I used to make rtv molds for Ricker Bartlet Pewter sculptures (both gravity and spincasting). Most pieces would have details like legs, arms, head, etc. To give myself a guide as to what the orientation of the piece was inside the mold, I used wood for the mold form sides and after the original piece was fixed in place, I would use a pencil to mark where those details were on the inside of the form. The pencil marks will transfer to the outside surface of the mold to give you a reference mark to cut open your mold. When cutting the mold open, the more zigzag cuts you have, the better your halves will fit together to avoid miss-alignment and flashing.
Hey brilliant video! Very helpful for a novice like myself! Apologies if you have already answered this, but just clarifying. I am looking to use this method of mold making for my silver masters, and I don't have a vaccum. So if I were to use a rice cooker, I cure the liquicast first in a bowl and again with the mold, both for two hours? Thanks :)
We vacuumed twice because the molding material expands under vacuum. We could vacuum just once when the material is in the mold form, and have done so with other mold materials. For this Mold material we find it best to vacuum in two stages. If you are not using a vacuum, at all, you would only put your mold frame (with the material in it) in your pressure pot or rice cooker. You don’t want it to cure in the bowl as then you’ll have mixed it for nothing.
Thanks for showing us Liqua-cast. Could a 2-part mold be made with that using talc or vaseline and not create a large parting line from injecting wax? I'm about to try some Smooth-On Mold Max 60 for high temp wax injection and metal casting (two uses, same material).
Never heard of Smooth-On Mold Max. I am not sure what you mean by two part mold...this is a two part mold material. Do you mean pouring a top and bottom? Not sure why you wouldn't just mold all in one. Generally you use talc or something similar with all molds before injecting. Flashing generally shouldn't happen if you are injecting your mold right. - Shannon
@@ClearMindJewellery You are right about the two-part old pouring a top and then a bottom. After watching what you do pouring it all at once and cutting it away looks like a better way = still researching new ways to cast. Thanks for the reply.
Correct, Liquicast expands massively so to prevent it from overflowing we turn the vacuum on and off. It's not the best solution, it should expand to its fullest and collapse on its own ideally.
Im surprised you didnt address venting the mold to eliminate trapped air when injecting. Somebody new to this would be clueless as to why their injections were failing.
Hey great vid, I read that if you don’t have a vacuum, you can instead just coat the wax piece with the liqua cast using a small paintbrush and then pour it in the mold like usual. Do you have any experience with this? If so, did it work?
We don’t have experience with it. It seems like it would work in theory. Although it’s going to be messy, definitely use a disposable brush. A neat trick, you can also cure liquicast in a low-medium heat environment like a rice cooker to make the process faster.
Smooth-On has clear options as does Freeman. This is a project video we did with the Freeman Jewel-sil th-cam.com/video/EgM5QmlzsyI/w-d-xo.htmlfeature=shared
Oh wow that’s amazing, I’ve always wondered how you make moulds of Hollowed items....Q: if I make a wax master of a hollow round Charm bead, the kind that goes on the popular pandora style bracelets, would I need to used it this same way or would the best way be to make a master in silver then use the pink rubber sheets ..don’t know the correct names as I’m new to this, I’ve had moulds made for me from my Cad file only, and they did a 3D printed master then made a silver master from that then they made a mould, it cost me well over £120 in the end.
In my opinion it would be better to go with liquicast to get all of the detail. If it’s a complete cage you would have to do it in halves and then put the wax parts together before cast. Hollow objects are tough. Im honestly not sure what kind of molding rubber Pandora is using the be able to pull the mold out from inside of their charms. If you’re working from 3D prints you can get a mouldable print material and skip having to cast a master to mold from, or if your doing a very limited run just cast straight front the prints.
Don't use this urethane product if you want your mold to have a reasonable library life. This is the same product as Smooth-on 724. Over time, even with care, the molds will turn back into a liquid and make a horrible gooey mess that is very difficult to clean up. Better off using a little more expensive silicone RTV if you want your molds to last a long time. This material also dulls scalpel blades fairly quickly.
I used to make rtv molds for Ricker Bartlet Pewter sculptures (both gravity and spincasting). Most pieces would have details like legs, arms, head, etc. To give myself a guide as to what the orientation of the piece was inside the mold, I used wood for the mold form sides and after the original piece was fixed in place, I would use a pencil to mark where those details were on the inside of the form. The pencil marks will transfer to the outside surface of the mold to give you a reference mark to cut open your mold. When cutting the mold open, the more zigzag cuts you have, the better your halves will fit together to avoid miss-alignment and flashing.
