.stevenjaysanford.com


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Re: Cork Shelf Life In reply to
I have some Wiley that is 30 years old and works same as it did when new. Black cork that I have which was from a walk in reefer box. Probably built 70 years ago works just fine. I did get some old black cork decoys that crumbled when touched and it appears that they were left out in the elements by the fading color. I had to use penetrating epoxy to solidify them which did work well. If reasonable care is exhibited in storage the cork will hold up well.

Joe
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Re: Cork Shelf Life In reply to
 

I have some pieces of Wiley cork, and large sheets of good dark cork that are well over 30 years old. Each are in fine shape and will make fine decoys, when called upon to do so. They are stored in dry areas, indoors.

Have made decoys from all types of cork, including life vest cork and old refrigeration cork. Ducks, geese, shorebirds, songbirds, owls, etc.


Very old, almost black, refrigeration cork IS THE WORST. As it crumbles very easily, and soaks up water like a sponge. If it does have a use, it can be ground very easy, and used in a slurry with Marine Epoxy, or Marine Varnish.


Seldom if ever do I take a knife to cork of any kind.

The intended project is cut out as well as possible on the bandsaw, and then shaped with rasps (after tail board, bottom board, etc. added).


my 2 cents
VP













"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
Forty years ago or so, I purchased black cork from a place in NJ. I believe it was called Rector Cork. Anyone remember them?
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Re: Cork Shelf Life In reply to
Mr. Eric
I'm no expert on this but my guess would be how it was stored.
With the dark or natural cork I believe that it's natural resins are the binding agent.
They may be affected by high heat and break down. The tan cork I believe use some sort of polymer for a binding agent
It may not be affected as much by high heat.
My 2 cents
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Re: Cork Shelf Life In reply to
Vince~


I'm not sure if I've ever used refrigerator cork - though I know many gunners who salvaged it for decoys.in the 1940s and 50s. In our When the Broadbill was King on Great South Bay documentary, Dick LaFountain describes how cork stool that had frozen could "explode" when tossed overboard. Only the head and keel remained attached to the anchor line!


I lost a Wildfowler Black Duck when it slowly sank throughout the course of one long hunt. I had been using the rig all season - with Great South Bay sneaking its way into the cork that had been unsealed for too many seasons.


All the best,


SJS

Steven Jay Sanford
Pencil Brook Farm
South Cambridge, NY
http://www.stevenjaysanford.com


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Re: Cork Shelf Life In reply to
Refrigerator cork, at least the examples Vince posted as "naked" birds, is the actual sheet of bark removed from this species of oak tree. Same generally holds true for the stuff used in life jackets, except it has more dowel pins in it to hold it together.Bill Cleary owned Soo Vending in Sault Ste. Marie. Michigan, he was an avid collector and waterfowler. We stopped at the Cleary Camp to drop off some smoked sturgeon on the way down to a tour of the Merganser when it was first set-up on the north shore of Munuscong Bay. Biill's son was a member of the newly formed duck club who was at his Dad's when Tony and I dropped-off the fish. Consequently, we received the "cook's tour" of the lower floor of the camp. Envision all the 'finds" from a business that had been operating for over a hundred years, catalogued and on display on the walls of their camp. Everything from antiques to waterfowling gear from previous eras to plaques and signs from businesses that operated in the second oldest settlement in the United States. One 8 gauge, one punt gun up above the bar, and several old double -barrel tens. The had an old cork insulated cooler that held several barrels of beer. The cork was fine granulated black cork that was compressed, indicated by its color and then held in place by a fine mesh copper screen, only time I have ever seen the old black cork arrayed that way. We followed Bill, jr the two miles down Kemp's point to the entrance road to the Merganser. The kitchen wall had three taps mounted through it fromt he cold storage room that had had a compressor and cook mounted on the read deck in a small enclosure. All of the cork that lined the cooler was all unground natural cork that was peeled form trees and cut to fin prior being dowelled together. It had an interesting musky smell when you got close to the inner walls. The Merganser was built in 1911.

They autoclave ground black cork and press it into sheets to employ the volotile resins forced out in the process to bind the particles. It only stands to reason that, if not sealed, these sheets would slowly lose their binder as it slowly evaporrates away when it BP is reached or exceeded, likely what Eric is experiencing with his black cork. Shape it and seal it well and you are likely to have a functional block when finished.
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Re: Cork Shelf Life In reply to
 
Steve,

Mr. LaFountain was a regular at the old Ohio show, He and I had many a good conversation. He is very knowledgeable and enthusiastic concerning Wildfowler Decoys and so am I.

