Project: Camptosaurus

More Camptosaurus Logs: Summer 2005 | Winter 2005

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April 29, 2005 06:13 PM
posted by Yvonne Wilson

Back to the big jacket with the Camptosaurus torso.

I got the okay to destroy the plant fossils. They are not identifiable according to a visiting paleobotanist (thanks Mandy). I like going through this section because the plants create layers within this very solid sandstone. The layering makes the rock break apart much easier, and I can move much more quickly. Pretty soon I find a flat section of bone that must be the scapula (shoulder blade).

Beside the scapula I uncover a large crack in the rock. I pry the crack open, and pull the rock away from the jacket. Unfortunately, a chunk of scapula sticks to the block of rock I am removing. It would have come off cleanly but for the fact that the scapula has been plastered to the rock. Apparently the block of rock had been fully removed, then glued in back into place with a layer of plaster. Why couldn't they have left it alone?

4-29-05 Camptosaurus jacket scapula plant.JPG

In this second picture you can also see that I have uncovered the layer of latex and sand bags in this portion of the jacket.

4-29-05 Camptosaurus jacket.JPG

April 24, 2005 05:50 PM
posted by Yvonne Wilson

I have set George with the task of jacketing the block that contains the hips. There is nothing protecting the bone the way it is now, nor anything to really keep the block together. The plaster that was smeared between the broken pieces of rock is eighty years old. George applies the burlap and plaster over the latex (I used the same method with the hips as for the big jacket.). When that is dry, he flips it over.
Here is the ridiculous looking result:

4-24-05 Camptosaurus hips prejacket 2.JPG

There is a big block of plaster and wood on top that was used as a pedestal when it all was on the ground. The pedestal has got to go, though I am not ready to attack the block yet. I do not want this weight sitting over the bones.

April 17, 2005 12:03 PM
posted by Yvonne Wilson

4-17-05 Camptosaurus Y in gear lookup 2.JPG

I have been spending a good amount of time just buzzing and whacking excess rock from the fossil jacket. I will remark on it a thousand times, but the strength of the rock is almost unbelievable. Happily, it preserves the bone nicely, but it is a bear to get through. Check out my fancy getup: earplugs AND earphones to block the constant roar of the equipment, goggles to stop the flying bits of rock, mask to keep out the dust, a bandana to keep the grit out of your hair, and an anti-vibration Darth Vader type glove. Don't I look beautiful?

By the way, please notice that we have started dismantling a second wall-mounted dinosaur. Behind me is the case from the Dryosaurus. Norman has removed the legs already, leaving a scar and a gaping hole.

4-17-05 Camptosaurus vert tp and tendons.JPG

I'm still contemplating the tendons. The vertebrae (back bones) cannot be separated without breaking them. What to do? Depending upon how things etch out, I may be able to make a mold of the tendons in place on the bones, then remove the tendons and place them into the mold. This will keep the tendons properly oriented while allowing us to take apart the vertebrae. What happens with them for the final mounting of the dinosaur? I'll get back to you on that.

Time to get back to work.

4-17-05 Camptosaurus Y in gear.JPG

April 06, 2005 11:42 AM
posted by Yvonne Wilson

It helps to maintain a level "playing field" when preparing fossils. Archaeologists do the same thing to make sure they preserve the layering in their excavations. For a fossil preparator, it makes things easier to see. In this case it will limit the stresses on the jacket and the fossils by keeping the weight evenly distributed. So I trim off rock with a hammer and chisel. My arms ache with the effort at the end of the day, and I can feel the ringing of the chisel in my hand even after I stop to take a break.

With this mindless work you get a little goofy. When I got off a particularly large hunk of rock, I raised it above my head and paraded around the lab with a loud "WOOHOO!" Ah, the simple pleasures in life!

April 03, 2005 11:29 AM
posted by Yvonne Wilson

We had previously seen ossified tendons on this specimen when the hip block broke away from the jacket containing the torso. Now that I am working back by that end of the jacket, I uncover more of these linguini-like tendons. They criss-cross to form a stiff lattice around the backbones. This helps support the weight of the tail.

