Making a Mold for a cold cast bronze

I just recently completed my Alto Relief sculpture  ‘ Moonlight Sonata’ 30″x 20″ and have decided to mold it for a cold cast bronze. Here is the steps, pictures and reference information I used for this process. I researched on the smooth- on website for similar sculptures to determine from the wide range of products they sell and decided on the best product for my Alto relief. I am going to use brush on 40 as I do not have a vacuum pump and many of the products they sell require one during the process.  The molding products you decide to use is determined by the size, material of your original (is it clay, concret wood etc) and what medium your final copy will be cast ( casting resin, concrete, metal, cold cast bronze?).

Reference:  Has technical information – excellent videos and step by step processes. Also a tech line available to answer questions. I found the advice and support EXCELLENT!
smooth- on technical support phone # (800)762-0744 or at (610)252-5800 or contact them directly on their website and use a digital form for questions.

continue reading or watch the youtube video Here:

Step by step ( using a different product list but the process is the same)
Materials list:

Brushes (disposable one use)
containers (graduated for easy measurement)
papertowels (cleanup)
Spray on shellac or super seal from smooth-on
Universal mold release
Smooth-on Brush on 40
Box of disposable rubber gloves
disposable stir sticks ( I used paint sticks but advised to use metal)
Thickener Cab-o-sil (mix with brush on 40 for undercuts 3rd layer)
So strong pigment ( color pigment every other layer to determine proper coverage of layers)
Safety Mask:

Step one:
Complete a final review of your sculpture for any necessary changes – once you start you cannot stop until the process is completed. According to the technical product information once the layers have cured completely you cannot add further layers as adhesion will be difficult. You will be adding layers onto ‘tacky’ rubber layers with a 45 minute interval between each layer.
Prepare the Model:
Ensure it is secure onto the surface  (glue with a glue gun)
(my model was leather hard clay stuck to a plastic sheet)
Spray the model with spray shellac

Let this coating of sealant (used to cover any porous areas)  dry thoroughly and ensure you have covered all the undercuts and small spaces.
Once the model is dry to the touch (about 30minutes +)  Spray on a light mist of universal mold release. Lightly cover the entire sculpture with a brush to ensure the mold release has covered the entire sculpture. Otherwise you run the risk of the rubber not lifting clean off of the model once the mold has been finished.
Let this dry for about 5 minutes and then mist another layer of the universal mold release over the entire model.
Let this completely dry for about 15-20 minutes.

Step 2:
Mix thoroughly equal parts A and Part B of the brush on 40 to cover your mold. I was surprised that the amount I actually required was much less than I expected. Consequently I mixed and used more than I needed -I put on a heavy layer and had excessive air bubbles. I had to remove this layer and then do a thinner layer repeating the process. IT IS VERY IMPORTANT TO DO A THIN LAYER FOR THE FIRST LAYER OF RUBBER.

 [  IF you notice in the above picture there is a TIMER – IMPORTANT remember you only have a working time of 20minutes to apply the layers – thin is better than thick – apply and mix in smaller batches if necessary or  more than one person applying the layers helps as well.  My husband and I worked on this together to get the first layer applied within the time frame.  ]

LET THE FIRST LAYER SET UP (GEL ) for 45 minutes PRIOR to next application of the brush on rubber. Test the rubber by touching lightly with rubber gloves the mold should be tacky and release from your finger – if not it is NOT ready for another application.
Third step:
Apply another layer of brush on 40 (mixing equal parts A and B) add pigment [this will assist you in ensuring complete coverage of layers)

IF you are doing a relief you will want to add ‘Keys ‘ to the mold by spraying a ice cube tray with the mold release and filling with the brush on 40 mixture and letting it set up. Release from the tray and place after the third layer around the mold.
Step four: Undercuts and adding keys –
Mix equal parts A & B and add cab- O- sill till the mixture is like a bread dough
Apply to undercuts and under the mold keys from the ice cube trays.


After first layer:

After keys have been added and undercut thickener:

Picture below –After last 2 layers of Brush on 40 (NO thickener added to last 2 layers)BETWEEN LAYERS LET SET FOR 45 MINUTES – MUST BE TACKY (TEST)BEFORE ADDING ANOTHER LAYER .

LET THIS CURE (SET /DRY) FULLY FOR 16HRS BEFORE MAKING THE MOTHER MOLD. The rubber mold should be approximately 3/8″ thick.
Making the rigid support or ‘mother mold’:

I have completed to this point and my model is in the curing stage the following is excerpted from the smooth- on website temporarily and will be replaced with my own personal pictures when I complete the following steps:

Using a sharp razor knife, cut excess silicone from the outer edge of the mold. Create straight edges and square off all corners.

Spray the rubber mold and surrounding surface with Ease Release® 200 to separate the support shell from the mold. In some cases, Smooth-On’s Sonite® Wax may be necessary to release surrounding surfaces from the support shell.

Creating the rigid support shell: Smooth-On’s Plasti-Paste® is a trowelable urethane resin designed to be used for support shells. It is mixed 1 Part A (liquid) to 2 Parts B (paste).

Combine 1A:2B and mix thoroughly.

Apply Plasti-Paste® over cured Mold Max® Stroke®.

Cover the entire mold with Plasti-Paste®. Important: Plasti-Paste® has a working time of 8-10 minutes. Do not mix more material than can be applied in this amount of time.

Mix and apply more Plasti-Paste® as needed. Be sure to apply material beyond the edge of the silicone mold.

