Woolly Rhinoceros skull repair?

[DV77]

Hello!

 

I'm a new member with a question. I hope it's ok for me to ask this question and I hope it's according to all the rules

I've been a fan of the forum for a while, but just mainly browsed a bit, but now I've got a bit of a problem...

 

I'm basically a giant newbie when it comes to this, so please treat me like one (I hope you don't mind).

So I've always had a very big fascination for the woolly rhinoceros. It's been a dream for me to own a rhino skull one day, so I had an opportunity recently and decided to go for it. 

 

I bought a damaged skull, originally from russia, which still looked pretty good. It had a few tooth left, the underside was a bit busted up, but the top and one side still looked spectacular. The price seemed very doable as well, for such a piece.

A few weeks later it arrived and needless to say, I was pretty bummed to see that the front had broken off, the three remaining teeth were loose and the underside was a total mess. 

There's a few large cracks, that make the piece very delicate to transport...

 

So... There's a few things I'd like to do, but I really haven't a clue where to start (I know, you might call me foolish, but the skull is in far worse shape then before it got shipped).

- I'd like to re-attach the front nose piece (and maybe a few of the smaller pieces, but those really aren't a priority to me)

- I'd like to fill/strenghten those large cracks 

- I'd maybe like to put those three teeth back in place

That's about it, unless there's other stuff that needs to be done, that I don't know off.
 

I never had any plans to really restore this piece. I actually like that it isn't complete, I though it had it's charm. But at the moment, it's just so fragile and sadly it's a bit in pieces :/ Also, don't mind the duct tape, it's all I had close to me when I unpacked haha. Sooo, I've got myself a little project here, but I'm looking forward to working on this.

Any help would be extremely welcome. Again, please treat me like I know nothing on the subject.

Many thanks!
D

 

 

 

Edited January 28, 2022 by DV77

[FossilDAWG]

Welcome to the Forum.

We have some members ( @Ptychodus04, @Harry Pristis, @Uncle Siphuncle and others)  who have a lot of experience with fossils like yours and who will likely be able to offer good advice.  My only advice is that you will have to treat everything with a consolidant such as paraloid B72 to ensure that things do not crumble any further, before trying to glue anything back together..

 

Don

[Uncle Siphuncle]

I put bone chunks back together with superglue, wiping excess off the surface with a paper towel within seconds.  If breaks are crumbly, cracks can be filled with PaleoSculp or similar epoxy putty.  Best of luck.

[Harry Pristis]

I endorse FossilDAWG's advice to consolidate every piece before using any glue.  You'll need a sand table (or equivalent) to support the skull (you can cover the sand with a plastic sheet).  You can use epoxy putty on open cracks once the skull is glued together.  Be ready to invest more than a few hours in the project.  Keep us posted, and good luck!

[Jared C]

can't wait to see this awesome fossil brought back to life! I'm also new to prep and found this link to be a helpful resource concerning paraloid b-72:

https://www.zoicpaleotech.com/pages/paraloid-b72-in-fossil-preparation

 

They do complicate it a bit though - they'll say things like "you need to suspend the pellets in solution with a teabag" and whatnot, to avoid clumping at the bottom. The clumping of the pellets is fine, and momentary - I guess it'll take longer for them to dissolve, but they do dissolve nonetheless. I usually give my mixtures a good several hours to dissolve completely since I don't bother to suspend them. Depending on the amount you have, it may be convenient allowing your mixture to sit overnight if they're clumped up at the bottom. No biggie.

 

@Ptychodus04 is also a really great person to ask

[FossilDAWG]

1 hour ago, Jared C said:

@Ptychodus04 is also a really great person to ask

Oops, that's who I meant to tag.

 

Don

[Ptychodus04]

That guy is a real mess, not one I’d call a beginner project. 

 

you definitely want to stabilize individual pieces before attempting to reassemble. I use Paraloid for this. As for the reassembly, I wouldn’t use superglue on something like this as the weight can easily surpass the glue’s strength. I would mix up some thick Paraloid and use it as your glue. You just need to be able to support the pieces being glued as it takes a while for all the acetone to evaporate.

 

I’d get the duct tape off asap as the glue will bond quite well with the bone.

[DV77]

Hi!

Thanks a lot for everybody's answers so far!

