workinforwood
Member
This is an ongoing extended event with the purpose of learning how to properly use and maintain silicone molds for the purpose of casting pen blanks and do so in the most economic manner.
My goal is to create a small chart of different silicone materials, maintained in different ways, a set pertaining to Urethane Resins and a set for Polyester Resins. These being the two most common mediums.
Why? Silicone molds do not come with a user manual. You can look up tons of information about silicone, but there are so many types, brands, uses, and misconceptions out there, it becomes impossible to get the truth. For example, I can be told a mold will be good for 150 pours. 150 pours of what though? PR, Alumilite, soft metals, candy, candles? And just how fancy and detailed are these molds? Every use has a different result. For some of us, pouring is just fun, and you pour one or two blanks, and that's just fine, but for some of us we pour thousands of blanks in a year, and we have overhead costs to meet, and the cost of silicone is part of the deal. Silicone is very convenient. There are other ways, but I have found none that are faster and more convenient and as simple to re-create as silicone, and time is not only money, but time is more money that the mold itself is worth, so therefore the mold should be maximized so it can be put to work for as long as possible, but on the flipside if it costs more money to keep the mold running than the extra blanks you achieve it is not worth it.
In the beginning, I thought a silicone mold would last forever. This might sound silly, but I bet many others may think or have thought the same thing. But, after a while, the resin starts to stick to the mold, and eventually will stick to the point where it tears chunks out of the mold. But..I thought nothing sticks to silicone! Oh..that's not true at all. Nothing sticks to silicone oil is the real truth. Now imagine this...at the county fair there is a square balloon tub and it is full of little balls and the kids jump into the balls. We've all seen and maybe even experienced this. Now if you take silicone and put it under a microscope, you basically see the same thing. It's billions of tiny balls stuck together. In the balloon room, there is air between all the balls. Now in Silicone, there is oil in between all the balls. This oil is what prevents anything from sticking to the balls. Once the oil is depleted then resin starts to come into the mold filling in between the little balls and when you pry the resin out it pulls silicone with it. Each time you use the mold, you lose more oil, drying out the mold and allowing the penetration that is the death of it all.
When you read about how to use molds, 1/2 the answers are to just use them as is..no problem. 1/2 the answers are to spray them with release. There are also people that use wax in the molds, and there is a process called baking the mold. Applying wax or release is self explanatory. You would apply these every time you use the mold. To bake a mold, you need some 200 silicone oil. Hard to find in small quantities, but Alumilite does carry it in one pound increments. You wipe the mold with the silicone oil and let sit 15 min only and then you bake the mold at 200 degrees for 1 hr. This will cause the oil to penetrate into the mold and the resin trapped inside to be pushed back out, rejuvenating the mold to like new status.
I am not a silicone expert. I have not tried all these techniques and have not experienced all the different types of silicone's out there either. I am told that some silicone's will last longer than others for what we do here, but the difference is going to be very minor. From what experiments I have done so far, I am finding that to be the truth. So an expensive silicone is going to lose money in the end. I was told this Dow Corning silicone would do 150 pours...as you will see in the pic, it made it to 117 pours before death, and this mold was used completely dry all the time, and with alumilite at an average 60lbs of pressure. I think pressure casting and non pressure casting would be drastically different, but that's only a theory, I have no evidence. I switched to Smooth-on, and went with a harder shore, 27T and achieved 121 pours, used dry only and it was 75% cheaper silicone than the Dow.
Anyhow...so here's where you guys will hopefully donate your molds to the educational research because it will take me too many years to try every option available! Not donate to me the mold itself, just the research. I need volunteers. It does not matter where you get your molds, if you make the silicone yourself or if you buy them from New London or Subbie. As long as they are silicone. As you can see in pic 2, I have set up a second experiment set of molds. I have the weight of the mold, and the type of the product on the mold. Then how the mold is being used and how many times. I already have a result on the dry for this type of mold, so I am going to switch that mold to be baked every 15 uses. The other mold I am going to spray with release every time I use it till it dies..and I'm betting that the mold will not last 200% longer with the spray but time will tell. This will be important too, because a bottle of spray is $16 so if the mold doesn't do better than half again as many pours, I lost money. My gut tells me that if you wax a mold with something like a can of Johnsons paste wax every time, and at a cost of $5 for a can of that stuff that lasts dang near till you die..the mold will last for many many years..but we shall see if I'm right.
So...Volunteers. You can volunteer more than once too, that's no problem. I already know that PTownSubbie and NewLondon88 provide a different product type. If you make your own molds, that's awesome too. This experiment is for maximum use of the product in real time. None of this, I poured over 300 dry and keep going as that's just a number you pull out of your butt..no, we need the real numbers. It's going to take some time.
I need, Alumilite users and PR users. Find out what the product is you are using if you purchase mold from someone.
I need volunteers for everything PR, as I don't do that.
I need calculations for dry pours.
I need spray release every time pours
I need baked every 15 uses pours
I need paste wax every time pours.
Tell me the product you are using and which method you will use. So if you use OOMOO 25, which is what Fred Pours, I need a volunteer for each of the above in PR and alumilite. So that's 8 experiments for OOMOO 25. I'm not sure what Charlie is currently using, perhaps he will let us know.
I realize results will vary from one user to another when using the same methods, but I do not believe results wouldnt change by much so long as the original experiment was consistent with his use and counting. Eventually I will form a small chart which will show the results of what people used and how they used it, which will allow people to make more educated decisions as to how they take care of their silicone molds, or if it's even worth taking care of them at all.
