Statue Forum 

Go Back   Statue Forum > Home Grown > Sculptor's Pit Stop

Thread Tools
Old 01-27-2014, 06:08 PM   #1
MeoWorks's Avatar
Join Date: Aug 2013
Location: Sacramento, CA
Posts: 34
[GUIDE] Creating Waste Molds On The Cheap & Wax Transfer Techniques

The purpose of this guide is to show sculptors, both novice or professional, how to make a cheap waste mold out of household materials easily purchased from local stores. The intent here is NOT to mold and cast a MASTER copy, but to mold and cast a WIP to another material such as hard wax to add additional details.

This process is especially useful for artists like me who create fast prototypes in a 3D environment and print them out using a DIY (FDM) printer. FDM printers, while affordable, does not allow the same details such as powdered printer services that can cost $1k+ per print. Often there are print lines and other small issues, but these are easily resolved with the tax transfer.

Materials List For Waste Mold:
-100% Silicone (GE, not Silione II; Walmart, Homedepot, Lowes...Any hardware store)
-Caulking Gun
-Cornstarch (Any supermarket)
-Liquid Glycerin (Walmart/pharmacy)
-Bowl Of Dish Soap Mixed w/ Water
-Mixing Cup (Anything you deem good for the job)
-Mixing Stick (Same as above)
-Gloves (Who doesn't carry gloves these days)
-Hot Glue Gun (Almost all stores will have these; try Walmart or any craft store)
-Smooth Surface

Materials List For Wax Transfer:
-Wax (Castilene from SculptureDepot; Your choice on waxes)
-Slow Cooker/Crockpot ($9 @ Walmart)
-Metal Ladles (Any home goods store should have them)
-60W Bulb w/Lamp Or Any Heating Source

So let's start with the materials and their roles:

-Silicone: Must be 100% clear silicone, Silicone II from GE will not work. I find that the cheaper the better since manufacturers tend not to add extra properties to cheap silicone. This is your main molding material that will capture a lot of your details.

-Cornstarch: Because household "window" silicone uses moisture as its catalyst, cornstarch will add that necessary moisture and accelerate the curing process while also adding hardening properties. The more starch you use, the harder the mold will be, but you'll lose some tear resistance. Cornstarch is a necessary addictive in my experience, without it, the silicone will cure from the outside in and will take ages to complete or make a sticky mess if you demold too soon. So add that starch!

-Liquid Glycerin: For people with the moisture content is HIGH. I like to add a few drops to the silicone mix just to speed up the curing process. The less starch you use, the more glycerin you'll have to add and that wastes money over time.

-Bowl Of Soapy Water: This is used after you've applied your silicone to your piece. Wetting your gloves in this solution will allow you to pat and shape your silicone without making a sticky mess.

-Mixing Cup: Any size is good depending on the size of the piece. Plastic is best since silicone will peel right off and one can reuse the cup forever.

-Gloves: Wear them, your skin will thank you. Since we sculptors will most likely deal with direct contact to these materials frequently, it's best to protect ourselves from prolonged exposure.

Now that the materials and their roles have been introduced, we can begin prep work and molding!

Prep Work:

**HINT: The thing about prep work is about 20% work and 80% mental prep. You should walk through the procedure in your head prior to starting and be familiar with the silicone mix's work time, all materials and their roles so you can adjust your mix on the fly without having to Google, and most importantly keep your work space clean.

-Clean the piece you want to mold. I don't usually wash my WIPs since I tend to mold my 3D printed pieces, but just to be safe, try to wash off most oils and other surface stuff that will cause problems. Common sense stuff. Dry thoroughly.

-You can mold your piece depending on the piece's design. My tree trunk, for example, is printed with a flat base for easy molding. With flat surfaced pieces, one can simply use a little bit of hot glue or any adhesive and attach it to a flat surface as shown. If the piece is oddly shaped or lack a flat surface, one can use methods such as 2 piece molds or by attaching a sprue.


**HINT: The silicone mix's work time varies on the amount of starch and glycerin added, there really isn't an exact science, but a mix of silicone:starch in ratio 3:2 will give you about a 10min work time and full cured in about 30min (50 or 60 to be safe). 3:2 is my preferred mix and will give a nice creamy, off white color.

-So now that you've prepared your piece and set it aside, we can start mixing the silicone mix. Take your mixing cup and start adding silicone using the caulking gun. Once you reach your desired amount, mix the silicone a bit to "open" it up and allow it to stick to the cup's sides. This will allow for easier mixing once starch is added.

-Measure/estimate out your starch using the ratio 3:2 (Silicone:Starch). Add a little at a time while slowly mixing in small, circular motions. Now add a few drops of glycerin. Keep mixing until all the starch is added and the mix is thoroughly mixed and has an even, off white color.

**HINT: You might want to mix near a fan or vent since this silicone gives off acetic acid (vinegar) as it cures. It doesn't bother some, but the smell can sting your nose and eyes and be quite strong for others.

-Using your mixing stick or a plastic knife, start adding the silicone to your piece. Make sure to work the mix into the piece's nooks and crannies in small, circular motions.

**Hint: Take care not to lift the stick or knife directly off, it might lift the silicone off the piece. Instead, wipe the stick or knife on the piece as you would after spreading peanut butter on bread. Then scoop more silicone mix and continue.

