A cabinet for a woolly mammoth tusk

[GaryR]

Sometimes I find unusual projects and sometimes they find me.

A few months ago a municipal road crew digging new water and sewer lines in front of a Starbucks in my town unearthed a complete woolly mammoth skeleton. How's that for a sentence?

Excavation stopped. Paleontologists from the local university were called in. Much excitement and discussion of what to do. Long story short: it happens that there are lots of these around here (!) so not very special and too expensive to halt work to remove the whole skeleton. But they did decide to take out and preserve one tusk because it is still pretty cool.

Mammoth tusk found at Corvallis construction site

For the second time in five years a visitor from 10,000 years ago has popped up when folks in Corvallis were digging in the dirt.

gazettetimes.com

The local public library, for some reason, decided to take it. The library got in touch with our local woodworking group and asked whether we would like to build a display cabinet for it. And could we make it viewable for children? Maybe look like it was just discovered, with some tools lying around?

We said we'd look into it. Although we all wanted to make a cabinet for a mammoth tusk, none of the members of our group has the space to stage it. We asked a local "maker space," a recently started private woodworking shop that rents space for woodworkers and teaches woodworking classes. They said they would love to help.

They put together a very rough budget, presented it to the city and library, and we just got approval to go ahead.

We have two people from the maker space and two from the woodworking group working on the design. A local metal fabricator is donating a frame for the glass or acrylic plastic top. A local glass shop is donating the glass/acrylic. A local timber/lumber yard is donating the wood. We hope to build the cabinet in late summer inviting local woodworkers to help.

The tusk is about 6 feet long and is now stabilized with plaster with a 4x4 (100 x 100 mm) post along the length underneath. Currently sitting in storage barn at the municipal water treatment plant.

Here is a sketch of how we are thinking about the cabinet so far. One concept is a taller cabinet with a pull out step for the little ones. I admit I don't like that design much since I complicates the construction and is a trip hazard. Another is lower cabinet. That might make it less visible to adults but emphasizes the view of the workers who found it.



None of us are sure how to construct the base below the tusk and and glass top. The tusk plus plaster weighs over 200 pounds/100 kg and is about 2 meters long. Plywood is an obvious option but we'd like to feature local hardwoods like oak or maple. Also, the space where the cabinet will sit is carpeted.

That is where we are today. Any suggestions, especially for construction concepts?

 

[Mike G]

Whenever I make one of these.................

Seriously, though. I think I would start with the understanding that the tusk was the focus, and you aren't trying to compete with it. I would build something subtle and muted, without contrasting timber or any decorative features. If no-one notices the display cabinet then you will have succeeded.

As for the construction method.......it doesn't much matter. The load is small.....little more than one over-weight adult. You could use a frame of 2"x2" construction timber and clad it, or you could make a ply or MDF box with multiple full-height cross members, or you could make it like a table and insert panels in grooves in the legs, or.......

Given that it's a woodworking group I suspect you'll go for something like the latter suggestion. Maybe a 6 legged table, but standing on a frame. Veneered MDF or ply panels in between the legs (yeah, I know you'll be tempted to do linenfold panels, or raised panels with carved coats of arms, or a carved mammoth, but don't). You could just plant on some diagonal bracing internally to prevent racking if someone fell against it. If the table-top was about 600 high everyone would be able to see it. Forget the silly step idea.

Edit....
As an aside, I'd thank the metalworker for his kind offer, but go with frameless glazing. A glazier will join some thick panes of glass at the edges in the same way they edge-join large panes of glass in shop windows.

 

[AndyP]

Fish tank for the glass immediately springs to mind. Very string and seamless

 

[Cabinetman]

Pretty much as Mike said really. I would go for a table type construction, heavy yes but not overly so, not even sure you need the panels at all, just 4” wide rails morticed into the legs- slightly tapered maybe.
Nice job to be involved in. Is the table and case to be freestanding or against a wall? If against a wall the back of the glass? could continue the theme of the muddy hole where it was found, or more photos of the skeleton perhaps.
Ian

 

[Mike G]

Is the table and case to be freestanding or against a wall? If against a wall........

