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7

The grit in your plaster pits the surface of your tools, especially if the plaster still contains moisture while you're carving it. And then when you clean your tools with water the water gets into the pits and if left to sit there it will eat way at the metal. Try to get the water off your tools as fast as possible. After cleaning your tools with water, ...


7

The first thing to bear in mind is that different grades of plaster have different properties. They can broadly be divided into (harder) alpha plasters and (softer) beta plasters. Obviously for carving there is a compromise between how easy it will be to work and how strong the finished article will be. A softer plaster will obviously be easier to carve but ...


6

The dye you have linked to is known as Blue 1, or Brilliant Blue FCF, and is, unlike my comments under the question, a synthetic dye. It is a dye that can be consumed by humans. It is not defined as a redox dye (indicator), so should not react to changes in pH, but it is derived from Methylene blue which does change colour from blue to clear in it's reduced ...


5

I would make a slip, made from the same plaster as the model was made from, and use the slip to "glue" my two pieces together. Scoring the inner surface slightly giving the slip a bit of a roughened surface to bind to. When the two halves are brought together you want to see the slip forced out of the joint. Just wipe off the excess with a damp cloth. If ...


3

Looks like the original plaster covered the wooden base, which makes for excellent repair possibilities. Though removing the existing base may prove tricky. As a result you may not want to remove it at all. As Fixer1234 points out you may run into some additional problems if any of the armature is under tension from how it was attached to the wood, ...


3

Your intention to salvage the statue is well placed. However, as already stated in a comment, your biggest enemy here is the fact that the structural integrity of the statue is affected, and therefore not reliable. Before fixing the details, you should make sure that the statue can survive the repairs, instead of completely collapsing together with said ...


3

Stone carving tools might be good to try, such as rifflers, files rasps. Made for stone they would easily survive being used on plaster. Image below is from http://www.fine-tools.com/liogier-riffler-rasps.html


2

The easiest solution is to paint with an emulsion, such as those used on interior household walls. Bare plaster needs to be suitably sealed before painting begins otherwise the paint will sit on the surface and come off very easily. You can do this either by applying a couple of emulsion mist coats: Dilute an initial solution of 60:40 water to emulsion ...


2

A lot depends on how hard the plaster is. Plasters are broadly divided into alpha (hard) and beta (soft) plus a range of hybrids of the two. Softer plasters (especially while still a bit damp) can easily be carved with knives and woodwork type chisels (but don't use expensive fine quality ones). Microplane/surform rasps are very effective on plaster, ...


2

The material you are looking for is sold in europe (or at least in germany) by the chemical name: calciumhydroxid (ca(OH)2. You can purchase it as a paste oder in powder form practically everywhere; your next door pharmacy, home depot store, aquaristic store or online.


2

Since you don't want to loose any surface detail in your casting and it's a porous material you are wanting to colour, have you considered using a dye or stain instead of a paint? Using dyes, you chemically change the colour of your material. Adding no thickness to the item being coloured. I don't have much experience with dyes other than colouring Easter ...


2

I'll start by asking are you 100% sure it's plaster? I kind of looks like paper clay to me, but that could be the effect of the photo. If it is plaster: Plaster likes to absorb all the water it can - from what I remember Modge Podge is rather watery in comparison to other glues. But I believe it can be used on plaster as it is basically a type of PVA. It'...


2

It works well. Dry mix the cement and plaster first - before adding water. Success really depends on what you’re doing with the mix. For instance, are you casting? troweling? With just cement and plaster you have no aggregate, like sand or gravel or binders, fibers, etc... so your structural performance will depend on several other factors. If you want to ...


1

Food safe, moldable materials are rare in general. The closest thing that comes to my mind is a kind or "organic plastic" made from milk, but it looked hard to work with and I don't know how food safe that really is on the long run. Take for example a simple porcelain dish: the porcelain itself is porous and would stain with food residue. It's the glaze ...


1

You can mix them, as with Gypsum Concrete. However, this will increase the water absorption of the concrete. I have personally had better experience with adding sand to plaster, because it hardens faster and has a nice, rough texture when unfinished.


1

Let's go through this step by step. For your plaster outer portion (mold), I recommend at least 8 pieces (2 pieces if it is single-use and you can break it up, in which case make sure to use a soft plaster). And you are going to put a styrofoam of balloon center in it when you go to cast. Make a 2 piece blank (master) of your shape around a solid center ...


1

It looks like you could blow up a ballon to get the shape of the interior. Then glue hex shaped objects to the surface of the ballon in the pattern of the holes. Then build a wire framework over the tops of the hex shapes to hold them in position and to support your mold's outer shell. Finally apply that outer shell as a series of glued vinyl sheets or ...


1

There are a variety of specialists which will stock a good range of plasters, these include sculpture and ceramics suppliers and well as those catering to industrial mould making. The plaster used for construction is not really what you want unless you find a supplier which caters for more traditional mouldings etc. A hard alpha plaster like CrystacalR ...


1

You're on the right path; the only things I would change in your plan would be not to remove the latex mould (often known as a print mould) before adding the supportive plaster mould (known as an overmould or mother mould). Shawn Thorsson's blog has a good tutorial on one piece moulds - he works in silicone rubber and plastic, but the principles are the same....


1

My approach would be to carefully drill holes into the glass very near one another, and then gradually break pieces away with long nosed pliers, or if you have a dremel with a tip for grinding glass remove the glass that way once the holes are dilled. I'm assuming you can get to the glass, perhaps not. A photo of the challenge would be a big help. Am I ...


1

I get my ultracal from Formx. They have a .nl website and a .eu website. I find the price acceptable but I don't have a reference what you are used to paying for it in the US. Obviously, in the EU the imported stuff is more expensive. What I learned is that Ultracal is not just gypsum or plaster of paris as it seems to be called, but a mix of gypsum, ...


1

Plaster is indeed particularly bad for rusting steel. It helps a lot if you give your tools a light coating of a hard paste wax (eg car polish) before use. This creates a water repelling surface layer which protects them in the short terms and also helps prevent wax from sticking. It is also good to keep a bucket of water hand to rinse the plaster off them ...


1

Most paints don't stick very well to cured plaster so it is often best to seal the surface first. If you have a lot of surface detail then shellac can work well as this will seal the surface without obscuring detail. This should take oil and acrylic paints. You can also use polyurethane varnish, this will cure OK on slightly damp materials and will take ...


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