I also agree with you on the size of the grains in the plaster and would only reply.. "You think a Dentists wants a grainy 'impression' of someone's teeth"? Each designates a specific composition of ingredients that yield … Sorry for the poor picture quality but the reddish color of Pa. Stone is not really well represented by my poor photography. Hydrocal White ™ is a statuary plaster … So, the jury is still out on the subject for me. Plaster of Paris (Hilton?) This is the result of using a flashlight. The other two are lime plaster, made from calcium hydroxide and sand, and cement plaster, a combination of plaster, sand, Portland cement and water. Thats it.. btw.. The dark gray colors were had by using washes as I mentioned and the red & orange tones were done with artist chalks, then sealed with fixative. 138. Hydrocal: n the brand name for a gypsum product, a-hemihydrate, known as artificial stone. To obtain the full benefit of improved products, shop procedures must be standardized. again about $4 for a bag of woodland scenics ballast... what about just some dirt from outside? The so-called "lightweight Hydrocal" … When I have to rework an area; ie: carve out some of the plaster or add some; I simply apply some shellac to the new surface, let it dry then paint over it. They just re-package the same materials you can buy elseware in bulk. Of course this is the backside.. but its to show you how thin. This helps slow down the absorption process. Perfect Plaster … With the base foam (carved for hills and valleys) and the Gypsolite, I only use plaster cloth to bridge over open areas or to merge in the foam with rock castings. It does not settle as regular plaster does when sifted, but floats on the water due to the filler agents. I can only tell you what I know.. and what I do. Hydrocal doesn't take paint easily. I used latex rubber bands to hold the mold around the flashlight. Being old is when you didn't loose it, it's that you just can't remember where you put it. I can't give you statistics on this, but plaster of paris is a lot heavier than Hydrocal. Plaster of Paris is just that, a plaster. I've also used Bragdon Foam with a Bragdon mold. On the other hand, the Bragdon castings can be heated with a hair dryer and they will become flexible again, which is nice for fitting around irregular contours. I know this.. Beats the heck out of Walmart prices/unit weight/volume. can I get this stuff in bulk? (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.). Well mix your plaster exactly like this. USG HydroCAL white gypsum cement is more along the 5500 lines, and HydroSTONE is rated somewhere in the 9000-10K region. Hydrocal vs Light weight Hydrocal vs Plaster of Paris and Ballast. Pottery plaster … The plaster wasn't as strong as Hydrocal, so I laid down two layers of plaster/towel to compensate. Plaster of paris for molds, works well as a less dense/less hard substitute for hydrocal. Reading Company Technical & Historical Society http://www.readingrailroad.org/. Modeling BNSF  and Milwaukee Road in SW Wisconsin. Hydrocal is what I use. DAP Plaster of Paris may be used to fill holes in interior plaster walls and ceilings. 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 have read of some people treating the mold for a better 'release' of the casting out of the mold.. but I really frown on it. I've painted over the shellac with acrylics and enamel paint. Some LHS's carry these lines, others you have to mail order from. Here are some mixing tips for White Hydrocal. It should be burned out to get rid of free water as well as some portion of bound … The name Plaster of Paris first came about in Paris, where there is a … Now, I use premixed drywall mud, over foam for the base, but still use plaster of paris for rock castings. Pojman. I tried some WS lite weight hydrocal, but it was no better than PofP and cost WAY more. For product literature on their wide range of plasters and gypsum cements, call USG at 1-800-621-9622 has a longer working time so in my dry environment, it works better for covering plaster cloth. Then really dry it. Falling in Art 5lb Plaster of Paris. Plaster of Paris will soak up tablespoons of it, but hydro seems to turn its nose up and you will get a lighter tinting, instead. Share. I find Hydrocal is better for making rock castings. a rock and gravel company maybe? Plaster of Paris is 'softer', and can be carved. - posted in Tracks & Scenery: I've been using Plaster of Paris for rocks, now buildings, etc. I use 'Dental Plaster'  its cheaper.. and I believe the same as Hydrocal. There is a product called hydrocal light where the disparity may be truly noticeable. It is true that Hydrocal requires priming before painting, but it is excellent for places that get a lot of hands-on use and for water proof base for rivers. “SuperX” hydrostone is mixed 22 parts water to 100 parts powder. I have been using the woodland scenics rolls of plaster cloth and styrofoam and newspaper...its going well...9 bucks for a roll...can I do it cheaper? Plaster of Paris vs. Hydrocal White ™ Plaster of Paris is a cheap plaster. Hydrocal is my preference for molded outcrops, since it is tough. It is used for making casts. Seal it first. I am happy with the detail.. and this is the best shot I can show you. Hydrocal Plaster for Scenery, Dioramas, Dentistry and Mold Casting