Can I cast "green" organic matter in epoxy?

[izavorin]

Lately I've been experimenting with casting various objects in epoxy. With "dead" things like rocks, shells and dried leaves it's fairly straightforward.

After watching a couple of YouTube videos, like this one and this one, I wanted to try casting "green" stuff like fresh leaves or pieces of moss or bark. So far all my experiments have been one spectacular fiasco after another.

Starting at about the 7-minute mark of the 2nd video, you can see what appears to be fresh moss or a similar plant being cast by simply pouring epoxy over it. And it seems to work like magic!

Not sure what epoxy product he used, but I experimented with two different ones, with more or less the same results: System3 Mirrorcoat and Alumilite Clear. All I got was lots and lots of small bubbles. The attached photo is a top view of one such attempt (sorry for the blurry photo, my phone camera sucks). Tried a small piece of bark that I dried at a lowest temp in a toaster for about 40 minutes. Where's the bark, you might ask? Trust me, it's there
Complete hidden by the bubbles that formed as the epoxy was curing.

What am I doing wrong? Are the bubbles caused by water in the bark evaporating from the heat of the curing epoxy? Or is this some gas which is a product of some sort of chemical reaction between the epoxy and something in the bark? Is there a way around it?

By the way, my ultimate goal is to incorporate this into my woodworking projects...

Thank you!

[Wipedout]

How thick are you pouring the epoxy? Also alumilite is really best used in a pressure pot to control the bubbles

[TomFromStLouis]

I know almost nothing about what you are attempting, but keeping bubbles out of a bar top finish is done with a small torch.

[Dave Diaman]

Try this product. it is made for what you want to do.

https://www.smooth-on.com/product-line/encapso/

[izavorin]

How thick are you pouring the epoxy? Also alumilite is really best used in a pressure pot to control the bubbles

Pressure or vacuum, right? I read about that, might give it a try if I exhaust simpler alternatives. Thanks,

[izavorin]

I know almost nothing about what you are attempting, but keeping bubbles out of a bar top finish is done with a small torch.

I don't have a torch (yet), might get one and try, although to me it seems there were just too many bubbles. Also, I think they kept forming even as the epoxy was already half-cured and really viscous, so not sure if a torch would help here. Thanks.

[izavorin]

Try this product. it is made for what you want to do.

https://www.smooth-on.com/product-line/encapso/

Thanks! From the description it sounds like exactly what the doctor ordered. Have you tried it yourself?

[Wipedout]

Pressure or vacuum, right? I read about that, might give it a try if I exhaust simpler alternatives. Thanks,

No just pressure. Vacuum is for stabilizing. Pressure pot makes the bubbles get smaller and smaller.  

You didn't say how thick you were pouring.   Alumilite is meant to pour thick and the pressure. Epoxy thick is a mistake. Never more that 1/4" at a time

[DogwoodTales]

While I did not encapsulate it, I once used cactus juice to stabilize a large piece (about 1.5sf) of tree bark. Worked very well. Maybe that might be a good first step prior to encapsulating it so as to eliminate the interior air of something like tree bark. You would probably still need to cure the epoxy under pressure to eliminate all bubbles.

I once saw a demo on line of what happens when using a vacuum chamber on something in regular epoxy. The result was worse than what you have above.

[Dave Diaman]

I do a great deal of mold making and casting and I use Smooth On products almost exclusively. I do encapsulation work also but I used optically clear epoxy which I don’t think would work for your application. If you look through the Smooth-On site they have a ton of info and videos. Their tech support is also really great. Something I would consider though is painting a thin film layer onto the object you want to encapsulate first creating an air tight shell around it. After the shell cures then pour around your object. Also as Wipeout stated most epoxies do not like to be poured thick. They simply generate too much heat and start to do bad things. If you do want to use epoxy Smooth on carries a product called EpoxAcast 690 that you can pour up to 2” thick at a pour that I have had good results with. I tend to try to make my pours thinner than that as there is a fine line and you can have disaster. You can also shape and polish the finished epoxy just like you would acrylic. I have made quite a few displays that would be handled and after the epoxy was cured I rounded all the edges with a router and polished them clear again with a buffing wheel. It was a really nice look.