So to sum up, this is what I know for sure so far:

 

- I'll first have to carefully wipe down the skull I think. On closer inspection, there's still a lot of dust and rock stuck to the pieces, so I'll try to get off everything that's not supposed to be there. Is it best to do this with just a piece of cloth and maybe a toothbrush? I don't really have any tools at my disposal, I just tried to carefully remove some of the dust with a toothpick too and it makes a lot of difference, so it seems.

 

- Next, I'll have to give everything a coat of the B72 mixture. I spent some time reading about it just now (thanks to Jared C for the article). It seems like the ratio has to be pretty spot on, so I'll have to look into that a bit deeper. I noticed some vendors sell a 10% ready to use mixture, but from what I've read, isn't that ratio too high for consolidation? 

On the other hand, a lot of the smaller pieces seem very fragile, so I'd really like to fixate those.

 

The process above seems a little scary to me, since I really want to do this the right way and don't want to ruin anything.

 

- Then I can start re-attaching the loose pieces. I believe I can use superglue for this? Is there any kind of superglue I should look out for?

Also, do you think I could seal those larger cracks with superglue as well, or is epoxy putty the way to go?

Sorry for the many questions! Again, any help is very welcome. I look forward to getting started

D

 

[DV77]

14 minutes ago, Ptychodus04 said:

That guy is a real mess, not one I’d call a beginner project. 

 

you definitely want to stabilize individual pieces before attempting to reassemble. I use Paraloid for this. As for the reassembly, I wouldn’t use superglue on something like this as the weight can easily surpass the glue’s strength. I would mix up some thick Paraloid and use it as your glue. You just need to be able to support the pieces being glued as it takes a while for all the acetone to evaporate.

 

I’d get the duct tape off asap as the glue will bond quite well with the bone.

 

Hi!

 

Yes, I know haha, I kind of misjudged this I think. But I'm up for the task

It would already make me very happy if I can get the piece stabilised and the front piece attached. The underside will still look very broken, but I don't mind that much to be honest. Despite the damages, I'm still very impressed with the top and overall look of the skull.

Ok, thanks for you opinion on the superglue! What kind of ratio would you use for the Paraloid glue then?
 

Thanks!

 

[LordTrilobite]

Ooh that looks like a very fun project!

[pachy-pleuro-whatnot-odon]

3 hours ago, DV77 said:

I'll first have to carefully wipe down the skull I think. On closer inspection, there's still a lot of dust and rock stuck to the pieces, so I'll try to get off everything that's not supposed to be there. Is it best to do this with just a piece of cloth and maybe a toothbrush? I don't really have any tools at my disposal, I just tried to carefully remove some of the dust with a toothpick too and it makes a lot of difference, so it seems.

 

Hmm... Kind of sounds like they just shipped the skull straight out of the ground without fully cleaning or consolidating it, which is probably what caused all the damage in transport in the first place. Since you'll need to work on this anyway, for best results, taking some time to carefully clean the specimen now might not be a bad idea, since once its impregnated with consolidant, it'll be harder to remove any remaining surface matrix... I think it should be safe to use whatever kind of soft mechanical means you have, such as, indeed, a tooth brush (soft hardness) or various types of paint brushes. Tooth picks should also be fine for removing bigger chunks of matrix, and should risk little damage, as long as they're less hard than the bone you're using it against. Dental picks are another option to go, but as these are metal the risk of damage is greater. Still, they may be useful for some more encrusted bits.

 

As everybody else has already said, consolidating the bone using Paraloid (make sure it's the B72 variant, not any other type!) prior to glueing it all back together is definitely the way to go. As you've discovered there are indeed various sellers who provide ready-made solutions, which can be very practical, especially when trying to lower the learning curve on your first prep-project (there's a Dutch vendor, for instance - PM me if interested in details). Not that it's difficult to mix up your own batch, but I can see how it might feel a bit much just right now. And while the 10% ready-made mixtures commercially available are on the edge what's useful for consolidation, in my experience (at least with this one Dutch vendor), this product sucks in sufficiently to be useful as a consolidant as well as varnish (then again, I've yet to work on such a massive project).

 

I'd indeed also not necessarily immediately go for superglue to put everything back together with, but would rather invest in proper glues as used by preparators, of different thicknesses - something like PaleoBOND or Starbond. Although, much like superglue, also CA-glues, their different thicknesses make them useful for different purposes, with the thicker variant being useful for gap filling or glueing together pieces with less than ideally matching surfaces. I can't speak for how these commercially available glues hold up against a thicker mixture of Paraloid, but I feel like the glues would be more specialised and, if chosen at the right thickness, should do just as good if not better a job than would Paraloid, which I view more as a consolidant/preservational product. @Ptychodus04 is a professional preperator, however, with tons of experience, so it may be wise to follow his advice.

