Composi-Mold - Reuseable One Part Mold Medium

[Jeffry Fontaine]

Found this today while visiting Emil the Enabler at Skyway Models.  I walk in and see some tubs of "honey" colored substance on the counter and the first thing that comes to mind is that Emil is keeping bees on the side and selling honey in the store. 

Upon closer examination and an explanation from Emil I discover that this stuff can be used over and over and over again to make a mold of something and when you are done with that mold you simple reheat the material to melt it back into the container or to create a new mold.  Just like their little sign says on the container and in this image from their web page:


Click on image or this link to go to the Composi-Mold web page. 

There is a video tutorial on the web page that shows how to use this stuff and I for one and elated that there is now a means to save money when casting things in resin and you are not burdened with the eventual waste stream issues of an expired RTV mold. 

Yes, I acquired some to experiment with and will report back on the results of my tests.

[GTX_Admin]

Loving forward to the report of your trials Jeff. 

[Rickshaw]

This sounds interesting.  Any further news?

[Frank3k]

I just got some - I haven't tried it yet, but it feels like a very solid rubber. I think it'll work well as a mold material for low volume casting. I had some problems with their online order form, but they answered my email within a day with a Paypal payment request and I got the stuff in 3 days.

[Jeffry Fontaine]

I am still preoccupied with other things at the moment so experimenting with this has been on the back burner.  Also need to pick up some resin before going ahead with molding as I would like to cast up what I try them old on.

[arkon]

any udates on this stuff?

[Rickshaw]

any udates on this stuff?

Ditto.  Any updates?

[Frank3k]

OK guys - remind me this weekend and I'll microwave and document making copies with the stuff (I've had the vat of the stuff unused next to my paint hood for over a year!)

[Frank3k]

After Action Report:

I decided to make a test of the Composi-Mold by making a mold of the Trumpeter 1/35 CH-47 instrument panel and fire extinguisher that comes with the crew figure set. I also decided to make copies of some resin New World Miniatures heads.

Most of the equipment:


I used Museum Wax to secure the bits to a random plastic box I found:



I added the mold release:


Ready to go! The instructions say microwave for about 3-5 minutes for the full container; I thought about cutting out a chunk and microwaving that first, but nah, what can possibly go wrong?

After a minute, the stuff was getting soft. After 2, it was mostly liquid and I could stir it up with a piece of sprue. "Hmm, this is getting a little warm". After three minutes, it was all liquid and pretty warm, so I used a pot holder to take it out of the microwave and pour it into the container.

"It was a nice trip, until it blew up"



Yeah, well... two minor details: This mofo liquid is hot  - lava hot. The random plastic container I used as a mold is a heat formed piece of plastic;  buterate or cheap styrene plastic from a random container.  Oh and the museum wax is just wax and softens with heat.

So I pour the lava into the container and it quickly starts to sag and melt, spilling  its contents all over the stove top. The heat melts the wax and the plastic parts start floating:

DON'T TELL MY WIFE:


Luckily, she was talking with her sister on the phone, blissfully oblivious to the little horror show going on in the kitchen.

In retrospect, it wasn't so bad:
 - the Composi-Mold cooled off quickly and I was able to peel it off the stove (and out of what was left of the container) with no residue or other issues. It is nice and flexible when solid.
- The stuff doesn't smell, which is good, I guess.
- I rescued the parts (which were skinned in solidified Composi-Mold) and they were undamaged and pretty easy to remove from the material.
- The Composi-Mold made an excellent reproduction of the parts, especially the instrument panel. The skinned material was too thin and floppy to use as a mold, though.

Next time, I'll make sure I use a PET container, or something that can withstand the heat of the Composi-Mold (maybe a Legos box). And I'll glue the parts down with a non-heat sensitive glue. I'll also cut out a chunk and melt that down, rather than heating the whole container.

[Kerick]

Looks promising. I've been kept away from casting by the price of the materials but if this is reusable it would last me a long time. Good to know about the heat and using heat resistant materials.
Please keep us posted.
BTW, my wife would have totally freaked if she had seen that on "her" stove (the one I use all the time).

[Frank3k]

I tried it again, this time with a heat resistant container. I believe the container is PET, so nothing sticks to it. I used pressure sensitive adhesive to attach the parts (same as last time, minus the fire extinguisher) to the container, then sprayed everything (including the inside of the container) with mold release.

 I warmed up the Composi-Mold for 2.5 minutes at high in the microwave, and let it cool for a minute. Not all of if melted, but I made more than enough to cover the parts. No disasters this time.

I placed the container in the sink and filed the sink with cold water until the container started to become buoyant. I noticed that the heat (or movement) had loosened one of the heads, which began to float to the top. I used a plastic stick to poke it back down. After about 30 minutes, the Composi-Mold had started to solidify; I pushed the head down into the thicker material at the bottom and this time it held.