My goal is to create a small chart of different silicone materials, maintained in different ways, a set pertaining to Urethane Resins and a set for Polyester Resins. These being the two most common mediums.
Why? Silicone molds do not come with a user manual. You can look up tons of information about silicone, but there are so many types, brands, uses, and misconceptions out there, it becomes impossible to get the truth. For example, I can be told a mold will be good for 150 pours. 150 pours of what though? PR, Alumilite, soft metals, candy, candles? And just how fancy and detailed are these molds? Every use has a different result. For some of us, pouring is just fun, and you pour one or two blanks, and that's just fine, but for some of us we pour thousands of blanks in a year, and we have overhead costs to meet, and the cost of silicone is part of the deal. Silicone is very convenient. There are other ways, but I have found none that are faster and more convenient and as simple to re-create as silicone, and time is not only money, but time is more money that the mold itself is worth, so therefore the mold should be maximized so it can be put to work for as long as possible, but on the flipside if it costs more money to keep the mold running than the extra blanks you achieve it is not worth it.
In the beginning, I thought a silicone mold would last forever. This might sound silly, but I bet many others may think or have thought the same thing. But, after a while, the resin starts to stick to the mold, and eventually will stick to the point where it tears chunks out of the mold. But..I thought nothing sticks to silicone! Oh..that's not true at all. Nothing sticks to silicone oil is the real truth. Now imagine this...at the county fair there is a square balloon tub and it is full of little balls and the kids jump into the balls. We've all seen and maybe even experienced this. Now if you take silicone and put it under a microscope, you basically see the same thing. It's billions of tiny balls stuck together. In the balloon room, there is air between all the balls. Now in Silicone, there is oil in between all the balls. This oil is what prevents anything from sticking to the balls. Once the oil is depleted then resin starts to come into the mold filling in between the little balls and when you pry the resin out it pulls silicone with it. Each time you use the mold, you lose more oil, drying out the mold and allowing the penetration that is the death of it all.
When you read about how to use molds, 1/2 the answers are to just use them as is..no problem. 1/2 the answers are to spray them with release. There are also people that use wax in the molds, and there is a process called baking the mold. Applying wax or release is self explanatory. You would apply these every time you use the mold. To bake a mold, you need some 200 silicone oil. Hard to find in small quantities, but Alumilite does carry it in one pound increments. You wipe the mold with the silicone oil and let sit 15 min only and then you bake the mold at 200 degrees for 1 hr. This will cause the oil to penetrate into the mold and the resin trapped inside to be pushed back out, rejuvenating the mold to like new status.
I am not a silicone expert. I have not tried all these techniques and have not experienced all the different types of silicone's out there either. I am told that some silicone's will last longer than others for what we do here, but the difference is going to be very minor. From what experiments I have done so far, I am finding that to be the truth. So an expensive silicone is going to lose money in the end. I was told this Dow Corning silicone would do 150 pours...as you will see in the pic, it made it to 117 pours before death, and this mold was used completely dry all the time, and with alumilite at an average 60lbs of pressure. I think pressure casting and non pressure casting would be drastically different, but that's only a theory, I have no evidence. I switched to Smooth-on, and went with a harder shore, 27T and achieved 121 pours, used dry only and it was 75% cheaper silicone than the Dow.
Anyhow...so here's where you guys will hopefully donate your molds to the educational research because it will take me too many years to try every option available! Not donate to me the mold itself, just the research. I need volunteers. It does not matter where you get your molds, if you make the silicone yourself or if you buy them from New London or Subbie. As long as they are silicone. As you can see in pic 2, I have set up a second experiment set of molds. I have the weight of the mold, and the type of the product on the mold. Then how the mold is being used and how many times. I already have a result on the dry for this type of mold, so I am going to switch that mold to be baked every 15 uses. The other mold I am going to spray with release every time I use it till it dies..and I'm betting that the mold will not last 200% longer with the spray but time will tell. This will be important too, because a bottle of spray is $16 so if the mold doesn't do better than half again as many pours, I lost money. My gut tells me that if you wax a mold with something like a can of Johnsons paste wax every time, and at a cost of $5 for a can of that stuff that lasts dang near till you die..the mold will last for many many years..but we shall see if I'm right.
So...Volunteers. You can volunteer more than once too, that's no problem. I already know that PTownSubbie and NewLondon88 provide a different product type. If you make your own molds, that's awesome too. This experiment is for maximum use of the product in real time. None of this, I poured over 300 dry and keep going as that's just a number you pull out of your butt..no, we need the real numbers. It's going to take some time.
I need, Alumilite users and PR users. Find out what the product is you are using if you purchase mold from someone.
I need volunteers for everything PR, as I don't do that.
I need calculations for dry pours.
I need spray release every time pours
I need baked every 15 uses pours
I need paste wax every time pours.
Tell me the product you are using and which method you will use. So if you use OOMOO 25, which is what Fred Pours, I need a volunteer for each of the above in PR and alumilite. So that's 8 experiments for OOMOO 25. I'm not sure what Charlie is currently using, perhaps he will let us know.
I realize results will vary from one user to another when using the same methods, but I do not believe results wouldnt change by much so long as the original experiment was consistent with his use and counting. Eventually I will form a small chart which will show the results of what people used and how they used it, which will allow people to make more educated decisions as to how they take care of their silicone molds, or if it's even worth taking care of them at all.
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