Phevo Posted September 12, 2020 Share Posted September 12, 2020 A year and some ago I bought a Krantz W 224 airscribe to start doing some mechanical preparation and promised to do a prep thread once I got started. Prior to this type of prep I have done a lot of silicone casting (which I might make a separate thread for) and on softer matrix used a mix of dental picks/tooth brushes. I have had several different setups over the past year, and the past 2 months or so can be seen on the following picture After spending a tedious amount of time with the rough matrix removal I decided to add a Cp9361 airscribe, which has sped things up a lot. Link to comment Share on other sites More sharing options...
Phevo Posted September 12, 2020 Author Share Posted September 12, 2020 I was lucky enough to buy some crab concretions from @RJB and will be showing those preps over the next couple of posts This is the first crab I prepped and it was unfortunately extremely sticky and poorly preserved, which made the prep much harder. In many places I scribed all the way down to the carapace, as there was no weak spot between matrix and the crab itself This is after 3 hours or so of prepping down to the carapace, Ron had made a window down to the crab and left it at that: After a few more hours the I made my way around the carapace: Then some back legs showed up and part of the left claw Then I followed the legs out and found the right claw From the front at this stage Then I exposed the front claws and what was left of the legs, smoothed the rock surrounding the crab and touched it up with alittle acrylic paint. Originally I had tried painting the whole thing, just to see what it would look like, and it looked as expected, like a plastic crab So I removed all the acrylic paint and did some spot painting instead View from the back: View from the front: More crabs will come after this, but I think this shows the process pretty well, even though the crab looks like it was dropped down an elevator Just to add, this took around 15 hours and is not a prep I am proud of, it was a warm up piece 4 Link to comment Share on other sites More sharing options...
Phevo Posted September 12, 2020 Author Share Posted September 12, 2020 The second crab was much nicer preserved, although I still did manage to bang him up pretty good unfortunately This first picture is almost how it was when received Then the claws and legs were exposed, the circle was for when I asked Ron what he did to patch up those dings The smoothing begins from the back, for this one I scribed along the table to get a flat surface for presenting the crab, another option is following the crabs legs and claw position Here is three pictures of the finished crab in dorsal position: I did end up re-smoothing the surface afterwards Link to comment Share on other sites More sharing options...
Phevo Posted September 12, 2020 Author Share Posted September 12, 2020 I decided to try prepping ventral, but it turned out to be very disarticulated as will be seen in the following pictures Ron had hit the ventral side before flipping it over and the first picture shows how it was received: This next picture is before smoothing and paint touch up, but I had to stop there as there was less than 5mm matrix between the two sides in places The next two pictures are of the finished crab before surface resmoothing, but after touch up This took around 15 hours to finish 3 Link to comment Share on other sites More sharing options...
RJB Posted September 12, 2020 Share Posted September 12, 2020 Well you deffinetly got some good practice in. If I may ask, can I get a closeup picture of your scribe tip? Seeing what youve left behind makes me wonder? Also, youve got a package coming your way sometime this coming week. RB 1 Link to comment Share on other sites More sharing options...
Phevo Posted September 12, 2020 Author Share Posted September 12, 2020 5 hours ago, RJB said: Well you deffinetly got some good practice in. If I may ask, can I get a closeup picture of your scribe tip? Seeing what youve left behind makes me wonder? Also, youve got a package coming your way sometime this coming week. RB Looking forward to it, and here is a picture of the tip of the scribe I plan on changing it for a longer tip bit, and change all the seals etc. as that is overdue now Link to comment Share on other sites More sharing options...
Phevo Posted September 12, 2020 Author Share Posted September 12, 2020 This next crab was split right down the middle. Parts of the carapace were stuck on both sides and some was lost presumably during the split. Originally I wanted to prep this one ventrally, but found it was missing the bottom part of the left claw so opted for a dorsal prep. This is how it was received: Part of one side had no crab carapace so was cut off Then the parts were glued together with low viscosity cyanoacrylate glue and with a grinder removed some of the overburden matrix Scribing down to the crab First glimpse Freeing the claws Starting to smooth the back Here is the finished crab so far. I decided to remove the back legs as they were so partially preserved and in the future I might do some tough up when I have more experience. I might experiment with adding some putty to all the parts missing and give it the right texture, but for now it will stay like this: I was worried part of the right claw had been missed, but it turned out to have been crushed together with the second limb of the claw aswell (the Carpus) 1 Link to comment Share on other sites More sharing options...
fossisle Posted September 12, 2020 Share Posted September 12, 2020 great practice!! Cephalopods rule!! Link to comment Share on other sites More sharing options...