 

Whatever your eventual choice, though, make sure to buy some pure acetone (certain vendors add additives to make the product less appealing for any use other than the one they've intended it for), probably from the DIY-market, as this can be used to clean up traces of CA-glue and Paraloid alike, as well as can be used to dilute and clean Paraloid from the surface of the bone in case its shine gets too strong for your liking. Because one of the things that Paraloid will end up doing is cause some shine to the bone, giving it, in effect, a permanent wet look.

 

6 hours ago, Jared C said:

They do complicate it a bit though - they'll say things like "you need to suspend the pellets in solution with a teabag" and whatnot, to avoid clumping at the bottom. The clumping of the pellets is fine, and momentary - I guess it'll take longer for them to dissolve, but they do dissolve nonetheless. I usually give my mixtures a good several hours to dissolve completely since I don't bother to suspend them. Depending on the amount you have, it may be convenient allowing your mixture to sit overnight if they're clumped up at the bottom. No biggie.

 

If you do decide to mix up your own batch of Paraloid (again, using pure acetone) you can indeed easily do so following Jared's instructions. No need to use a tea bag or cheese paper approach if you're not in a hurry and don't need very thick mixtures: it'll just take more time for the Paraloid to dissolve after forming an initial mass at the bottom of your container. Occasionally swirling the acetone inside will increase surface exposure, so that the mass at the bottom will dissolve more rapidly.

 

7 hours ago, Harry Pristis said:

You'll need a sand table (or equivalent) to support the skull (you can cover the sand with a plastic sheet).

 

3 hours ago, Ptychodus04 said:

You just need to be able to support the pieces being glued as it takes a while for all the acetone to evaporate.

 

Here's the thing: the thicker the glue, the longer it'll take to dry (while with thin glue things may be stuck together as soon as the two parts touch, with thicker glue it may take a couple of minutes). Over this period, you'll need some way to support the different parts of your specimen that you're glueing together. There are different ways to do this, with a sandbox being the traditional way. And the name really is what you make it out to be: a pile of sand that can easily be shaped and dug out to fit your specimen into in the most perfect way to glue two pieces together. Of course using pillows or bits of cloth as support may also work, but the mould and support will be less ideal as with sand. Another point to be made here is that the CA-glues I mentioned earlier come with a hardener, a spray that will trigger a reaction in the glues so that they'll harden faster. This is a trick often used by preparators to speed up preparation without having to wait for the glue to set. I do get the impression, though, that this results in a somewhat weaker bond, but in addition to speeding the process up, it also means there's less risk of the perfect connection becoming undone by accidentally bumping into the sandbox and things like that. Another thing to keep in mind is that you should always glue pieces back together two at a time (i.e., one bond), and let that dry properly before trying to add a third to the mix. This is because otherwise it becomes difficult to properly connect pieces, which may start to shift once additional pieces are being added.

 

3 hours ago, Ptychodus04 said:

I’d get the duct tape off asap as the glue will bond quite well with the bone.

 

I fully agree with this one. In order to prevent damage to the bone, it'd be best to take it off quickly, but with care. Otherwise it may leave glue-stains.

 

The below thread my also be of interest to you, by the way, as it deals with similarly aged material with like preservational issues also faced by a novice, thus presenting much the same concerns you might have:
 

 

Good luck, don't be a stranger, and looking forward to seeing your project progress

Edited January 29, 2022 by pachy-pleuro-whatnot-odon

[FossilDAWG]

I would get a set of good artists paint brushes with various sizes.  Initially you can use there to gently brush or loosen dirt and dust.  Later you can use them to apply the paraloid b72 if you need to touch up spots.  I sometimes get those "dust-off" spray cans of compressed air you can get in computer stores.  They are good for blowing off dust, but to have to watch that you don't lose bits of the fossil as the air stream can be strong.

 

You can pour b72 over the fossil, or make up enough to soak the pieces.  You want the b72 to penetrate deeply so the fossil is hardened throuout.  Use a thin mix so it can penetrate all the pores.  Make sure your pieces are very dry to start as the b72 will react with water to make a white mess.  Do all this in a very well ventilated place as breathing acetone is a bad idea.

 

As others have said this is a complex project.  One you have consolidated everything you could wait until you have more experience.  At least the pieces should be more stable and you could set them aside until you're ready.  If you do choose to go ahead, the advantage of using a thicker b72 solution for glue is that if you make a mistake it is reversible with acetone, unlike super glue.