4-03-05 Camptosaurus tendons tps ilium.JPG

The rounded parts you see are the parts of the backbones that protrude towards the side (transverse processes). Now that I see the tendons link these processes tightly together, I am wondering how in the world to remove everything. A challenge.

March 30, 2005 11:20 AM
posted by Yvonne Wilson

With the hardware out of the way, I can work my way into the plaster. Using a combination of the airscribe, hammer and chisel, and the cast cutter, I plow through it down to the level of the rock.

3-29-05 Camptosaurus jacket flipped Y opening.JPG

Just looks like a hunk of rock now. Yet a dinosaur lurks beneath.

3-30-05 Camptosaurus jacket flipped plaster gone.JPG

I attack the rock lump with hammer and chisel. On rock this hard (arrrg!) this method is much faster than an airscribe. Though I still feel like I am trying to wear away a mountain with dress pin. There are several cracks in the rock that were not visible on the front. Remember that originally the preparators covered the front with a layer of pebble-encrusted plaster.

A large block of rock comes off when I exploit one of the existing cracks. This has a hash of plant fossils -- nothing pretty to look at. Just a bunch of carbon films, with little detail. Okay, here it is anyway. A picture is worth a thousand insults, right? Plants are both to the right and left of the ruler.

3-30-05 Camptosaurus plant fossils.JPG

I wish we had a paleobotanist available to check them out. Though I cannot see anything worthwhile in these specimens, someone with a trained eye might. They might also be significant in that they are directly associated with the Camptosaurus. I will hold off before whacking through them.

March 29, 2005 05:40 PM
posted by Yvonne Wilson

Getting into this jacket is quite a task. There is so much metal and wood on this it is funny. The metal was just there to bind the wooden board onto the back of the rock. It took a lot of prying and cutting to remove just the hardware. For fun, here are pictures of all the accessories accompanying the fossil jacket:

3-30-05 Camptosaurus jacket hardware  .JPG

3-30-05 Camptosaurus jacket hardware 2.JPG

March 25, 2005 07:40 PM
posted by Yvonne Wilson

The stinky task ends and the messy task begins. (I have such a funky job.) It is time to wrap the entire package of bones and rock in burlap and plaster. I have found that colors in the plaster can help you tell how close you are to bone, so I make the first layer of the plaster jacket a nice shade of green.

George has made jackets too in the field, so the two of us encase the Camptosaurus in this protective shell. It is a preposterously messy process.

3-25-05 Camptosaurus plaster mess.JPG

The end result looks like Shrek laid an egg.

3-25-05 Camptosaurus jacket green 2.JPG

The next day I wrap it in a second layer (white, not green) with embedded wood for support. This can be flipped and opened on the back side.

Here I have rolled it over. The board is the same one we could see from the back of the case. The gap is where I drilled through to see the bone early in the project.

3-29-05 Camptosaurus jacket flipped.JPG

March 24, 2005 07:20 PM
posted by Yvonne Wilson

Yuck. Time for stinky stuff. To protect the bones from the vibrations of the tools, I am layering the entire surface in latex rubber. The uncured liquid rubber paints on in slow-drying layers that stink of ammonia. Happily the smell goes away when it cures. I can do all the stinky work under our fume hood, which sucks all the vapors outside. Otherwise I'd gas out all the volunteers.

Post latex painting:

3-24-05 Camptosaurus latex dorsals 2.JPG

Here you can see there are still areas that need to be supported. This undercut is not safe for the bones.

3-24-05 Camptosaurus latex undercut shadow.JPG

My options for support here are to use expanding foam (like we used for Samson), something solid like plaster, or sand glued together with a consolidant fluid. The foam or consolidated sand takes a day to dry, however. Plaster seems too rigid and heavy. I decide to go with wet sand packed in plastic bags. It's a quick and inexpensive choice.

3-25-05 Camptosaurus latex and sand bags undercut.JPG

Next I will jacket the beast and flip it over...

March 20, 2005 07:01 PM
posted by Yvonne Wilson

All the parts that stuck out from the jacket and could be removed have been removed. I still have a few portions of bone here and there that cannot be taken off yet, but protrude too far to ignore. I want these parts that stick out to stay safely in place, so I encase them in plaster to immobilize them. First I wrap them in foil to make the plaster easier to remove.

