Ancient Elder Bio ~ Bio Sculpt, Mold and Cast project.
- Thread starter Uratz
- Start date
Uratz
Sr Member
Update: Demolded the top case mold, its holding together, not as thick as I thought but still strong. Not so heavy just very big. I drilled air holes along the keys and concaved areas for air to escape..
I tried to mold it in silicone but didn't realize that it was 30 degrees C (86F) which is a bad temperature for pouring. After wasting about 14 kgs worth of silicone curing way faster than I can pour i realize I should've a/c the room down to 21 degrees C to slow down the cure time. Also should get a silicone that has a working time of about 30 mins or more and lower viscosity. My research showed that it would cost me 70rmb/kg which is about 10 dollars per kg to get this other kind of silicone. This is a 90:10 ratio catalyst mix (syrupy viscosity) which is also good for mixing. The watery kind of catalyst i was using was hard to mix since the viscosity was too far apart, like pouring water on jello and trying to mix the 2.
Buying silicone tip: Catalyst and the Silicone should both be thick and syrup like so that mixing is easier
So I'll have to fix my sculpture again, surface has some uncured silicone and surface detail have been ripped off. I did manage to pour right on top of the sculpt and got a trial molding and saw what i could do to improve my sculpt to get a perfect 1 piece mold. I will need to do some dremeling later and resculpt some areas. My patience is being tested to the max (and my wallet is being drained of fund$)
Anyway for anyone reading this, I hope that all of you learn from my mistakes so that you can save some silicone, money and heartache. Will post pics later.
"Practice makes perfect, but along the way you'll be wasting money to learn from your mistakes."
I tried to mold it in silicone but didn't realize that it was 30 degrees C (86F) which is a bad temperature for pouring. After wasting about 14 kgs worth of silicone curing way faster than I can pour i realize I should've a/c the room down to 21 degrees C to slow down the cure time. Also should get a silicone that has a working time of about 30 mins or more and lower viscosity. My research showed that it would cost me 70rmb/kg which is about 10 dollars per kg to get this other kind of silicone. This is a 90:10 ratio catalyst mix (syrupy viscosity) which is also good for mixing. The watery kind of catalyst i was using was hard to mix since the viscosity was too far apart, like pouring water on jello and trying to mix the 2.
Buying silicone tip: Catalyst and the Silicone should both be thick and syrup like so that mixing is easier
So I'll have to fix my sculpture again, surface has some uncured silicone and surface detail have been ripped off. I did manage to pour right on top of the sculpt and got a trial molding and saw what i could do to improve my sculpt to get a perfect 1 piece mold. I will need to do some dremeling later and resculpt some areas. My patience is being tested to the max (and my wallet is being drained of fund$)
Anyway for anyone reading this, I hope that all of you learn from my mistakes so that you can save some silicone, money and heartache. Will post pics later.
"Practice makes perfect, but along the way you'll be wasting money to learn from your mistakes."
Uratz
Sr Member
Ordered the Expensive low viscosity silicone about 30kgs worth of the crap. Cost me 300$ plus cab fare cuz i gotta go pick it up at the post office which is stupid. Anyway we do this cuz we just love sculpting and mold making don't we tears
Oh I also got a thermometer for my molding room, cheap but will save you million$ in silicone mistakes. 23 degree C is the curing temp for most silicones. any higher will speed it up, lower temp slower. So when pouring it helps to cool the room down to 20-21 degree C but not lower than 18 degree C, this will also slow down the curing while pouring problems. When Pouring is done, the a/c is turned off and windows opened to the hot 30 degree C summer weather (I'm doing this in my porch studio) then the silicone will cure faster - all in theory. Will let yaw know if this method helps.
Pictures below: Top case mold with air holes drilled and Predator sculpt sitting on the bottom case mold. Ready for silicone pouring.
Oh I also got a thermometer for my molding room, cheap but will save you million$ in silicone mistakes. 23 degree C is the curing temp for most silicones. any higher will speed it up, lower temp slower. So when pouring it helps to cool the room down to 20-21 degree C but not lower than 18 degree C, this will also slow down the curing while pouring problems. When Pouring is done, the a/c is turned off and windows opened to the hot 30 degree C summer weather (I'm doing this in my porch studio) then the silicone will cure faster - all in theory. Will let yaw know if this method helps.
Pictures below: Top case mold with air holes drilled and Predator sculpt sitting on the bottom case mold. Ready for silicone pouring.
Uratz
Sr Member
Update: Successfully molded the dam thing in the new blood red silicone that I got. FLOWS LIKE HONEY!
Now I'm thinking if I should do a back mold for a pourable resin mold or simply open it for a brush on resin. This method wastes brushes and potential loss for resin. Open mold casting is good for fiberglass which I think I might try it.
Its tough for me to get these chemicals thru the delivery system.
The top and bottom case mold is holding together except for the edges which cracked a bit during demolding, I still made it too thin and should be min 1 inch (2.5cm-3cm) thick. I'll have to reinforce it with more epoxy putty. I also have to make keys on the side edge of the silicone so that it can jsut stretch apart during the casting stage.
