Depends on the type of silicone. A baking form is made from a type of silicone which is made to withstand higher temperatures. A silicone from an arts and crafts store for moulding your own items and casting resin in might not withstand the temperatures of molten lead.
The off gassing is common among new silicone molds. I have used talc powder, graphite powder and graphite or molybdenum spray cans as a mold release and protectant. Less boiling and better definition are the results.
Hi, this is a high school laboratory stove I bought when they were selling off old equipment. It doesn't work very well at these temperatures, I think it is intended for heating liquids, etc... not melting metals. I had to supplement heat with a propane torch, then this heater maintained it.
The reason you didn't get good features is because of the temperature differential between the hot lead and the silicone mold. If you popped out the first pour and immediately poured a subsequent one it would probably look much better. But at the same time, the RTV would be getting much hotter and I have no idea if it would stand up to that. Good video.
i did the same thing with silicone lago icecubic trays i found out you need to use the mould a fue times then brush some char coal powder (ash) in to it so it forms to the mould better and helps with the bubbling.
Tip: place the mold in an airtight bag with a small bottle cap full of sodium hydroxide powder for at least 24 hours. This will draw any moisture out of the mold.
If you look at the mold at 2:37 and 2:38 inside the mold that you used top right it seems to allow more light through than rest of the mold. Not certain if it is just lighting messing with me or not but may have burnt off some silicon. Not certain. Just got into your channel. Awesome videos.
That could be as well. The boiling is a common problem with open casting. Really any thing porous like synthetic plastics and silicons don't make for good molds due to the fact you can't preheat them and they hold air and moisture. If you get crazy with your lead you can always have a brass mold made. They are not that much and last forever. I used copper pipe to store my lead in. It just seemed easy to store and melt that way. I could just melt in to the mold from the pipe.
The reason you lost some detail in the 1st 1 is probably because the lead is heavy and the silicone is soft and flexy and stretched the shape out of the mold a bit. The 2nd 1 had more detail (less stretch) and I bet if you put even less in the detail would be perfect. You gotta remember these were only made to support the weight of water.
Did you try to cast in this mold more then once? Maybe the boiling stuff wold have been boiled out on the second cast. You could also try pre heating the silicone at 300 degrees to see if its water being cooked out.
It is not uncommon for companies to coat any item in order to make it stay and look new on the store shelves This could be what is burning off. Similar to how you are supost to pre fire a new cast iron pot to burn off the anti rusting agent they put on them. The only way to tell who is right would be repeated casting to see if it goes away or not..
Interesting idea, I wonder if having the mold placed in a shallow bath of cold water would help anything?, or maybe pressing the mold into moist sand would help cool the lead faster as well as help bring out the molds features?.
peter chessell Dont get the water under the surface of the lead and it would be fine. I would probably put the mould on a wet towel or something though.
Silcone rubber will not "melt" - once it has cured it is "set" - though it will degrade and/or burn with excess heat. However as the video showed, the mold certainly was able to cast the piece (albeit with limited definition) at least once and I am guessing if a simple shape is all that is required, the mold would survive a good number of castings.
Thats What I was thinking. as he is pouring the visible portions of lead in the ,old are solidifying and becoming weighty. Mold being a thin silicone now deforms those features he was loosing due to the weight of the lead. I think, just as billy jojo mentioned sand or a support mold for the silicone mold would indeed retain the features. Nice team work Y'alll! :-)
Silicon is a chemical element with a melting point of 1414 °C, and SILICONE is a polymer that decomposes around the melting point of lead. So no, it won't do easily. It will do, but barely. In order to cast lead and expect complete filling of the mold, it has to be hotter. Silicone can barely withstand such temperatures.
He says this below: Hi, this is a high school laboratory stove I bought when they were selling off old equipment. It doesn't work very well at these temperatures, I think it is intended for heating liquids, etc... not melting metals. I had to supplement heat with a propane torch, then this heater maintained it.
Sure, if you're looking at consumer level - silicone is a polymer because it was mixed with compounds for different purposes. Such as silicone caulk, MDX, and so on. However on science level - no. Yeah, it doesn't stand temperatures near 2700°C however it does stand temperatures near 2700°F. You aren't that slick trying to switch F with C. This melting point does not apply to compounds that silicone was mixed with.
Your casting would have been great if u made vents in the details, just bury your silicon mold in sand ( beach sand is ok for this ) well thats about it if you are willing to fix it.
It's not plastic it's silicone and we can make our own molds from it. It's mixed together from two liquids, rather than melted and molded like plastic. BUT they do "rate it" at 400-450F which is 200f below Pb melting temp.
