Gypsum hardeners

Gypsum hardeners

rhuarch
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rhuarch
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Joined: February 1st, 2018, 9:22 pm

February 1st, 2018, 9:39 pm #1

Hi there everyone!  I'm new here and just trying to get my bearings while doing research to jump into this hobby.  Has anyone here used gypsum hardeners like Stalite from the plasterguys web site?  Are they useful, or completely unnecessary?  I'd love to read your experience if you have used products like this.  Thanks all!
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Vail Marston
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Vail Marston
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Joined: September 23rd, 2013, 6:31 pm

February 3rd, 2018, 2:28 am #2

I don't have any experience with these products, but they have been discussed on these boards in the past.

If I remember correctly, the upshot is that the higher end plasters recommended by most here,like Merlin's Magic, already have hardeners and you wouldn't get much benefit adding more. It also might negatively affect properties like micro bubbles and set up time.

It might be beneficial with the lower end plasters, but you would probably be better off spending the money on superior plaster if it's available to you.
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rhuarch
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rhuarch
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Joined: February 1st, 2018, 9:22 pm

February 6th, 2018, 4:09 pm #3

Vail Marston wrote: I don't have any experience with these products, but they have been discussed on these boards in the past.

If I remember correctly, the upshot is that the higher end plasters recommended by most here,like Merlin's Magic, already have hardeners and you wouldn't get much benefit adding more. It also might negatively affect properties like micro bubbles and set up time.

It might be beneficial with the lower end plasters, but you would probably be better off spending the money on superior plaster if it's available to you.
Thanks for your reply.  That makes a lot of sense to me.  
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phialphatheta
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phialphatheta
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Joined: February 3rd, 2018, 11:25 pm

February 19th, 2018, 11:45 pm #4

Welcome to the hobby rhuarch. I found adding Durham's Water Putty will add some strength and a touch of earth tone color. As others have mentioned, go with a higher quality product. I am currently  using some old Plaster of Paris making ruin parts with a heavy amount of weathering. Arguably this is now a lower grade material from the time I purchased it, so it's "poor" performance is what I am looking for. This makes it difficult to achieve a crisp cast; so unless a very weatherworn look is what you want, stay high end. 
Also, if you have not, you should review the casting instructions on the Home Page, this will save you some frustrations with air bubbles and crisp lines. Pay articular attention to the use of rinse aids. Good luck, I am looking forward to some posts.
 
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amykins3
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amykins3
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Joined: April 18th, 2011, 10:30 pm

March 13th, 2018, 12:24 pm #5

phialphatheta wrote: Welcome to the hobby rhuarch. I found adding Durham's Water Putty will add some strength and a touch of earth tone color. As others have mentioned, go with a higher quality product. I am currently  using some old Plaster of Paris making ruin parts with a heavy amount of weathering. Arguably this is now a lower grade material from the time I purchased it, so it's "poor" performance is what I am looking for. This makes it difficult to achieve a crisp cast; so unless a very weatherworn look is what you want, stay high end. 
Also, if you have not, you should review the casting instructions on the Home Page, this will save you some frustrations with air bubbles and crisp lines. Pay articular attention to the use of rinse aids. Good luck, I am looking forward to some posts.
 
So I have been looking for a long time for a way to add something that would allow me to pick up a cheap product at home depot and add a hardener to make it stronger. Bags of plaster of Paris are dirt cheap, and no shipping costs. If anyone knows a way please bring it here.

PoP is like $5 for a $25lb bag, vs the $100+ I spend on Excalibur after shipping.

I've cast in PoP plenty and its... Ok, but definitely not as strong as Excalibur or the other dental stones I've used.
There is one ingredient in particular some sort of silica, is impossible to find. Probably causes cancer or something equally hideous.

Any know how to acquire that ingredients?
Molds: At this point its easier to put the molds I DON'T have:91,86,311,90,204,206,210,211,265,266,74,76,79,88,261,260,295,340,421,422,423,180,181,182, 222,223
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Galileo
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Galileo
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Joined: June 2nd, 2005, 7:26 pm

March 13th, 2018, 11:23 pm #6

amykins3 wrote:
phialphatheta wrote: Welcome to the hobby rhuarch. I found adding Durham's Water Putty will add some strength and a touch of earth tone color. As others have mentioned, go with a higher quality product. I am currently  using some old Plaster of Paris making ruin parts with a heavy amount of weathering. Arguably this is now a lower grade material from the time I purchased it, so it's "poor" performance is what I am looking for. This makes it difficult to achieve a crisp cast; so unless a very weatherworn look is what you want, stay high end. 
Also, if you have not, you should review the casting instructions on the Home Page, this will save you some frustrations with air bubbles and crisp lines. Pay articular attention to the use of rinse aids. Good luck, I am looking forward to some posts.
 
So I have been looking for a long time for a way to add something that would allow me to pick up a cheap product at home depot and add a hardener to make it stronger. Bags of plaster of Paris are dirt cheap, and no shipping costs.  If anyone knows a way please bring it here.  

PoP is like $5 for a $25lb bag, vs the $100+ I spend on Excalibur after shipping.

I've cast in PoP plenty and its... Ok, but definitely not as strong as Excalibur or the other dental stones I've used.
There is one ingredient in particular some sort of silica, is impossible to find. Probably causes cancer or something equally hideous.

Any know how to acquire that ingredients?
Can you get https://www.quikrete.com/productlines/s ... rglass.asp  from your local DIY store? (Home Depot, Lowes, or similar) -- it looks to be very decent stuff.
It's NOT denial. I'm just very selective about the reality I accept. -- Calvin (Calvin and Hobbes)
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oldasa
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oldasa
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Joined: April 1st, 2018, 7:21 pm

April 9th, 2018, 2:33 pm #7

US Gypsum makes a 10K psi product known as Hydrostone. (if you can find it locally because of the shipping weight and way to much volume for me) Personally I use "Perfect Cast" at Hobby Lobby. It's just as hard as Hydrostone.  Almost as strong is a product called Densite Plaster acquired at Blick Art suppies in hopes of saving on shipping costs. Hope this helps.
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