Instructions for Making Molds

Basic Vulcanizing Instructions When Using the DIY Castings Mold Holder

 

Before Starting: Read all direction carefully!

Safety:

Always wear safety glasses and a properly fitting dust mask to avoid breathing the powder. Wear appropriate clothing for jewelry work, have a good ventilation system to remove fumes related to vulcanizing rubber. Use caution when using a toaster oven, especially when putting items inside and removing. Some models suggest unplugging the unit when the hands are inside to help avoid any kind of electrical shock, especially from used or older style toaster ovens.

Caution:

* It is suggested that only adults (18 and over) purchase and use this equipment unless supervised by an adult.

* Read all MSDS sheets regarding the mold rubber being heated in the toaster oven.

* Never use the same toaster oven for heating food if it has been used for making molds. Many mold rubbers are not considered food safe.

 

 * Customer assumes all risks when purchasing tools and supplies from Craig Dabler, the company Craig Dabler Jewelers INC., doing business as 'DIY Castings' or Craigs Castings, or anyone associated with these websites.

Copyright Craig Dabler Jewelers, Inc 2018

 

1) Make sure the Mold Holder is clean and free of any oils or chemical residues. Clean with Acetone if needed. ***Never mix organic rubber with silicone rubber.

2) Make sure that your  hands are clean and free of any polishing compounds or oils that might rub off into the molding rubber and cause poor adhering of the layers of rubber.

3) Make sure the pattern to be molded is clean and finished. All surface blemishes will show up in the mold so a finished pattern is always better than an unfinished pattern. If possible, have the sprue already soldered onto the pattern so that when molded the sprue doesn't need to be cut into the mold by hand.

4) Start by turning on your toaster oven and setting the temperature as recommended setting for the type of molding rubber being used.***The mold rubber supplied with the kit requires the toaster oven to be set at 330*-350* F.

5) Add Talc or Mica power to the bottom plate of the mold holder and inside of the aluminum mold frame. Set the aluminum mold frame onto the bottom plate-centered. Teflon spray also works well or a combination of the two.

6) Add the 3mm brass rod through the hole in the mold frame but do not go through until later.

7) Option 1: If using 1/4" thick spin casting rubber to make a powder separation mold, cut out 4-2 1/2" discs and take the first disc of mold rubber and peel off the paper making sure that no little bits of paper remain. Knead the mold rubber on the edges with the thumbs and fingers in order to stretch the mold rubber out to the diameter of the aluminum mold frame. Lightly talc or mica powder one side and place powdered side down into the frame. Again, press the edges of the rubber out to the edges of the mold frame.****Skip 8 and to 9.

8) Option 2: If using molding rubber that is like putty which will be cut apart, roll out a 1.6 ounce ball, flatten it into a disc which will fit into the aluminum mold frame, powder the underside and place powder side down into the aluminum mold frame. Push edges out against the frame, insert brass rod and cone, and insert object for molding pushing it into the rubber about half way in. Now, using 2.10 ounces of rubber, roll into a ball, flatten into a disc, place on top of object being molded and press into aluminum mold frame making sure to keep mold rubber within the inner edge of the aluminum mold frame. once in place, add powder to both the top of the mold rubber and to the surface of the top plate of the mold holder and tighten each wing nut evenly. The top plate should be snug all around the aluminum mold frame with no ore than 2-3mm of gap. Hand tighten only.****Skip 9-13 and go to 14. Note: if molding a ring or something with a deep undercut add extra rubber into the finger hole or undercut to help with that area filling up with rubber.

9) Next prepare a second disc of molding rubber by pulling all the paper off, kneading the edges to stretch the disc larger, then place the rubber (no powder) down onto the first disc of rubber and pack the two together and out to the edges of the aluminum mold frame.

10) Add powder to the mold rubber surface and now place the brass cone so tat the brass rod can be pushed into the hole of the brass cone about halfway inside. Then, put your pattern in place by fitting the sprue halfway into the cone.

11) Once the pattern is in place it's time to add the mold locks. Place them into the mold rubber nose first and about 3/4 of the way deep. Again, add powder so that it lightly creates an even layer over the molding rubber and the pattern. Caution: Don't get too much powder into the detail of the pattern and clean out if needed with a small brush.

12) It's now time to prepare the third disc of mold rubber by following the same steps as previously instructed but adding powder to the one side facing down. Place rubber onto the pattern and packing it down snug against the side of the mold frame as well as squished over the pattern and the mold locks.

13) Next, prepare the last disc of mold rubber (no powder) and place it over the third layer and tightly pack it inside the rim of the aluminum mold frame. Once in place, add powder to both the top of the mold rubber and to the surface of the top plate of the mold holder tighten the top plate into place. Make sure the aluminum mold frame is centered as you tighten each wing nut evenly. The top plate should be snug all around the aluminum mold frame with no more than 2-3mm of gap. Hand tighten only.

14) Finally, check the temperature of the toaster oven and then carefully put the Mold Holder inside onto the rack (remove the pan and use the open wire rack only). Close the door and bake for 50 minutes at the set temperature. *Do not forget and leave it in too long as it could cause excessive shrinkage or distort the mold.

15) Once the time is finished, turn off the toaster oven, put on high temperature gloves and reach in and remove the very hot Mold Holder onto a fireproof surface (a large mass of steel works well) so that it can cool down to the point it is just warm to the touch. It's now time to separate!

16) Start undoing the wing nuts. IF one is stuck, undo the easier ones first and then the stuck one should loosen. If it doesn't, carefully use a pliers (don't touch the bolt threads) and loosen it so it can be removed by hand.

17) Take off the top plate (a standard screw driver may be needed) and continue to take the mold frame off of the Mold Holder's top and bottom plates. Once off, push the mold out of the aluminum mold frame, pop out the brass cone, and cut off the extra mold rubber that squished out.

18) Finally, either cut apart the mold using a sharp Scalpel type knife OR pull apart the two mold halves, remove the pattern, remove the mold locks (some kinds don't remove), and cut away any extra mold rubber that doesn't belong. The mold should now be ready to use.

 

Safety:

Always wear safety glasses and a properly fitting dust mask to avoid breathing the powder. Wear appropriate clothing for jewelry work, have a good ventilation system to remove fumes related to vulcanizing rubber. Use caution when using a toaster oven, especially when putting items inside and removing. Some models suggest unplugging the unit when the hands are inside to help avoid any kind of electrical shock, especially from used or older style toaster ovens.

Caution:

*it is suggested that only adults (18 and over) purchase and use this equipment unless supervised by an adult.

 

* Customer assumes all risks when purchasing tools and supplies from Craig Dabler the company Craig Dabler Jewelers INC., doing business as 'DIY Castings', nor anyone associated with this site, for injuries or even death which occur as a result of using the equipment or techniques related to these products or website.

 

Copyright Craig Dabler Jewelers, Inc, DIY Castings 2018