Original Material: Collected in North Central Montana, Hell Creek Formation
Project Timeline: September 2007 - October 2007
Replica Availability: To be determined
Preparation & Casting Outline:
Table Below: The table below shows images of the 6 teeth from field collection through preparation. You can click on each image for a larger view. Lab journal is below the images.
Preparation of Tyrannosaurus rex teeth
Lab Journal
CK Preparations / C. Morrow
9/23/2007
10:30am
I am beginning the preparation of the Tyrannosaurus rex teeth for the client. Five of the teeth were collected in September 2007. Tooth #2 had an associated tip but it is not certain that the tip belongs to the tooth. The teeth are from the Hell Creek Formation. The teeth were stabilized in the field using Starbond Thin CA.
The first step was to photograph the teeth in their current condition. I also took video (tape #86). Then, I submersed all of the teeth in vinac for about 3 minutes.
11:30am
Micro blasted Tooth #2 – Most of the blasting was done at 70psi (Sodium Bicarb for abrasive). The tooth cleaned well, the enameled surface is very durable and cracks were cleaned about ¼ mm in, may fill in at the end with putty. The base/root area of the tooth was cleaned at about 100psi, mainly due to the CA mixed with sand. The area was not cleaned completely; I am dipping one more time in Vinac for about 5 minutes. This will help to stabilize the thin wall areas for the remainder of the blasting.
12:06pm
I am starting tooth #3. This tooth does not have most of the surface enamel and has several cracks along with a few gaps. It does have serrations on both sides though a bit warn.
12:23pm
Finished micro blasting. A majority of the tooth was blasted at 50psi due to the weaker enamel surface. It cleaned fast and well. Once dipped in Vinac it should look very nice. I will soak in Vinac for another 5 minutes. All prep and dip is on tape #86.
12:38pm
I am starting tooth #4. This tooth appears to have some good enamel and the rest appears dull but still there. The dull areas tend to be soft so care will be taken during preparation. There is also a bit of matrix still around the tooth so it is hard to tell of the condition of the serrations and enamel underneath.
1:22pm
I am about half way through preparation. Now that the surface glue is removed, there appears to be very little good enamel on the surface. The serrations are interesting, appearing to be inverted on both sides. Under the bulk matrix, the surface is a bit weaker, so I am going to dip the tooth again to stabilize it at this point. I am also re-dipping tooth#1. I feel that the side with the organic material (roots) is going to be quite soft. I will re-check the surface again before prepping to ensure it will be stable. I will only dip it for about two minutes, as I do not want to destabilize the inside.
6:13pm
I am starting tooth #1. The surface appears to be stable now, but I will prepare at a low psi to begin.
6:31pm
Switch tape (#84) – Have micro blasted half of the root area. The side with the roots is quite soft. The stronger half was blasted at 70psi, but the soft half cannot go over 30psi.
6:50pm
Finished micro blasting the hard areas. A majority of the surface is extremely soft and the microblaster will penetrate even at 5 psi. I am re-dipping in Vinac and will prepare the soft surface using acetone and a soft brush. Because of the organic material, the CA could not penetrate the soft areas. Once I have removed the field glue, I can Vinac the surface and it should prepare better. The tooth is going to look amazing!
6:54pm
I am going to prepare tooth #5 & #6. Both are tips and should prepare quickly and look great.
7:05pm
Finished tooth #5 & #6. Both prepared well and I am now dipping them in Vinac. These two are now finished and ready for casting.
7:16pm
I am going back to tooth #4. There are still chunks of matrix on the tooth. I am going to apply some CA in the cracks to stabilize so that the pressure on the large chunks will not pull on the tooth surface. Then I will microblast.
7:59pm
Changing tape to #85.
8:19pm
Finished microblasting #4. Cleaning out the root area was tough, but came out very nice. I dipped it again in the Vinac and it is now ready for casting.
8:24pm
I am finishing tooth #2. All that needs to be done is the root base.
8:46pm
Finished microblasting tooth #2. I dipped it again and it is now ready for casting.
9/24/2007
8:30am
I am going to try lightly scrubbing the surface of tooth#1 with acetone and a soft toothbrush. This should remove the layer of CA and matrix without damaging the surface.
9:14am
I finished scrubbing tooth#1. The acetone scrub worked very well. I also used a dental pick to aid in removing the clumps of matrix. All of the matrix and organic material has been removed from the surface. I finished the scrub in the Vinac dip tank to fully clean the surface and to help the Vinac penetrate into the soft enamel areas. Where the organic material was, most of the strong enamel is gone, but what was there has been saved. Microblasting this surface would have removed what little enamel remained so this is a success! I will let the tooth soak for 5 minutes in the Vinac and then allow it to harden. I still need to clean out the root area with the microblaster and touch up some areas on the tooth surface.
10:09am
I am now going to prepare tooth #2-6 for molding.
11:30am
Finished preparing tooth #2-6 for molding.
1:40pm
Ready to pour the molding rubber for tooth #2-6.
2:06pm
Finished pouring the molding rubber for tooth #2-6.
2:12pm
I am going back to tooth#1. The inside root area is all that remains for cleaning with the microblaster.
2:55pm
Finished cleaning out the root area. The acetone had weakened the bond on the matrix, which allowed for easier cleaning. I used a dental pick and air scribe along with the microblaster. After cleaning out the root area, I applied CA to the inside to stabilize the thin wall of the root. I will re-dip the tooth one more time and then it will be ready for molding.
9/25/2007
8:30am
I am setting up the mold for tooth #1.
9:05am
Finished setting up the mold for tooth #1.
4:49pm
Pouring the mold for tooth#1.
5:00pm
Finished pouring mold for tooth#1.