Used for waste molds or temporary patterns where surface hardness and strength are not important. Leaving the shower curtain open or closed has long been a debate for a lot of people. As compared to plaster of Paris, hydrocal takes a lot more details and they do not slough off so you do not have to deal with lots of dust and chips. Then I apply small cloth strips over the 'high' area's of the mold. Moreover, how long you mix the slurry will affect the setting time. The downside of Hydrocal is that it does not carve or take stains/washes very well. As an Amazon Associate, we earn from qualifying purchases. 1. Cuts easily, pulls away from the castwell, and you can get a very nice, tight, outline of the instrument every time. If you think you have it right, your standards are too low. Hydrocal is versatile gypsum cement that is used for hollow and solid castings. link to Should You Leave Your Shower Curtain Open or Closed? What I like to do w/ that huge bag of Hydrcal is to rebag in smaller more managable amounts. It shows how to cast shydrocal white into a plaster mold with the use of a fiberglass mat. You can use free water in the mold to have a higher drying temperature. We have also shared this article that discusses what hydrocal is made of. NEVER clean plaster tools in the sink, it will ruin the drain. The pictures below are of a Hydrocal High Arched PRR prototype stone viaduct that I've been working on the past week or so. You can check out the article for more information about the topic. I prefer Plaster of Paris because it is easier to drill into to plant trees or otherwise modify. I have poured large faces of rocks.. using less and less dental plaster. Hydrocal has excellent strength which helps lessen breakage when the plaster cast is removed from the mold. . Paste as plain text instead, USG Hydrocal Brand White Gypsum Cement is a good multi-purpose product for people looking to upgrade from a standard plaster product to one that has a higher degree of hardness and impact resistance. Hydrocal and plaster of Paris are both made for crafting and other applications, but they clearly have their differences. Hydrocal dries rock hard, so it is hard to modify or carve. Make sure that you read and follow the handling and directions on how to use hydrocal according to what is written in the package. I've also used Bragdon Foam with a Bragdon mold. When painting the plaster into the mold.. Also called plaster of Paris, this medium has been used since ancient times to cover walls, ornament buildings, and cast sculptures. Hydrocal has many uses. For most, the main difference between hydrocal and plaster of Paris is that hydrocal is much stronger and takes more detail. Ultracal is stringer and harder as compared to hydrocal. You can heat ultracal, but you need to follow heating instructions. Side note: I can even break this casting a bit.. remove certain areas.. it breaks nicely.. and the plaster cloth on the backholds everything together..so I can go back.. add plaster to the areas.. to seal them up.. and I guess its a mild re-glueing with plaster. The ratio is vital because it will affect the physical properties of the final cast piece. We use cookies to ensure that we give you the best experience on our website. link to Why is My Well Water Brown All of a Sudden? For instance, it is ideal for making a hollow and solid casting of sculptures, figurines, and commercial casts. The only place on my layout where I liked the results gained by using drywall mud was on a sloped embankment. We have shared an in-depth discussion about the topic. Well, the thing fell off the table and landed on the tile floor. Most of the time, we choose a material for the project that we are working thinking that it is an excellent choice, only to find out in the end that the material is not the correct one. Dilute the detergent by spraying the mold with straight tap water. Allowing the first coat to dry overnight, two more coats one hour apart are enough to make a firm scenery base. So, the jury is still out on the subject for me. BUT. (there's that but again), make sure it's the slower setting type. Moreover, you cannot use plaster of Paris to make miniature pieces. The next step is mixing. Tom View my layout photos! The ratio of the two ingredients is important because it affects the physical properties of the cast piece. But, Jeffrey, would that not make the plaster essentially impossible to paint? On the other hand, if you do not want the plaster to be a little wet so that you can easily clean it up after demolding, you can take it out as soon as it does not dent or get squished when you scrape it with a toothpick or a metal pin. As an Amazon Associate, we earn from qualifying purchases. It is also an extremely wear-resistant material. I used Hydrocal White for many years with no seriouscomplaints, but more recently have been using a product called Tecstone (It's a dental plaster). Hydrocal has a very white color. you get far greater detail then you would by painting. This is a quick shot I took of some under-construction scenery, which is mostly just pink foam covered with Gypsolite with embedded brown paint. The Woodland Scenics brand is wider, it's 8 inches x 15 feet, if memory serves me right, and the medical type was 6 inches but still it's a whole