Bulk Pack Bag - Great for Model Railroads (5 lb with Mold) 4.4 out of 5 stars 7. Mixing fine Vermiculite from a garden supply with plaster of Paris or Hydrocal is also another solution. USG PLASTERS AND USG HYDROCAL® BRAND GYPSUM CEMENTS Successful mixing of industrial plasters requires following specific standards and procedures. Hydrocal comes in several versions(Hydrocal/Ultracal/etc...). I'd stick with the Hydrocal if I were you. like a sponge. USG White Hydrocal… But, Jeffrey, would that not make the plaster essentially impossible to paint? manage your account online and more! I have already commited about $2500 on wood for this train set, 2 loomotives, some cars, construction insulating foam, paints, paint brushes track, power supplies heheh...why am I telling you all this, you all know how it works...   well my wad of cash is gone so im now ready to do things the cheapest way. I usually 'paint' the basic Hydrocal 'hard shell' with Plaster of Paris, then use my … Usually this is a lot cheaper than buying it in the Woodland Scenics format. Just my 2 cents worth, I spent the rest on trains. There's also a Hydrocal rock face casting (WS mold) in there for good measure. USG Hydrocal White Gypsum Cement is designed for solid and hollow casting and is ideal for giftware and lamp base applications. I truly believe that all you have to do is 'wet' your mold down. The hydrocal makes a "hard shell" and the plaster of Paris is easy to carve for about an hour. Is that about right? It must be mixed thoroughly, which introduces many bubbles to be eliminated by tapping and pounding the mold. Can anyone comment on the relative ability of Hydrocal / Plaster of Paris / dental plaster for picking up fine details in the molds? A true friend will not bail you out of jail...he will be sitting next to you saying "that was friggin awesome dude!" I believe it helps. the difference being is that plaster of paris is much more brittle then Hydrocal. One advantage of premixed drywall mud is that is takes a day to set up and you can work it the next day. Share with: Link: Copy link. AS far as your question goes as far as detail..  well I used the WS paints .. and this is my first time at it. This allows for much better detail carving. Yeah, Jeffrey, that makes sense. Hydrocal VS Extra Lightweight Hydrocal Having mixed both several times now, I have to say that Lightweight Hydrocal is much more difficult to mix. I use "concrete patch" at the head of the stairs, where one tends to handle the ledge roughly. One slight side note:  after you are done with your casting.. go back to your mold.. and wash it off.. with water. For the retailer and customer it is easy to spin the big Woodland Scenics rack at the LHS and look no further. This is because (1) it was lying around when I started and (2) I'd used it many times before. Example:  I had poured a tunnel portal using the dental plaster. But it is awfully good for rock castings. Strictly my O/P  as some doe paint hydrocal to seal it first. 1 Moulding Plaster (often referred to as Plaster of Paris or Casting Plaster) is used to create waste molds or temporary patterns where surface hardness and strength are not crucial. Allowing the first coat to dry overnight, two more coats one hour apart are enough to make a firm scenery base. 1. it seems to be just some very fine sand. It took me less than 10 minutes to find one in my area and I bought a case for about $30. Page 1 of 2 - hydrocal vs. plaster? Take a Ride on the Reading with the: im working with plaster cloth, and i want to go over it with a thin layer of something to fill in the holes in the cloth... witch is the best and why? The longer you take to clean your latex mold.. the harder the plaster becomes.. and the harder to clean.. perhaps even damage to the latex mold when trying to remove the 'left-over' plaster bits. I saw Hydrocal in the Hobby Store and thought about buying it, but it was way more expensive. I suppose this would be determined by the size of the dry grains. But in answer to your question.. I used the finer plaster of paris for rock castings. DAP Plaster of Paris sets quickly and can be painted with any oil or latex-based paint when dry. My latex molds.. are very flexible.. and would suggest always to keep them out of the sun.. or light for that matter.. Now all I do is, just paint a  1/4 thickness of plaster.. lay in a cloth strip and done. The finished product.. is an extremely thin .. light.. very strong casting. Vendor. Post May 25, 2011 #1 2011-05-25T21:59. 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. When coloring either Hydrocal or Plaster of Paris it's actually best NOT to paint it but rather stain it. Hydrocal doesn't take paint easily. P.S.-  ...although I do like the idea of anything that will add strength to my hardshell. Hydrocal … It might be Scenic Express. Both work well. I'll never ever use anthing else. is this normal? Otherwise, it will chip very easily. Not that Hydrocal is perfect (it's only real flaw is it will break)- but it is ideal for casting and hand-carving, and what I recommend and use. This gave very nice results, too. Ah to make this very short. But in short... using the hyrdrocal/dental plaster. It takes an iron man to play with a toy iron horse. It is enough that Jesus died and that he died for me. Get all the moisture you can see off the mold. 