Doctor Mud Posted October 1, 2014 Share Posted October 1, 2014 So here's a picture of both halves. You can see in the picture to the left that we are looking at the underside of the crab. Anterior (front) of the crab is towards the top. Most of the crab is in this block. The large pincer and some of the tips of the legs are on the other block (picture on the right). Some other bits came off but I have them and they fit nice and snug. The two circles just above the right pincer (looking from below) on the picture on the left is the front of the carapace. The right pincer curves underneath and this made me think that prepping the underside might be best to start for the best view of both pincers. I could glue the halves back together and work back down using a scribe, but this would be a lot of work. If I had a rock saw I would almost be tempted to cut out the section with the large pincer and legs and just glue this on and scribe down to the other side. Any thoughts? Link to comment Share on other sites More sharing options...
Doctor Mud Posted October 1, 2014 Share Posted October 1, 2014 Same picture as above with labels Link to comment Share on other sites More sharing options...
Doctor Mud Posted October 1, 2014 Share Posted October 1, 2014 I was thinking once option was to glue completely back together and work to once side. Or work on the underside since the pincers seem to curve under. It seems like a lot of work to completely work back down to the underside since most of it is nicely exposed. An alternative could be to cut out just the circled bit and glue it on. Link to comment Share on other sites More sharing options...
Doctor Mud Posted October 1, 2014 Share Posted October 1, 2014 Last post: Some close ups of the halves. Like I said, I have all the bits, about 5 bits came off in the split but they fit back on snug. Thanks in advance for your advice. Link to comment Share on other sites More sharing options...
Ludwigia Posted October 1, 2014 Share Posted October 1, 2014 Hi Doctor Mud, I'm afraid I can't be directly of help, since I don't have much experience myself at prepping crabs, but one of my Steinkern colleagues, Axel Cordes just published a description of the preparation of a Tumidocarcinus which he recently aquired from a friend in Australia on our homepage: http://www.steinkern.de/praeparation-und-bergung/tips-tricks-und-fallbeispiele/1055-tumidocarcinus-giganteus-aus-neuseeland.html He's been working on crabs, particularly the ones from Lyby beach in Denmark for many years and has lots of experience. Of course it's in German, but maybe google translater can help out a bit and there are lots of pictures to study. He's also published a book on preparing crabs, which, unfortunately for us is also in German: http://www.lyby-fossil.de/ 2 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
CH4ShotCaller Posted October 1, 2014 Share Posted October 1, 2014 Hey Dr Mud, I have only restored 3 or 4 that became damaged and made sure the glue was bonded into/inside the broken pieces(s). Often, if damaged, I leave as is... gives 'em a bit of character; especially if the damage was done by nature and not me. That's a good piece, I would attempt restoration if it was mine. Good luck. I've seen some of the restoration process from MB, he does outstanding work. Anyone who has never made a mistake has never tried anything new. -Albert Einstein Link to comment Share on other sites More sharing options...
caterpillar Posted October 1, 2014 Share Posted October 1, 2014 Latest preparation: "Xanthilites" macrodactylus from the Thanentian (Paleocene) of southern France (from Cater... ) Je les reconnais bien! http://www.paleotheque.fr Link to comment Share on other sites More sharing options...
MB Posted October 1, 2014 Author Share Posted October 1, 2014 (edited) Thanks all. Roger, usually I'm using cyanoacrylate, applied on them with the tip of a needle. Cater, tu le sais bien... j'aime bien tes crabes Edited October 1, 2014 by MB http://www.mbfossilcrabs.com/ Link to comment Share on other sites More sharing options...
Ludwigia Posted October 1, 2014 Share Posted October 1, 2014 Good old superglue! Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
crabfossilsteve Posted October 1, 2014 Share Posted October 1, 2014 Doctor Mud I've had to split many of my crabs since I live on the east coast and have to travel to the west coast to collect. Unless you really want to prep the ventral side, I'd glue the lose pieces back on with super glue and then cover both halves with super glue and clam them together with big C clamps and clamp it down as tight as you can. Since you now know the level in the concretion where the crab is you could cut some of the top off with a saw or start whacking pieces off the top till you get closer to the crab. Then I start grinding down till I just see the surface of the carapace (with diamond grinding wheels). Then start with your air tools. I know many people don't like super glue. but I've been using it for years. Hope that helps some. Good luck with either way you go. 1 Link to comment Share on other sites More sharing options...
Doctor Mud Posted October 2, 2014 Share Posted October 2, 2014 Thanks for the input and encouragement guys! Sorry the quote function doesn't seem to work on the computer I'm using but I'll be back home tomorrow. Superglue seems to be the way to go. I was wondering if I should avoid getting it on surfaces that will ultimately be exposed (like the surface of the big pincer). It would be difficult to remove rock that is super glued to crab shell. Even though the pincers curl under some, I have been tending towards crabfossilsteve's suggestion of working from the top after reattaching the loose bits and glue+clamping the concretion. This will make for a nicer looking crab in the end since any minor damage to the underside will be obscured. Thanks Ludwigia for the links to the info on crab prep. I'll take a look with Google Translate when I get home. This looks like extremely useful info. There are also some beautiful pictures of the Glen Affric site there for those that are interested in one of the "homes" of Tumidocarcinus Link to comment Share on other sites More sharing options...
