Can I cast "green" organic matter in epoxy?

[izavorin]

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

So Alumilite is not epoxy? I've been calling all of these products where you mix two parts epoxies, but maybe this is wrong. Why is vacuuming good for some of them and bad for others?

I think I initially poured Alumilite 1/2-3/4". What the photo does not show -- because it's a top view -- is several layers of this product, one for each (failed) experiment. Since I had cured bubbles on top of each layer, the bottom wasn't even flat, so it's impossible to tell how thick I poured top layers.

[izavorin]

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.

Never even heard of cactus juice stabilizer before. Learning more and more!..

Thanks

[izavorin]

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.

OK will poke around their website to figure out what to try next. Do you know if their products stick to wood well? What I want to try eventually is to combine casting with large wood hole filling. So of course I don't want the epoxy piece to fall out of the hole.

Thanks!

[Dave Diaman]

I have a few friends who make slab furniture. They all use smooth-on epoxy to fill the gaps in their pieces. They went away from traditional epoxy due to bubbles.

[Wipedout]

I have done some slabs and use epoxy. Bubbles isn't an issue because I pour in layers and I use a heat gun twice after doing it. Once initially and once 10 minutes later 

However the smooth on products look interesting and your endorsement Dave speaks volumes. 

Here is a couple of mine

   

   

[izavorin]

I have done some slabs and use epoxy. Bubbles isn't an issue because I pour in layers and I use a heat gun twice after doing it. Once initially and once 10 minutes later 

However the smooth on products look interesting and your endorsement Dave speaks volumes. 

Here is a couple of mine

Very nice! Is the brown fill in the middle of the 2nd table coffee grounds?

[Wipedout]

Very nice! Is the brown fill in the middle of the 2nd table coffee grounds?

So in the middle of the second one (dining room table) it is 2 inch thick epoxy.  It goes all the way thru the bottom. I backed it. Poured a layer about 1/8 thick painted it black then filled it with multiple clear layers until all the way. The cool thing is you can see inside and see the bark all the way down.

The first picture (bartop) at the end you see the black epoxy v where the boards go apart.  I dyed the epoxy black poured two layers and then poured clear layers till done. You can see the natural edge when you look into it. 

Both give them a feeli and look of depth.

[MyKidsDad]

I think with that volume of bubbles and the white color, a lot of that must be cause by moisture in whatever you're trying to cover with the epoxy. I just used a pour-on two-part epoxy on a maple slab. I had bubbles but nothing anywhere near what you are showing in your photo. The instructions of the product I used said that any moisture would cause it to dry hazy instead of clear.

[izavorin]

Ordered a trial size of EpoxaCast 690, will give it a try

[izavorin]

FWIW, got a reply to my earlier email to Smooth-On that I sent before I ordered the 690:

Thank you for contacting Smooth-On with your inquiry. Please be aware that urethane systems are sensitive to moisture. You would need to contact the manufacturer of your products to verify if the systems you were using were epoxy or urethane resin chemistry’s.

If you’re interested in an epoxy resin for your small scale testing we have a few options to choose from.

Tarbender® is a UV resistant clear liquid epoxy that can be poured over a variety of surfaces to provide a strong, high gloss coating. Parts A and B mix together and flow easily. Tarbender® epoxy cures at room temperature and offers high impact resistance. Tarbender® is an excellent wood bar top coating and can also be poured over plaster, concrete, foam, fabrics, etc. You can use Tarbender® to encapsulate 3-D objects or coat flat objects, paper and more. You can learn more about this product at the following link;

https://www.smooth-on.com/products/tarbender/

If you are looking to perform encapsulations, EpoxAcast® 690 is a UV resistant clear casting epoxy that is ideal for applications requiring a rigid, clear finished product. This product does require an accurate gram scale for measuring and the recommended casting thickness maximum is 2 in. / 5 cm.

https://www.smooth-on.com/products/epoxacast-690/

You may also be interested in the following example when considering your project needs;

https://www.smooth-on.com/spotlight/repa...epoxamite/

Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.