Search the Community

G'day everyone! My dad and I have tried making some paraloid glue by mixing 25% paraloid with 75% acetone. The paraloid has been dissolving for a few hours and a thick solution with the consistency of wood glue has settled to the bottom. Do we use this thick solution at the bottom to glue and strengthen our fossils? Thanks, Dan

I am not particularly a fossil collector, I have come across some cheap Spinosaurus teeth. I know they probably aren't particularly interesting from a collection standpoint, but I think they are quite fantastic. I want to make them as hard and protected as possible, for the sake of ornamentation. I hope that isn't heresy. Point being, I am comfortable with using products that may not be appropriate for fossils that are of higher value and going on a shelf. I've read some about Paraloid B-72, and that it can be mixed (at a ratio of 1 paraloid/10 solvent??) with something like acetone. If I do that, would I want to just soak the fossil in the solution to maximize the penetration? How long should that be done? And I see that in drying I have to be careful since the wet fossil can end up bonding to whatever it's sitting on. Any other suggestions? And thanks for your time! And I can't figure out how to get notified of replies once I've posted, so I'm adding this to turn on notifications.

I received an awesome set of Moroccan matrices from @caldigger (thanks again!) that included a cracked elasmosaurus tooth. I didn't consolidate the tooth before prepping, as the matrix surrounding the tooth was far harder than the rest of the block, leading me to believe it had been sufficiently consolidated. It split at the crack whole handling it before prep work even begun, so I continued with the rest of the tooth and got the rest out pretty cleanly. The fossil isn't valuable, so I'm not too worried about perfection! Its all part of the learning experience for me. My question is about the correct order to go about repairing this tooth. When you line up the pieces, there is still a small hole from a missing section, and I suppose filling it with the matrix and then adding a layer of Paraloid dilute would be the best way to go? So here is my (tentative) plan of repair: Consolidate the pieces in the dilute Super glue the bits back together as cleanly as possible Fill in the cracks with wet matrix (?) Let it dry, then gently coat again with the dilute solution Would exposing it to the dilute twice be overkill? And I know acetone tends to dissolve super glue, but I assume the glue would hold if it's inside the tooth and the second coat of Paraloid goes on just the outer layer after it has all dried? Hopefully I explained my intentions well, and I'm looking for ideas as to what would be the best order to attempt these steps in or otherwise a preferable method (if there is one) of repair!

JohnBrewer kindly sent me some paraloid, i've gone out and bought some 98% acetone and a glass jar. How much Paraloid should i put into a small coffee jar? Thanks

Hi friend, I am working on a cluster of shark vertebrae and need advice on preservation. I have decided to clean up the whole sample and expose some of the fragments of different bones which are in the matrix surrounding the vertebrae. I need to stabilize the whole sample after I finish but I can't get here in Czech republic Butvar b76 as many people recommend. Can I use PARALOID B72 or AKEPOX 1005? Will I be able to apply paraloid with a brush and is it even suitable for this? Can you please advise or recommend other product?

I’ve tried searching through the forum and it seems that there are mixed reviews about using paraloid on wet specimens. I have a couple of chunks of wet sand/clay with bivalves and gastropods that are extremely fragile. Everything will crumble with the slightest touch. So, what is the general consensus on using paraloid on wet specimens? Should I risk it and dry them out first?

Folks, I need an archival consolidant that doesn’t dry glossy. The problem is the plant material I want to protect from flacking is sorta clay/soft shale. Even 5% w/v Paraloid in acetone is giving a glossy appearance. Not too bad on the fossil but looks horrible on matrix and fossil. In fact to increase contrast I like it on the fossil. Coating just the fossil isn’t an option. @Ptychodus04 @RJB @jpc @Harry Pristis

I found a US source, Talas, for small quantities of Butvar and Paraloid consolidants in 1 and 5 lb quantities. http://www.talasonline.com/Butvar-Resin For a great bottle to use with Butvar and probably other consolidants see my post:

My first shot at prepping ANYTHING! I will describe by process with the hope of some constructive criticism. PIX 1: I used only dental picks for this Oreodont partial jaw as the matrix is soft. I also found that a Qtip with water, softened some of the tougher spots. PIX 2: I used a soft bristle brush to apply a dilute acetic acid which served well to remove the last of the residual matrix. PIX 3: I neutralized the acid with a soak in Sodium Bicarbonate PIX 4: Into the oven at 200 F for one hour to drive off all moisture. PIX 5: Into a 5% solution of Paraloid. I used Pyrex brand with a snap lid and seal that does not react with the Acetone nor does the lid seem to get gummed up with the Paraloid. The piece was still warm when I put it in the Paraloid solution and it bubbled vigorously for several minutes as the solution soaked in. All told the bubbles lasted for 1 hour. PIX 6: Cool shot of air escaping the piece. PIX 7: To slow down the evaporation of the Acetone, I sealed the piece in a ziplock and placed in at 25 F (note the snow!!! this is Minnesota) I could see the Acetone condensate on the bag. After 1 hour I opened the bag and let it dry completely. PIX 8: Finished and on the way to my 8 year old grandson in Florida!

Heres how I prepare Paraloid b-72 for use as an adhesive and consolidant. Generally I use the approximate mixing ratios shown below which have been taken from a paper written by Amy Davidson and Gregory W. Brown called Paraloid b-72: Practical tips for the vertebrate fossil preparator, which can be found here: https://www.academia.edu/1237393/Paraloid_B-72_Practical_Tips_for_the_Vertebrate_Fossil_Preparator Approximate mixing ratios: Paraloid ratios.tiff However, if you want to create a solution of a known weight by volume percentage such as 20% (w/v) theres a trick. Since weight by volume solutions are worked out as the mass of the solid in the final volume of the solution, you need to know the volume of your final solution. For example if you had a 100ml bottle that you want to fill with a 20(w/v) solution of Paraloid what you would do is: 1) fill the bottle with 100ml of liquid. 2) mark on the bottle where the top of the liquid is. 3) weigh out the amount of Paraloid, which in this case would be 20g = (20/100)x(100 mL) as Mass of Paraloid = (Percentage of solution/100)x( final volume of the solution). 4) add the Paraloid to the bottle and fill with the solvent (acetone in this case) up to the 100ml mark. Say you wanted to make 2 litres of a 5% solution of Paraloid. You would follow the above steps replacing the 100ml with 2000ml = 2 litres. The mass of Paraloid would be (5/100)x(2000) = 100g. Note: it is important to keep you units consistent so if your volume is in mL your mass will be in grams. If your volume is in litres your mass will be in kilograms. Another form of concentration is a weight/ weight percentage, which is the percent by mass of the final solution where: Concentration of solution %(w/w) = (mass of solute)/(mass of final solution) This is a bit more complicated as you don't know how much volume of solvent to add or what the final volume would be. This technique is usually used to make big batches of the solution and is probably not all that useful for the weekend warrior. Hope this helps someone.