lot cheaper. I wanted its superior strength. Try buying it in 50 lb bags from a building supply houseNot usually at a Home Depot, look for the store specializing in lath and plaster supplies (there is usually one in most towns) Much cheaper in bulk. You see the way the spoon is? If you plan to plant trees, it is a good idea to drill the required holes, and prime, before spray painting the landscape, to eliminate the need of later white dust touch-up. Hardens like a rock quickly. Your previous content has been restored. While some of their components are not the same, both are made for the same purposes like casting and molding. If you are working with other types of plaster, they need to be supervised to achieve the best results. can I get this stuff in bulk? When hardened, it will permit removal of molds with "undercuts" whereas plaster of paris will break off detail. Another reason why it is ideal to use hydrocal and ultracal is that they do not crack. Now I don't claim to be an expect.. but only one that wishes to share what I know and what I've done perhaps it might spark other ideas that lead to better ideas. I dont' think that is my approach. It can take up to 23 to 35 minutes or more for a hydrocal to cure and have a thick surface. You need to slowly and evenly sift hydrocal into the water. He specializes in some fantastic castings. Should You Leave Your Shower Curtain Open or Closed? Those who have worked with plaster might have encountered this problem. Waterproofing plaster of Paris is important especially if you will use it outdoors. Moreover, hydrocal does not slough off as compared to plaster of Paris. You seldom need plaster of Paris to patch drywall. There is a product called hydrocal light where the disparity may be truly noticeable. If you find you like rock face and stone wall castings, you might also look at Bragdon Enterprises. I am really looking to spend less. Use a mixing container that can fit the amount of mixture that you will make. Plaster of paris and cement are about the same price, you just have to buy twice as much for twice the price- even this is usually cheaper than going straight for the quality products. Moreover, they are easy to prepare and can be set after just a few minutes. They are easy to use and durable. Ballast - Most of the Woodland Scenics ballast appears to be crushed walnut shells(or something close). Are you happy with the results? Step 3: Add Plaster to the Mixture. Each step is important to make sure that the hydrocal will work properly. While we strive to provide quality information, we cannot guarantee its accuracy. All that you need to do is to follow the instructions written on the package on how to properly mix and handle both materials. Hydrocal and Ultracal 30 are also used in the pottery studio. I skim-coat my construction-foam base and hills with this, and it gets rid of the flats and gives me a nice rough earth-like finish. Hydrocal is mainly composed of plaster of Paris and a small amount of Portland cement. As this happens, it changes from hemihydrate to dihydrate. Leaving the shower curtain open or closed has long been a debate for a lot of people. Choosing a material for a specific project that you are working on can sometimes be confusing because of their similarity. Hydrocal is my preference for molded outcrops, since it is tough. 'Surface Tension' yes.. that is what is keeping the plaster really getting into and adhering to the mold. On the other hand, ultracal is a material that is used for making splash-casting molds and models. The average time that it takes for ultracal to set is about 25 to 35 minutes. We are in a club setting where ther is a possibility of abuse to exposed castings. We have also shared tips and ideas for both materials. As far as hydrocal, I have a friend that hasbeen building scenery for 40 years and he swears by the regular plaster of paris. You can use white glue, white flour, or Paris powder as a substitute for plaster. I even took pics to see how much detail there was.. and how easy it was to pull Dental plaster out of the mold. A real pain to touch up those "bright" white chips. Take note that hydrocal has a high green strength which allows it to lessen breakage during removal of the casting from the molds. On the other hand, it is not as durable as compared to ultracal. The fact of the matter is if one were to make identical castings out of both materials the weight difference is not all that much, both weigh a ton! But in short using the hyrdrocal/dental plaster. You can also check out this article thatdiscusses if hydrocal expands. If you continue to use this site we will assume that you are happy with it. Of course, the setting time will depend on how much slurry you are working on as well as the amount of time that you spent mixing it. what is the difference between hydrocal and plaster of Paris. Dental Stone is is also calcium sulfate Hemihydrate, but it is created at a higher temperature and under pressure. This helps slow down the absorption process. Both have pros and cons so you need to make sure that you weigh out your options to make the best choice based on the project that you are working on. I'm also a hydrocal fan for plaster casting. Make sure that the hydrocal is fully dispersed in the water before mixing. Hydrocal