Hyn Patty

I'd go with one of the bisque fix materials myself. Adding paper IMO just makes for a bulkier but weaker filler. Once fired the paper will leave a lot of voids. Great for light weight, not so much for strength. If you can roughen up the edges of the cracks you'll get a stronger join so the bisque fix has something to 'grab' and hold together better than smooth surfaces. Some small diamond coated files or diamond coated dremel tips will make short work of roughing and slightly widening the cracks. Good to remove any loose pieces too that would otherwise be at risk of flaking off.

I'd go ahead and fire it as it is - breaks can be fixed post firing as you mentioned. If she still wants a mold made of it then she could use a brush on silicone rubber like Mold Max Stroke, make a plaster mother mold shell around it, then cast her back up in other non-clay materials like plaster or resin. This is called a waste mold and isn't intended to be used for lots of production casting. If she wanted to cast a lot of resins or plasters then she'd want a rubber block mold. She could then cast a thin hollow rubber version using Mold Max Stroke, filled with a plaster core after the rubber sets, from which she can then practice making plaster molds for slip casting. Fill with resin instead of plaster if it's particularly fragile with thin parts. Making the rubber thin and supporting it with plaster (either core or mother shell depending on whether it's the mold negative, or the master positive,) would save her a ton of money on casting rubber which isn't cheap. The smaller sample bottles available from places like Smooth-On are ideal for projects like this if her piece isn't very big.

Good advice here already but I have a suggestion. Swap out your stoneware embedding clay for oil clay.

Just want to say BRAVO! Have no fear and jump right in. Even if you ruin it, you'll learn from it. Biggest problem I run into teaching is that people are /afraid/ of failure. I've killed countless plants learning how to grow and propagate them, and I've ruined many a painting and sculpture, mold, and casting. But I learn best by DOING. So jump right in and don't be afraid. You got this! Start simple, take small steps and if you need help, that's what we are here for!

Here is another VanTiki video, this one only focusing on making a plaster mold. This one also shows you about how to make your mold walls using wood (usually a simple box you can slide to adjust sizes, this one is more of a chair form. You can also make your molds using Lego blocks instead of sealed wood which is my choice when I'm making smaller molds to pour.

You already got great reponses here so I have little to add! Most of my originals are sculpted in oil clay and initially I did all of my plaster molds directly from them. If you are careful to use oil clays that are sulfur free you can also avoid most issues with rubber conflicts. As already noted however, if you are pouring large plaster sections the heat can cause your oil clay originals to melt and deform just like with wax originals. Once you get some practice and confidence, and you move into higher end pieces you invested a lot of time into sculpting, you may also wish to consider casting rubber masters. If you make a rubber master of your original, and rubber master pieces of your mold parts you planned to use in plaster, then you can simply recast more plaster production molds over and over again from your rubber masters. Plaster molds, especially those with very fine detail such as my work, are only good for about ten to twenty casts before the molds will begin to show wear. The more detailed and complicated the mold the faster you will see problems, especially if you do not clean and store your plaster molds properly after each use. Simple, low detail molds will last a lot longer. VanTiki posts wonderful Technical Tuesday Youtube videos that may be hugely helpful to you to learn mold making. There are also some great blog posts out there if you do internet searches. Here's a great video on rubber master molds for plaster slip casting right here. He posts a lot of videos on regular plaster mold making so look him up!

Sharp sand is just builder's sand. Get it at any building supply store - as opposed to play sand which is finer and more like dust.

