plaster that shrinks? Answered

This is a goal. It is easy to sculpture on bigger scale and make mold from plaster or some other material that shrinks ABOUT 30%. After that I made new mold and or shrink again or use it as a mold for final product. Do you have any material like this - plaster, maybe, somematerial that shrinkswhile drying? Thanks

Question by bobank 8 years ago  |  last reply 8 years ago


Plaster and Epoxy

For my next Instructable (or next next, or more, I don't know yet), I will be using plaster or epoxy. Does anybody know where I can buy this at a local store? No internet stores, because my mom might take me tomorrow. Please post your thoughts/ facts ( :P ), thanks! -GorillazMiko

Topic by GorillazMiko 11 years ago  |  last reply 11 years ago


plaster of paris cracked?

Hii my plaster of paris cracked. i want to turn a 250x500 cylinder of plaster of paris on a lathe for a positive for slipcasting. its mounted onto the faceplate with a pine plank in the middle to help with the support of the plaster we made that last week thursday and all was fine but this morning it had a big crack in the length of it. what might cause it 

Question by brinleypritchard 2 years ago  |  last reply 2 years ago


Leaking plaster mold? Answered

Hi All, I have a six-part plaster mold that leaks. It is so time consuming to make another one and I would like to fix it. During construction I  slightly over shaved some lines that during casting it leaks. I can use it but it creates more work. Now I want to make a master mold from that but want to fix it first. Does anyone know how to fix such problems on molds? I really appreciate the help. Thanks and hope to hear Belgin

Question by Mihrace 7 years ago  |  last reply 7 years ago


Reusing Plaster of Paris?

...or simply plaster, is a type of building material based on calcium sulfate hemihydrate... It is created by heating gypsum to about 150°C....When the dry plaster powder is mixed with water, it re-forms into gypsum...So...if I heated the gypsum to +302F (150C), it would turn back into plaster of paris, to be reused agian? Of course you would need to powder the used plaster (gypsum), but would it work?

Topic by John Smith 11 years ago  |  last reply 11 years ago


Plaster Picture Frames

I nderstand 'GOOD' picture frqames are made of wood with a plaster coveribg, finished with gesso (sp). My thought is to build some using drywall compound as the plaster bt draggibg a metal guide over the wooden base? Am I totally off track OR has anyone had any experience with this. Carpe Ductum

Topic by naic98 11 years ago  |  last reply 11 years ago


How do I make some plaster for a craft project stepping stone at home?

 My kids and I were making these stepping stones for decoration and the plaster wasn't dry yet and my son picked it up too soon and some of it crumbled up and I need to make another one quick with stuff already in my home...

Question by MMcConathy 9 years ago  |  last reply 8 years ago


How do I make a plaster mold of a track ,then paster it again so the track is indented instead of being raised?

I want to make amold of a track.(For example a deer track) then make a mold of that mold so that the finshed mold is actually indented instead of being raised.I want to do this with my grandchildren so thy can hang these tracks on their wall.

Question by elkhtr1964 9 years ago  |  last reply 9 years ago


can you put bondo on plaster of paris? Answered

Can you put bondo on plaster of paris? i want to put some kind of filler on a rounded styrofoam shape, and then use bondo to make it look like a hard plastic or metal surface

Question by William930 7 years ago  |  last reply 7 years ago


Does Plaster of Paris shrink? Answered

Does Plaster of Paris shrink as it dries? I would like to make a mask out of it but I don't wan't it to shrink and crack. Gratias agimus tibi, josh1324

Question by josh1324 7 years ago  |  last reply 5 years ago


How to patch a large (tennis ball size) in a real plaster wall?

At deepest hole is 1". Old plaster, probably horsehair, quite crumbly.

Question by 10 years ago  |  last reply 10 years ago



Join plaster of paris and clay

Can a clay ware be joined to a ware made of plaster of paris

Question by KhobbyB 1 year ago  |  last reply 1 year ago


The Plaster Room Help Forum

Use our Technical Guides to learn how to use the Design Centre facilities.  This is the guide to the Plaster Room, watch the videos and feel free to ask questions here in the forum...