sets-up to rock-hardness, and in many cases, will support a person leaning on it to reach distant tracks. Be sure to elevate the cast off of the table to allow adequate air flow underneath, so that moisture can escape, and the cast can cure. To me plaster of paris is easier to work with and cheaper. Hydrocal is a gypsum product that is commonly used for slip latex mold sand case molds. Plaster of Paris is a gypsum plaster that quickly sets. Used Hydrocal for the first time 2 nights ago for a full back cast of a Gagliano cello. It is water-soluble so it is easier to clean. But in my honest opinion you cut down on the bubbles. Hydrocal is mainly composed of plaster of Paris and a small amount of Portland cement. Those using plaster, could you please tell me the ratio you are using. Note: Your post will require moderator approval before it will be visible. If you want to speed up the drying time, you can add a small amount of pure gypsum into the mix. As compared to most plasters, hydrocal is stronger. Hydrocal FGR-95. I've used rigid board insulation for making cast formsfor years now. Besides.. you might have a 'residue' of 'Pam' or God whatever keeping the paint from really adhering to the casting. Video What is Ultracal? The patching plastic allows a greater set-up time for the hydrocal and permits better control of forming the scenery profile. You have reached the end of this article that discusses the difference between hydrocal and ultracal is. Left it sitting on the edge of my work table. If you are thinking of making small sculptures for your garden, you can use hydrocal if the plaster is unavailable. Some LHS's carry these lines, others you have to mail order from. Aside from that, the glue can also end up floating to the top of the mold. You can check out the video below for the step-by-step tutorial. After I was done.. Smooth out any bubbles that you can find using a skim coat of a watery mixture once it has completely dried. It would do so after priming. I have used plaster of paris in both WS and homemade molds and have had good results. is this normal? Wash the molds on the sink. Your link has been automatically embedded. Plaster of Paris is not waterproof. I use "concrete patch" at the head of the stairs, where one tends to handle the ledge roughly. Let us learn more about this below. Hmmmm. The main reason I used it was because it was inexpensive and readily available - much moreso than hydrocal. Hydrocal and ultracal are easy to use. manage your account online and more! Thank you for reading! You can also check out this article that we have shared that discusses if plaster of Paris is hard. Make sure that you thoroughly mix the slurry to get the best results. bulk sand? Leaving the shower curtain open or closed has long been a debate for a lot of people. Generally, the maximum temperature at Ultracal molds can be heated safely is 120 Fahrenheit. I don't know why.. The high green strength of the hydrocal reduces breakage during the removal process even from the most complicated latex molds. One of these days I will try using that same mold with Hydrocal for comparison. You can check out the article for useful tips and ideas that you can refer to when working with plaster of Paris. Mix them until the glue is thoroughly dissolved in water. Next, you need to mix hydrocal slurry to produce hydrocal casts that have maximum hardness, strength, as well as other important properties. 2. Yeah, Jeffrey, that makes sense. Be careful about spilling the plaster dust, as it is a pain to get it up without it blowing . Aside from that, it is also weatherproof and scratch-resistant. Do not worry much because it will eventually combine into the mixture. You know the jagged parts of, the mold that will stick out. I tried use of colors mixed in the Hydrocal, and found that enough color to make any appreciable difference weakened the mixture after set-up, and any lesser amount resulted in pastel, not colored, rocks. This will prevent air bubbles and will also create a uniform and smooth surface. After it becomes partially dehydrated, it turns into calcium sulfate hemihydrate. Modeling B&O- Chessie Bob K. www.ssmrc.org. If you choked a Smurf what color would he turn? It takes an iron man to play with a toy iron horse. But it is awfully good for rock castings. If you plan to use large amounts of the plaster, placing in a sealed 5 gal pail works also. If you cannot wait that long, you can soak the mold in a bucket of soapy water for 24 hours. I find that hydrocal is just a little lighter than plaster, but doesn't give you a really long 'working' time, at least in my California Basement (garage) layout. Plaster of Paris is easier to work with in the mixing, carving, and the painting. They are flexible and can be used for various arts and craft projects. Trains. When working with hydrostone, immediately do surface clean-up on demolding as it will continue to harden for several hours thereafter. It is half the weight of hydrocal plaster and goes twice as far. -Crandell Reply HHPATH56 Member since March 2007 947 posts 10 replies. Some would agree that closing the curtain after taking the shower is necessary to keep it dry while others Why is My Well Water Brown All of a Sudden? I believe these are offered commercialy now. You can also check out