 

Good luck!

 

Don

[Ptychodus04]

3 hours ago, DV77 said:

 

Hi!

 

Yes, I know haha, I kind of misjudged this I think. But I'm up for the task

It would already make me very happy if I can get the piece stabilised and the front piece attached. The underside will still look very broken, but I don't mind that much to be honest. Despite the damages, I'm still very impressed with the top and overall look of the skull.

Ok, thanks for you opinion on the superglue! What kind of ratio would you use for the Paraloid glue then?
 

Thanks!

 

You can wipe your fossil to clean the pieces with a rag soaked in acetone or ethanol.

 

I like a 50:1 ratio of acetone to Paraloid for consolidation. This yields an approximately 2.5% solution. Soaking is the best method of consolidation but liberally brushing it on is effective. You can also pour it into the broken edges of the specimen to help consolidate the interior. 
 

For the glue, I like a consistency of cold honey. You want it to pour but just barely. You can simply add Paraloid to some of your consolidation solution until it is thick enough. It will take a long time to fully dissolve the plastic as it gets thicker. Then, spread it onto both pieces and strap/clamp them together for a couple days. You’ll wind up with Paraloid oozing out of the crack so do it on a piece of cardboard. You can remove the excess after it is dried with acetone.

 

 

[pachy-pleuro-whatnot-odon]

8 minutes ago, FossilDAWG said:

I would get a set of good artists paint brushes with various sizes.  Initially you can use there to gently brush or loosen dirt and dust.  Later you can use them to apply the paraloid b72 if you need to touch up spots.

 

I concur with this suggestion, as I find that having a good set of brushes of different hardnesses and sizes is an essential on a lot of preparation projects. I have, however, noticed that different types of brush hairs react differently to being soaked in different glues/consolidants, however, so it may be useful to check which work good for you. I believe the brushes that work best for me in combination with Paraloid are brushed meant for acrylic paints...

 

7 minutes ago, Ptychodus04 said:

You can wipe your fossil to clean the pieces with a rag soaked in acetone or ethanol.

 

I'd be less eager to suggest using pieces of cloth to wipe your specimen down with, as bits of cloth fibre can stay behind if you use the wrong type of cloth (i.e., the fibrous kind). Certainly take care using cotton pads or the likes. However, if you do want to moisten your specimen in cleaning, acetone or ethanol are indeed the way to go, as both of these solutions are anhydrous (you don't want to get your specimen in contact with water) and evaporate quickly. For one of the issues to watch out for during consolidation is that the more a specimen soaks in Paraloid, the weaker it may initially become (just like a piece of wet paper), until it has dried. Overly soaking a specimen may therefore be risky if the specimen is too frail, and surface application using a brush or pipette may, in these cases, be recommended. In general, however, soaking is the best, in order to allow greatest surface contact and longest exposure to the consolidant, allowing it to fully suck in.

 

17 minutes ago, FossilDAWG said:

Make sure your pieces are very dry to start as the b72 will react with water to make a white mess.  Do all this in a very well ventilated place as breathing acetone is a bad idea.

 

Luckily, most mistakes with the application of Paraloid can be undone using acetone. However, it is indeed generally a good idea to ensure your specimen is fully dry before applying the consolidant. Some people therefore recommend only working with Paraloid on sunny days. But as this is, of course, not always feasible, heat lamps or even baking in an oven at low temperatures are good (I'd say even better) alternatives to ensuring your specimen is properly dessicated. Heating a specimen prior to submersion in Paraloid further helps the Paraloid penetrate the specimen too as the hot air will quickly escape the specimen giving the Paraloid room to penetrate.

[Jared C]

oh and one more thing! I know all the information you're getting must feel like drinking from a fire hose, but one last tiny important detail! When you get the acetone for your paraloid, make sure it's like the proper, workshop acetone, like the type that you would get from a hardware store. Don't use the type for cosmetics and whatnot, it has too much other stuff mixed in. I would've probably made that mistake had no one told me

[Ptychodus04]

On 1/28/2022 at 7:44 PM, pachy-pleuro-whatnot-odon said:

 

I'd be less eager to suggest using pieces of cloth to wipe your specimen down with, as bits of cloth fibre can stay behind if you use the wrong type of cloth (i.e., the fibrous kind).