We shared info, and references prior to his book. He sent me a large manila envelope full of Wildfowler info that is in my library, and highly valuable to me. He may remember me, and he may not, as we were both much younger then. Wink

Going into his room to converse, and look at the decoys he brought was always something I very much looked forward to, and always enjoyed. He had decoys that made me really consider. "Do I really have to pay the rent and utility bills this month?"


Concerning cork decoys exploding, after they absorbed water, and then froze after gunning. That pretty much describes the first black cork decoy rig I made, working at my kitchen table.

Made the very bad mistake to think Thompson's Water Seal actually worked. What a bad joke and lesson I learned, along with NEVER store wet decoys of any kind in yer boat in freezing and below freezing temps.

Never had them explode entirely, but they sure did develop some serious issues. There is no doubt in my mind that a well soaked, frozen, and then tossed in water could make the decoy go Bye - Bye.


Pretty much from the get go I came to the conclusion that decoys, like fishing flies, are "Disposable Art" when used and abused as intended.

In my world, the primary reason we keep on making them, and repairing the ones that are worthy.

It's what we DO (and you do so very well). Thank God.



Best regards
Vince











"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
Rick~


I have always heard "refrigerator cork" to mean the pressed "black" product - manufactured in 4 and 6 inch sheets. It was used for refrigerated buildings, such as for storing ice, foods and furs - before the post WW II prevalence of rock wool, fibreglass and other building insulations. I have never heard whether it was used in household ice boxes and refrigerators - but your tale of the cooler suggests it likely was.



The natural cork birds Vince posted known here along the Atlantic Tidewater as "life -preserver cork" - as you described, slices of bark. from the Cork Oak. The rectangular slabs used to fill the vertical pockets in the old life preservers were sawn to shape - and sometimes pieces were pinned together with dowels to achieve the desired dimensions as you describe.


As far as I know, decoys made from life preserver cork first arose on Long Island - because of the many life preservers that would wash up along the Atlantic Ocean beaches after shipwrecks. Savvy and practical baymen repurposed them - as some now do with dock foam and pot buoys.



All the best,


SJS





Steven Jay Sanford
Pencil Brook Farm
South Cambridge, NY
http://www.stevenjaysanford.com


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Re: Cork Shelf Life In reply to
Steve,

These LI, old decoys are made from black cork. Seen lots of service and paid the price. I plan on using the Black duck one last time, and not for very long.Smile


ALL the refrigeration cork I have seen, and used over many years was never 4" and 6". Most is 2" and some of it less. Also much of it has a black tar adhesive, applied to one side, or both.

If you would like some. I can send it, and it should arrive some time within the next month or two. Free of course.


VP

















"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
 
The naked cork, is LIFE VEST CORK. Taken from old life vests, found many years ago around the docks in Buffalo, NY by a friend of mine.

Sealed correctly they make very good decoys, for water and land use.

The GWT are now in the rig of the friend that gave me the cork.


VP











"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
Patrick,

Ya hit the nail on the head.

Storage is the the key.

Extreme heat and cold are very destructive for long term storage. The less sun, and UV the better.

All once living things have a shelf life, and only rock decoys will outlast them all...


VP











"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
If you want to get rid of some of that cork before it goes bad 😁. Let me know, I?ll take some of it off your hands.
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Re: Cork Shelf Life In reply to
Steve, natural cork morphed into refrigerator cork via the sheets Vince describes being ground-up and pressed. The senior Cleary stated that nearly all the ice storage facilities they used or supplied in the early years were sawdust insulated or had natural cork sheets on them. He built that small cooler room for the camp beer kegs from a cool storage room at a commercial facility when it was torn down because the cork insulation was so unique. From what I recall, Murphy's decoy plan book (blue plan box) has a discussion on the use and shortfalls of refrigerator cork sheets when used for decoys in the pre-War era.
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Re: Cork Shelf Life In reply to
Tan cork appears to slowly deteriorate in direct sunlight when left unsealed. Of course carpenter ants greatly accelerate the process.




Here is some of that tar covered refrigerator dark cork. It was held in multiple layers with dowels. This particular cork came from the original freezers at Patuxent Wildlife Research Center that held wings from the waterfowl harvest survey. I have plans on making a commemorative decoy with this historic cork for some colleagues. This cork was probably installed in the 1950s and was removed in 2014 when the building started to collapse.



