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Other Stuff => Workbench => Topic started by: Cacique Caribe on April 18, 2022, 08:36:32 PM

Title: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Cacique Caribe on April 18, 2022, 08:36:32 PM
Which one you choose can make all the difference:

https://youtu.be/4SwgnbuCDeg

Dan
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Codsticker on April 19, 2022, 02:32:55 AM
Same approach as with pancakes- liquid mix into dry mix. :D
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Fitz on April 19, 2022, 03:19:33 AM
When I was working in the Canterbury Museum display department, we were using plaster 20 kg at a time. We always added the plaster to the water, usually through a flour sifter, because it gave us much, much better and more reliable and repeatable results than adding water to dry plaster.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Cacique Caribe on April 19, 2022, 05:53:36 AM
Same approach as with pancakes- liquid mix into dry mix. :D

LOL.  That’s exactly what my wife said to me on this topic.  :)

Dan
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Daeothar on April 19, 2022, 08:37:18 AM
When I did my re-enforced concrete road pieces during last year's BSC, I did a lot of plaster pouring.

And I added the water to the plaster, simply because I also added pigment powders to the plaster, and I had to mix those with the plaster before adding the water, since the pigments were heavier than water and would sink if not mixed with the powder beforehand. Plus I reckon that doing it the other way round, mixing them evenly would be much more difficult.

Also, I looked it up, and several trustworthy sites advised to add the water to the powder. Apparently using lukewarm water is also better than ice-cold water. Probably this has to do with the chemical hardening process, which also generates (a bit of) heat.

@ Fitz: I can imagine handling these quantities requires a different approach, but mixing plaster at miniature levels is usually well within the strength bracket of the average human ;)
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Golgotha on April 19, 2022, 09:25:33 AM
Stopped using plaster for a number of reasons:

Time to set
Soaks up a great amount of paint
Heavy
Degrades and weakens turning to powder - tried adding white glue to the mix but this did not effectively alleviate these problems
Due to the liquid content will warp the materials it is being placed on.
Does not effectively pick up detail in molds
Any breakage shows up glaringly white. 

Having said that when soaked into bandages it seems to work well for helping broken bones to heal  lol

Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: sundayhero on April 19, 2022, 01:31:33 PM
synthetic plaster is a bit more expensive, but a way easier to use, and solid as rock.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Daeothar on April 19, 2022, 06:07:10 PM
Yup. I'm using dental plaster and it takes a concentrated effort (and tools) to actually break the stuff...
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Mammoth miniatures on April 19, 2022, 10:58:59 PM
Sculpture technician here - Always plaster to water.
It helps ensure an even and consistent mixture free of voids/powder lumps and also ensures a nice and timely chemical reaction.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Golgotha on April 19, 2022, 11:48:26 PM
Is this the right sort of dental material? See: https://www.ebay.co.uk/itm/371098478049?var=640262347223&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338723872&toolid=20006&customid=jfX1chAPAAAAdrTOprIku_BunyUIAAAAAA
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: sundayhero on April 21, 2022, 01:46:46 PM
I don't know, the brands are diferent here in France. But I believe any kind of synthetic plaster will do the job. MIxing is a way easier and forgiving, and the result is great, both details and strength.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: OSHIROmodels on April 21, 2022, 01:47:45 PM
Plaster to water for the best results.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: sundayhero on April 21, 2022, 02:08:23 PM
by the way - with synthetic plaster you can do the both ways  lol When I say it's forgiving, it is  lol
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Sangennaru on April 21, 2022, 02:27:32 PM
synthetic plaster is a bit more expensive, but a way easier to use, and solid as rock.

This. I haven't used anything else in the last 10 years (in terms of plaster alternatives). Not cheap, but it has so much potential!


Is this the right sort of dental material? See: https://www.ebay.co.uk/itm/371098478049?var=640262347223&mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338723872&toolid=20006&customid=jfX1chAPAAAAdrTOprIku_BunyUIAAAAAA


Search for Raysin100, it's available throughout europe, should be also in UK!
I personally use Diplast, which is sold by a company in Rome.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Cacique Caribe on April 24, 2022, 06:53:08 AM
Synthetic plaster?  I guess I’ve just learned something new!  :)

Having worked at a dental laboratory in my early 20s I was familiar with plasters, hydrocal and other natural gypsum products.  But not a fully synthetic product.  I miss those Stone Age days.  :)

Dan
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: sundayhero on April 24, 2022, 07:47:01 PM
If I remember correctly (not used it a for a while) I was using staturoc product.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Golgotha on April 25, 2022, 09:04:33 PM
For plaster and other terrain features, perhaps, standing the test of time see:

https://www.youtube.com/watch?v=Ezq_AnRWDbw&ab_channel=GeekGamingScenics
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Cacique Caribe on May 02, 2022, 02:20:33 AM
Thanks Golgotha!  That board looks almost as good as when he first made it.

Dan
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Golgotha on May 02, 2022, 12:32:20 PM
What then are the advantages of dentist/synthetic plasters over resin for molding?
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: Digits on May 02, 2022, 01:44:18 PM
Dental plaster is very hard when dry….we used it a lot to cast Hirst Arts Bricks.  You needed to work them / carve them whilst still damp otherwise difficult when dry.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: snitcythedog on May 02, 2022, 02:02:52 PM
What then are the advantages of dentist/synthetic plasters over resin for molding?
Cost, ease of use and chemical damage to moulds.  Resin tends to be harder and lighter.  You can extend the life of silicone moulds by using a good mould release with resin but the mould will still wear out faster than if you just use silicone. 
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: SotF on May 03, 2022, 01:23:36 AM
What then are the advantages of dentist/synthetic plasters over resin for molding?

One thing is that, for stonework, you can do a lot with various washes when on stonework where the resin needs certain paints to let you then use those techniques (The larger bottles of Applebarrel white craft paint, if applied unthinned, gives you a slightly chalky texture and it takes inks, washes, and stains much like plaster...it's already a very thin paint, but I've done that with a lot of things I wanted to look like stone). Plasters also work better for making a cohesive whole with some of the ground texture options such as the sculptamold or some of the patching compounds which work to blend it into other stone if you want something to look like it's carved from the stone there.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: sundayhero on May 04, 2022, 12:56:12 PM
Cost, cost, cost, and mould durability.
Title: Re: Do you add your plaster to water, OR do you add water to your plaster?
Post by: white knight on May 09, 2022, 10:31:52 AM
Search for Raysin100, it's available throughout europe, should be also in UK!
I personally use Diplast, which is sold by a company in Rome.

Interesting. How is the weight? Heavy like plaster or lighter?