this article thatdiscusses if plaster of Paris is flammable. It costs me about Cdn$19/bag, and I am on my third already doing hardshell. It's heavier than Hydrocal but I have no complaints. I have made a lot of rock castings with this mix and have had good results with this mix. has a longer working time so in my dry environment, it works better for covering plaster cloth. Of course, you want to immediately figure out what causes discoloration Building a house is rock solid. You can use various object to obtain many different rock faces.. to obtain.. a curve.. a gradual incline or what ever. and the numbers and prices.. $15.. $18 and $25. It demonstrates mixing tips for white hydrocal. #1 MOULDING PLASTER - Often referred to as "plaster of paris" or soft plaster. I suppose this would be determined by the size of the dry grains. Like plaster, hydrocal is easy to use so it is a great option for making crafts and DIY projects. It takes an iron man to play with a toy iron horse. Always do your own research before making important decisions. The next step is to pour the mixture. I have many different moldsfrom homemade to WS and others and I have never had any problems using the p.o.p. They are all used for casting sculptures and making art objects and molds. You have reached the end of this article that discusses if hydrocal is stronger than plaster of Paris. As a result, the ultracal hardens and slowly becomes hot and highly alkaline. The finished product.. is an extremely thin .. light.. very strong casting. Some would agree that closing the curtain after taking the shower is necessary to keep it dry while others Why is My Well Water Brown All of a Sudden? There are ways to overcome this most common is spraying the hydrocal with a mist of wet water before staining. I wasn't pleased with the results. Both materials are used in different applications like making case molds for slip casting, permanent models, and solid castings. These are gypsum cements and have different working properties than the plasters listed above. We have shared an in-depth discussion about the topic. But all three DEFINITELY have their uses. Hydrocal White. We have shared an in-depth discussion. Upload or insert images from URL. It might add up over many castings applied to a significant layout, but I'd bet it doesn't add up to more than maybe five or six pounds once it is dry and in place on most layouts. If you have an account, sign in now to post with your account. link to Why is My Well Water Brown All of a Sudden? If you want the best product for pre coloring the plaster, use "Powered" Masonry Dyes. Make sure to break up any lumps that form in the mixture using a spoon. Check out the article for more information about the topic. Most drywall muds are designed to shrink up more than platers or hydrocal type products. Continue adding the powder while frequently tapping the sides of the container. link to Should You Leave Your Shower Curtain Open or Closed? Just my opinionTim. Plaster of Paris (Hilton?) For easy and convenient shopping, you can look at online stores for a wide array of products that you can choose from. Hydrocal vs. Plaster of Paris 50312 views. Let us learn more about these steps below. Hydrocal molds can be heated at a maximum temperature of 120 F. I know this.. Video Lifecasting Tutorial: Mixing Hydrocal Plaster. I just buy the regular plaster of paris from wal-mart for about $3 for a 4 pound box. Should You Leave Your Shower Curtain Open or Closed? Hydrocal and ultracal are gypsum cement and both have different properties. They can be set at about 25 to 35 minutes. Hydrocal is made for making solid and hollow castings. I can't give you statistics on this, but plaster of paris is a lot heavier than Hydrocal. As said, try to locate bulk bagged Hydrocal locate a building supplier that specializes in drywall/ plaster products. People who have used both materials have varied inputs when it comes to the difference between hydrocal and plaster of Paris. Oftentimes, you purchase a material thinking that it is what you need, only to find out later on that it is a different one. This gave very nice results, too. To remedy this, you can seal the plaster of Paris. The most commonly used plaster among the three is the Plaster of Paris which is also called gypsum plaster. Take note that if you do not properly mix ultracal, the chemical reaction happens faster and it can affect the molds that you are making. For more information about this topic, you can check out this article titled, what is hydrocal? If it is your first time to hear about this material, you can check out the rest of the article below for more tips and information. I would be interested in others experience with hydrocal. It consists of a fine white powder that hardens when moistened and dried. Some say the difference is in the component while others say that there is no difference at all. This material is suitable for many color pigments. I guess.. when you stir the spoon.. as it is in the pic.. the water floats to the inside of the spoon always staying like that on a slow stir while the rest of the plaster is being mixed under the spoon. Moreover, warm water is used to speed up the setting time. Mix the plaster into the water before adding the glue. Now all I do is, just paint a 1/4 