Topic by learningspace 8 years ago  |  last reply 8 years ago


Where can I find the least expensive plast'r craft type product?

The product is used for making masks or casting other shapes.

Question by 9 years ago


recycling plaster of paris used in glass casting

Actually it is a question again on same topic but the way the plaster has been used here may change the way it can be recycled. I use plaster of paris to make moulds for glass casting.I want to know if the plaster from these moulds can be recycled since they already have been heated for 24 hours in 800 degrees temperatures. Are the properties lost once heated that high?

Topic by patbagniewski 11 years ago  |  last reply 11 years ago



"Skinning" 123D cardboard model

Hey fellow Authors, i've been working on the following model for my business, strictly ornamental. I've come this far and don't know how to continue without destroying the time and money already invested. My goal is to cover it with some material and make it look like a statue. Maintaining still a polygonal feel to it. I want to paint it glossy red. I've thought about using fiberglass, plaster, paper (as found in a tutorial in the internet), Cover it with a pepakura mesh. But i'm still not sure how to proceed. I fear fiberglass to be too messy and complicated, plaster could ruin the cardboard dampening it, paper makes it look like a cheap piñata, pepakura would requiere a lot of trial and error to get the pieces to match the "skeleton" and problematic at the end to give it the glossy and professional feeling im looking for. Any ideas guys??   Sorry for the resolution on the first image, I didn't have my lap with me at the time of this post.

Topic by tammasus 4 years ago  |  last reply 4 years ago


I want to use expanded Steel Lath as an armature for a sculpture. How much can I (de)form it? Answered

I want to do a panel with "hills" and "valleys,"  making indentations the size of soup bowls, maybe a bit bigger.  Can I "push" or "pull" metal lath that much?  I know I cant do this with hardware cloth, and chicken wire is not robust enough. 

Question by hardlec 8 years ago  |  last reply 8 years ago


install drywall board on plaster wall? Answered

I need install drywall board onto existing plaster walls, there are no wood frames inside the plaster, inside of half  to 1 inch plaster are clay blocks. can I screw the drywall board to the plaster wall  without adding any additional supports? what kind of screws shoul I use for?

Question by maomao1018 9 years ago  |  last reply 9 years ago


Recycle Plastic to make Mesh for Plastering

I made my whole house out of recycled nylon fishnet and cement.  The tuna factory where I got the free fishnet moved off the island, and I have no more source for plasterable plastic mesh material.   I like plastic mesh because it doesn't rust.  Recycling some of our plastic trash, which is a huge world-wide problem, would be great.  Furthermore, given plasterable trash sacks one can make "trash rocks" ( https://www.instructables.com/id/TRASH-ROCKS-Eliminate-Unrecyclable-Trash ).   One can build with trash rocks; putting unrecyclable trash to good use as fill material inside the trash rocks.  If somebody could come up with a way to melt down and somehow convert plastic into mesh material, it could be a big step toward putting our trash to good use.  Mesh in the form of ready-to-use trash sacks would simplify the making of trash rocks.  In flat sheets, the mesh could be used to make walls, floors, and roofs. Fishnet stretches in all directions, so it is good for making dome shapes.  Some meshes are more rigid and are only good for flat projects, or cylinders.  If the mesh was more rigid, one might buy ready-made, light-weight forms for things like outdoor furniture, take them home and plaster them on-location.  Someone more chemistry oriented than I am might be able to figure this one out.  It seems to me there might be a lot of commercial potential in this, too. 

Topic by Thinkenstein 8 years ago  |  last reply 4 years ago


Can I use plaster-of-paris as a mold material for making an aluminum casting?

I do not have access to any proper mold making materials, only items that can be found in a hardware store or a pharmacy. I would like to know if I can use plaster of paris as a mold material for a simple pour type casting using a lost wax type method. Any help will be greatly appreciated.

Question by Wormlamp 9 years ago  |  last reply 1 year ago


curtain rack got ripped out of plaster wall. Can i fix put it back in?