Pour slower next time and less. Make them really thin. Be careful though...i wouldnt try this..and for the love of god DONT add water under the pour. EXPLOSION!!!! BOOM! THEN POOF OFF GOES ALL YOUR HAIR.LOL
I didn't know that silicone could withstand this! Thanks for posting!
Depends on the type of silicone. A baking form is made from a type of silicone which is made to withstand higher temperatures.
A silicone from an arts and crafts store for moulding your own items and casting resin in might not withstand the temperatures of molten lead.
The off gassing is common among new silicone molds. I have used talc powder, graphite powder and graphite or molybdenum spray cans as a mold release and protectant. Less boiling and better definition are the results.
FINALLY i get to use up the rest of my "Ms. Moly" !
Hi, this is a high school laboratory stove I bought when they were selling off old equipment. It doesn't work very well at these temperatures, I think it is intended for heating liquids, etc... not melting metals. I had to supplement heat with a propane torch, then this heater maintained it.
These will make great stocking stuffers for Christmas.
Oh, I can definitely see the potential for DIY sinkers!
The reason you didn't get good features is because of the temperature differential between the hot lead and the silicone mold. If you popped out the first pour and immediately poured a subsequent one it would probably look much better. But at the same time, the RTV would be getting much hotter and I have no idea if it would stand up to that. Good video.
FACTS👍👍👍
i did the same thing with silicone lago icecubic trays i found out you need to use the mould a fue times then brush some char coal powder (ash) in to it so it forms to the mould better and helps with the bubbling.
Tip: place the mold in an airtight bag with a small bottle cap full of sodium hydroxide powder for at least 24 hours. This will draw any moisture out of the mold.
Well, molten lead exceeds the specified temperatures for this silicone so I think the silicone was burning and offgassing perhaps. Thoughts?
it was gassing because the mold was cold, you need to preheat it before you pour in the lead and it'll come out perfect.
If you look at the mold at 2:37 and 2:38 inside the mold that you used top right it seems to allow more light through than rest of the mold. Not certain if it is just lighting messing with me or not but may have burnt off some silicon. Not certain. Just got into your channel. Awesome videos.
well it did pretty well, didn't expect it to survive molten lead.
That could be as well. The boiling is a common problem with open casting. Really any thing porous like synthetic plastics and silicons don't make for good molds due to the fact you can't preheat them and they hold air and moisture. If you get crazy with your lead you can always have a brass mold made. They are not that much and last forever. I used copper pipe to store my lead in. It just seemed easy to store and melt that way. I could just melt in to the mold from the pipe.
The boiling was moisture in the silicon. It is porous an holds moisture.
Thanks for posting! This is really helpful.
The reason you lost some detail in the 1st 1 is probably because the lead is heavy and the silicone is soft and flexy and stretched the shape out of the mold a bit. The 2nd 1 had more detail (less stretch) and I bet if you put even less in the detail would be perfect. You gotta remember these were only made to support the weight of water.
silicone is silicone. the "destruction" or thinning of the mold is likely the dye failing.
Yea I dont know if it was boiling or if that was a reaction with the Silicone or something on the silicone.
Did you try to cast in this mold more then once? Maybe the boiling stuff wold have been boiled out on the second cast. You could also try pre heating the silicone at 300 degrees to see if its water being cooked out.
It is not uncommon for companies to coat any item in order to make it stay and look new on the store shelves This could be what is burning off. Similar to how you are supost to pre fire a new cast iron pot to burn off the anti rusting agent they put on them. The only way to tell who is right would be repeated casting to see if it goes away or not..
Maybe small amount of water remains in silicone?
Maybe stick the empty silicone mold in the oven at like 300 degrees to bake out any captured moisture?
NICE!👍👍👍
Interesting idea, I wonder if having the mold placed in a shallow bath of cold water would help anything?, or maybe pressing the mold into moist sand would help cool the lead faster as well as help bring out the molds features?.
cold water molten lead.....explosion stupid comment.
peter chessell
Dont get the water under the surface of the lead and it would be fine. I would probably put the mould on a wet towel or something though.
+Enfant de Lumière silicone rubber is insulating, it will make no difference and water... you for real?
stickytwat
I am as real as the laws of thermodynamics, ....what alternate dimension are you from?.
Where good sense is common.
Doesn't silocone melt down with hot led? What kind of silicone is that?
Why was it bubbling when he first poursw it out?
The lead isn't boiling, there are gasses or something coming from the silicone. Boiling lead would be not good. Very not good. :)
Melting point of Silicone rubber 300 degrees celsius. Melting point of lead 327 degrees celsius.
