Concrete Casting: How to Make a Concrete Sink Mold

http://www.smooth-on.com/Concrete-Casting/c1235/index.html to learn more about concrete casting.

Casting a reproduction concrete sink basin by making a 2-part Vytaflex production rubber mold.

Step One: Construct Mold Box
Measure original sink basin. Use melamine board (formica coated) to make mold box segments, which will ensure easier separation from mold rubber.

Step Two: Create Spacer Board
Center model on board to use as a spacer board. Create perimeter outline for cutting. Center model on baseboard. Position spacer board and align with baseboard. Mark alignment point on baseboard and spacer board. Use modeling clay to create a gasket. Use non-sulfur based clay only. This will prevent rubber from going underneath model. Modeling clay will fill negative space between original model and spacer board. Remove excess clay.

Step Three: Acorn Nuts will be Used to Create Registration Keys
Hot melt glue will be used to secute acorn nuts. Place extra key for mold orientation.

Step Four: Assemble and Seal Mold Box
Screw melamine boards together with dray wall screws. Seal seams with hot melt glue.

Step Five: Release Mold Box and Model
Apply Universal Mold Release to all surfaces.

Step Six: Measure, Mix and Pour VytaFlex 40 Mold Rubber
VytaFlex 40 mix ratio: 1 part A to 1 part B by volume. Measure, mix, and pour the liquid rubber. Do not pour beyond sink hole. Let rubber cure for 16 hours at room temperature.

Step Seven: Prepare to Make Second Half of Mold
Use non-sulfur clay to fill in surface irregularities. Measure and cut reverse side baseboard. Secure reverse side baseboard. Turn over mold box. Remove original baseboard to expose concave half of model. Remove spacer board. Remove acorn nuts from rubber mold. Remove clay gasket. Remove clay residue.

Step Eight: Seal Drill Holes and Release Mold Box
Fill drill holes with non-sulfur clay. Seal seams with hot melt glue. Apply Universal Mold Release to all surfaces.

Step Nine: Measure, Mix and Pour VytaFlex 40 Mold Rubber
Let rubber cure for 16 hours at room temperature.

Step Ten: Demold Original Model
Remove mold box side walls. Gently pry original model to expose mold cavity. Concrete mold ready for casting.

Step Eleven: Casting Concrete
Apply In and Out II release agent to all surfaces. Secure 2-part mold with straps and baseboards. Place mold on vibration table. Fill mold with concrete and vibrate. Let concrete cure 24 hours.

Step Twelve: Demold Concrete Casting
A perfect concrete reproduction of the original. Concrete mold is ready to be cast again.

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Category:

Howto & Style

Tags:

• mold making
• casting
• concrete mold
• concrete molds
• how to
• tutorial
• concrete casting
• concrete
• concrete sink
• smooth on
• smoothon
• smooth-on
• molding
• moldmaking
• diy
• vytaflex

[d4nish1234]

I am wondering, how long does it take to have the mold ready (including the waiting time for it to dry) and for the concrete replica of the original model to be made?

[SmoothOnInc]

@d4nish1234 This is a multi-day process. Each half of the mold should cure overnight.

[sfasilver]

What is the recipe mix for the concrete and how would you make a granite finish.

[SmoothOnInc]

@sfasilver I would recommend contacting the folks on the concretecountertops forum for some advice.

[JohnnyDesaint]

I HAVE AN ULTRA RARE SIDE LENS OF AN OLD CAR THAT I WOULDNT MIND DUPLICATING WHAT RESIN DO YOU RECOMMEND FOR AUTOMBILE LENSES?

[SmoothOnInc]

@JohnnyDesaint Search for 'red buses gallery' on our site for more info on using our crystal clear resin for your application.

[Gatorfingerboard]

Very nice, but what do you do at the bottom of the sink where the hole is. It looked pretty thin. Thanks

[MrChocolate7777]

Thumps up if you came here while ypu are searching how its made

[swaggboi800]

but i dont have a house

[johnnnyreb51]

Nice but unpractical for most home users. Cost of mold materials and the other supplies make it cost more then buying a single unit. Now if you are going into production and are making multiple units that's another story. The more units you make the better your production profits become.

[iiAvenGeR]

thats effort.

[krap101]

I couldn't tell from the video, but since you didn't fill the first half all the way up, it seems you've lost the detail from the bottom of the bowl, and it ended up just being flat? Or was the original bowl the same way?

[Damoskinos]

That is clever

[philipcairos]

Absolutely brilliant, well done.

[laxchick01588]

Thank you for creating a straight forward, easy to understand, unbiased educational video. This is probably the best advertising tool out there. Like barrycondicasting said, "You guys actually show someone how to do something without tooting your own horn". Thanks!!

[nbaietti]

WHY would you dislike this video?!?