Rated 4.1 out of 5 by 10
Rated 5.0 out of 5.0 by Mart Excellent for making molds and detailed casts
I use Plaster of Paris to make molds and small casts of detailed objects.
It sets up quickly and is very strong. Larger molds can be reinforced with
cut-up fiberglass cloth. Antique ceiling details and old plaster lamps
can also be repaired (when clean and dry) with new Plaster of Paris, but
working time is very short. Very large plaster pieces should be reinforced
with something stronger, like metal rods.
When set-up and completely dry, Plaster of Paris accepts all paint, varnish,
and other surface treatments I have used. Note: Even in a desert climate, it can take
up to a week for larger plaster pieces to dry. It also does not sand as easily as drywall mud.
Plaster of Paris sands better with a rasp.
Not recommended to texture overall wall surfaces. Drywall mud is better for that purpose.
April 14, 2015
Rated 5.0 out of 5.0 by Vincent7 vinegar
A little vinegar added will delay the drying time.
Giving you more time to work it.
August 23, 2014
Rated 3.0 out of 5.0 by 24368 Not for plaster wall repairs
Do not try to use this product to patch holes in plaster walls, or to add a smooth top coat to plaster walls. This product sets up too quickly - at best 20 - 30 minutes, and if it's old can set up much quicker. DAP makes a product called "Plaster Wall Patch" that sets up in 2 hours, and according to the manufacturer can have a working time of up to 90 minutes. You need that extra working time to be able to smooth out the patch or top skim coat. This product is best for craft projects or plaster molds. Since I can not seem to find Plaster Wall Patch at Home Depot I went to DAP's web site and got a list of stores I can get it from.
September 25, 2010
Rated 5.0 out of 5.0 by d34532 Great product
This product is great. They should provide more info for option is setting time. Below are some tips but if you want more tips and how to mix plaster correctly do a search for "how to mix plaster"
To slow down cure time and have more work time:
1. The colder the water do longer it takes to cure. (chemical reaction aka the harding process is long at lower temp)
2. When the Ratio of plaster to water is higher it cure faster. IE Plaster:Water 2:1 is going to cure faster then 1:1 mixture however 1:1 will be less denser then 2:1 mixture. 1:1 ratio is much denser then any premix and even denser then the drywall sheet. Personally use 1:1 ratio for my use.
3. Never add water to the powder it should always be powder added into the mixing containor with water in it already.
4. Don't start mixing unless both powder and water are fulled added together and the powder has time to soak up the water. Mixing early start the cure produces.
1. pour water into the powder. See above #2 and 4 your powder to water ratio is powder ratio is much higher and the act of pouring the water into the powder also the mixing also.
January 7, 2012
Rated 5.0 out of 5.0 by Manny Plaster of Paris for moldings/not drywall jobs
I agree with many here. Plaster of Paris is in most cases used to create moldings and not to be used for patching. Most people who've used this product for the later, as we've read have had a hard time due to the fast-dry process. There are several things that you can add to the mix in order to extend the drying process but in most cases I've found that it gives me a different consistency for what I was looking for in a plaster mold. I usually create my plaster molds with Plaster of Paris, seal it with a few coats of clear/dark primer, paint with acrylics, seal with a couple of clear coats of enamel based sealant, and then mount my projects with either liquid nails or some other durable and strong adhesive. The best thing about Plaster of Paris is that it can be sanded, sculpted, and you can even use a rotary tool to create whittling-type of works. Try it, it's ton of fun. Just wear a dust mask because it does get everywhere.
April 10, 2012
Rated 5.0 out of 5.0 by 2345678 Good for model railroading
This plaster is great if you are making a model railroad. It is much cheaper then the recommended type, and sets quicker.
July 27, 2013
Rated 2.0 out of 5.0 by Chowder Sets much too quickly
I have tried several different methods to increase the set time on this plaster, but have never had any success. When mixed exactly per the instructions, you will find the plaster setting in 10 minutes or so. Such a small time frame requires that you work like a fiend, and the chance of finishing with a result you are happy with is very small. Disappointing since it is so convenient in 25 pound bags.
September 27, 2011
Rated 3.0 out of 5.0 by HDKevin Hardens fast
I bought this product to pour under a shower base. I mixed it but didnt have enough water on hand. It took less than a minute to harden and become useless. When you mix it, make sure you have plenty of water on hand or make it soupy and keep adding powder to the mix.
August 23, 2010