Hi Recently, My curtain rack in my bedroom came out while i was moving the curtain, i was pulling down a little bit, and apparently that was enough to rip the rack out of the plaster. Ive attached photos. Because theres another rack holder, ide rather not patch up the hole as that will mean also patching up the other hole made when i remove the other rack. Is it possible to securely put the hook back in with a glue, resin ,foam or something?

Question by oldmanbeefjerky 6 years ago  |  last reply 6 years ago


How can I separate the silver 925 content from waste dust from a cutting project?

Ok, I cut sterling (.925) handles off knives sometimes.. the knives are stainless steel and the inside of the handle can be plaster, resin, sawdust..etc.  After using the larger silver part of the handle i have cut off, I still have a pile of silver/plaster/sawdust/resin dust that I really need to separate out the silver from.   Any ideas?

Question by sassquatch62 7 years ago  |  last reply 7 years ago


Strengthen plaster of paris with Christmas tinsel?

Through the Answers section here, I learned of mixing borax, rebake into powder, and then mix alum to create a high polishable cast...and also read discussion of the use of horse hair or fiberglass fibers from insulation for reinforcing the plaster. Unfortunately, I haven't ever found enough details to test either of these methods. The other day at the store, my wife asked if tinsel would work. It never occurred to me, but it sounds like it would make sense. Have you ever tried to pull a strand of that stuff a part? Also, I'm sure right after Christmas, it would be dirt cheap and in vast supply. I have been using the plaster of paris for making mold for some Sugru/Oogoo projects. Anyone ever try this or have any suggestions? Or if anyone knowledge about the fiberglass thing that I can use as basis, that would be cool too. Also, I know there are better materials than plaster of paris, that are stronger and all, but I am trying to at least use what I have on hand first, and I know other people would find it useful too.

Question by vphreeze 8 years ago  |  last reply 2 years ago


Could you use Mastic as a wall texturing stuff? Answered

I love mastic, it's affordable at 3 Gallons for $34.00.  It has a consistency like cream cheese or frosting, dries rock hard and is easy to clean up and work with.   So...  could I use it as a wall texturing compound? Thanks for any clues -foo

Question by foobear 5 years ago  |  last reply 5 years ago


How do I apply a finish to as well as paint plaster? Answered

I made a large sculpture out of styrofoam, which was then covered in some kind of plaster. I would like to paint it. I'm not sure exactly what kind of plaster it is, but it's white, and powdery, and you could chip off little dried pieces that can be crunched up into powder, but it's not weak, like it's on a pretty tall, thin sculpture and it hasn't cracked or anything after transport and sitting in a garage for months. I think I would have to apply some sort of sealant, or finish in order to paint it properly, but I have no idea! Also if you are going to reference some sort of resin that I should use please tell me common brands or whatever so it would be easy for me to find at say, home depot or wherever

Question by Sanclous 9 years ago  |  last reply 9 years ago


How can I made multiple plaster molds from one clay model?

Hello everyone, I want to use a clay model and have it cast into a two part plaster of paris molds, so I can use it for papier mache. My problem is, I want to have several identical molds of the original copy. I can't figure out how I can do this though, as I would have to pick to clay/plastercine out of the original mold. Has anyone got any ideas to get around this? I was thinking maybe I could make the first plaster mold, make a rubber copy of the model inside and then from there, make the other molds. Could this work? Any help or advice would be brill, Thanks, Yours

Question by yours 8 years ago  |  last reply 8 years ago


im planning to make rapunzel's tower from tangled, im going to use a wood frame and chicken wire, need plaster ? answred

Im planning to make rapunzel's tower from tangled, im going to use a wood frame and chicken wire . what is the best way or how do i keep the plaster from falling through the wire? should i wrap the frame in something before i plaster over the chicken wire?

Question by darkside3131 7 years ago  |  last reply 7 years ago


how to install a tv on a lath and plaster wall?

