Pugaboo Posted February 9, 2016 Report Share Posted February 9, 2016 I need to make some new damp boxes. I have to order the pottery plaster online since I have no supplier near me. For 150lbs of pottery plaster they want $75 in shipping! The plaster itself only costs $50. So I am wondering for damp box usage would the plaster of Paris I can get at my local hardware store be ok? T Link to comment Share on other sites More sharing options...
Amy Eberhardt Posted February 9, 2016 Report Share Posted February 9, 2016 I used straight up, old fashioned POP that I got from Home Depot, Pugaboo. I've had zero problems with it, even in my very large (by my standards ) damp box. Just be sure to pop the slab out, once it has set of course, and clean off any residual bits that splash up on the sides during pouring into or mixing in the box. Then take a sure-form, or something like it, to clean the rough edges of your slap before placing back in the damp box. I use a simple green scrubby pad for this and it works just fine for my purposes. Link to comment Share on other sites More sharing options...
Pugaboo Posted February 9, 2016 Author Report Share Posted February 9, 2016 Thanks! I'll get a bag at Home Depot T Link to comment Share on other sites More sharing options...
perkolator Posted February 11, 2016 Report Share Posted February 11, 2016 For a damp box it likely won't make any difference since I'm assuming it's the type with just a slab of plaster. If it's slip casting molds then it likely would. I've always known regular gypsum plaster to be "weaker" than the Pottery #1. Your mold will degrade faster and won't hold the detail as long. I also think they have different absorption rates. Link to comment Share on other sites More sharing options...
Pugaboo Posted February 11, 2016 Author Report Share Posted February 11, 2016 No mold making just damp boxes. I've made a couple small ones before but just used what plaster I had on hand but it's gone now. This time I am making several large ones to hold assembled mugs, boxes, etc to keep at the leather hard stage for decorating. I dislike having an idea to paint or design then have to spend time making the item I wish to work with, it puts a damper on the artistic muse. So thought I would try large plastic bins about 18x24x12 with several inches of plaster in the bottom to store assembled "blanks". I thought being that big it would be better to use pottery plaster BUT at $75 for shipping plus the plaster itself that causes an issue. I will try plaster of paris if the plaster slab breaks when I pop it out to clean up then I will know I have to fork over the major bucks for pottery plaster. T Link to comment Share on other sites More sharing options...
jrgpots Posted February 11, 2016 Report Share Posted February 11, 2016 My damp box is made from normal plaster of Paris. my base of by damp box is 15 x 26 and the slab is 2 inches thick. No problems so far. Jed Link to comment Share on other sites More sharing options...
Amy Eberhardt Posted February 12, 2016 Report Share Posted February 12, 2016 You don't really have to pop the cured slab out of the box, Pug. The main reason for doing so is to prevent small bits from flaking off and getting into your work. If you clean up the slab in place, let it dry thoroughly, and there are no small bits around, you should be safe in just leaving it in the box. As dear old dad always said...."Work smarter, not harder" Link to comment Share on other sites More sharing options...
MaryOwens Posted June 8, 2020 Report Share Posted June 8, 2020 I have some unpainted figurines and s fee small statues That I purchased many years ago with the goal of painting them. The shop where I bought them is now closed and looking at them I can’t tell if they are bisque or if they are some sort of plaster. Could anyone here tell me how to tell the difference between the two is there a way you can test it in someway?? They are all white and painted and I remember my late husband And a kiln and fired ceramics and I remember a person need to use different paint On bisque so you can fire it again and then glaze it but I don’t know if these are plaster so I don’t know what to do with them or what kind of paint to use. Could somebody please tell me how I can figure out what these are made of thank you very much I would really appreciate it if someone could help meCould somebody please tell me how I can figure out what these are made of thank you very much I would really appreciate it if someone could help me figure this out thank you again figure this out thank you again Link to comment Share on other sites More sharing options...
Hulk Posted June 8, 2020 Report Share Posted June 8, 2020 Hi Mary! If the figures are clay, still unknown is the type of clay - particularly, the maturation temperature. A good start might be bring your figures to an experienced potter, then go from there? Link to comment Share on other sites More sharing options...
Denice Posted June 8, 2020 Report Share Posted June 8, 2020 If they are plaster you should be able to scrape some easily off the bottom, I can tell if something is plaster by smelling it. The paint on the statues might keep it from having that distinctive plaster smell. Denice Link to comment Share on other sites More sharing options...
liambesaw Posted June 8, 2020 Report Share Posted June 8, 2020 Plaster figurine will be solid, a clay one would be hollow Link to comment Share on other sites More sharing options...