This was far superior to the video. I dont mean to hate. Lets say this complemented the video. :)
your equipment is so clean.....
This was 4-5yrs ago so they were a bit newer back then but we still try to keep everything clean as silica dust is no joke.
Hey brilliant video! Very helpful for a novice like myself! Apologies if you have already answered this, but just clarifying. I am looking to use this method of mold making for my silver masters, and I don't have a vaccum. So if I were to use a rice cooker, I cure the liquicast first in a bowl and again with the mold, both for two hours? Thanks :)
We vacuumed twice because the molding material expands under vacuum.
We could vacuum just once when the material is in the mold form, and have done so with other mold materials.
For this Mold material we find it best to vacuum in two stages.
If you are not using a vacuum, at all, you would only put your mold frame (with the material in it) in your pressure pot or rice cooker.
You don’t want it to cure in the bowl as then you’ll have mixed it for nothing.
Thanks for showing us Liqua-cast.
Could a 2-part mold be made with that using talc or vaseline and not create a large parting line from injecting wax?
I'm about to try some Smooth-On Mold Max 60 for high temp wax injection and metal casting (two uses, same material).
Never heard of Smooth-On Mold Max.
I am not sure what you mean by two part mold...this is a two part mold material. Do you mean pouring a top and bottom? Not sure why you wouldn't just mold all in one.
Generally you use talc or something similar with all molds before injecting. Flashing generally shouldn't happen if you are injecting your mold right. - Shannon
@@ClearMindJewellery You are right about the two-part old pouring a top and then a bottom. After watching what you do pouring it all at once and cutting it away looks like a better way = still researching new ways to cast. Thanks for the reply.
thanks for this great video!
a query, you turn the vacuum on and off in the second round so that the mold does not overflow?
Correct, Liquicast expands massively so to prevent it from overflowing we turn the vacuum on and off. It's not the best solution, it should expand to its fullest and collapse on its own ideally.
Im surprised you didnt address venting the mold to eliminate trapped air when injecting. Somebody new to this would be clueless as to why their injections were failing.
We didn’t address it as we’ve never needed to do it.
Hey great vid, I read that if you don’t have a vacuum, you can instead just coat the wax piece with the liqua cast using a small paintbrush and then pour it in the mold like usual. Do you have any experience with this? If so, did it work?
We don’t have experience with it. It seems like it would work in theory. Although it’s going to be messy, definitely use a disposable brush.
A neat trick, you can also cure liquicast in a low-medium heat environment like a rice cooker to make the process faster.
@@ClearMindJewellery great, thanks :)
Is there an alternative that is clear? It would be easier to cut the mold and see what’s happening during injecting.
Smooth-On has clear options as does Freeman. This is a project video we did with the Freeman Jewel-sil th-cam.com/video/EgM5QmlzsyI/w-d-xo.htmlfeature=shared
Liquia-Fast and liqui-Cast seem to do the same thing. What's the difference other than clear vs pink(?).
Oh wow that’s amazing, I’ve always wondered how you make moulds of Hollowed items....Q: if I make a wax master of a hollow round Charm bead, the kind that goes on the popular pandora style bracelets, would I need to used it this same way or would the best way be to make a master in silver then use the pink rubber sheets ..don’t know the correct names as I’m new to this, I’ve had moulds made for me from my Cad file only, and they did a 3D printed master then made a silver master from that then they made a mould, it cost me well over £120 in the end.
In my opinion it would be better to go with liquicast to get all of the detail. If it’s a complete cage you would have to do it in halves and then put the wax parts together before cast.
Hollow objects are tough.
Im honestly not sure what kind of molding rubber Pandora is using the be able to pull the mold out from inside of their charms.
If you’re working from 3D prints you can get a mouldable print material and skip having to cast a master to mold from, or if your doing a very limited run just cast straight front the prints.
@@ClearMindJewellery yes I think the best way would be to cast directly using the printed material, thanks 🙏
nice vide. The zig zig LOCK cuts on the side would be very helpfull.....
Don't use this urethane product if you want your mold to have a reasonable library life. This is the same product as Smooth-on 724. Over time, even with care, the molds will turn back into a liquid and make a horrible gooey mess that is very difficult to clean up. Better off using a little more expensive silicone RTV if you want your molds to last a long time. This material also dulls scalpel blades fairly quickly.