Lmshoemaker Posted October 18, 2013 Share Posted October 18, 2013 I've recently received some dolomite from a pottery store which has made prepping much easier. Here is some of my recent work: An Eldredgeops. A paciphacops. A Juvenile Eucalyptocrinus. The paciphacops needs cleaned on the left hand side (not shown), and the eldredgeops had a segment come off on the opposite side, but I'm getting better with it. Link to comment Share on other sites More sharing options...
Jed '06 Posted October 18, 2013 Share Posted October 18, 2013 (edited) Lookin Good! Waiting on my Paasche air eraser still! Is dolomite the best for trilos? I have a prone trilo in shale I want to try first, it's missing some pieces but would be a good first project. It's sitting on top of the shale, just mainly needs cleaned up on top . Edited October 18, 2013 by Jed '06 Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Lookin Good! Waiting on my Paasche air eraser still! Is dolomite the best for trilos? I have a prone trilo in shale I want to try first, it's missing some pieces but would be a good first project. It's sitting on top of the shale, just mainly needs cleaned up on top . For shale dolomite should work without any problem. The only thing I have heard dolomite not being good for is some really hard Moroccan matrixes. Dolomite might be too harsh for trilobites with limbs or antennae preserved, but I'm not sure. I typically work at 40-60 psi, some people go higher or lower, but I guess it depends on the job being done. Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Lookin Good! Waiting on my Paasche air eraser still! Is dolomite the best for trilos? I have a prone trilo in shale I want to try first, it's missing some pieces but would be a good first project. It's sitting on top of the shale, just mainly needs cleaned up on top . Oh yeah, the paasche is only recommended to work at 55 PSI or lower, so please disregard what I said about going any higher. Link to comment Share on other sites More sharing options...
Malcolmt Posted October 18, 2013 Share Posted October 18, 2013 (edited) Jed ,You can always start with arm and hammer baking soda, it is slightly softer than the dolomite. Cryptidsaurian.... 40 to 60 is really more PSI than you need with the Paashe for those trilobites. For those trilos you should be good between 20 and 30 PSI with dolomite. It will take longer to blast but you will have less chance of burn through and less chance of blasting pieces of the trilo off. If you keep you box clean and have a sieve you can immediately find the piece you blast off and put it back on with cyano glue or a dilute PVA solution. On those first two trilos I would probably been blasting at about 18 - 22 PSI on my COMCO unit. You should also look at my post where I talk about modifying the air eraser with the needle from a blunt dispensing syringe in the 18 to 22 gage range. There is a picture of a modified Paasche in my gallery http://www.thefossilforum.com/index.php?/gallery/image/21030-paasche-air-eraser-with-dispensing-needle-18-gage/ http://www.thefossilforum.com/index.php?/gallery/image/21029-paasche-units/ These will allow you to be far more precise in directing the spray. The air eraser on its own has a lot of overspray because of how the nozzle was designed. Edited October 18, 2013 by Malcolmt 2 Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Yeah I have been wanting to modify my paasche with a dispensing needle for a while, it would also concentrate the abrasive to help compensate for the lower PSI and be much better for the area between the segments on trilos. I am also looking to making a blasting cabinet. Thanks for the advice! Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Just curious Malcolm, do your eurypterids require any prep when you find them? Link to comment Share on other sites More sharing options...
Malcolmt Posted October 18, 2013 Share Posted October 18, 2013 The main prep for a eurypterid is gluing the matrix pieces back together. It is rare that they actually come out in one piece at the locality I hunt as the rock is very fractured from thaw cycles and the blasting that occurred above the layer that has the eurypterids in it. Some time there will be a small prep to expose a bit of the eurypterid in a different plane than the natural fracture. For the most part the material generally splits exactly on the eurypterid. Remember that the eurypterid for the most part is just a very thin film over the matrix. Though we do occasionally find very well preserved three dimensional ones which some speculate are the ones that are not molts. For the most part however what we find seem to be molts. Some specimens that are at risk of flaking off and oxidizing I will paint over with a very dilute solution of PVA (Polyvinyl acetate) in acetone . I do this under a scope with a very fine sable brush. This also enhances the contrast between the eurypterid and the matrix which is a grey dolomite waterlime. 2 Link to comment Share on other sites More sharing options...
Jed '06 Posted October 18, 2013 Share Posted October 18, 2013 (edited) Thanks cryptidsaurian & Malcom, very good info! I'll definitely have to do the needle conversion, some of the trilos I have are very small. For the occassional small prepping is the paasche the way to go? I've been reading everything on FF and from the Paasche there seems to be I very big jump in type of equipment and cost. My idea is to have the Paasche, a smaller air scribe, set of sieves for the media and a set dental picks to start out with. Cryptidsaurian, on the TCP Global website they have several blast cabinets that are cheaper priced than others but I like your idea of building one. Any ideas yet on design and materials yet? Edited October 18, 2013 by Jed '06 Link to comment Share on other sites More sharing options...