 

I find that a piece of cotton t-shirt works well for this application. I don't wind up with fibers on the specimens when I use it. Cotton towels are banned from my lab for cleaning purposes as they are terrible about leaving bits on the specimens.

[DV77]

Hello!

 

First of all, thanks to everybody for all the information. I'm truly grateful for this and I learned a lot alrady!  @FossilDAWG @Ptychodus04 @Jared C @pachy-pleuro-whatnot-odon @Harry Pristis @Uncle Siphuncle

 

Ok, so I cleaned my specimen carefully during the past few days. A lot of dust, stone and other stuff came off, the colour is much richer now, as expected. I used my paint brushes I still had lying around and a wooden toothpick for the harder to remove stuff. Most of the stuff is gone now.

 

So I was looking into consolidating. I understand it shouldn't be too difficult to make the mixture, but I'd feel just a bit safer maybe if I bought a pre-made mixture. I noticed a website where they sell Paraloid B72 in ethylacetate. I noticed only aceton and ethanol have been mentioned, but do you think the mixture I mentioned is also usable? It says on their website it's used for consolidation of ceramics, paintings, fossils, ... They have different mixtures, so I was maybe planning on buying a few 150ml bottles of 5% mixture for consolidation and then e few of 10% for a surfice coat and larger cracks. I don't know if all of this sounds ok? Would this be too much/too little mixture?

 

I also read the specimen needs to be as dry as possible. It feels and looks very dry to me, but I want to make sure. Putting it in an oven is just not possible because of the size. It might sound stupid, but would it be interesting to heat it with a hair dryer for a while? 

 

I'd postpone the glueing just a little for now.

 

Again, thanks to everybody for their help so far!
D

 

[Ptychodus04]

1 hour ago, DV77 said:

Hello!

 

First of all, thanks to everybody for all the information. I'm truly grateful for this and I learned a lot alrady!  @FossilDAWG @Ptychodus04 @Jared C @pachy-pleuro-whatnot-odon @Harry Pristis @Uncle Siphuncle

 

Ok, so I cleaned my specimen carefully during the past few days. A lot of dust, stone and other stuff came off, the colour is much richer now, as expected. I used my paint brushes I still had lying around and a wooden toothpick for the harder to remove stuff. Most of the stuff is gone now.

 

So I was looking into consolidating. I understand it shouldn't be too difficult to make the mixture, but I'd feel just a bit safer maybe if I bought a pre-made mixture. I noticed a website where they sell Paraloid B72 in ethylacetate. I noticed only aceton and ethanol have been mentioned, but do you think the mixture I mentioned is also usable? It says on their website it's used for consolidation of ceramics, paintings, fossils, ... They have different mixtures, so I was maybe planning on buying a few 150ml bottles of 5% mixture for consolidation and then e few of 10% for a surfice coat and larger cracks. I don't know if all of this sounds ok? Would this be too much/too little mixture?

 

I also read the specimen needs to be as dry as possible. It feels and looks very dry to me, but I want to make sure. Putting it in an oven is just not possible because of the size. It might sound stupid, but would it be interesting to heat it with a hair dryer for a while? 

 

I'd postpone the glueing just a little for now.

 

Again, thanks to everybody for their help so far!
D

 

 

I've never used a premixed solution, so I'm not going to be much help here. Mixing your own solution is far lees complicated than one might think. It's not an exact science, so the ratios are only guidelines. An extremely thin solution simply requires a close approximation of weights (50 parts acetone to 1 part Paraloid) and the paraloid will completely dissolve in that much acetone quickly. I've never had an issue with the Paraloid clumping in such a dilute solution.

 

What did you wet the specimen with to clean it? If you used alcohol or acetone, you don't need to worry about trapped moisture. If you used water (not recommended for fossil bone), you will want to wait for several days to weeks, depending on how wet you got it, before you attempt to stabilize it.

 

[FossilDAWG]

You should make sure to work in a well ventilated area, regardless of the solvent.  Ethyl acetate is quite irritating to the eyes and when inhaled, and it can be absorbed directly through the skin so use gloves.  It is also highly flammable.  The same can probably be said about acetone, and to a lesser extent ethanol, as well.  I have not heard of ethyl acetate being used before, but that is likely because it's not so easy to get as acetone or ethanol.  One advantage of ethanol is that it is less volatile as acetone, so it can penetrate more deeply before evaporating.  Maybe that is also the case for ethyl acetate.  All in all though, I would prefer to buy the beads and make my own solutions.

