I am planning to sculpt/cast a bottle in clear tinted resin, but am having a time wrapping my head around how to mold and cast this shape. Is this possible to achieve with a single mold and resin pour?
Tips on casting a bottle?
- Thread starter Hecubus114
- Start date
With a transparent bottle, the biggest issue you will face is keeping it a consistent thickness throughout, because drips or thicker areas are going to show and it will not look like a real bottle. If you plan on using silicone to mold a real glass bottle, make sure you use a release on the glass, because silicone will bond to clean glass.
Do you think it would be easier to cast in halves then glue them together? Or would that be too difficult to do and not look messy?
Also, to get a clear casting without a ton of bubbles, is a pressure pot the only answer? Or are there clear resin that can do this with one?
Also, to get a clear casting without a ton of bubbles, is a pressure pot the only answer? Or are there clear resin that can do this with one?
robstyle
Master Member
moulding a bottle is just as with moulding anything, except youll need to coat the glass itself in a thin coat of mould release or if you want it extra shiny a thin coat of Vaseline then hit that coat with a heatgun/hair drier to get the surface even with no brush marks. Even if youre not going to mould a real glass bottle, the Vaseline trick will work with anything you want a gloss finish on, even a sculpted bottle out of clay. You can poor mans rotocast it by pouring the material into the mould, clamping the mould, plugging the vent hole/holes and simply turn it around by hand. A faster curing material helps a lot. The bottles from the POTC films were done this way mostly to keep the uneven and hand blown glass look. Some had contaminants intentionally added to get the bubble glass and wavey look.
Hecubus,
If you want a bottle with the cliche' look, lumpy with lots of bubbles, then hand roto casting may work, but if you want your piece to look like a real bottle, or a modern one, then you have a trickery issue to deal with.
It would help to see an image of the bottle you are trying to replicate. Perhaps instead of two halves, I would suggest (depending on the bottles shape) cutting the bottom off and making a mold with a inner core. One mold for the upper portion of the bottle and one for the bottom. This way you have a controlled volume in which to pour resin, and then you could use a pressure pot. If your bottle is mold blown (the glass was formed in a mold) then there will be a seam near the bottom you can use to hide the seam in your cast bottle.
I have roto cast, by hand, bottles for film and it is pretty hit or miss. The best results I obtained were using epoxy resin in silicone molds and I heated the mold and warmed the resin. The heating the resin lowers the viscosity, and thus traps less air. Heating the mold adds more heat to the resin and helps it cure more evenly as you slush it around in the mold. But you have to work quick, as the heat will cause the resin the set quickly. If you get lucky, you may get something acceptable on the first one or two. If you don't, you have to study the failures and try to adjust you technique accordingly.
robstyle,
Hand blown glass is typically even, and bubble free. I'm afraid the modern idea of hand blown items being bubbly and lumpy is just a result of poorly skilled novice glass blowers trying to replicate historic pieces. I have worked with hot glass and made and helped make many different types of glass and it's all even and bubble free, as well as quite thin. Even ancient Roman mold blown glass was smooth and bubble free.
I'm not sure to which bottle you refer in the pirates movie, as the hero bottles in Stranger tides were made by Historical Glassworks and were even and bubble free. Perhaps the bottles used for Blackbeard's ship collection were roto cast in resin.
Here is one of the hero bottles from Stranger Tides. The slight modeling you see in the color, is the color, not thickness. (I think this was an alternate color not chosen)
If you want a bottle with the cliche' look, lumpy with lots of bubbles, then hand roto casting may work, but if you want your piece to look like a real bottle, or a modern one, then you have a trickery issue to deal with.
It would help to see an image of the bottle you are trying to replicate. Perhaps instead of two halves, I would suggest (depending on the bottles shape) cutting the bottom off and making a mold with a inner core. One mold for the upper portion of the bottle and one for the bottom. This way you have a controlled volume in which to pour resin, and then you could use a pressure pot. If your bottle is mold blown (the glass was formed in a mold) then there will be a seam near the bottom you can use to hide the seam in your cast bottle.
I have roto cast, by hand, bottles for film and it is pretty hit or miss. The best results I obtained were using epoxy resin in silicone molds and I heated the mold and warmed the resin. The heating the resin lowers the viscosity, and thus traps less air. Heating the mold adds more heat to the resin and helps it cure more evenly as you slush it around in the mold. But you have to work quick, as the heat will cause the resin the set quickly. If you get lucky, you may get something acceptable on the first one or two. If you don't, you have to study the failures and try to adjust you technique accordingly.
robstyle,
Hand blown glass is typically even, and bubble free. I'm afraid the modern idea of hand blown items being bubbly and lumpy is just a result of poorly skilled novice glass blowers trying to replicate historic pieces. I have worked with hot glass and made and helped make many different types of glass and it's all even and bubble free, as well as quite thin. Even ancient Roman mold blown glass was smooth and bubble free.
I'm not sure to which bottle you refer in the pirates movie, as the hero bottles in Stranger tides were made by Historical Glassworks and were even and bubble free. Perhaps the bottles used for Blackbeard's ship collection were roto cast in resin.
Here is one of the hero bottles from Stranger Tides. The slight modeling you see in the color, is the color, not thickness. (I think this was an alternate color not chosen)
Last edited:
robstyle
Master Member
im talking a little further back to the first couple sequels. The rum bottles, some drinking glasses and such as well as the jar of dirt. We actually made a couple clearish rubber jars of dirt as well.