-Once the piece is completely covered, add the rest of the silicone mix if there's any left.

-Wet your hands with soapy water and gently tap the silicone to shape. Keep moistening your hands with the soapy water and work the mold to a desired shape. As you work the shape, start tapping harder so the silicone fills in all the voids you may have missed. In the end, you'll end up with a dense hunk of silicone.

-Wait at least 60min before demolding.
MeoWorks is offline   Reply With Quote
Old 01-27-2014, 06:08 PM   #2
MeoWorks's Avatar
Join Date: Aug 2013
Location: Sacramento, CA
Posts: 34
-After the wait is over, it's now time to demold. If the piece is complex, you may need to cut it out as shown. If the piece is rather straight and simple, it should wiggle right out.

-You're done!

Wax Transfer:

Now comes the real fun! It's now time to perform a wax transfer so even more details can be added.

-Go ahead and give the mold a nice rinse with warm water and soap.

-Add your wax to the Crockpot and turn to medium or low setting. High might burn the wax if you're not careful.

-While the wax melts (be sure to gently stir the wax to prevent separation), place your silicone mold under a 60W bulb or any heat source. This will warm the mold allowing both a smoother pour and also prevent very noticeable shrinkage. It'll also dry off the mold.

-Once the wax is melted and evenly mixed and your mold warm to the touch, it's time to pour the wax. Take your metal ladle and give the wax one last gentle stir before scooping. This can get messy so I recommend pouring over newspaper or other surface protector.

-Once the mold is filled, gently tap the mold's sides to release any trapped bubbles. If you didn't boil your wax, there shouldn't be any bubbles. Let the mold sit while the wax cools.

-After sufficient time has passed, demold and inspect your work. Repeat if the transfer was botched.

**HINT: Small pockets caused by bubbles can be filled in. If the transfer is filled with small bubbles, it means your wax might be too hot, try reducing the heat and stir gently instead of vigorously. If you have access to a pressure chamber, feel free to pop the entire transfer into the chamber to rid all bubbles.

-Now add your finishing touches

Thank you for checking this guide out, I hope it was useful. Occasionally I will edit for spelling errors or other minor issues, but if there is a major update in technique or materials, I will notify accordingly.
MeoWorks is offline   Reply With Quote
Old 01-27-2014, 07:44 PM   #3
Artificial Intelligence usually beats real stupidity.
Darkeye's Avatar
Join Date: Jan 2012
Location: i live in a small village near Aylesbury in Buclinghamshire, UK
Posts: 395
wow, that's ace. thankyou for posting this guide. I will have to have a go at this....

atb --tim
Darkeye is offline   Reply With Quote
Old 01-27-2014, 07:54 PM   #4
Sey hallo to my lille fren!
growler321's Avatar
Join Date: Mar 2013
Posts: 134
i will def try this nice guide m8
growler321 is offline   Reply With Quote
Old 01-30-2014, 10:26 AM   #5
Home Grown Mod
GedTasker's Avatar
Join Date: Sep 2011
Location: Liverpool uk .
Posts: 1,579
Thanks for this fantastic guide mate!! Think it deserves to be a 'sticky'...

*Right t's done.. gives people a chance to see it*

Last edited by GedTasker; 01-30-2014 at 01:49 PM.
GedTasker is offline   Reply With Quote
Old 01-30-2014, 11:05 PM   #6
MeoWorks's Avatar
Join Date: Aug 2013
Location: Sacramento, CA
Posts: 34
Thanks for the comments and the sticky! I hope this will help our more budget oriented artists out there
MeoWorks is offline   Reply With Quote
Old 03-10-2014, 02:17 AM   #7
Join Date: Mar 2014
Posts: 1
Will this technique work to make a waste mold on an oil based clay object? w/ undercuts? I'm using klean klay and REALLY need to get my model into another type of clay before I go nuts!
tollertwins is offline   Reply With Quote
Old 03-10-2014, 03:19 PM   #8
MeoWorks's Avatar
Join Date: Aug 2013
Location: Sacramento, CA
Posts: 34
So long as the clay is free from sulfur, it should be safe to use. Try a test on some spare clay and see if the silicone sets.
MeoWorks is offline   Reply With Quote
Old 03-11-2014, 05:57 AM   #9
Kiss my shiny metal arse!
jollyskeleton's Avatar
Join Date: Apr 2008
Posts: 4,105
This is way awesome MeoWorks! Thank you!!!

I'd been concerned about trying out wax transfers due to cost, but now looks like I have a viable solution to making wax transfers of my Chavant NSP sculpts!!
jollyskeleton is offline   Reply With Quote
Old 03-11-2014, 01:12 PM   #10
MeoWorks's Avatar
Join Date: Aug 2013
Location: Sacramento, CA
Posts: 34
Agreed on the cost, professional silicones just for waste molds would be a killer!

Honestly the only cons I see in using store bought silicone are #1 it SMELLS and #2 it's sticky and will be a pain to work with your first few times before you develop a good method of shaping it.

Please do post back if you need some more hints or even with some updates!
MeoWorks is offline   Reply With Quote

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Powered by vBadvanced CMPS

All times are GMT -4. The time now is 03:03 AM.

Powered by vBulletin®
Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.