 

Don

[DV77]

Hello

 

Thanks to both of you for the quick answer! @Ptychodus04 @FossilDAWG

Ok, I'll give it a bit more thought.

Whatever I choose to do (pre-made or do it myself), does anyone have an idea (approximately) how much I of the mixture I would need to go over the specimen fully? 

I know this might be a tough question, but any direction would be helpful  

 

[DV77]

5 minutes ago, FossilDAWG said:

You should make sure to work in a well ventilated area, regardless of the solvent.  Ethyl acetate is quite irritating to the eyes and when inhaled, and it can be absorbed directly through the skin so use gloves.  It is also highly flammable.  The same can probably be said about acetone, and to a lesser extent ethanol, as well.  I have not heard of ethyl acetate being used before, but that is likely because it's not so easy to get as acetone or ethanol.  One advantage of ethanol is that it is less volatile as acetone, so it can penetrate more deeply before evaporating.  Maybe that is also the case for ethyl acetate.  All in all though, I would prefer to buy the beads and make my own solutions.

 

Don

Thanks for the tips on handling the products, very useful!

[FossilDAWG]

One other thing, in the insect taxonomy course taught in my department they use ethyl acetate in the kill jars they use for killing insects.  Unless you have access to a fume hood, or you can work outside in a very open area, I would be reluctant to use ethyl acetate as a solvent.

 

Don

[Harry Pristis]

A quick perusal of the Safety Data Sheets for ethyl acetate and acetone gives me the impression that ethyl acetate might be a good substitute for a solvent.  The evaporation rate is slightly slower, but the fumes may be less noxious.

[pachy-pleuro-whatnot-odon]

7 hours ago, DV77 said:

So I was looking into consolidating. I understand it shouldn't be too difficult to make the mixture, but I'd feel just a bit safer maybe if I bought a pre-made mixture. I noticed a website where they sell Paraloid B72 in ethylacetate. I noticed only aceton and ethanol have been mentioned, but do you think the mixture I mentioned is also usable? It says on their website it's used for consolidation of ceramics, paintings, fossils, ... They have different mixtures, so I was maybe planning on buying a few 150ml bottles of 5% mixture for consolidation and then e few of 10% for a surfice coat and larger cracks. I don't know if all of this sounds ok? Would this be too much/too little mixture?

 

Up until recently, when my supplier ran out of ready made mixtures, I used to buy my Paraloid ready made from a Dutch vendor, all prepared based on acetone. When they ran out and I didn't want to pause my preparation work for lack of Paraloid, I simply decided to try mixing it up myself, and found that it's not hard at all. Moreover, the lower the volume-percentage, the easier (and presumably quicker) the Paraloid-beads will dissolve in acetone. Thus, while I don't think there's a problem buying ready made solution, you may just as easily create it yourself. The only concern in that case - at least, as far as I was concerned - is to have a suitable container for it: jam jars etc. will allow the acetone to escape and thus evaporate your solution prematurely - but so do most other containers. Plastic containers, moreover, run the risk of themselves getting dissolved by the acetone (at least, as I understand it). Thus, I'm just re-using the jar I got with my last order of ready-made Paraloid solution, but have some stored in smaller glass containers as well.

 

How much you'll need I can't really tell you - at least not for the low volume-percentage used for consolidation. For the surface coat, about 150ml should suffice, but you might need 300ml. It all pretty much depends on how much your specimen will still suck up, how thick of a varnish you intend to apply and how large the specimen is. But 150 ml should last you a good while under normal conditions. Hence, I'd say between 150ml and 300ml should suffice.

 

7 hours ago, DV77 said:

I also read the specimen needs to be as dry as possible. It feels and looks very dry to me, but I want to make sure. Putting it in an oven is just not possible because of the size. It might sound stupid, but would it be interesting to heat it with a hair dryer for a while?

 

You can definitely give this a careful try. While certain specimens don't need to be dried beyond the environmental conditions in which they were found, it's good practice to ensure your specimen contains as little water as possible before applying the Paraloid. This can be done in various ways, including placing your specimen next to a heater, under a heat-lamp, in an oven or using a blow dryer. I myself have tried the latter and it works quite well.

[paulgdls]

Heartily agree with all the recommendations made previously. Here is a Woolly Rhino femur put back together using these techniques, with the missing bits filled with a mixture of plaster of paris and papier mache.

 

Good luck with the reconstruction and please keep us informed about your progress.

 

P.S.

I think the fossil will be plenty dry enough now for the application of paraloid. 

 

Edited February 2, 2022 by paulgdls