attempt at casting embedded objects

[pssherman]

My first attempt at casting embedded objects was a disaster. I was embedding pasta noodles which would trap air so I applied a vacuum to try to remove the trapped air. As you can see the expanding trapped air pushed a lot of the noodles and resin out of the tubes. My second attempt was embedding accorn caps in a block mold, I don't have pics of this one. I used a vacumm again and it looked like there was an explosion in the middle of the block mold. I used masking tape to extend the sides of the mold hoping to contain the expanding air and resin. It wasn't enough, resin and accorn caps littered the bottom of the pressure tank. Since I opened the tank after the vacuum was applied I was able to scoop out most of the accorn caps and resin from the bottom of the tank. I think I am going to go with pressure only and live with the voids caused by trapped air. Maybe they won't be too big.

 

[jttheclockman]

May want to try an epoxy resin for casting Lot longer open time and I use pressure only. I use Liquid Diamonds and get at Turners Warehouse.

 

[JohnU]

Urethane resin will work fine as long as you don't wait to pour it. Just get it mixed, colored and pour. Pressure compresses the air so you can't see it. I do it all the time with no issues. Just be sure to warm the objects prior to casting. Resin adheres better to warm objects.

 

[Brandy]

That's so frustrating! I have had good luck using a pressure pot vs a vacuum. Some objects do better if you mix them in the resin then pour it all (resin and whatever you're casting) into the mold. I also find that some stuff floats soo you really have to pack the mold full.

I found some plugs that work well to prevent the resin from leaking out of the bottom of the mold

Maker Select Silicone PVC Plugs, PVC Pipe

Maker Select Silicone PVC Plugs, PVC Pipe Available in a range of sizes. Get the silicone plug or get the silicone plug and PVC pipe! PVC pipe is Schedule 40or Clear PVC Removable plugs make for easy de-moldingMold release 100% required for Epoxy Resins or you will stick the cast in the mold...

www.turnerswarehouse.com

They're not a perfect fit but do help a lot.

I've also seen some good videos on YouTube by a guy who casts a lot of different stuff. He has good tips about casting all sorts of different things.

https://www.youtube.com/@ZacHiggins/videos

Hope some of this helps! I've been playing around with casting different things (candies, fordite chips/shavings, a variety of seed pods, acorn caps, pine cones, leaves, flower petals, popcorn, etc.) in resin and more than half of it doesn't go as well as I hoped. There is a lot of trial and error but it is a lot of fun to see how it turns out and when you end up with a successful blank (that doesn't explode on the lathe) it can be worth the frustration.

 

[Kenny Durrant]

It sounds like I use a similar process that John U. uses. I also warm the B side, the thicker part, before mixing. Also if using colors I mix it in the B side by itself while warming. That way I know it's mixed well and it takes a little less time.

 

[walshjp17]

Perhaps you may be using the wrong kind of pasta. Try using Rotini or Rotelle. The are open twist pasta shapes rather than the closed shapes of the noodles which could contain a lot of trapped air. I had great success a few years back with Rotini and Alumilite White. Granted, this is not a pen, but they were pen blanks originally.

 

[JohnU]

It sounds like I use a similar process that John U. uses. I also warm the B side, the thicker part, before mixing. Also if using colors I mix it in the B side by itself while warming. That way I know it's mixed well and it takes a little less time.

Yep, using Alumilite Clear, I warm side B to around 90-100 degrees before mixing. Side A is always cooler so it brings the overall temp down to ensure enough working time while making mixing much quicker because B isn't as thick. I also use a drill to mix instead of a stick, cutting that process down to less than a minute. I've never had issues with air pockets under pressure using this process.

 

[pssherman]

Here are 2 of my attempts at casting embeded objects in a block mold. The first was done without heating the mold and acorn caps. There are large voids visible on the sides and bottom. The second was done with heating of the mold, rotini and part B of the resin. There are no large voids visible. So, I will continue to apply the heat and see if it improves the results on the acorn caps, sweet gum balls and pine cones. Btw, the blocks are 6 x 5.25 x 2.6 inches and should yield 21 blanks.

 

[JohnU]

Your voids aren't because you need vac, they appear to be from moisture in the acorn caps. Any time you see white foam along something in resin it's most likely from moisture. If they are already dry from sitting and not directly from the yard, put them on a cookie sheet and bake them at 215-225 degrees for 30 minutes before you cast them. That should fix your problem. If you recently picked them up you may need longer. I usually store my items in a breathable cardboard box for a year before I use them, but if they are wet when I pick them up I let them dry for a few days before boxing so they don't mold. Good luck!