3-20-05 Camptosaurus trans proc foil.JPG

Here I have made a moat of white wax to hold the plaster against the bone while it sets. The plaster will protect these parts of the bone from getting snapped off.

3-20-05 Camptosaurus foil and wax.JPG

March 19, 2005 06:45 PM
posted by Yvonne Wilson

Now that the jacket with the torso is in a workable position, I can really start in on it. I want to attack it from the back, however. This means rejacketing the front side in burlap and plaster and flipping the whole thing over. But placing this on its front side is somewhat dangerous. There are exposed ribs and vertebrae (back bones) that hang over the body cavity with no support. Flipped over, the weight of the rock could break all these pieces. So I start removing all the bones that have an airspace below them. Using the airscribe, I take off one rib from the left side (Allen took off six earlier), and three from the right side.

The right hand ones I remove are mostly attached with plaster. They have been previously prepped from the rock matrix. I notice one is kind of odd. I thought that I broke it as I worked around it, but it seems to have been previously broken. No big deal...that is what glue is for. Until -- uh oh -- it doesn't seem to want to go back together properly. Boy, do I feel stupid.

I don't feel stupid for long. As I start removing shellac on the little bit of rock still attached, I realize that this rib is not as it should be. They globbed shellac over the bone and about a quarter-size hunk of rock with it. What looked like a chunky rib is really a chunk of rock with a tiny, graceful rib inside. And what's more, they have turned the rib head backwards and attached it to the rest with a big glob of plaster. THAT is why the pieces don't fit. They aren't supposed to!

This is the orientation I found the rib in. The entire left portion was covered in shellac, making it all look like bone. Once I got the shellac off the rock (the exposed rock is a pebbly white horizontal stripe), it looks much different. Notice the awkward break in the middle.

3-19-05 Camptosaurus cervical rib backwards.JPG

And this is the way it is supposed to look:

3-19-05 Camptosaurus cervical rib correct.JPG

I feel much better now.

March 13, 2005 11:30 AM
posted by Yvonne Wilson

I cut with the reciprocating saw through each side of the case, just below the top board. Allen and Alan (two guys that are taller than I am) lifted the top off.

So we have gone from here:

1-13-05 Camptosaur case front 3.JPG

To here:

3-17-05 Camtosaurus case demolition top gone.JPG

March 13, 2005 11:18 AM
posted by Yvonne Wilson

Michael and my volunteer Mike get to do the fun stuff. They get to rip apart the remaining case.

Power tools and hammers thunder through the lab!

3-13-05 Camptosaurus case demolition Michael 2.JPG

Afterwards, Michael said he had way too much fun. I think there is some innate need for all living things to rip stuff apart. Ever watch a puppy with a cardboard box?

This tail (a plaster fake) is being tossed out. You can see the ribar protruding past the break.

3-13-05 Camptosaurus tail on rod close.JPG

Bye bye to Camptosaurus' case. He is committed to being a 3-D mounted dinosaur. (He? She? Who knows? We know it's little as Camptosauruses go, but we can't tell what gender it was.)

March 09, 2005 06:33 PM
posted by Yvonne Wilson

All that is left to prepare is the torso, which is mostly in the jacket. I decided it was too dangerous to lift the case over the jacket, so we are lifting the jacket up and out of the case. The coracoid bone (next to the scapula, or shoulder blade) is sticking vertically from the jacket. It is likely to break during the lift process, so I have to remove it before the jacket goes anywhere.

3-09-05 Camptosaurus  R coracoid removal 2.JPG

In the above picture you can see large khaki straps draped over the bones. These will help us lift the jacket. They get looped onto a hook at the end of a chain hoist, which is mounted on a nine-foot-high wheeled frame. We roll the frame over the corner of the case so that the lift is as vertical as possible. It is not completely vertical, though, so we use a piece of wood to lever the jacket away from the side of the case.

3-09-05 Camptosaurus lift onto table 2.JPG

Up and over

3-09-05 Camptosaurus lift onto table 5.JPG

Settling it on the table

3-09-05 Camptosaurus lift onto table 6.JPG

Rocking the jacket to pull out the lift straps

3-09-05 Camptosaurus lift onto table 9.JPG

Many thanks to Norm and Allen for their assistance moving the beast, and to Christina for taking these pictures.

