Architectural Restoration: Making a Rubber Mold of a Plaster Column

This video tutorial features the making of a brush-on rubber site mold. Some of the columns in this commercial building are damaged -- a brush-on rubber mold with plaster mold shell is made of an intact column in order to cast plaster replacements for the damaged columns.
Mold Materials: Poly PT Flex 20 (a soft, polyurethane rubber) and a Plaster/Burlap Two-Part Mold Shell. A full list of materials used are listed at the end of the video.
The Steps:
Part I: Prepare Column & Make Brush-On Rubber Mold
Step 1: Establish Mold Area
Step 2: Apply Sealer [Pol-Ease® 2350 Release Agent] & Let Dry
Step 3: Make Flange Supports for the Top & Bottom of the Mold Area
Step 4: Apply Release Agent [Pol-Ease® 2300 Release Agent]
Step 5: Mix Rubber
Step 6: Brush On Rubber
Allow Rubber to Fully Cure
Part II: construct Two-Part Plaster Mold Shell
Step 7: Spray & Brush Out Release Agent [Pol-Ease® 2300 Release Agent]
Step 8: Mix Plaster & Construct Two-Part Mold Shell
Allow Plaster to Fully Cure
Part III: Remove Mold Shell & Rubber Mold
Step 9: Carefully Remove Mold Shell
Step 10: Carefully Remove Mold
Part IV: Cast Plaster in Mold
Step 11: Pour Plaster into Mold
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Music Credits:
“Our Ego [Feat. Different Visitor]” (freemusicarchiv...) by Broke for Free (freemusicarchiv...)
“The Great” freemusicarchiv... by Broke For Free (freemusicarchiv...)

[@kcstoneguy]

I've seen this done before on historic jobs It's amazing to watch These guys are artists for sure

[@wiredcer]

would this work on marble?

[@tonybeadle8392]

I appreciate that you are a company selling molding materials, but this would have been a lot quicker and cheaper to just run a new lengh on a bench, but lets say it was more ornate and could not be run on a bench, using long strips of jute scrim or whatever you are using starting from the top would surely be a much quicker and a less messy job, the use of location ridges would make lining up the rubber mold into the case easier and more accurate. just my humble opinion.

[@WW-lm5ji]

What would the materials for this specific application you did cost?

[@PolytekDevelopmentCorp]

Hello wolf smith - thank you for watching! We used somewhere between one and two gallon kits of PT Flex 20 polyurethane rubber. Each gallon kit is $149. We used a quart of Pol-Ease 2350 Sealer & Release Agent ($12.00) and one can of Pol-Ease® 2300 Release Agent ($13.00/can). I'm not exactly sure what the cost is on the plaster, burlap, and additional tools.