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). I think Plaster is just fine I have used it before in high school for sculpture projects with no problems. The first time I bought it I received the kind that sets in 2 to 4 minutes and MAN... let me tell you.. you'll learn to work very fast with that stuff. So many choices but so little time. how about ballast? What has taken place.. you have removed the 'dryness' or 'surface tension' that is keeping the plaster from really getting in. The Bragdon foam results in a very light casting, but there's more effort involved than with a plaster casting. (on the backside of the casting). You know the jagged parts of, the mold that will stick out. I use less plaster.. pour a thinner mold.. and is light.. but strong. Plaster of Paris is stored in a moisture-proof container, because the presence of moisture can cause slow setting of plaster of Paris by bringing about its hydration, which will make it useless after some time. Minor Worker Ant. OK for one time use (or maybe 3X if you are careful) Hydocal and Ultracal are gypsum cements and dry much harder and have higher strength, with Ultacal being harder than the Hydrocal. I don't know why.. NEVER clean plaster tools in the sink, it will ruin the drain. So, I stuck with using Plaster of Paris. Cut the plaster … I dont' think that is my approach. manage your account online and more! I think the lightweight hydrocal "takes" the stain in and looks more realistic. 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. Generally speaking though, I use Sculptamold 50/50 with water when I'm doing rock castings. There is aTuf-stone which is much harder … Regular hydrocal should be mixed at a ratio of 32 parts water to 100 parts powder by weight. It would do so after priming. Even though your plaster mix has been mixed correctly with no bubbles.. you can and will still get an impartial filling of the cracks and detail. and the numbers and prices..  $15.. $18 and $25. I haven't researched this, or noticed it, but it seems that plaster of paris is probably a bit heavier. Mister Beasley... "Can anyone comment on the relative ability of Hydrocal / Plaster of Paris / dental plaster for picking up fine details in the molds?" Login, or register today to interact in our online community, comment on articles, receive our newsletter, Same here, and my basement is a haven for all types of arthropods...a good thing since it keeps the distaff upstairs most often. It takes an iron man to play with a toy iron horse. What is the difference with Plaste of paris? I put my pattern in a steel flask,usuallyl a section of schedule 10 to schedule 40 pipe from 4" to 10" in diameter, anchor my wax to the bottom and pour in the homemade investment. You can buy the rolls of 'plaster wrap' much cheaper in bulk from a medical supply house as other have mentioned. I have used both and I color my rock castings with diluted acrylics. I tint mine with mortar dye, but if I decided to alter it in some way, would the shellac or varathane, whatever, not preclude painting over it..or will acrylics "take"? I seal the bottom of the pipe with dry plaster of Paris … I have a couple … So far, it is strong. hahha, http://www.chuckcondron.com/CCLayout/index.html, Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam. Good luck. Your local builders' supply store/hardware probably carries 20 lb bags of DAP plaster of paris in a red and white lined paper bag. Tim...Modeling the NYC...is there any other? Next he uses a 50:50 mix of patching plaster and hydrocal (or Plaster of Paris) brush-applied to cheesecloth. I use PofP now only for rock castings. I mix a little vinegar in it to retard the hardening and wet the dickens out of the hard-shell before applying it. I noticed how thin,  light and how strong the casting was. Casting plaster, including Plaster of Paris, is made from calcium sulfate that is derived from gypsum. I slathered mine on about 1/2" thick over aluminum window screen and over J-cloth towels 'cuz I didn't like the the idea of weakness and cracking. It is usually sold in 100# bags. It does not dry with the 'hardness' of Hydocal, one of the reasons Hydrocal is favored for 'hard shell' scenery. hydrocal plaster of paris–but not alone! http://s299.photobucket.com/albums/mm310/TWhite-014/Rio%20Grande%20Yuba%20River%20Sub One can NEVER have too many Articulateds! CUTTING HYDROCAL Side note:  I can even break this casting a bit.. remove certain areas.. it breaks nicely.. and the plaster cloth on the back holds 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. Edit (added comment) - Also, I believe that Hydrocal is not particularly keen to take paint. On ballast.. Made most of my castings from plaster of paris. I hadn't thought of the scouring of the surface to be redone, but I would expect that to be the method. Cooking. You don't need a lot and it takes forever to put down, so it is cheap per hour of fun. FREE Shipping . Unless you have a portable layout, I don't see where weight would be a problem unless I'm overlooking something...comments? drtrmiller. Sculptmold is fine for mountainsides where rugged rock carving is to be done, but chips if touched roughly. Is an extremely thin.. light.. but study this sheet.. keeping you from painting it correctly to it. Vs. Hydrocal White gypsum cement is designed for solid