Jawbone flats
Community Member
My method is probably not for all but it works for me.
For this diy thread you will need :
Mix your plaster per mfg directions and pour into initial mold.
For this demo I poured the plaster about 3/4" deep
I used a 6 x 6 plastic food container like gladware or tupperware.
Step 2: Let this sit for about an hour or two for your slab to set up.
then just pop the plaster slab out of the container.. since it is plastic the plaster wont stick to the bowl so it should just about fall out.
Step 3: Take your new plaster slab over to your work table and using the Forstner bit drill down into the plaster slab about 1/8 to 1/4"
The plaster will be firm and solid but it is very fragile at this time. so dont drop it.
When milling it you will see that the plaster is still wet and will clump and stick to your mold. I used a can of air to blow the residual plaster from my slab Mold
Step 4: Now using your 1/2" drill bit. drill out the center all the way through. (slow down right before you pierce through the bottom for a neater exit hole.)
Your finished Mold should look like this.
Step 5: Let this Mold Dry for at least 3 days or even a week. it has to be BONE DRY in order to work correctly with the liquid slip material
Step 6: Take your Duct Tape and place strips accross the bottome covering all the small holes
Step 7: Fill your mold with the Casting Slip - I used one of those picnic mayonaise squirters so I could be neat and not get liquid clay all over the place.
Over fill them a little bit like the picture shows
The Theory here is that the Plaster will Absorb all the water out of the Casting Slip and turn the liquid slip into a leather hard Clay.
As the plaster absorbs the water out of the clay the center of the frag plug will sink down.
You can leave it this way ( I like the little divot for mounting sps frags. ) or you can just add more casting slip to fill the void as it dries.
Let the plugs dry in the mold for at least 4 to 6 hours (depending on humidity), then just turn the mold over and pull of the duct tape. your plugs should just drop out. or you can push them out with your pinky.
Ok now you have to repeat from step 6 depending on how many plugs you want. ( I only use my molds at the most 2 or 3 times a day and let them dry between castings for a couple of hours. )
Step 8: Once you have all your plugs made you now need to let them dry for at least 5 days. your plugs are now in the Greenware Stage.
Step 9: Now following your Kiln Instructions fire them to the Cone setting of the Casting Slip you purchased. ( or take them to your Friend who has a kiln or your local pottery store will fire them for a price I am sure )
I wait till I have five hundred to a thousand frag plugs or so before I fire them in the kiln because electricity is not free.
when I do fire them I just pile them into the kiln and fire them... they are literally just in a big pile I dont worry about them sticking together becauese there is no glazing on them so they wont stick.
Once they are cooled down they are Reef Safe.
Casting Slip is Non-Toxic to begin with and since they are fired in excess of 1900 Degrees Fahrenheit they become inert and are completley reef safe.
Be creative you can use different color Casting Slip and YES you can actually paint ceramic Glaze on them and they are still Reef Safe.
Also you can just use the forstner bit and not drill out the center hole and just make Ceramic Frag DISCS
My actual molds are 20 plugs per slab and they have been re-used many many times. just be sure to let them dry betwing castings
all these pictures are from my cell phone so dont rag on me for quality.. but I think they came out ok for a diy post.
I hope you get something out of this.
For this diy thread you will need :
- A Ceramic Kiln or access to one.
- A Drill (I used a drill press but it is not necessary)
- A roll of Duct Tape. ( If your not sure what this is, please refer to the Red Green Show ).
- Pottery Plaster or plaster of paris (obtain from pottery store or whatever home store is in your town... at the time of this writing I paid 12 dollars for 25 pounds of dry mix)
- Cone 06 Liquid Casting Slip (obtain from local pottery store or online, I think the smallest size is 1 gallon)
- Container to pour the plaster into (gladware or similar square plastic food storage container )
- 1-1/4" Forstener bit ( I used 1-1/4" for this demo but you can go smaller or larger )
- 1/2" Drill Bit ( I used 1/2" for this demo but you can go larger or smaller )
Mix your plaster per mfg directions and pour into initial mold.
For this demo I poured the plaster about 3/4" deep
I used a 6 x 6 plastic food container like gladware or tupperware.
Step 2: Let this sit for about an hour or two for your slab to set up.
then just pop the plaster slab out of the container.. since it is plastic the plaster wont stick to the bowl so it should just about fall out.
Step 3: Take your new plaster slab over to your work table and using the Forstner bit drill down into the plaster slab about 1/8 to 1/4"
The plaster will be firm and solid but it is very fragile at this time. so dont drop it.
When milling it you will see that the plaster is still wet and will clump and stick to your mold. I used a can of air to blow the residual plaster from my slab Mold
Step 4: Now using your 1/2" drill bit. drill out the center all the way through. (slow down right before you pierce through the bottom for a neater exit hole.)
Your finished Mold should look like this.
Step 5: Let this Mold Dry for at least 3 days or even a week. it has to be BONE DRY in order to work correctly with the liquid slip material
Step 6: Take your Duct Tape and place strips accross the bottome covering all the small holes
Step 7: Fill your mold with the Casting Slip - I used one of those picnic mayonaise squirters so I could be neat and not get liquid clay all over the place.
Over fill them a little bit like the picture shows
The Theory here is that the Plaster will Absorb all the water out of the Casting Slip and turn the liquid slip into a leather hard Clay.
As the plaster absorbs the water out of the clay the center of the frag plug will sink down.
You can leave it this way ( I like the little divot for mounting sps frags. ) or you can just add more casting slip to fill the void as it dries.
Let the plugs dry in the mold for at least 4 to 6 hours (depending on humidity), then just turn the mold over and pull of the duct tape. your plugs should just drop out. or you can push them out with your pinky.
Ok now you have to repeat from step 6 depending on how many plugs you want. ( I only use my molds at the most 2 or 3 times a day and let them dry between castings for a couple of hours. )
Step 8: Once you have all your plugs made you now need to let them dry for at least 5 days. your plugs are now in the Greenware Stage.
Step 9: Now following your Kiln Instructions fire them to the Cone setting of the Casting Slip you purchased. ( or take them to your Friend who has a kiln or your local pottery store will fire them for a price I am sure )
I wait till I have five hundred to a thousand frag plugs or so before I fire them in the kiln because electricity is not free.
when I do fire them I just pile them into the kiln and fire them... they are literally just in a big pile I dont worry about them sticking together becauese there is no glazing on them so they wont stick.
Once they are cooled down they are Reef Safe.
Casting Slip is Non-Toxic to begin with and since they are fired in excess of 1900 Degrees Fahrenheit they become inert and are completley reef safe.
Be creative you can use different color Casting Slip and YES you can actually paint ceramic Glaze on them and they are still Reef Safe.
Also you can just use the forstner bit and not drill out the center hole and just make Ceramic Frag DISCS
My actual molds are 20 plugs per slab and they have been re-used many many times. just be sure to let them dry betwing castings
all these pictures are from my cell phone so dont rag on me for quality.. but I think they came out ok for a diy post.
I hope you get something out of this.