MB Posted October 2, 2014 Author Share Posted October 2, 2014 Hi Dr. Mud, I'm using superglue for repairs, broken parts and crab shells, but for to glue the halves of concretions I use two components glue. Good luck http://www.mbfossilcrabs.com/ Link to comment Share on other sites More sharing options...
Doctor Mud Posted October 6, 2014 Share Posted October 6, 2014 (edited) Thanks MB. I followed your advice. I used superglue to re-attach the fiddly bits and an epoxy adhesive for the concretion. This allowed more time for application and putting together. It's now clamped with two 200 mm C clamps. Looking forward to getting to work on this one! Edited October 6, 2014 by Doctor Mud Link to comment Share on other sites More sharing options...
MB Posted October 31, 2014 Author Share Posted October 31, 2014 I can't wait http://www.mbfossilcrabs.com/ Link to comment Share on other sites More sharing options...
DLB Posted November 2, 2014 Share Posted November 2, 2014 My first prep of this kind of crab I think it came out all right. Link to comment Share on other sites More sharing options...
fossisle Posted November 2, 2014 Share Posted November 2, 2014 Nice work DLB Cephalopods rule!! Link to comment Share on other sites More sharing options...
DLB Posted November 2, 2014 Share Posted November 2, 2014 Thanks it was a little tricky Link to comment Share on other sites More sharing options...
caterpillar Posted November 2, 2014 Share Posted November 2, 2014 Holà! Problem with the posterial legs http://www.paleotheque.fr Link to comment Share on other sites More sharing options...
DLB Posted November 2, 2014 Share Posted November 2, 2014 Holà! Problem with the posterial legsThey weren't preserved vary we'll Link to comment Share on other sites More sharing options...
RJB Posted November 16, 2014 Share Posted November 16, 2014 Ok, im having problems with this concretion. Ive already posted this on FaceBook but decided to post it here too. This conc is so even in all directions that I cannot for the life of me figure out what is dorsal/ventral. I know there is a good crab in here and don't want to just 'whack' it open. Ive got 2 pics here, one showing the conc sideways and then another pic of one of the pointed ends showing 3 legs. If anyone out there in crab land can tell me whats ventral/dorsal, they will be my friend forever. and thanks in advance for any advice. Oh, im betting that there is at least a 6 legger Pulali in this rock. RB Link to comment Share on other sites More sharing options...
bruce Posted November 16, 2014 Share Posted November 16, 2014 Hi Ron, I know that anxious feeling. What I do is take a marker and line off an area that will still provide enough pedestal if I choose the wrong side. Then I take the ME9100 and start to work down, When I get to where I think I might run into crab material, I switch to a smaller tool, like a Microjack 5 and continue under the microscope until I run into Pulalius shell which is usually thick or, if I chose the wrong side, softer thinner ventral material. Most of the time, if you look real closely on the finished specimen, you can see the “mark of discovery.” This takes about an hour and about 60% or more , I’ve chosen the right side and can continue prepping. Considering the importance of specimen, I feel it is worth the investment. If I find something that is questionable, I’ll turn it over, mark it and do the other side, until I can determine what I have. If its still ambiguous after boring down the other side, I take a hammer to it. Here are some of the ones, I’ve explored and put aside to continue prepping. 1 Link to comment Share on other sites More sharing options...
fossisle Posted November 16, 2014 Share Posted November 16, 2014 Wow Bruce!!! Cephalopods rule!! Link to comment Share on other sites More sharing options...
DLB Posted November 17, 2014 Share Posted November 17, 2014 Ok, im having problems with this concretion. Ive already posted this on FaceBook but decided to post it here too. This conc is so even in all directions that I cannot for the life of me figure out what is dorsal/ventral. I know there is a good crab in here and don't want to just 'whack' it open. Ive got 2 pics here, one showing the conc sideways and then another pic of one of the pointed ends showing 3 legs. If anyone out there in crab land can tell me whats ventral/dorsal, they will be my friend forever. and thanks in advance for any advice. Oh, im betting that there is at least a 6 legger Pulali in this rock. RB a qoick look I would say that thefirst pick the crab is upside down u have top down I thinck at least that Is the way it looks Link to comment Share on other sites More sharing options...
Doctor Mud Posted November 17, 2014 Share Posted November 17, 2014 a qoick look I would say that thefirst pick the crab is upside down u have top down I thinck at least that Is the way it looks If the legs are nearer the bottom in the second image I'd be with DLB. Are the circular bits towards the bottom the legs or the ovals near the top? In the absence of weathering there usually seems to be more concretion on the bottom of the crab than the top. To be safe I would go for Bruce's technique and pick the side you think is the top based on this. Here's hoping for a good one! Link to comment Share on other sites More sharing options...
RJB Posted November 17, 2014 Share Posted November 17, 2014 Thanks everyone. DLB, In the photo the conc does look flatter on the bottom, but belive me, that is not the case. Nice try though. If it was easy to figure out I would have figured it out already. Bruce, thanks for all that, and that was going to be my next option. Ive done that technique many times before, but this being such a nicely shaped rock I was trying to be 100% on this. I guess ive got a 50/50 chance at getting it right. I will be very nervous once I get started, that's for sure. RB Link to comment Share on other sites More sharing options...
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