If against a wall I'd put a mirror behind it so it could be seen all round.

 

[Woodbloke]

As Mike said above, 'subtle and muted' but to compliment the tusk, it's got to be a 'quality' build, however it's done. Again, steps up to view it would be a trip hazard so are best avoided and good lighting will be needed to highlight it at it's best - Rob

 

[AndyT]

I'd start by looking at what big national museums do. Old-school glass cases had nice features such as three way corner joints for thin mahogany glazing bars. (Maybe less of a challenge for you and your Japanese joinery skills.) Newer ones will have wood-free bonded joints.

I expect many will have discrete LED lighting installed inside the case, so will need somewhere for a switch and wiring.

I agree that the base doesn't need to be much more than a sturdy table, but I expect you will come up with something a bit more special!

 

[Lons]

I'm with the others.
Simple, plain unobtrusive stand with a bonded edge glass or polycrbonate case. If you want it to look like a hole in the ground than the base top under the tusk could be sculpted with plaster, stones etc. and be made to look very realistic.
The woodworking artistic licence could perhaps come into play with whatever is envisaged to hold the obligitary text and photographs detailing the find and it's history.

 

[Pete Maddex]

I guess once you have chewed over the design you will have a project you can get your teeth into.

Pete

 

[GaryR]

I agree with all of the above. Now to convince my colleagues.....

Thanks for the tip about having a frameless glass enclosure. I hadn't thought about that. The case will be tucked into corner of a room where it will backed by the corner walls. A mirrored back would make sense.

The library mentioned the idea of making the tusk look like it was being dug out of the ground. I'm not sure who would do that part. I know I would make a mess of it.

 

[GaryR]

Here is a version with a 6 legged base, 600 mm/2 ft to the glass top. I've set it the corner where it will live and sketched in a sign board above. There is room below for a step stool if a little one needs it, but I don't think they will.




And a first stab at a structure. It won't quite work as drawn but I think the concept is OK. The tusk will sit on a ply base that drops into the rebates on the aprons and legs.





What have I got wrong?


Also, maybe of interest, I was contacted by a friend of a friend who wrote:

Gary,
I will donate any wood you need for the tusk display project. I live in [a nearby town] and have been milling local hardwoods for over 25 years. My day job was in agricultural research housed at [the local university]. I retired after 42 years in 2021.

I have wide qs Oregon white oak, bigleaf maple, madrone, golden chinquapin and several others in boards, slabs and cants. The wood is dry, has been heat treated to kill insects and is ready to go.

The gentleman sent me pictures of his lumber and some might work fine although all of it is salvage logged and selected for figure rather than straight clear grain. But at that price it is definitely worth a look.

 

[duke]

You need some way to easily remove the tempered glass enclosure or hinged lid for cleaning inside.
And cleaning outer back and sides, possible the unit needs to be mobile.

 

[Mike G]

When I suggested a height of 600, I was meaning to the table top/ underside of the tusk. I suspect it may be a little low if the glass is 600 off the floor.

Why not do it as a traditional table, and have the skirts set back from the face of the legs? And I would have the skirt continuous through the middle leg, otherwise it would be vulnerable when moving, and put additional cross pieces/ bearers at the midpoint of each gap. You would then plant an overhanging mitred frame on top surrounding your ply base/ table-top. With everything flush as you have it, there is no allowance for skirting boards (I believe you might call them base boards) in the location where it will stand.

Oh, and you'll want rift sawn rather than quarter sawn stock for the legs.

 

[GaryR]

Ah, I read your other post too quickly. I actually do have the skirts (I'd call them aprons) set back 3 mm. Could be more. I didn't detail how that would pass through the middle leg but yes I agree that is best. And more cross pieces.