Phevo Posted September 13, 2020 Author Share Posted September 13, 2020 4 hours ago, fossisle said: great practice!! Yes, this therd one was especially tricky with all the glue and missing carapace, still not sure how to finish it off Link to comment Share on other sites More sharing options...
Phevo Posted October 5, 2020 Author Share Posted October 5, 2020 So here comes crab 4, another pulalius vulgaris from Washington state It was split at an angle across the crab, I removed alittle material above the carapace with a grinder Scribing down to the carapace Found the top Here you can see one leg was lost when the crab was split, only the impression was left This crabs skirt came out from under her Here some of the legs are exposed and the first leg tip can be seen I dug quite a bit for the right claw but did not find it, maybe later I will dig some more or do a semi ventral prep Finished crab from the top, might do some more detailing when I have more experience A view from the side where one leg tip is seen going vertically in the rock 1 Link to comment Share on other sites More sharing options...
RJB Posted October 5, 2020 Share Posted October 5, 2020 Nice job my friend. Sad that the right 'Cheliped' is missing. Could be way underneath? I wish you the best of luck RB Link to comment Share on other sites More sharing options...
FossilDAWG Posted October 5, 2020 Share Posted October 5, 2020 Nice job! You even got some tippy-tips, and it's neat that you can see the abdomen. Given that the abdomen and legs are still attached, I would guess that the other cheliped is still there, just bent down below the plane of the rest of the crab. However, it could have been lost before the crab died. Only one way to know, unless you know someone who can do an X-ray or other sort of a scan. I've done things like that with the vet school here in the past. Don 1 Link to comment Share on other sites More sharing options...
Top Trilo Posted October 5, 2020 Share Posted October 5, 2020 very cool crabs, whenever I invest in an air scribe I will definitely get a crab 1 “If fossils are not "boggling" your mind then you are simply not doing it right” -Ken (digit) "No fossil is garbage, it´s just not completely preserved” -Franz (FranzBernhard) "With hammer in hand, the open horizon of time, and dear friends by my side, what can we not accomplish together?" -Kane (Kane) "We are in a way conquering time, reuniting members of a long lost family" -Quincy (Opabinia Blues) "I loved reading the trip reports, I loved the sharing, I loved the educational aspect, I loved the humor. It felt like home. It still does" -Mike (Pagurus) “The best deal I ever got was getting accepted as a member on The Fossil Forum. Not only got an invaluable pool of knowledge, but gained a loving family as well.” -Doren (caldigger) "it really is nice, to visit the oasis that is TFF" -Tim (fossildude19) "Life's Good! -Adam (Tidgy's Dad) Link to comment Share on other sites More sharing options...
jpc Posted October 5, 2020 Share Posted October 5, 2020 From the photo of your scribe, I'd say it could stand for a little sharpening. you need to use a diamond wheel to sharpen the silicon carbide bits. There are a few choices available for things like a Dremel tool. 1 Link to comment Share on other sites More sharing options...
Ludwigia Posted October 5, 2020 Share Posted October 5, 2020 Good job! 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Phevo Posted October 5, 2020 Author Share Posted October 5, 2020 Thanks for all the replies 2 hours ago, FossilDAWG said: Nice job! You even got some tippy-tips, and it's neat that you can see the abdomen. Given that the abdomen and legs are still attached, I would guess that the other cheliped is still there, just bent down below the plane of the rest of the crab. However, it could have been lost before the crab died. Only one way to know, unless you know someone who can do an X-ray or other sort of a scan. I've done things like that with the vet school here in the past. Don I also think the claw should be there, it does not show on the picture but the hole on the right side goes straight down from the carapace so I would expect to hit a Carpus or Merus by now, but I suppose it could be bent all the way under the crab? Time will tell, it still has some way to go and I left the right legs until I convince myself how to finish them 1 hour ago, jpc said: From the photo of your scribe, I'd say it could stand for a little sharpening. you need to use a diamond wheel to sharpen the silicon carbide bits. There are a few choices available for things like a Dremel tool. Yea it is pretty dull, I wrote to Ron and he was kind enough to tell me how he sharpens his scribes Link to comment Share on other sites More sharing options...
Ptychodus04 Posted October 6, 2020 Share Posted October 6, 2020 I just found this thread. You’re learning curve is pretty steep and you’re picking it up fast. It helps to have @RJB Ron feeding advice. I wish I had him 20+ years ago when I started. Well done. Please tell me you’re wearing a respirator. 2 Regards, Kris Global Paleo Services, LLC https://globalpaleoservices.com http://instagram.com/globalpaleoservices http://instagram.com/kris.howe Link to comment Share on other sites More sharing options...
Randyw Posted October 6, 2020 Share Posted October 6, 2020 Same here. Somehow I missed this thread too. Those are some great looking crabs! Link to comment Share on other sites More sharing options...
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