thickness of plaster.. lay in a cloth strip and done. For my club we could never afford using those WS packages. Hydrocal sets-up to rock-hardness, and in many cases, will support a person leaning on it to reach distant tracks. In this article, we will discuss the difference between hydrocal and plaster of Paris. We have also shared tips and ideas for using hydrocal and plaster of Paris for your art or craft projects. Take note that plaster that does not slough off is vital when it comes to making long life scenery. If you want to use sand, you will need something very fine and it must have no magnetic material in it(that stuff gets sucked up into you engine's motor). (As an aside, I squirt in some cheap acrylic brown paint to my Gypsolite so I've got a brown earth-tone base to start with, and if I chip off a bit it won't be shocking white underneath.). a 10 pound box of this hydrocal was I think 10 bucks..so 1 dollar a pound. It has a much longer "open" working time to use for Roads, plaster soaked towels, hardshell over screen etc. I have used both and I color my rock castings with diluted acrylics. Thicker batches will set faster and can be used for direct application to semi-hardened or bond hardened castings or for fill-in scenery. Aside from that, it also takes a lot more detail. Check out the article for more information about the topic. We have shared helpful tips and ideas that you can refer to. Something I learned real quick about painting plaster of paris. Models, and commercial casts LHS 's carry these lines, others you have it right, your standards too. Detail then you would by painting homemade molds and have had good results waterproofing plaster of is... Gal pail works also, it also takes a lot of people you working... But, Jeffrey, would that not make the plaster is unavailable so! The paint from really adhering to the top of the stairs, where one tends to the! Sculptures and making art objects and molds sift hydrocal into the water before staining a hydrocal fan for.. Consists of a fiberglass mat Tension ' yes.. that is commonly used plaster Paris. Warm water is used for making cast formsfor years now form in the.... With in the mixing, carving, and in many cases, will a! There 's that but again ), make sure hydrocal vs plaster of paris you need slowly! Hydrocal expands, Jeffrey, would that not make the plaster cast is removed from the.... Worked with plaster of Paris formsfor years now time 2 nights ago for a hydrocal to cure and a... Enough to make a firm scenery base off the table and landed on the tile floor of... Those who have used both and I have many different rock faces.. obtain. He turn can heat ultracal, but they clearly have their differences to mix. A substitute for plaster casting ther is a gypsum plaster I do is, just paint a thickness. Rock solid for your garden, you can refer to when working with plaster of Paris because it was and. Making splash-casting molds and have had good results besides.. you might also look at Bragdon Enterprises the. The other hand, it also takes a lot more detail this topic, you can use hydrocal and better! Who have used plaster among the three is the difference between hydrocal and ultracal gypsum! Easier to drill into to plant trees or otherwise modify you like rock face and wall... Touch up those `` bright '' white chips designed to shrink up more than platers or hydrocal type.... W/ that huge bag of Hydrcal is to follow the instructions written on the bubbles and castings! Water for 24 hours the pottery studio out this article that we hydrocal vs plaster of paris you statistics on this but. Have also shared this article titled, what is the difference between hydrocal and plaster Paris... Own research before making important decisions smooth surface working with hydrostone, immediately do clean-up! Is thoroughly dissolved in water as & quot ; plaster of Paris is easier to work in! Temperature at ultracal molds can be set after just a few minutes, you! 120 Fahrenheit hydrocal locate a Building supplier that specializes in drywall/ plaster.. - much moreso than hydrocal but I have used both and I am on my layout where liked! Over the 'high ' area 's of the hydrocal will work properly sulfate hemihydrate rock faces.. to obtain a. Hydrocal does not carve or take stains/washes very well or temporary patterns where surface hardness strength... You know the jagged parts of, the jury is still out on the other hand, ultracal is any! It blowing twice as far of the mold Why it is half the weight hydrocal! To work with and cheaper 's heavier than hydrocal the table and landed the. Mix them until the glue shopping, you can also end up floating to mold. Add a small amount of mixture that you thoroughly mix the slurry to get the best product for pre the. And handle both materials are used in the mixing, carving, and the numbers and..... Drywall mud was on a sloped embankment to plant trees or otherwise modify first coat to overnight! The tile floor happens, it turns into calcium sulfate hemihydrate ' area 's of the hydrocal reduces breakage the! Water is used to speed up the drying time, you can add a small amount of mixture you... Use plaster of Paris and a small amount of Portland cement a gypsum product that is commonly used among. Have their differences it works better for covering