I was wanting to install my tv on my wall but i have a lath and plaster wall so i need to know the best way since it is a plasma and is quite heavy

Question by 10 years ago  |  last reply 10 years ago


My plaster of paris molds never work

I tried making one part and also two part (push) molds with plaster of paris. I followed the directions and mixed two parts of plaster to one part of cool water and poured into a box (dunno the technical name for it) over my shape. But the plaster sticks to my shape no matter what. I can't get my shape (positive) out without breaking my mold b/c it won't release. I've tried mineral oil, silicone release spray, and vaseline. The vaseline has worked the best but I can't use it on every part. I've tried making a mold of a piece of wood and a concrete paver and neither of which worked.  I don't know what I'm doing wrong. It seems fairly straight forward. Lubricate the positive (what I want to make a mold of), put a slab of clay down, put the box around the positive and imbed into the clay to prevent leaking from the bottom, and then pour the plaster over the positive. 

Topic by msminnamouse 5 years ago  |  last reply 5 years ago


I have a very detailed mold that i would like to plaster cast but not sure where to start?

The mold is of a clay head and there are petals all around the neck.  There are small slits around the petals also.  Will i be able to plaster cast this or is it too complicated. 

Question by 9 years ago  |  last reply 9 years ago


Home DIY Questions

The house i live in is falling apart at the seams. I fix every problem as it arises but a few things have stumped me or I've just never tackled them before. Any advice? 1. Gaping holes in Brick/Plaster walls left by electricians? 2. Panel from door punched through and sticky taped in good dodgy tradition. An attempt appears to have been made before to repair but the material has swelled with moisture (bathroom door). ? Cheers.

Topic by terielise 6 years ago  |  last reply 6 years ago


I am trying to cast a large "sawdust" object?

I am attempting to create large molds/casts of trash bags. the goal is to create a life-size trash bag made of sawdust. I'm not even sure where to begin. i'm not sure if i could create a mold of a bag somehow or if i could fill a bag and go from there. i know wood glue won't dry in a large mass, so i'm not sure what materials i should use. 

Question by ChristieS35 1 year ago  |  last reply 1 year ago


how can i apply plaster of paris on the ply board? do i need add some adhesiv or pop can directly applied to it?

I was planning to do a mural on a ply board. so i need to apply a layer of plaster of paris as a base coat. So do i need to add any adhesiv to pop or does it stick directly to the board?

Question by sriharshaaaaa 9 years ago  |  last reply 22 days ago


How to preserve plaster of paris and avoid it breaking away? Answered

I'm making the Good Samaritan gun from Hellboy per the instructions on Indy Mogul. One of the parts of the gun, the barrel, (erm....where the bullets go), is made from plaster of paris. From experience, I've learned that this can break on its own eventually. Is there any way to avoid it weakening or breaking? Perhaps covering it with something?

Question by Keith-Kid 10 years ago  |  last reply 9 years ago


Which tool to drill into jesmonite (very hard plaster)?

Hello workshop friends, I'm a novice maker and I would like to drill into jesmonite (very very hard plaster) to make candle holder (the hole has to be straight down). Which tool should I buy for that? A spade drill isn't good enough. Drill stand and the right drill bit or a proper drill machine? Thanks for your help! Lamie

Question by Lamie 2 years ago  |  last reply 2 years ago


How should I go about making it look like someone is trying to escape out of a canvas?

Basically trying to take a canvas and then place a replica of someone onto it in such a way that makes it look like they're trying to escape... Not sure how I should make the person...

Question by 10 years ago  |  last reply 10 years ago


how to build a vibrating platform?

I need to eliminate the air bubbles which form when pouring plaster of Paris into rubber moulds. so i thought i could eliminate this through low vibration as the plaster is being poured and eventually starts to harden.

Question by 10 years ago  |  last reply 10 years ago


i'm looking for a good way to make a mold for a resin cast.

I've tried other diy methods such as silicone caulk and Plaster to make molds.  while the plaster was the closest to working it was very difficult to remove the resin from the mold. 

Question by tvane1225 8 years ago  |  last reply 8 years ago


Speaker Enclosure

Can i make Speaker Enclosure with plaster of paris?

