gooie pine cone

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mostangrypirate

mostangrypirate

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Joined
Jan 4, 2009
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261
Location
Palestine, TX.
I cast a pine cone in PR w/burnt umber. 70lbs. of pressure for over 24 hours. 3/4 inch mold, 3.5 oz. resin, 20 drops mepk, 75degrees. an hour after coming out of the pot, it started to fiz. I put in in the toaster over for 2 hours. after 2 days it is still a bit sticky, not just tacky. do you suppose that when the PR seeps into the pours of the cone, it then becomes too thin for the amount of catylist to work properly? or did I miss something, I really want to turn this thing.
 
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I had heard that some pine cones contain moisture in the form of sap and that can have an influence on casting. Haven't tried em yet tho.


Manny
 
Lol of course not. I started to write contains moisture then I thought it would be better to say sap.... just came out that way.

Let me know what you learn. I have some cones chopped and ready to go.


Manny
 
I did mine with Alumilite so can't help with the PR but I did notice that the Alumilite seemed grainy and wondered if it was because of the sap in the pine cones.
 
I wonder if you soaked the pine cone in a solvent and dried it out before casting if that would solve the problem? I don't know if alcohol would work but turpentine or acetone might.
 
I cast mine in alumilite all the time. Never have any problems, they don't look weird, they look very cool. I especially like the short fat ones with the large tips...ok, that doesn't sound right. I better learn my pine cones! If the cones are open, they are dry. Dry is why they open. Maybe they get wet in the rain, but you bring them inside they will re-dry within a few days. I don't know much about PR. Any time I try it it's always coming out sticky or tacky. If you had used alumilite, you could have made 50 pens by now, that I do know!
 
The thing with PR is that most start casting with Easy Cast, Silmar 41 or Poly-lite without knowing that it is a laminating resin. They are manufactured without the surface curing agent (wax) which means the outside is always going to feel tacky particularly if casting in silicone. Laminating resins are made so you can put layer after layer on... i e: surfboards. There are several ways around the "tackiness". Post-curing in a dedicated toaster oven is one way. If you're casting in silicone you can wax your molds before-hand or warm them in a toaster oven for an hour at 150 degrees (also before you pour).

Many casters prefer to work with Alumilite because it doesn't smell as badly as PR. I prefer PR because the longer working time allows me more freedom to play with more colors.

Pine cones can be cast very well with PR. Jeff (workinforwood) sent me a box full of various pine cones from his neck of the woods. They have all come out very very well. (Thanks Jeff!:wink:) Charles (Glass Scratcher) helped me really learn about what I'm working with and how to work around the problems I encountered. (BSBH Charles)
 
the mold was fizzing from the inside. the PR that penetrated thr cone was not drying. I did this with a piece of real pourous wood and it reacted the same(and yes it was moisture free) even after it seemed dry and I turned it, after a few hours this new pen started leaking resin. I had waited 3 days before I turned that one.
 
I don't think PR normally would be set and cured in 3 hrs. If you didn't add enough catalyst, it will take much longer to cure. If you add any tints or colors, it effects how much catalyst to put in. It will still cure...put it in the oven like everyone says, it will work, done that myself when the wife was out, and when she came back I denied knowing anything about a strange smell in the house. Fizzing sounds like bubbles are trapped inside. The pot doesn't squeeze out the bubbles. In alumilite, the pot squeezes the bubbles to such a small size that they don't seem to exist any more, but in PR I think it's different because it is thicker. I'd suggest buying an ultrasonic cleaner to remove any air bubbles and then transfer your mold into the pot, or maybe you don't even need to use the pot then...just use the heated ultrasonic cleaner.
 
70# of pressure seems like a lot of pressure. I suspect that your fizziness is due to the resin being uncured when you take it out of the pot and then expose it to sea level pressures.... Kinda like opening a soda bottle.

Make sure that your cones are dry. But, since the same thing also happened with some wood that you had tried to cast, check that the dye you are using is made for PR. (Some coloring agents are not compatible.) You can try pre warming the resin or increasing your MEPK, but 6 drops/oz should be more than enough.
 
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