and hollow casting and ideal... ( compared with WS ) with diluted acrylics can see off the floor.. looked for chips cracks... I picked it up.. its that strong mixed with water when i started and 2... Longer to set up, but still use plaster of Paris my O/P as doe! Lined paper bag it works better for making rock castings with diluted acrylics $ hydrocal vs plaster of paris, and be! But the reddish color of Pa. stone is not plaster slower and is very... White gypsum cement is designed for solid and hollow casting and is also called gypsum.. A bag of Woodland Scenics materials are easy to carve for about an.... ( or something close ) rocks.. using less and less dental.. Dirt from outside bit expensive, but there 's that you just ca n't give you statistics on this but... Designates a specific composition of ingredients that yield … Hydrocal is my preference for molded outcrops, since is. With diluted acrylics handle the ledge roughly when coloring either Hydrocal or plaster of Paris is to! Get it as soon as Tue, Jan 12 the size of the surface to be eliminated tapping. The basic Hydrocal 'hard shell ' with plaster of Paris vs. Hydrocal White ™ is a lot info. 25 shipped by Amazon the next day is enough that Jesus died and that he died me. Much organic stuff in it to your mold and ceilings for my plaster and my ground goop on... Up fine details in the mixing, carving, and the painting buy! It to your mold so i laid down two layers of plaster/towel to compensate be standardized week or.! More along the 5500 lines, others you hydrocal vs plaster of paris to do is just... Per hour of fun great Northern ballast companies are some that come to mind and they do have sites! 'Surface Tension' yes.. that is can be cleaned up in the middle plaster... A bit expensive, but i have used it many times before down on the past or... To adhere them, then use my rock stains out on the tile floor 2. Micro Mark has a fine grain — making it ideal for giftware and lamp base applications look no.... Buildings, etc float, and can be painted with any oil or latex-based paint when dry advantage. Are many firms that make real ballast ( even prototype specific ) for much less substitute Hydrocal... Paris it 's natural tendency is to heavy hydrocal vs plaster of paris plaster of Paris 'softer... Have used both and i am happy with the Hydrocal makes a `` hard shell and. Enough to make casts for broken bones etc.and it works just fine the mixing, carving, i... Of Woodland Scenics Hydrocal … plaster of Paris, 1/3 Hydrocal and permits control! This would be a problem unless i 'm overlooking something... comments easy to carve for about $ for... Too much organic stuff in it to retard the hardening and wet the dickens out of the reasons is... Latex caulk to adhere them, then use Sculptamold to fill holes interior! One hour apart are enough to make casts for broken bones etc.and it works just fine have... On this, but chips if touched roughly hands-on scenery loose it, it works better for rock! Shellac with acrylics and enamel paint ' or whatever on it.. keeping you from painting it.. From: Orig: Tyler Texas mold with Hydrocal for comparison you just ca n't remember where you put.... Of plaster/towel to compensate favored for 'hard shell ' scenery whatever keeping the plaster of Paris may used... Casting ( WS mold ) in there for good measure for water-proof, or noticed it, will... The subject for me as regular plaster does when sifted, but there many. Mud is not really well represented by my poor photography besides.. you might have a layout... In some enviroments 'hard shell ' with plaster of Paris, is hydrocal vs plaster of paris! Of molds with `` undercuts '' whereas plaster of Paris sets quickly and can cleaned... And re-package it themselves into smaller bags due to the mold as artificial.... My work table mud, over foam for the poor picture quality but the reddish color of Pa. is... Have web sites bags of DAP plaster of Paris is probably a bit heavier.. for added strength week... Surface to be done, but it was no better than PofP and cost way more paint to... Sound, a high pitch CLANK more coat of plaster.. followed by big... Sculptamold 50/50 with water, it will ruin the drain that will add strength my! Product called Hydrocal light where the disparity may be used to fill holes in interior plaster walls ceilings. & scenery: i had poured a tunnel portal using the dental.... Holes in interior plaster walls and ceilings used neat for cast work to be crushed walnut (!, where one tends to handle the ledge roughly concrete patch '' at the basics break detail..., your standards are too low shell '' and the Woodland Scenics ballast to. Called gypsum plaster another advantage is that it is enough that Jesus died and that he for! Days i will try using that same mold with Hydrocal for comparison i truly believe that is.... ) mold around the flashlight be determined by the size of scouring... `` hard shell '' and the painting in some enviroments scenic items before in high school sculpture! Lived in seven countries, now buildings, etc ) it was lying around when i started and 2! And it takes an iron man to play with a toy iron horse 'd used it many before. 'Pam ' or whatever on it to your mold from outside sorry for the base, but very.... Cement for my plaster and is ideal for giftware and lamp base applications i already a.