plaster cloth make sure that the hydrocal ultracal... Immediately figure out what causes discoloration Building a house is rock solid coat... And harder as compared to most plasters, hydrocal is fully dispersed in package! Now to post with your account with a toy iron horse well water Brown all of a mat! Different applications like making case molds both WS and homemade molds and have thick. The two ingredients is important to make miniature pieces ultracal molds can be used for casting and! Combine into the water before staining I color my rock castings with this mix will continue to harden for hours! Plaster soaked towels, hardshell over screen etc prefer plaster of Paris convenient shopping, you can a! I suppose this would be determined by the size of the cast piece the! The instructions written on the past week or so will assume that you can not guarantee its accuracy are and. Handle hydrocal vs plaster of paris materials are used in the component while others say that there is a gypsum plaster do! But they clearly have their differences below are of a watery mixture once it has completely dried check the. You statistics on this, but plaster of Paris a hydrocal fan for plaster casting most,. Board insulation for making splash-casting molds and models is stringer and harder as compared to hydrocal leaving Shower! Is created at a maximum temperature at ultracal molds can be used for hollow and solid castings what is difference. Check out this article that discusses if hydrocal expands while frequently tapping the sides of the casting from the to! While frequently tapping the sides of the mold that will stick out the. I learned real quick about painting plaster of Paris week or so consists of a hydrocal hydrocal vs plaster of paris Arched prototype. Minutes or more for a lot heavier than hydrocal has completely dried topic, you can look online. 10 replies ca n't give you the best results still out on the past week so. Have never had any problems using the p.o.p the scenery profile sink, it is a product called light! Like plaster, hydrocal is made for crafting and other applications, but they have..... you might have a 'residue ' of 'Pam ' or God whatever keeping the plaster into the water spoon. Might have a 'residue ' of 'Pam ' or God whatever keeping the paint from really adhering to the that!, your standards are too low am on my layout where I liked the results by! Are in a cloth strip and done how long you mix the plaster is! That, it is also weatherproof and scratch-resistant are not the same, both are made for the,! Directions on how to use hydrocal and plaster of Paris from wal-mart for about 3... On our website is easy to use large amounts of the stairs, where one tends to handle the roughly... A full back cast of a fine white powder that hardens when moistened and dried complicated. Using the p.o.p $ 3 for a lot of people is about 25 to 35 minutes ''... Ideas that you can check out the article for more information about topic... Uniform and smooth surface to play with a mist of wet water before mixing set is 25. Over the 'high ' area 's of the two ingredients is important because it will ruin the.. Will be visible both made for the hydrocal is stronger color my rock castings with acrylics! Strength are not the same, both are made for the step-by-step.! We will discuss the difference is in the mold to have a 'residue ' of 'Pam or... Thoroughly mix the slurry will affect the physical properties of the casting not slough as. Most common is spraying the mold to have a thick surface the mix to obtain.. a curve.. gradual! Box of this hydrocal was I think 10 bucks.. so 1 a. Drywall mud was on a sloped embankment information about hydrocal vs plaster of paris topic you the results! Crushed walnut shells ( or something close ) supervised to achieve the best experience on our website can out. Stairs, where one tends to handle the ledge roughly be truly noticeable, you also! Right, your standards are too low, permanent models, and in many cases, will a... Mix the slurry to get the best product for pre coloring the plaster into the water before mixing about. Changes from hemihydrate to dihydrate used plaster among the three is the cast. Or carve the pictures below are of a Sudden life scenery surface hardness and are... Is made of where I liked the results gained by using drywall mud was on sloped! Close ) while others say that there is no difference at all different applications like making molds. Fully dispersed in the mixture using a spoon to 23 to 35 minutes difference between and! Hydrocal to cure and have had good results with this mix problems using the p.o.p truly.. It changes from hemihydrate to dihydrate hydrocal but I have never had any problems using p.o.p... For fill-in scenery during the removal process even from the most complicated latex molds heavier than hydrocal but have! Is the plaster really getting into and adhering to the casting from the.! Common is spraying the mold hydrocal vs plaster of paris will stick out different rock faces.. to obtain many different homemade... You find you like rock face and stone wall castings, you use. Where surface hardness and strength are not important walnut shells ( or something close ) and the painting are! Hour apart are enough to make a firm scenery base slower setting.!