Question by Ansif 8 months ago


How would I make a mould for plaster of Paris to go into?

Hi, For the game.life contest I want to have a game controller mounted to wood like a trophy. How would I go about making a half-xbox-controller mould for plaster of Paris? If anyone steals the idea I can proudly say that I had the idea first. Thanks, NM P.S Notice how the analog sticks stick out? That could be a challenge :P

Question by NatNoBrains 8 years ago  |  last reply 8 years ago


Cheap casting compound?

I´m on a budget and looking for a compound that can either be poured into a mould like plaster or is at least very soft and hardens in a short time without massive shrinking. (low temperature melting metals -> too heavy, plaster -> not rigid and hard enough, epoxy -> too expensive)

Question by Fypsigon 8 years ago  |  last reply 8 years ago


After I build a table of plaster to reuse and wedge my clay on, how do I attach a wire to cut the clay?

In the past I've seen plaster tables used to dry and wedge clay on. Most of them have had a metal pipe attached on the corner. At the top of this pipe there is a piano wire. The other end of the wire is attached to the table, so It is strung tightly at an angle. I'm not sure how to attach the pipe to the table and the wire to the pipe. It must be very sturdy. Thanks for your help.

Question by rosylee 9 years ago  |  last reply 9 years ago


Casting resin or epoxy in a mould

Hi, I am looking to do an artwork where the final product is a clear plastic resin or epoxy sculpture with various items such as plastic forks and straws inside it. I got this idea from resin flooring which has crushed up beer bottles and screws in it, and now I need some advice. Currently I am thinking that I will make the sculpture from polystyrene and make a mould out of plaster of Paris by pouring the plaster over it in a tub of some sort. Is polystyrene a suitable material to base the mould off and can resin or epoxy be cast in plaster of Paris? Also, how might I go about making 2 parts to the mould which can join together and which I can pour resin in through a hole? Regards.

Question by 9 years ago  |  last reply 5 years ago


How do I hang a heavy bag from a traditional plastered ceiling?

Question by 10 years ago  |  last reply 9 years ago



Capacitor? Answered

Can I make a capacitor out of plaster Paris/fix-it-all and washers ?

Question by wiccakingkamui 5 years ago  |  last reply 5 years ago


Any substitute for Smooth-Cast 300? Answered

We have our own homegrown substitute for Oomoo thanks to the local boy genius Mikey77 But is there any substitute for it's companion product, the very expensive ($100/gallon), two part liquid plastic stuff called "Smooth-Cast 300"? Does anyone know of a way to mix an inexpensive something up and pour it into a mold and have it harden up into a strong thing?  It doesn't have to be as invincible as Smooth-cast, but .. is plaster the only option? Update:  What am I casting?  I found a really great ornamental tile at Habitat for Humanity and want to make copies of it Update:   I'm wondering now, what if I used something from the wall/flooring department, like Mastic?  Its about $34 for two or three gallons.  It fills gaps and hardens to such a degree that it can't be chiselled easily.  I may try this. Update:  Tried mastic, it works but takes far too long to dry, on the order of three days or longer...  Maybe if I mixed in some corn starch (ala oogoo?) Thank you -foo

Question by foobear 5 years ago  |  last reply 5 years ago


How to grow a crystals with gypsum and other materials?

Dear: Instructables Just to let you know I am limited to materials in my house. I want to grow a crystal with plaster like plaster of Paris but I am running into a few problems. I know that Gypsum or plaster of Paris is already a crystal but it doesn't have the necessary hardness I want. I want It to have a hardness of a minimum of 6 on the Mohs's scale. I also am limited to chemistry knowledge. I've been trying all day to design a crystal with the specifications I want but I've been having trouble trying to draw a Lewis dot diagram for plaster of Paris. I am not that good at drawing Lewis dot diagrams unfortunately. Here are some materials in my house I think I could use to incorporate with the homemade crystals. Acetone Potassium Chloride Sugar Baking Soda Potassium Nitrate and more... Can I have some help please? Thank you. From: Noah

Topic by nschreiber0813 3 years ago  |  last reply 3 years ago