Silcone rubber will not "melt" - once it has cured it is "set" - though it will degrade and/or burn with excess heat. However as the video showed, the mold certainly was able to cast the piece (albeit with limited definition) at least once and I am guessing if a simple shape is all that is required, the mold would survive a good number of castings.
More on silicone molds...surprised how they handle the heat...
th-cam.com/video/wwaIZYb9M0U/w-d-xo.html
funny how that doesn't add up with what works.
wonder if would work better with the silicone in a thin ice water bath, want to do this in the Han Solo in cryptonite silicone trays
that is a dandy heat source. What is it?
where did you get the heater and equipment, could you tell me the name of the equipment
i wonder what the highest temp those silicon trays can handle..
Now pour it into Bullet ice tray :D
Maybe the lead was so heavy it squished the mold?
Thats What I was thinking. as he is pouring the visible portions of lead in the ,old are solidifying and becoming weighty. Mold being a thin silicone now deforms those features he was loosing due to the weight of the lead. I think, just as billy jojo mentioned sand or a support mold for the silicone mold would indeed retain the features. Nice team work Y'alll! :-)
Silicon is a chemical element with a melting point of 1414 °C, and SILICONE is a polymer that decomposes around the melting point of lead.
So no, it won't do easily. It will do, but barely. In order to cast lead and expect complete filling of the mold, it has to be hotter. Silicone can barely withstand such temperatures.
Silicone molds for lead...
th-cam.com/video/wwaIZYb9M0U/w-d-xo.html
the weight of lead deforms thin silicon molds
silicone doesnt melt. it sublimates straight to gas....and that doesnt happen till about 2700 degrees C.
the reason the features didnt turn out was because the lead was so heavy, it just flattened out the silicone features. Sooo yea. got it?
in the presence of nitrogen and 300*F silicone out-gasses formaldehyde. be careful.
I wonder if I can cast some slugs out of the gumdrop mold............
I'm super curious what you are using as a melting system... foundry and pot? Do you have a link or something to this product?
i was wanting to know the same thing
He says this below:
Hi, this is a high school laboratory stove I bought when they were selling off old equipment. It doesn't work very well at these temperatures, I think it is intended for heating liquids, etc... not melting metals. I had to supplement heat with a propane torch, then this heater maintained it.
Sure, if you're looking at consumer level - silicone is a polymer because it was mixed with compounds for different purposes. Such as silicone caulk, MDX, and so on. However on science level - no.
Yeah, it doesn't stand temperatures near 2700°C however it does stand temperatures near 2700°F. You aren't that slick trying to switch F with C. This melting point does not apply to compounds that silicone was mixed with.
You can see the Silicone or another substance out gassing and bubbling through the Lead. That can't be good
Your casting would have been great if u made vents in the details, just bury your silicon mold in sand ( beach sand is ok for this )
well thats about it if you are willing to fix it.
Add a water bath underneath and the durability/longevity of your mold may increase dramatically!
+Jeffrey Nguyen no if the lead and water meet together it can cause a really bad explosion from the evaporation of the water.. look it up lol
+Goober's Life That is true! I just thought the mold wouldn't last long at that kind of temperature, but I could be wrong
+Goober's Life Wouldn't be hard to keep them seperate and sealed.
That is a god awful idea
Pouring water into lead is a bad idea........lead into water, not so much.
He's saying silicone, that's it. Not the kind that is mixed with polymers.
WHAT KIND OF WITCH CRAFT IS THIS!?!?!?!?!? THE PLASTIC SHOULD HAVE MELTED?!?!?!?!?!?!
It's not plastic it's silicone and we can make our own molds from it. It's mixed together from two liquids, rather than melted and molded like plastic. BUT they do "rate it" at 400-450F which is 200f below Pb melting temp.
Snowman ☃️ lead ingots
I like reading comments but why are they all so long?
You over heates it
You rlead is boiling that is waaaay hotter than 700 degrees if it is boiling O_o
You have some weird icecubes...
Stay away from science if it does not make sense. Also, the period goes into the quote when ending a sentence.
lead snowman heads
Could have just looked this up and be sure. Wikipedia:
Lead melting temperature: 327.46 °C
Silicone melting temperature: 1414 °C
So will do easily.
lol, silicon is different than siliconE. lmao.
wow! don't be a dumbo and expect it will not melt the tray! its made for the opposite temp! and cool does not melt sillicone
More video on silicone molds. Surprised at the heat they withstand...
th-cam.com/video/wwaIZYb9M0U/w-d-xo.html
Pour slower next time and less. Make them really thin. Be careful though...i wouldnt try this..and for the love of god DONT add water under the pour. EXPLOSION!!!! BOOM! THEN POOF OFF GOES ALL YOUR HAIR.LOL