when you make the original mold with the silicone or whatever - does it damage the original sculpt you are casting at all?
I'm not sure what it is you're asking. Let's start with this. The silicone that cast the pieces IS the "mold". The thing that comes out the mold is the "casting". The original piece that you made a mold of is the "master". Now with that clear let me try to anwer your question. The master depending on what it's made of may or may not get damaged when you remove it from the freshly cured mold. I use sculpy or sculpting wax as well as other materials when I make a master. It all depends on what it is I'm trying to sculpt. A head for instance I would sculpt in wax. Depending on how complex it is I make a two or three part silicone rtv mold. I use a pressure pot to eliminate bubbles within the mold. Now if the head has tiny parts like hair or theeth etc those usually will break during or after the mold making process. You just have to be carefull when you handle the master. When demolding the master I usually don't care if a break happens as long as the mold turns out good. I would just keep the first "perfect" cast as the "new master". When casting reproductions the castings as long as the resin is fully hardened should not get damaged when you demold. Unless ofcourse you made a bad mold or just got impatient and demolded when the resin is juuust fully cured. Now I either just confused you more or actually answered you question
yes that helps. i have no clue how to do any of it, but i was actually interested in getting a reproduction made by someone out of my smogun to toy around with... and i didnt want to ruin the original
Silicone RTV molds are kinda pricey. A 1 pound pot usually runs like $25 - $35. If I was to repro say a Skullbee I would need about 2-3 pounds of RTV mold. I usually pull about 100 good castings out of a well executed mold. 200-300 on high strength RTV molds. I wouldn't consider it worth while to make a mold unless I plan to atleast make a bare minimum of 20 or 40 castings.
oh ok that might make the decision then. this guy wouldnt have any use to make more of the smogun, and it isnt something that i would sell or anything like that. thanks for the help
A theoretical question for Rob: let's say you were planning on making a mold of an existing vinyl toy, like pickle suggested with Smogon. Would the hollow nature of it be problematic? Would you have to worry about thin vinyl deforming under the pressure of the mold-making material? Would you have do something like seal up the hollow parts, or fill them with something solid (or liquid)?
No prob. Something I didn't think about (and this might benefit those that are thinking of something like this) is the fact that the smogun would have to be taken apart to be reproduced properly. I would have to plug the cavity with clay to prevent the silicone from going in. So you're looking at 4 (head, body, arms)or 6 (head, body, arms, legs) separate molds. When I use to do this professionally small molds like that would run about $200 per mold and that was cheap
makes me wish i could do this stuff myself i think youd only have to do 2 parts on this one because as far as i can tell, the smogun is only seamed at the waist.
Good question. If you want a silicone mold thats been cured in a pressure pot yes. I would fill the hollow part completely with resin or clay which would render the original master useless as a displayable toy. The pressure pot crushes air bubbles to a barely visible size so when you cast you have a bubble free or pin hole free casting. If you have a naturally de-gased mold then you only need to plug the hole enough to prevent the liquid rtv compound from seeping in. the down side of this is you cannot use this mold in a pressure pot when casting. The pressure pot will crush the trapped bubbles within the mold which will result in a warped casting. You will also have to contend with surface bubbles and pin holes that you have to fill.
No prob. Something I didn't think about (and this might benefit those that are thinking of something like this) is the fact that the smogun would have to be taken apart to be reproduced properly. I would have to plug the cavity with clay to prevent the silicone from going in. So you're looking at 4 (head, body, arms)or 6 (head, body, arms, legs) separate molds. When I use to do this professionally small molds like that would run about $200 per mold and that was cheap
I've been messing around with some toy related duplication projects lately, and I will say that in my experience it isn't necessary to fill the entire hollow portion of any given part of the master with resin or clay, even while using a pressure pot. I don't know what level of pressure you are employing, but my pressure pot is set to bleed off at over 23 P.S.I. At this level of pressure I can obtain nice silicone molds without internal leakage simply by sealing a sheet of the appropriate wax to the open end of the part. Later it is easy to remove the wax with a little bit of boiling water and the master is completely undamaged and unaltered. Incidentally, if the part is small enough, the same (flexible) sheet wax can be used to create a coddle to pour up your mold. I might add that some very nice (and comparatively cheap) results can be had with irreversible hydrocolloid (a.k.a. alginate) if one is skilled with the material and willing to make a mother mold over the top of it. Dealing with undercuts and re-approximating duplicated sections after they have been cast are some technical issues, but it is way cheaper than RTV silicone... I'll have to dredge up some photos of these experiments.