The Composi-Mold was allowed 3 hours to cool, or until it no longer was sticky.



Like bugs in amber:



It was pretty easy to remove the Composi-Mold from the container, probably because of the mold release. This is the underside- some material seeped in under the instrument panel, but I removed the excess and threw it back into the Composi-Mold container:



Here's the instrument panel section in detail:



I can't tell if the bubbles are on the surface or just below; I'll find out when I pour some resin. Clearly, some air was trapped in some of the instrument dials.

So far (other than the less than promising first try) I'm really impressed with this material. It's flexible, dense and didn't tear when I pulled out the resin heads. I think in terms of durability, it's similar to the softer silicone rubber mold materials, except it's clear.

Some observations:

1- This stuff gets hot. Not boiling hot, but hot enough to affect some glues and possibly some heat sensitive materials. The Composi-Mold hold heat very well, so cooling it in a bath is recommended.
2 - The material seems to be somewhat water soluble when liquid - don't get water into the liquid Composi-Mold! It does have a slight orange or citrus odor, similar to Goo-be-Gone.
3- The liquid Composi-Mold is pretty viscous; moving the container around can cause waves that'll knock your parts off.
4 - Heat resistant containers and surfaces have to be used. Gluing the parts to a thick styrene, MDF or water proofed wood surface should work. Use CA or epoxy. Waxes or modeling clay will not work.
A Legos box around the parts (held in place with a modeling clay dam) may work. The Composi-Mold is very fluid when hot, and it may seep through gaps in the Legos, though.
5 - Use a mold release!
6 - I think it should be easy to pop bubbles that are on the part surfaces. I was too distracted by the floating head to look carefully for bubbles.
7 - it's easy to cut. Since it's transparent, it should reduce the need to make two part molds.

I ran out of time to pour resin - that's next week's project.

[Rickshaw]

That's an excellent report!  I think I'll be ordering some soon.  I have several projects I want to mould.

[GTX_Admin]

Most useful reporting. :)

Keen to see the results when you use these moulds

[arkon]

great report on your tinkering so far, what have you used for mold release agent?

[Jeffry Fontaine]

Frank,

Have you considered pouring the Composi-Mold into a container and then suspending the parts you wish to make castings of into the mold material from above?  Like what is done when making candles but instead of a wick being suspended over the container it would be all of the items you wish to replicate suspended on sprues or something similar but rigid into the Composi-Mold from above.  You would have everything at the same elevation and it resolves the problem of parts floating free as you have already experienced.  With the masters removed you have a mold that is then secure in a container that will keep it clean when not in use by sealing it with the original container cover. 

[Frank3k]

Mike - I used "Mann Ease Release 200" https://www.google.com/#q=mann+ease+release+200&safe=off
although just about any mold release should work. The Composi-Mold people say PAM works as well, and that's available in just about any supermarket.

Jeff - that's a great idea; I hadn't thought about dipping the parts in. I think suspending from a sprue or gluing the parts onto a thick sheet of plastic and "floating" that on the Composi-mold should work. Since the stuff takes hours to cool off, it may be possible to brush the Composi-Mold onto the parts (eliminating bubbles and voids) then dipping the parts into the Composi-Mold container to provide support.

I think I should have been more careful with my first experiments with this stuff; it looks like I'll have to filter the crap floating in it next time.

[Jeffry Fontaine]

Mike - I used "Mann Ease Release 200" https://www.google.com/#q=mann+ease+release+200&safe=off
although just about any mold release should work. The Composi-Mold people say PAM works as well, and that's available in just about any supermarket.

I guess that makes PAM a "food grade" mold release?

Jeff - that's a great idea; I hadn't thought about dipping the parts in. I think suspending from a sprue or gluing the parts onto a thick sheet of plastic and "floating" that on the Composi-mold should work. Since the stuff takes hours to cool off, it may be possible to brush the Composi-Mold onto the parts (eliminating bubbles and voids) then dipping the parts into the Composi-Mold container to provide support.

I think I should have been more careful with my first experiments with this stuff; it looks like I'll have to filter the crap floating in it next time.

Floating the parts attached to a sheet of plastic on top of the Composi-Mold sounds like a good idea too as that gives you a solid base that is not going to break free and float away as it is already floating :)

[Frank3k]

I guess that makes PAM a "food grade" mold release?

Well, Composi-Mold is food safe (you can cast food - like chocolate - in it) so PAM would work. I can't use the PAM I have at home because it's butter flavored and it would attract the unwanted attention of at least one butterholic cat.  Maybe I'll get "Vet flavored" PAM next time. That'll keep them away...