Cast Stone

NJ Brickie

I am interested in making some cast stone. The stone will be for my own house I plan on building (once some more funds are available). I set cast stone often and know they are expensive. I have a few questions for anyone that has any info on the process.

I researched awhile on the internet and could not come up with a mix ratio. The stone i will be making will be white, so I know I need white portland cement and white sand, but what type of aggregate should I use? Also should I use an admixtures? What is a standard ratio for the mix?

I also found out that the best process for making the stone is to mix the materials with a low water content. Then vibrated and tamped into the mold. Can this process be done with out any special equipment?

What type of material is best for making the form work? Plexi-glass, plywood covered in formicia, something else? Most of the pieces will not have any detail in them but the arches I would like to add "tiered" look. What type of material should I use to scribe the details in for the form?

I know I have alot of questions but any help would be great. Thanks in advance.

Tscarborough

The guy I use has mostly plywood/formica, but does have fiberglass for some of the most heavily used shapes (like keystones). Dry tamped requires nothing special, other than a hand-held vibratory tamping device (usually air driven). It is time consuming though. The look of dry tamped is different than wet poured, though. Wet pour is the easiest to do in my opinion.

As for formulas, you would probably have to kidnap and beat a formula out of my guy and I am sure others the same way. A good starting point for dry tamp would be standard C-270 Type M portland/masonry cement mix, since you will want to stay away from lime.

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lukachuki

Good question! I've wondered about this myself!

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NJ Brickie

Seems like this might be one well guarded secret. I've spent some more time online looking and haven't found much. I can't find anything on a mix or even a hand held tamping device. I think I might try a wet pour and maybe acid wash it or try to sponge finish while it is wet. I would like the look of the dry packed stone. Any info in the future would be appreciated.

Tscarborough

After thinking about it some more, all he buys is portland, so he is using just portland and sand. The mix has to be in the range of 1 part portland, 3-5 parts sand. The mix when used is crumbly, just enough moisture for hydration when packed. I will go see him tomorrow and get a model number for the tampers and some more info on his mix.

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NJ Brickie

I would really appreciate the model number for the tamper. I figured the mix would contain no lime. Something more like a concrete mix with out a course aggregate. From what I understand i will need to wrap the stone in plastic and keep wet for a few days. Thanks for the help Tscarborough.

Tscarborough

I didn't make it today, I'll try again tomorrow.

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It ain't Rocket Science unless you are building rockets.

NJ Brickie

Not a problem at all, take your time. This is not something I am going to be rushing into. I am really just in the idea gathering phase here. Building a new house is a dream of mine so I want to take my time and plan everything out well (not to mention save some more money). I recently purchased a drafting program for the computer, so like I said I'm still a long ways off from starting any construction. Thanks again

CaseyJones

There is a lot of useful info on cast stone at
http://www.strombergarchitectural.com/

and
http://www.strombergarchitectural.co...als/cast-stone

NJ Brickie

Thanks for the site. I will check into it. Work has been so busy I haven't had the chance to start messing around with some mixes yet. Thanks again