making molds

[howlin mad jack]

I've seen lots of props made from molds, but have never made any myself, what's the best way to make them, and where would I find instruction on mold making?

[DarkShadows]

check out the smooth on vids on there website, www.smoothon.com

[Allen H]

HMJ,
I sculpt and mold things ....alot! Im at work right now getting a floor plan for my dungeon together. Tonight I will have time to answer this as its a doozy, there is no quick reply. but I will give a try at giving you all the info you need. I will tell you that you need more courage than knowledge at this stage, make the leap!
Allen H

[howlin mad jack]

Cool beans... really lookin forward to it!!

[howlin mad jack]

check out the smooth on vids on there website, www.smoothon.com

Thanks for the site. I guess I'll have to dive in and give it a go!!

[howlin mad jack]

HMJ,
I sculpt and mold things ....alot! Im at work right now getting a floor plan for my dungeon together. Tonight I will have time to answer this as its a doozy, there is no quick reply. but I will give a try at giving you all the info you need. I will tell you that you need more courage than knowledge at this stage, make the leap!
Allen H

Cool beans...really lookin forward to it!!

[Allen H]

There are several different kinds of molds and several different kinds of mold making materials.
I am going to way simplify things here because if not it would be a book.
You are in Miami so you can get ultracal 30 from someone on this list
http://www.gypsumsolutions.com/distributor/StateDistributors.asp?t=D&state=10

Ultracal 30 is a pretty versatile mold making material and can be used to make several types of molds. It is also one of the best materials for casting latex pieces. To simplify this post I am pretending that you are casting in latex in a plaster (ultracal 30) mold. I will also assume you a molding a waterbased clay sculpture. Your sculpt should have minimal undercuts. The best way to explain undercuts is to imagine making a mold of a ball. If the ball is more than halfway molded then it is to big to come out of the mold, the plaster grabs onto it and you get what is called a mold lock or a mechanical lock. slight undercuts are fine as the water based clay will pull out and the latex is flexible so it can collapse on itself and the pull free, but it is good practice to avoid major undercuts.
I recommend making a one piece mold to start.
Things that can be made using a one piece mold have a flat back. (wall sconces, gears, flat back skulls, I did barnacle and crab sheets for my pirate haunt this way, Half masks, and 3/4 masks). The flat part will be flat against the table and the sculpt will be up. Find a vessel or bucket that can fit over the sculpt with an inch or two clearance all the way around, The more clearance the heavier the mold and the more plaster it will take, so a perfect fit is better and wastes less material. Cut the bottom out of the bucket so you have basically made a ring or a square depending on your bucket). I like to use silicone caulk and "glue" down the bucket around the sculpt, that will keep liquid plaster from running out from underneath it. Before pouring spray the inner sides of the bucket with pam cooking spray, just a light coat works wonders.
Then you will want to mix your plaster. ALWAYS add plaster to water, not water to plaster. Put enough water in your bucket to cover your sculpture (two of the same bucket would be great for measuring) Then pour 1/3 of that out. What you are left with is how much you will need. If you dont have enough to cover the sculpt no big deal mix some more and top off. It takes alot of plaster to get the right consistancy. I like mine to be between milk and pancake batter. The thicker the mix the faster it sets, the warmer the water the faster it sets. To give yourself time use cold water.
Mix by hand until there are no lumps. Once the plaster is mixed tap the bucket to bring all bubbles to the surface or Vibrate, you will get a feel for this the more you do it.
Use a natural haired chip brush and paint on the first layer then pour in the plaster in a thin steady stream around the edges making sure all parts are covered. when its covered you are done. It will get hot, heat will come off of it, the thicker it is the more heat. You want to just cover the sculpt by about 1/2inch.
It is called ultracal 30 because it takes 30min to cure. It will be hard in about a half hour (depending on water temp and consistancy). It will be ready to demold in about 4 hours, it will fully cure in 24 hours. Attempt to lift the mold off of the table, the lip of the bucket will help you. You may be able to run a wire under the bucket that cuts the clay free from the table. Next dig out the clay with wooden tools (metal can scratch the plaster). or use water to melt away the water based clay. I use a pressure washer on most molds ( I used to sneak them to the car wash).
Let it dry. When its dry and clean of all clay you are ready for latex.
Put the mold down open side up (the bottom should be flat because the plaster leveled itself out) Pour in the latex very slowly all the way to the top. You are now "dwelling" the latex. The longer the latex is in the mold the thicker the pull (finished product) will be. Try 15 minutes at first, then if you think that is to thin leave it in longer next time. When the time is up you pour the latex from the mold back into the latex bucket to be used again. In roughly 24hrs you should be able to pull the dry latex from the mold. the exposed latex will be shiny, powder it with talc (baby powder) or it will stick to itself and not come unstuck easily.
Look at the piece you pull out of the mold, it will tell you where any issues are. you can mix up small thick batches of plaster and patch air bubbles.
Thats a pretty good description of the process, It is second nature to me now so I may have forgotten something, please add it if I did. I hope this helps.
Once you make a one piece mold post it, then I will once again risk carpal tunnel and tell you how to make a two piece mold.

[DarkLore]

Very good description Allen. I know a materials supplier in Richardson. Perhaps, since you are in the Dallas area, you have some you'd like to recommend to local haunters?

[DarkLore]

Brick In The Yard (http://www.brickintheyard.com/) has online tutorials on different molding techniques.

[Allen H]

I get all my clay and plaster from trinity ceramic
I get my latex shipped in by Chemionics in Ohio
I get alot from Mitch at Bity also
what haunt do you work at Dark?

[pagan]

What are you thinking about making, HMJ?

[howlin mad jack]

Thanks Allen and Darklore for all the info. The process seems easy in theory I guess I'll give it a go!! I'm in the process of sculpting a piece so I'll make it a flat back piece and let you know how it goes. I'll take pix and if it goes well I'll post them.

[howlin mad jack]

What are you thinking about making, HMJ?

I'm in the process of sculpting a daemon like critter. I have some of the skull formed out of styrofoam and I'm going to put epoxy clay over it. I'm taking some pix and I'll post as it starts to form up.

[DarkLore]

I get all my clay and plaster from trinity ceramic
I get my latex shipped in by Chemionics in Ohio
I get alot from Mitch at Bity also
what haunt do you work at Dark?

Sorry...lost track of the thread. Be sure to post photos along the way Jack. Can't wait to see how this comes along.

Allen - I don't work at any haunt. I'm a noobie yard haunter.

[The Archivist]

I particularly like this site. Easy to follow, and relatively cheap.

http://www.makeyourownmolds.com/

[HallowEve]

I get all my clay and plaster from trinity ceramic
I get my latex shipped in by Chemionics in Ohio
I get alot from Mitch at Bity also
what haunt do you work at Dark?

Allen, what type of latex do you purchase from Chemionics? Do you use it just for casting and/or is there a specific type from them that you could use for corpsing? Also how are their prices?

Sorry for all the questions, just courious.

[Allen H]

Call them and ask for a sample of their casting and their mold making latex. They will most likely send you a gallon or so of each. I use their casting latex It is great for corpseing out props also. The latex is called RD-407 its the same latex that death studios uses for their masks. its some of the best latex out there.