First, glad to help if I am able. Also, thank you for the kind words about my website. Another issue I thought of that might be worth keeping in mind - but you may already be aware. Do NOT handle bisqueware with your bare hands unless you have thoroughly washed them with soap first, or wear gloves. I have to pre-fire all of my bisqueware clients send to me in a low fire before glazing. They are always handling their bisques and getting skin oils and dirt over the surface. This is not as huge an issue with earthenware but with porcelain bodies (and especially bone china) this can cause serious issues with the glazes, or even underglazes, to not stick to the bisque. Especially in firing it'll encourage the glazes to crawl or flake off! So, cleanliness is a must when handling bisqueware. Any contaminants, even dust, can cause this problem. Keep that in mind when you are ready to glaze. Also the coefficiency of the glaze you are using vs the claybody can cause problems. Just like in blending types of glass, if your glaze expansion and contraction rates are not a good 'fit' for your clay it can cause issues later, though not usually the kind you are having. Even so, it may be worth testing another brand of glaze to see if you have less problems. Simply changing to a leaded glaze, or off of a leaded glaze for example can make a big difference.

Any luck so far? Yes, feel free to ping me and we can discuss it. And no, you don't need any special glazes. I glaze fine bone china all of the time using standard low fire glazes. Now the thread is about a year old I imagine you've moved on but if you are still having trouble getting your glaze to stick, you can also put a thin layer of white underglaze onto the china body first as that is often easier to get to stay put. I use an airbrush but you can brush or sponge it thinly. LOW fire it to something like cone 04. That'll give you a toothier surface to work with that can grab your real glaze layer you want over the surface. Then fire normally at whatever cone you need for that last glaze layer - the underglaze will be fine. DO NOT try to apply your glaze over the underglaze before you have fired the underglaze into place. Obviously if the other tricks mentioned earlier work, and can save you a step and a firing, that is better but this will also work if nothing else is! When you overfire low fire overglazes they just turn glossy and go darker but if you use a white underglaze that won't matter. It may knock down some of your transparency slightly, but assuming you apply it thinly in a single layer you probably won't even notice because it goes from opaque to pretty transparent once a glaze is applied over it. Unless you put it on too thickly. Another option of course (depending on the effects you are aiming for) is to skip a glaze entirely and use a low fire overglaze directly on your bisque. China paints or enamels. They don't handle like a glaze at all but still give you amazing effects. Final finish can be adjusted with a flux layer over it for high gloss, satin, matte, etc. The only limiting factor of using overglazes is that many of them can be toxic and not food safe. There are however non-toxic varieties if you look around. Good luck!

Depends on the results you want. If you leave glass etching paste on too long it'll make your glaze turn frosty, somewhat opaque white! In this case it could make the sculpture look pink. But if you don't leave it on very long you can kill that gloss and not have any substantial frosting. So test a small discreet area first or prep a test tile to decide how long to leave it for best results. The paste isn't cheap so you don't want to waste it by applying it and then wiping it off too soon, then have to apply it again...

Also you might want to swap to Kanthal wire. I used to use Nicrhrome wire myself but it was too low fire. Kanthal can go all the way up to cone 10 and I've had much fewer problems with it since I swapped.

There are several ways you can do it. As mentioned you can sand blast it to subdue the finish. Or you can simply reglaze it using a satin or matte glaze right over it and refire it - as long as you aren't having to fire it at a higher temperature than your other materials already used. I do suggest you do a test tile first with the various steps but this technique has worked well for me. You want to be sure the glazes are compatible and if your kiln cools down too fast you may need to ramp your cool down to allow time for the satin or matte glazes to mature properly. I've also done the reverse - fired a piece with a matte or satin glaze, then found glaze fit issues that caused crazing that might lead to dunting. To fix it, I refired the piece with a lead based gloss glaze right over the original glaze I had applied and it fixed the issue just fine. Just be very careful if you need to fire higher than previous firing steps as it can really mess with things underneath, change colors, cause pin holing, etc. Yet another method would be to over glaze using flux or overglaze that has zinc oxide or similar matting agents added. Then you fire it at the much lower overglaze temperature for that new layer. Depending on how much matting agent you apply you may get a slightly lighter tint to the finished piece. Such a matting agent can be applied by hand though I get the best results when using an airbrush (properly ventilated and wear a respirator of course). And yet ANOTHER way to do it is to apply glass etching paste such as you buy at the hobby and craft stores to etch glass! Simply apply it only to the glazed areas, not the non-glazed clay. I suggest yet again doing tests first because you will want to see how long you need to leave it on to get the desired finish you want. Lastly, if all that is just too scary, you can also simply apply a matte artist's grade non-yellowing varnish over your gloss. It will hold up and not scratch off like sprays - get a bottle and apply it using a brush. There is a long tradition of mixed media in the fine arts ceramics sculpture venue through history so don't be afraid to mix it up and even add non-ceramic elements. You only need to be a purist if you intend to enter this piece into ceramics competitions. If so, see above options. Good luck! Nice piece!