One consideration is that we have to design it to accommodate the tusk + plaster + 100mm beam underneath it plus a plywood base to contain surrounding sand or earth or whatever is needed to make it look like a paleontological dig.

Another is we'd like to offer the library the option of an entirely closed cabinet base rather than a table. That design is next.

 

[AJB Temple]

Before I put pen to paper or plane to wood, personally I would have a look at the style of cabinets in the venue and what their health and safety requirements are. They will want it to fit in aesthetically and be compliant. Like an idiot I once got involved with helping to make a funded bequest display cabinet for a historic property (someone else did the glass, and another person did the finishes). The list of requirements was unanticipated, long and included inter alia:

Must be capable of being moved on their special trolley (dimensions given)
Must not be able to be tipped over from a person leaning on the front if the security chain was unclipped
Must have a special lock that fitted their key system
Must not use any finish that would be harmful if a child licked or in some way ingested the cabinet (I kid you not)
Must not trap fingers if the top was unlocked and fell
Must withstand impact from wheelchair without any collapse of framework. Did not specify chair speed or mass of occupant.
Must use shatter proof glass of specified type and light conductivity
....and so on.

 

[Woodbloke]

Before I put pen to paper or plane to wood, personally I would have a look at the style of cabinets in the venue and what their health and safety requirements are. They will want it to fit in aesthetically and be compliant. Like an idiot I once got involved with helping to make a funded bequest display cabinet for a historic property (someone else did the glass, and another person did the finishes). The list of requirements was unanticipated, long and included inter alia:

Must be capable of being moved on their special trolley (dimensions given)
Must not be able to be tipped over from a person leaning on the front if the security chain was unclipped
Must have a special lock that fitted their key system
Must not use any finish that would be harmful if a child licked or in some way ingested the cabinet (I kid you not)
Must not trap fingers if the top was unlocked and fell
Must withstand impact from wheelchair without any collapse of framework. Did not specify chair speed or mass of occupant.
Must use shatter proof glass of specified type and light conductivity
....and so on.

I think that's definitely going to be the same (or similar) for this project and would impose pretty strict limitations on what could and more importantly, couldn't be built. Possibly a bit of a 'poison chalice' to coin a phrase - Rob

 

[GaryR]

Must be capable of being moved on their special trolley (dimensions given)
Must not be able to be tipped over from a person leaning on the front if the security chain was unclipped
Must have a special lock that fitted their key system
Must not use any finish that would be harmful if a child licked or in some way ingested the cabinet (I kid you not)
Must not trap fingers if the top was unlocked and fell
Must withstand impact from wheelchair without any collapse of framework. Did not specify chair speed or mass of occupant.
Must use shatter proof glass of specified type and light conductivity
....and so on.

That is very helpful, Adrian. None of us involved has ever built a work for a public space and the extra hoops that must be jumped through are daunting. I'm not sure even the library has thought about these issues, although we are going to talk with the curator of a local historical museum to see what they specify for their display cabinets. The four of us are also going to to look at the tusk next week to take pictures and measurements and talk further about the design.

I'll be thinking about lickable finiish....

 

[AJB Temple]

They may be quite relaxed. But the US is a litigious environment and personally I would not do work without a written liability release and a written OK of the design and specification and intended purpose, and for them to take responsibility for the risk assessment their public liability insurance is likely to require (whether they are aware of that of not). If only to concentrate their mind and make sure you have no public negligence risk. Somebody smacking into it with a wheelchair or mobility scooter and it then falling on them is a realistic risk. I've got involved with two small woodwork projects for a high traffic historic building (the other one was a chair), both paid (not much!), and they were annoyingly pedantic but very clued up about accidents. I learnt a lot: mainly never to do it again.

 

[GaryR]

We got to visit the tusk yesterday to make some measurements and get a better idea of what we have to do. Apparently the is only the distal half of the tusk. The base remains behind in the ground.

 

[Alasdair]

That is a fantastic project, I would echo what others have said about the public liability issue though.