PIc later tonight. Check back!
Now I'm thinking if I should do a back mold for a pourable resin mold or simply open it for a brush on resin. This method wastes brushes and potential loss for resin. Open mold casting is good for fiberglass which I think I might try it.
Its tough for me to get these chemicals thru the delivery system.
The top and bottom case mold is holding together except for the edges which cracked a bit during demolding, I still made it too thin and should be min 1 inch (2.5cm-3cm) thick. I'll have to reinforce it with more epoxy putty. I also have to make keys on the side edge of the silicone so that it can jsut stretch apart during the casting stage.
PIc later tonight. Check back!
Uratz
Sr Member
Here is the picture. epoxy putty and all around the edge of the mold. Made the keys, which I should've done during the wet clay stage, but now have to cut away the edges of the silicone mold and use epoxy putty to stick it to the case mold hopefully by tomorrow it will be dry and stone hard
Uratz
Sr Member
I've researched some ways to fiberglass stuff on a hocky mask tutorial. Seem like the resin usage is less than simply pouring. The fiberglass process needs resin to hold together the glass fibers which make it rigid, lightweight and strong. Even too much resin is bad for it. I don't have much resin and rather have a strong bio rather than a resin rich helmet. Seems like the way to go.
I got some PU resin already not sure if I need to get gel coat for the first layer then apply the fiberglass+ resin layers. Its tough for me to find this gel coat substance in China. Or should I just start brushing on 2 layers of resin then start fiberglassing... Anyone know the best way to fiberglass a bio?
I got some PU resin already not sure if I need to get gel coat for the first layer then apply the fiberglass+ resin layers. Its tough for me to find this gel coat substance in China. Or should I just start brushing on 2 layers of resin then start fiberglassing... Anyone know the best way to fiberglass a bio?
predamaker
Well-Known Member
the way i do it is to brush on a good layer of gelcoat then start to put the fibreglass and resing in, u just gotta watch out for airbubbles in between the gel coat and resin.
if u cant get gel coat then perhaps u could just brush the resin in with a couple of layers then fibreglass it. probably be what i would do but im not that nolagable as some members of the lair.
if u cant get gel coat then perhaps u could just brush the resin in with a couple of layers then fibreglass it. probably be what i would do but im not that nolagable as some members of the lair.
Uratz
Sr Member
I'll have to try the resin + FG only option. Still can't find the gel coat yet, but will look for it.
Thanks for the info Bro
frosty
Sr Member
You've done a great job, very well done.
When using plaster i use scrimm or hessian to reinforce the plaster, less breakage that way, you can use a polyurathane resin instead of a gel coat, i use this method when i mix filler powders into the top coat, like alluminium or brass, works better than gelcoat, you can also mix some ordinary filler powder into the alli resin to thicken it
Anyhow, can't wait to see the finished bio's
When using plaster i use scrimm or hessian to reinforce the plaster, less breakage that way, you can use a polyurathane resin instead of a gel coat, i use this method when i mix filler powders into the top coat, like alluminium or brass, works better than gelcoat, you can also mix some ordinary filler powder into the alli resin to thicken it
Anyhow, can't wait to see the finished bio's
Uratz
Sr Member
You mean "cold casting" ? Never done this before. I'd like to try it as well. Cold casting the first layers then reinforce it with Fiberglass- it'll be a kick ass helmet. I'll look into the filler powders just not sure what its called in China otherwise i can look for them on Ebay china version. If this works I might do to all of the helmets I make.
Uratz
Sr Member
Sorry for the lack of update on this molding. I'm actually test molding my Iron Monger faceplate in plaster to make sure demolding is ok, so a lot of time invested on testing the case mold so i don't waste any resin. I split the mold in half and built a jacket to hold the split molds together while casting.
I will also test mold the predator helmet in plaster first to see if I need to split case molds. The idea is that the helmet is a thin fragile cast & the silicone mold must be gently peeled off the mold and not ripped out directly from the case mold which may damage both the rubber mold and cast. So the mother mold should be split in half but can be held together with an external jacket during casting stage. Seems like a lot of trouble but this way I can do multiple casts by preventing damage to the rubber and case molds.
Picts below of the Plaster Casted
I will also test mold the predator helmet in plaster first to see if I need to split case molds. The idea is that the helmet is a thin fragile cast & the silicone mold must be gently peeled off the mold and not ripped out directly from the case mold which may damage both the rubber mold and cast. So the mother mold should be split in half but can be held together with an external jacket during casting stage. Seems like a lot of trouble but this way I can do multiple casts by preventing damage to the rubber and case molds.
Picts below of the Plaster Casted
Uratz
Sr Member
Ancient Predator Bio now casted in plaster. This is a trial plaster cast prototype to see how the mold is holding up. Will attempt the fiberglass this week. Pics below
I casted my Iron Monger in FRP @ http://www.thehunterslair.com/index.php?sh...st=0#entry87470
I casted my Iron Monger in FRP @ http://www.thehunterslair.com/index.php?sh...st=0#entry87470