This is the boy I'm working on resculpting right now with an all new mane and tail (shown in progress, not finished). This piece is an 8 inch tall resin waste casting descended from my original oil clay sculpture. With grey primer over the white resin, I sent his first version off to be 3D scanned. After casting a resin edition, I can shrink down my work for 3D printing smaller versions, mirror flipping, etc. This version is destined to be produced in resin, English fine bone china, and earthenware ceramic. Each version has to be handled differently. I will no doubt have to make alternations to simplify some of the finer details to facilitate easier molding and casting in the various media. For bone china or porcelain some parts will be cut off and molded, then the greenware reassembled and individially cleaned after casting but before bisque firing. It's good to finally get back to producing my own sculpture in ceramics again. I'll be custom glazing some of this boy by summer, I hope. I do my own casting in studio but I also use outside mold makers and casters as well - so I can run multiple editions in a year. It's just too much for one person to do it all by myself. I will also utilize guest artists to paint or glaze pieces for me to spread the love around and get his edition out there faster.

Thank you, Rae! I hugely appreciate people jumping in and commenting here. I happen to host workshops on all the various things I know how to do - but that's only convenient if you can come out to the mountains of Western North Carolina! The fun thing about over glazes is that you are NOT limited to china paints! There are both opaque and transparent enamels as well - and it's good to read up on all the various pros and cons and arrange your firing schedules accordingly. So don't be afraid to dive right in. If you want to do more overglazing, the internet is wide open for you to search. Materials for you to order and try. Experiment, see what works for you! If you take careful notes you'll know what not to do next time, or what was a raging success and how to replicate it again!

Thank you, Jeff! Molding these is so much fun and a great challenge! I myself do rubber molds for casting in resin, plaster molds for ceramics slip casting, and rubber masters for both. It is a steep learning curve but there are a variety of resources out there to help. Artist's blogs or Facebook pages are rich with shared information and photos. Smooth-on posts free tutorials for rubber and resin casting, etc. A lot of what is there must be adapted to whether you are working with rigid materials or flexible and a lot of it is trial and error, but if you are determined to try and not afraid to fail and try again, you can make some serious progress in time! I always have a ton more I want to learn. Kudos to those sculptors whose pieces I admire so much, and kudos to those who mold and cast them - because I do know how much work and thought has to go into it, too.

Lastly for today, here is one of my own sculptures shown here in progress getting reworked. This is 'Wee Bairn' which I did years ago in a small 10 piece edition in earthenware. Now I am reworking the oil clay over wire to be a slightly different breed of foal (Welsh in this case) and once done I will be making a rubber waste mold and casting. From these I will produce plaster production molds for slip casting the new edition in earthenware and English fine bone china in my studio. When I get to making those molds I can post some updates to that process in the mold making and slip casting forum. He's gotten a lot of refinement work since this shot was taken.

Here is an English fine bone china bisque with the raw, unfired black underglaze. Here I have just begun work using masking fluid for the larger white areas and a craft utility blade to add the hair pattern and ticking. This first layer of underglaze will be fired at cone 04 and then additional layers will be added for the eyes, pink nose, mapping of the pattern, and to add soft silvering so that only a few areas will remain black once clear glazed. Airbrushed unfired underglaze is VERY fragile at this stage and very easy to scratch or scuff so care must be taken handling the piece.