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Re: Cork Shelf Life In reply to
Thanks Brad, that is the granulated original Quercus suber that was used so frequently to make refrigerator cork sheets. I have a bunch of copper wire bundles that Jim Wicks negotiated from the contractor that was doing the remodel at the MDNR's Steve T Mason building that is hanging off decoys as part of their swing keels-ringnecks (24), six goldeneyes, and a dozen buffleheads.


I knew there was a maturation interval prior harvest, but never was aware it was over two decades. Interesting to find that carbon sequestration is inhanced by bark harvest, another secondary benefit contributed by decoy carvers. Now, I also realize why I find small stones so often in compressed black cork.

Species Profile: Cork Oak (Quercus suber) | Rainforest Alliance (rainforest-alliance.org)
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Re: Cork Shelf Life In reply to
Good morning, All~


Vince~ I'm not sure why I have this vivid image in my head of very thick black cork from salvaged from a big refrigeration plant - maybe a fur storage - on LI. But, I trust your information over my aging brain.... It is one more question I wish I had asked of my Dad and his gunning partners whilst they were still available. (In fact, there is one nonagenarian I know down in the Sunshine State with an encyclopedic memory - and a knack for storytelling. I need to write him.)



I have a full collection of the different cork types, including the tarred cork. Someday I will use the life preserver cork to make a traditional Great South Bay Black Duck - just to honor the type.


Thanks to all or the great information!


SJS

Steven Jay Sanford
Pencil Brook Farm
South Cambridge, NY
http://www.stevenjaysanford.com


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Re: Cork Shelf Life In reply to
What an informative post. I didn't think this question would garner such discussion, but I'm glad it did. Based on all the above I'd say there is hope for my cork, and perhaps if it is getting crumbly care when carving followed by a good sealant will keep it intact and extend its life considerably.

The cork in my picture is actually "community property". Thomas and two friends spent a fair amount of time helping me move Jeff's things to my shop. They were really interested in the cork for decoys so I told them the cork would be community property amongst all of us to use today and tomorrow. One day I expect to try my hand at decoy carving and the boys expressed the same interest. I figure that day will come and they'll have a cheap way to get started and enough cork to put together an entire rig. As an added benefit every time I look at it I'm reminded of my friend.

Eric
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Re: Cork Shelf Life In reply to
 
Steve & All,

The thick black cork of which you write about could be. Either as a solid piece, or several pieces layered to make a sheet. Could be that the high quality cork was used in certain situations, but not the norm. It is certainly not out of the question.

I have large blocks of 4 inch thick black cork of very good quality, that I purchased in the early 1980's.


Much of the refrigeration cork that came into my possession was taken from old Rail Road Refrigeration Box Cars. Other pieces have come from other refrigeration containers of years gone by.

With condensation being a major factor in refrigeration. The tarred application I do believe, was more to protect the cork from absorbing moisture/water during thawing and freezing. This would help to deter the cork "explosions", that your wrote about.


This has been a very informative and educational conversation. Thanks to all that are taking part. Another example of why duckboats.net needs to BE.


Best regards
Vince











"Art does not reproduce what is visible - but makes things visible." ~ Paul Klee, artist, 1920
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Re: Cork Shelf Life In reply to
Eric, based on working black cork via Stanley Sureform rasps, draw knives, and power carvers, I would encourage you to use a Foredom with a fine tungsten cylindrical or cone bit to work crumbly cork down into its final body shape and 80 grit wet/dry flint paper for final sanding prior sealing. The Foredom enables you to establish a rate fo cork removal that is compatible with the status of the block, slower in crumbly areas and at higher rpms where texture and composition is firmer. These also enable you to grind-in feather borders and other body contours that better depict a live bird, epoxy as a sealer keeps primaries and high points from snapping-off or wearing away. While expensive, I would also encourage sealing with thinned epoxy or a penetrating epoxy.

Last edited by:

RLLigman: Jan 10, 2021, 10:28 AM
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Re: Cork Shelf Life In reply to
I was told that the cork decoys I picked up two years ago where made of refrigerator cork. They have held up from the wear and tear of two seasons in the salt. Some of the cork does seem crumbly ( a head detached revealing the true cork composition) but the bodies have held together fine. My plan is reshape the bodies and the heads this summer to have a less blocky appearance. I will post before and after photos.




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