Mark C. Posted June 10, 2020 Report Share Posted June 10, 2020 And I thought the plaster was made in Paris-They are famous for baked goods and plaster right?? Link to comment Share on other sites More sharing options...
liambesaw Posted June 10, 2020 Report Share Posted June 10, 2020 13 hours ago, Mark C. said: And I thought the plaster was made in Paris-They are famous for baked goods and plaster right?? I thought it was fried shoestring potatoes Link to comment Share on other sites More sharing options...
blackthorn Posted June 10, 2020 Report Share Posted June 10, 2020 Thanks for editing Liam. Glad I held off responding to your comment. Link to comment Share on other sites More sharing options...
AprilW Posted June 17, 2020 Report Share Posted June 17, 2020 I poured out my clay on some bats that I made from both PoP and Potters plaster and when the clay was dry enough it pulled up some of the plaster. Does this mean I didn't let the plaster dry enough or my clay dried too much and will this damage my clay? It happened with both kinds of plaster just worse with the PoP. Link to comment Share on other sites More sharing options...
liambesaw Posted June 18, 2020 Report Share Posted June 18, 2020 If the plaster is weak it was mixed with too much water, if it is strong but brittle, it was mixed with too little water. Did you weigh your plaster and water when you mixed? Link to comment Share on other sites More sharing options...
AprilW Posted June 18, 2020 Report Share Posted June 18, 2020 I didn't measure because the videos I watched showed how to do it without measuring. Link to comment Share on other sites More sharing options...
AprilW Posted June 18, 2020 Report Share Posted June 18, 2020 Will it affect my clay? Do I just need to throw it out? Link to comment Share on other sites More sharing options...
Min Posted June 18, 2020 Report Share Posted June 18, 2020 1 hour ago, AprilW said: Will it affect my clay? Do I just need to throw it out? Not worth taking the risk of having lime pops if you're not sure you can get rid of all of it. If you ever make plaster molds you can use the contaminated clay for (unfired) slump/hump molds or forms or walls when pouring plaster, just don't fire it. Just bag it up and label it really well. Link to comment Share on other sites More sharing options...
liambesaw Posted June 18, 2020 Report Share Posted June 18, 2020 2 hours ago, AprilW said: I didn't measure because the videos I watched showed how to do it without measuring. Always mix to the manufacturers directions. After you do it a dozen or so times and recognize how it's supposed to look and feel, you can probably do it by eye. But if this is something you're just getting into, might want to do it by the book until you've got it down. Link to comment Share on other sites More sharing options...
Chilly Posted June 18, 2020 Report Share Posted June 18, 2020 7 hours ago, AprilW said: I didn't measure because the videos I watched showed how to do it without measuring. I always, always measure. "Islands" method is too hit'n'miss for me. Link to comment Share on other sites More sharing options...
Karolina Posted September 16, 2020 Report Share Posted September 16, 2020 On 2/11/2016 at 12:31 PM, perkolator said: For a damp box it likely won't make any difference since I'm assuming it's the type with just a slab of plaster. If it's slip casting molds then it likely would. I've always known regular gypsum plaster to be "weaker" than the Pottery #1. Your mold will degrade faster and won't hold the detail as long. I also think they have different absorption rates. Does this mean I can use regular plaster for slip pours casts? it just means they won't last long. If I only want to make 10 objects. Then I can use regular plaster? I'm just asking. Due to covid and living remote I have no other option. Appriciate the knowledge. Cheers On 2/11/2016 at 12:31 PM, perkolator said: For a damp box it likely won't make any difference since I'm assuming it's the type with just a slab of plaster. If it's slip casting molds then it likely would. I've always known regular gypsum plaster to be "weaker" than the Pottery #1. Your mold will degrade faster and won't hold the detail as long. I also think they have different absorption rates. Link to comment Share on other sites More sharing options...
liambesaw Posted September 16, 2020 Report Share Posted September 16, 2020 16 minutes ago, Karolina said: Does this mean I can use regular plaster for slip pours casts? it just means they won't last long. If I only want to make 10 objects. Then I can use regular plaster? I'm just asking. Due to covid and living remote I have no other option. Appriciate the knowledge. Cheers Yes you can use normal plaster of paris. It is just weak and doesn't wick moisture as well. Link to comment Share on other sites More sharing options...
Mark C. Posted September 18, 2020 Report Share Posted September 18, 2020 the edges cab crak off as its very weak. As noted above its not great a wicking moisture (which mold work needs)-10 pours and toss it sounds ok-as long as the form is simple. Link to comment Share on other sites More sharing options...
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