Making a Brush-On Silicone Mold | Mold Making Tutorials, Part 1/2

http://www.smooth-on.com/Silicone-Rubber-an/c2/index.html for more information about Smooth-On silicone rubbers.

Making a Brush-On Mold with Rebound 25 Liquid Silicone Rubber (Part 1 of 2)

For this demonstration we are going to use a small plastic model.

Step One: Secure Model to Baseboard
Hot-melt glue is used to secure model to baseboard.

Step Two: Measure and Mix Rebound 25 Silicone Rubber
Measure equal amounts of Part A and Part B. Combine Parts A and B into a mixing container. Parts A and B are mixed thorougly for at least 3 minutes. No color streaks indicates liquid rubber material is well mixed.

Step Three: Apply First Layer "Detail Coat"
A thin first layer ensures minimal bubble entrapment in the finished mold. Use brush to work rubber into fine detail. Do not over-apply rubber. Create rubber flange: cover baseboard at least 3 inches (7.6 cm) out from the base of model. Ensure thorough coverage: check model carefully for missed areas. Mix and apply more rubber if necessary. Let the first coat cure for a about 60 minutes at room temperature until tacky. Tacky = Sticky to the touch by does not come off onto glove.

Mold Maker's Tip
Touch rubber off model. If rubber comes off onto your glove, it is not ready for the next layer.

Rubber is tacky and ready to receive next layer of rubber.

Step Four: More material is measured and mixed for the second, thicker coat
Dispense equal amounts of Parts A and B. Mix thoroughly for 3 minutes. No color streaks indicates material is well mixed.

Step 5: Apply Second Layer
Apply thicker second layer using more fluid strokes. Make sure rubber is applied to all detail and undercuts. Let second coat cure for about 60 minutes until tacky -- not wet to the touch.

Step 6: Creating a cut seam with thickened silicone rubber
For this model we apply the cut seam down the back of the model. Dispense equal amounts of Part A and B. Mix thoroughly. Add four drops of Thi-Vex II per 1 oz of rubber. Mix thoroughly for 3 minutes. Scrape bottom and sides of container. Rubber is now noticeably thicker. Build cut seam. Use thickened rubber to fill in undercuts, indentations and deep detail, and to reduce sharp edges and angles.

Step 7: Measure and Mix Rebound 25 Silicone Rubber
Dispense equal amounts of Parts A and B. Mix thoroughly for 3 minutes.

Step 8: Apply Third Layer
Let third coat cure for about 60 minutes until tacky -- not wet to the touch.

Step 9: Measure and Mix Rebound 25 Silicone Rubber with Thi-Vex Silicone Thickener
Purpose: further build up cut seam. Also fill in undercuts and indentations. Dispense equal amounts of Parts A and B. Add four frops of Thi-Vex II per 1 oz of rubber. Mix thoroughly for 3 minutes.

Step 10: Apply thickened rubber to further build up cut seam
Further fill in undercuts. Use thickened rubber to reduce sharp edges and angles.

Step 11: Apply Fourth Layer
Dispense equal amounts of Parts A and B. Mix thoroughly for 3 minutes. Final Mold Thickness: 3/8 inch (1 cm). Let silicone rubber cure for 6 hours at room temperature.

Step 12: Trim rubber flange with razor knife
Rubber flange extends 3 inches (7.6 cm) in all directions. Ready to apply support shell.

Make It Now! with Smooth-On
http://www.smooth-on.com/
http://www.facebook.com/SmoothOn
http://twitter.com/SmoothOn

Category:

Howto & Style

Tags:

• silicone rubber
• silicone mold
• silicone molds
• liquid rubber
• liquid silicone
• silicone molding
• mold making
• casting
• smooth on
• silicone
• smoothon
• smooth-on
• brush on mold
• molding
• moldmaking
• diy

[pooponastick3214]

Can you reuse the excess silicone used to make the mold at the base that was cut off at the base if it is reheated and turned back to liquid? If not what is done with it?

[SmoothOnInc]

@pooponastick3214 It cannot be reheated or liquified. This material is inert and is disposed of.

[BlueGirlHaley]

can you do this with neoprene tails? You see, I'm trying to make a silicone mermaid tail that I can swim in. so, would this work for it? Thanks!

[SmoothOnInc]

@BlueGirlHaley I would recommend casting the scales first, then adhering them to the neoprene with Sil-Poxy, as neoprene will inhibit platinum silicone.

[japichic]

Is it really necessary to use a brush? Can you just pour the silicone into a cup to make the mold like with the OOMOOO 30?

[SmoothOnInc]

@japichic This mold rubber is too viscous for pouring. our Mold Star series is a platinum, pourable silicone rubber.

[EpicSteamer]

I typed in RUBBER SNUGGIES and got sent here......

[BlueGirlHaley]

@SmoothOnInc your videos have been very useful! thank you!

[stickydoyle]

@SmoothOnInc im based in Plymouth , a bentley chemicals rep visited my employer a few months ago, i was really interested is using your product for some of my own work , but never managed to talk about pricing and options.