And in Amy's words, "So the easy part is over."

March 06, 2005 06:36 PM
posted by Yvonne Wilson

Finally I have cut all the way around the jacket. It has been a tough job, leaning over all day while chiseling and prying away the wire-backed plaster. But going home tired at the end of the day can be satisfying. I am enjoying myself.

The vibrations have broken completely through the developing crack in the hip. There was not much that could have been done. It was an old break. By cutting a hole beside the portion of the jacket that broke off, I am able to climb in and remove the broken piece.

3-06-05 Camptosaurus jacket removed second block close.JPG

What remains:

3-06-05 Camptosaurus tipped loose jacket pelvis removed.JPG

By cutting lines with the reciprocating saw, I am able to cut around and remove the funny old-fashioned Camptosaurus picture. It is a sculpted slab of plaster.

3-06-05 Camptosaurus picture removed 2.JPG

There is not much left attached to the case. We will trash the tail because it is fake, and merely a sculpted plaster slab. The bones are not even 3-dimensional.

3-06-05 Camptosaurus tipped picture removed jacket tail.JPG

March 04, 2005 05:43 PM
posted by Yvonne Wilson

Now that the case has been tipped on its back side, I have to first completely detach the fossil jacket from the mount and case. I will also set free the amusing, old kangaroo-style picture of the Camptosaurus. I use a hammer and chisel, a crowbar, a drill, and the red reciprocating saw (POWER TOOLS!).

3-03-05 Camptosaurus tipped tools.JPG

The fun part is that I get to climb all over the "rock" face. The not so fun part is trying to get through all the nailed-in wood supports and ultra-thick plaster sections. Here I have almost cut all the way around the jacket.

3-03-05 Camptosaurus tipped loose jacket almost.JPG

Despite the wooden slats we screwed to the back of the case to support the jacket, it is sagging in the middle for some reason. Not good. Further investigation reveals that the sag is where the jacket ends and bare rock begins. It runs mostly along an old break. Unfortunately, a crack develops through the left ilium, the blade of the hip bone.

3-03-05 Camptosaurus tipped loose jacket crack.JPG

This is NOT the way I wanted it to go. But you work with what life hands you. To prevent more sagging and further damage, I jam sand bags underneath the area of the break.

3-03-05 Camptosaurus tipped loose jacket crowbar Yvonne.JPG

Continuing with the freeing of the jacket, I have to keep cutting through these almost randomly-placed wooden supports. These wouldn't even be so bad except that the wire mesh is nailed onto the wood, so I have to deal with wood, wire and nails along with the plaster. I finally use a picture of the back of the case to plan where I will cut. In this way I can minimize the lumber and metal I have to cut through.

3-03-05 Camptosaurus tipped loose jacket.JPG

These pieces of lumber are a laugh. It is obvious they used whatever scraps they had on hand. Some pieces are painted black on one side, and they run the gamut from small blocks to 2x2's to 2x6's, of random lengths. But I suppose they ended up with a mount that lasted all these years. I shouldn't complain. It gives the project character.

March 03, 2005 05:46 PM
posted by Yvonne Wilson

I had to protect the ends of the right hand ribs. They were sticking over the edge of the original jacket supporting the torso. Using the classic jacketing technique, I dipped burlap strips into plaster and smoothed these over the rock. They will dry into a nice tough shell to keep the ribs safe.

2-27-05 Camptosaurus jacketing R ribs.JPG

And lastly before we tipped the case over, we took out the feet and the right hand. These are sub-standard reproductions that we hope to replace with casts from another Camptosaurus.

2-07-05 Camptosaurus fake feet and hand rem.JPG

Sorry, but I can't show you the next step. We needed all the hands we had to help tip the case over, so nobody was available to take pictures. We attached metal banding behind the jacket to secure it to the case. Then we screwed two long boards onto the back of the case so that the jacket would not rest directly on the floor. We strapped the case to Big Joe, the forklift, and eased it onto its back side.

More Camptosaurus Logs: Summer 2005 | Winter 2005


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