Apply at least 3/8” (1 cm) thickness, making sure rubber mold is thoroughly covered. Large molds may require added thickness for support shell stability.

Wooden blocks are attached to the support shell with additional Plasti-Paste®. These blocks will help level the mold during casting and allow for easier handling.

Once all Plasti-Paste® has fully cured (approximately 90 minutes), carefully remove the support shell from wall.

Edges of the support shell can be sharp. Sand Plasti-Paste® to make handling safer and easier.

Seat the rubber mold into the support shell. The mold keys added in the previous step will make aligning the mold with the shell very easy.

Making a cold cast bronze video:

Mom’s Handbuilt Sauerkraut Crock

Start of relief Well my Mom needed a birthday gift for my dad and as his birthday loomed she had no idea what to get him.

Anything feminine like a romantic getaway would of made him the laughing stock at work – did I mention he is a redneck heavy duty mechanic from northern BC? For instance  he would never admit during work hours  that he likes hawaiin pizza or correction should I say  ‘girlie pizza’  but orders ‘MEATLOVERS’ instead —satisfying the over abundant male testosterone that he works with everyday. Mom on the other hand is a hopeless romantic. When it comes to his birthday she thinks of dinner parties with discussions of art, wine, the scent of fresh flowers filling the air– I digress. Well he is also a health fanatic and has been spending hours watching ‘ How to make sauerkraut’ on youtube of late.
Fantastic !!
Besides the fact that after watching about 26 video’s on the subject – I think we have it pretty much figured out… So we decided to make him a handbuilt sauerkraut crock. Because sauerkraut apparently is an almost perfect food, it’s raw, it harmonizes the digestive system with much needed probiotics –I have been informed.

In Progress start of relief

The pot is in progress with the relief started and is 12″ high and approximately 9 1/2″ wide. Still need to make the lid. I think I better get him a card too and yeah maybe add a  jackhammer.

Grapevine relief

And just for your added viewing pleasure here is his favourite sauerkraut youtube video: How to make homestead sauerkraut in Alaska….

Garth's Sauerkraut Pot

Garth's Sauerkraut Pot- P.S Dad loves it

Art Tile

I have been working on art tile relief sculpture. Now that my sketchbook has been sent and all of my other pending projects have been either completed or back benched I can now put my energy into my relief tile. I completed a fairy clay sketch – which is faster than drawing it out.  I will be posting some of my techniques over the next couple of months.  Here is a ‘rough clay sketch’ of a fairy. From here I will let the clay dry and will bisque fire it and once it is fired I can (if needed) add more detail by carving and sanding. Once I am happy with the results I will  stain and clear glaze the piece to bring out the relief and high fire to cone either 4 or 6. My clay is a porcelain with grog and will come out a very nice ivory color when fired.

The fairy tile is currently in progress and here are several other tiles where the sculpting work is completed.

Recent Art Activity

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Here are some pictures of recent work:

  1. An acrylic painting ‘Carried Away’ 11″ x 14″ on board
    ‘Carried Away’ Remember the day we laughed in our embrace? We lived with every moment and loved with our whole hearts. We sang from our souls , we played everyday
    You carried me away…
  2. A 3d figurative sculpture with relief titled ‘king of arts’ – a story of a boy puppeteer ‘the king’  a painter and poet(writer) the queen -a dancer and a joker- musician. A handbuilt sculpture incorporating all the arts: performance (music and dance), literary, visual.
  3. Vase – 22″ handbuilt with figurative relief sculpture in porcelain
  4. Vase-20″ handbuilt with figurative releif  for the Havanese Fanciers of Canada dog show held end of oct 2010 

My poem ‘Flora’s Daughter’ written for a painting of my daughter Bethany for the Art in Bloom exhibition at the Victoria Art Gallery and Museum has been selected as a finalist in the poetry competition held by the Poetry Institute of Canada. The poem will be published in a book titled ‘Island Mists’ an anthology of verse (National Library of Canada, Ottawa ISBN 978-1-926774-02-2).

My artwork has also been selected by the jury of the Sidney Fine Art show to be exhibited with the other amazing artists in BC October 15 – 17th at the Mary Winspear Center.

I work in painting, sculpture and drawing and I firmly believe artists should be versatile in a variety of artforms. 3d and 2d are synergistic in the training of an artist and both mediums are important to our growth and progress as an artist. Currently I am working on sculptured vases, a sketchbook project (handbound with acrylic painted hardcover), a figurative oil painting and a china painted handsculpted teapot with cups and saucers. pics to follow once I get some new batteries for my camera.

Here is a site I just found
My next challenge will be to submit to either Oil painters of America, ARC and/or  greenhouse gallery Salon International this year.
ARC prospectus – deadline dec20. 2010
Greenhouse gallery Salon International deadline jan21 2011

My most recent poem:     
The Wisest Words
The wisest words that were ever told
are not from cry or plea
shouted above the crowd
nor spoke on bended knee
The loudest or the softest breath
will not its matter make
In the still of silence is where the wisest words take place
Tis not heard at all
For in the quiet of our thoughts
God’s understanding falls
listen to hear his call

A work in Progress

This is my next painting project.

Be the One
Be the One

Currently working on this painting – not sure of whether it will be oil or acrylic or mixed media yet. hmmm. anyway I will be calling it ‘ come dance with me’ or ‘Be the one’ from a poem I wrote. I will be posting my progress as I am very excited about an artistic idea I have for this painting and you will have to come back and check if you want to unravel the mystery of how this painting will turn out.sketch for new paintingsketch for painting