Malcolmt Posted October 18, 2013 Share Posted October 18, 2013 The Paasche is a good and economical way to start out. When I started I used a pair of them for about a year (one loaded with dolomite, one loaded with Baking soda. There is a brass plug with air holes in it in the hopper and it will eventually wear through. After a while the screw on the top will become very difficult to use as the threads will get damaged by the abrasive. There is a big jump in cost, a dental unit will run $400 to 1200. I have two dental units and rarely use them anymore. The one that is built into a cabinet is just too small a blast container for a lot of the material I find and is difficult to light properly for use with a scope. A new high end professional unit will run $3500 to $6000 but can sometimes be found used in the $1000 to $2000 range. I have a COMCO unit and use it for 95% of my work. I still use the Paache occasionally for baking soda as it is a pain to change abrasive material on my single tank COMCO. 1 Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Thanks cryptidsaurian & Malcom, very good info! I'll definitely have to do the needle conversion, some of the trilos I have are very small. For the occassional small prepping is the paasche the way to go? I've been reading everything on FF and from the Paasche there seems to be I very big jump in type of equipment and cost. My idea is to have the Paasche, a smaller air scribe, set of sieves for the media and a set dental picks to start out with. Cryptidsaurian, on the TCP Global website they have several blast cabinets that are cheaper priced than others but I like your idea of building one. Any ideas yet on design and materials yet? I feel that when starting out the paasche is a great way to start out, and a small air scribe is also good. Sieves are a must or your paasche will clog often. I don't have any suggestions for how to make a blasting cabinet, but I'm going to shop around this site for ideas. If I find anything I'll pass it on here. Link to comment Share on other sites More sharing options...
Malcolmt Posted October 18, 2013 Share Posted October 18, 2013 (edited) I built mine from white enameled particle board with the white to the inside of the box. Used screws to put it together. Drilled holes first so the wood would not split. It has a Cheap replaceable picture frame glass for the window ( 11" * 14 ") and I used white silicone caulk to seal the inside on all joints (need to make it air tight. Three picture frames with glass for $10 at Michaels when they have a sale. Attached a vacuum attachment to the outside with epoxy and drilled like 30 1/8 inch drill holes to provide the air flow directly opposite the vacuum attachment. Use heavy duty green rubber gloves. Have 5 inch round hand holes in the front that I cover inside and out with strips of facecloths that are thumbtacked to the wood. I line the side of the hand holes with the window seal strip as it makes it more comfortable on your arm.The lid is hinged and uses window seal stripping on the lid and the top of the box. It is then pulled down tight with latches on both sides that makes it airtight except for the hand holes (Air needs to be able to flow into the box for the shopvac to do its thing. The dimensions of the box are 24 inches wide by 20 inches deep by 12 inches high. The only thing I might have done different on hindsight is to make it 1 to 2 inches taller. Works perfect all in cost less than $50 Edited October 18, 2013 by Malcolmt 1 Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 18, 2013 Author Share Posted October 18, 2013 Do you have a photo of your cabinet Malcolm? Link to comment Share on other sites More sharing options...
Malcolmt Posted October 19, 2013 Share Posted October 19, 2013 Actually I do not, wont be today but will see if I can snap one. Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 19, 2013 Author Share Posted October 19, 2013 Thanks. Link to comment Share on other sites More sharing options...
Jed '06 Posted October 19, 2013 Share Posted October 19, 2013 Great info Guys! Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 20, 2013 Author Share Posted October 20, 2013 Here is another, an Eldredgeops: And a Platystoma (still needs a little bit of work): 1 Link to comment Share on other sites More sharing options...
Malcolmt Posted October 20, 2013 Share Posted October 20, 2013 Looking Good !!!!!!!! Link to comment Share on other sites More sharing options...
Lmshoemaker Posted October 21, 2013 Author Share Posted October 21, 2013 A little more work on the paciphacops, exposed the left side of the cephalon. (I kind of like that little node on the first segment) 1 Link to comment Share on other sites More sharing options...
Fossildude19 Posted October 21, 2013 Share Posted October 21, 2013 Good prepwork there, Lincoln! Keep it up. Regards, Tim - VETERAN SHALE SPLITTER VFOTM --- APRIL - 2015 __________________________________________________ "In every walk with nature one receives far more than he seeks." John Muir ~ ~ ~ ~ ><))))( *> About Me Link to comment Share on other sites More sharing options...
Lmshoemaker Posted May 26, 2014 Author Share Posted May 26, 2014 Its been a while, but I got a new air compressor and have been able to get back to work. Here are two more; a Glyptambon and Calymene from the Waldron shale. Link to comment Share on other sites More sharing options...
squalicorax Posted May 26, 2014 Share Posted May 26, 2014 Nice Glypt. Those take forever to prep! My Flickr Page of My Collection: http://www.flickr.com/photos/79424101@N00/sets Link to comment Share on other sites More sharing options...
Lmshoemaker Posted May 26, 2014 Author Share Posted May 26, 2014 Absolutely, but they are definitely worth it Nathan! Link to comment Share on other sites More sharing options...
Lmshoemaker Posted May 27, 2014 Author Share Posted May 27, 2014 A nice Lyriocrinus a friend gave me, it cleaned up quite nicely. Link to comment Share on other sites More sharing options...
quietfocus Posted May 27, 2014 Share Posted May 27, 2014 I'm loving this thread. Really nice work man. -Clayton "We are like butterflies who flutter for a day and think it is forever" - Carl Segan Link to comment Share on other sites More sharing options...
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