Nylon stockings work well as mold because they will help hold the shape of your concrete piece and give you lots of flexibility in the shapes you make.
Uncoated wood is routinely used to make large molds for curbs and house footings. After curing, the concrete will unstick from the wood relatively easily. But using wood coated with a slick surface will make the release even easier. For this, a 3/4-inch thick MDF board topped with melamine is ideal.
Using cardboard boxes as a forming material for concrete is great because they come in a huge range of sizes and you can get them for free. The versatility of duct tape makes it ideal for temporarily water-proofing and reinforcing the cardboard box.
Concrete will stick to some plastics, wood, metal, vinyl, cloth and other porous surfaces. But that's about it. Concrete won't stick to molds, smooth metal, glue, paint, oil, mortar, other concrete or most masonry products. If you're looking for a bonding material concrete probably isn't the best choice.
Glass and plastic bottles can be repurposed to make concrete molds for planters, candle holders, vases and even pendant lights. Get inspired to upcycle with concrete!
One respondent summed it up: "Aluminum and concrete don't mix, either in the plastic or hardened state." Aluminum reacts with the alkalis (OH) found in portland cement concrete.
Slide the 1 inch plastic ring around the silicone mold to hold it tightly together. Mix the concrete, following the instructions on the bag, and pour the mix into the mold. Tip: Make the concrete a little more watery than usual to help it pour easier into the small mold.
Concrete also sticks very well to plastic. Treating plastic with a release agent prior to coming in contact with concrete is the best way to ensure your plastic buckets and tools remain free of dry concrete.
Nearly all types of plywood panels can be used in concrete-forming, from common roof and wall sheathing to sanded panels.
Make a Silicone Concrete Planter Mold Using PVC Pipes. Add a Pottery-like Glaze! So not only can you create a concrete planter from an existing object using silicone (like I did here- Textured Silicone Cement Planter), but you can also make a silicone mold for pots from pretty much any type of supplies.
Using EPS foam molds for concrete gives the versatility for both CNC machine shaping and hand finishing of the mold. For many entrants in the National ASCE Concrete Canoe competition, organized by the American Society of Civil Engineers, EPS foam from Universal Foam Product has been their first choice.
Make a 1-part soap, 10-parts water mix and add your construction silicone. Press your desired shape into the clay and wait a few hours for it to dry. Or, knead together 1-part silicone 2-parts cornstarch. Press your shape into the dough and wait just 20 minutes for your mold to dry.
You can cast concrete on anything. You can cast it on wood, metal, rubber, plastic or dirt. You can cast it on whatever you want, and you will find that invariably you get what you asked for.
Before pouring your concrete mix into the molds it's a good idea to use a release agent, this will make removing the concrete from the mold after it has cured very easy. There's special concrete release agent, like Pol-Ease 230, but ordinary cooking spray works just as well.
Cover filled mold with plastic sheeting and allow concrete to harden in a cool (and level!) location for two days before removing from mold. After demolding, cure stone another week before setting in ground.
Concrete Silicone 2 sealant is a high-performance, 100% silicone and 100% waterproof sealant ideal for concrete, mortar and stone projects.
Fresh concrete corrodes aluminum with subsequent release of hydrogen. After the chemical reaction, the concrete loses its properties and deteriorates. The concrete is no longer homogenous.
Engineered for demanding applications, double-sided duct tape is easy to tear and use, and delivers high tensile strength and a strong bond on a variety of surfaces, including concrete, tile, hardwood and irregular surfaces.
The most commonly used gas-liberating agent in concrete is aluminium powder. Hydrogen released in the reaction of aluminum with calcium hydroxide causes the formation of pores in the size range of 0.1–1.0 mm in the concrete [9], which results in an increase in the porosity of the concrete [9,10,17,18,19].
Instead of using your silicone for silicone molds, keep it and make silicone castings. And use ComposiMold for the mold making. ComposiMold is a one part molding material that can be remelted and reused to make new molds any time you want. ComposiMold is a heat and pour mold making material.
Mix one teaspoon of baking soda along with two cups of water and shake in a spray bottle. When thoroughly dissolved spray the solution onto the mold and scrub with a brush. Repeat if necessary. Once cleaned, wipe the area with a wet, clean cloth to remove the solution.