Castin Craft

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nsfr1206

nsfr1206

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Joined
Jun 10, 2010
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529
Location
Gainesville, Alabama
I received a mold today from London88 and was gonna try it out. Put a couple of label blanks in it and picked up my can of CC. Had poured two blanks out of it maybe nine months ago. The rest of the can looks like it has set up into one big blank:rolleyes:. Does this stuff have a shelf life after opening? So I didn't get to try the mold out but I can say it sure looks nice.:biggrin:
 
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I think you just found the answer to your question.:biggrin: The answer is yes, there is a shelf life. Not from when you purchased it but from when it was packaged...6 months is the time I've been told by one supplier I use. The polyester resin we use is prepromoted which means catalyst is added when it is manufactured and packaged. So, it starts setting up as soon as it is in the can....but slowly. The catalyst we add then completes the process. Purchasing Castin' Craft or other polyresins at hobby stores is no guarantee it is fresh. It may have been on the shelf for months before you purchased it. Those of us who seriously cast purchase from suppliers that sell lots of polyresin so what we get it fresh.
Do a good turn daily!
Don

nsfr1206 said:
I received a mold today from London88 and was gonna try it out. Put a couple of label blanks in it and picked up my can of CC. Had poured two blanks out of it maybe nine months ago. The rest of the can looks like it has set up into one big blank:rolleyes:. Does this stuff have a shelf life after opening? So I didn't get to try the mold out but I can say it sure looks nice.:biggrin:
Click to expand...
 
There is no catalyst in the resin. It is promoted with accelerators such as cobalt napthanate and dimethylanaline.
The MEKP (catalyst) that is added when pouring helps begin the polymerization. It will cure without adding the catalyst.
Casting resin is considered slow-promoted resin.



its_virgil said:
I think you just found the answer to your question.:biggrin: The answer is yes, there is a shelf life. Not from when you purchased it but from when it was packaged...6 months is the time I've been told by one supplier I use. The polyester resin we use is prepromoted which means catalyst is added when it is manufactured and packaged. So, it starts setting up as soon as it is in the can....but slowly. The catalyst we add then completes the process. Purchasing Castin' Craft or other polyresins at hobby stores is no guarantee it is fresh. It may have been on the shelf for months before you purchased it. Those of us who seriously cast purchase from suppliers that sell lots of polyresin so what we get it fresh.
Do a good turn daily!
Don

nsfr1206 said:
I received a mold today from London88 and was gonna try it out. Put a couple of label blanks in it and picked up my can of CC. Had poured two blanks out of it maybe nine months ago. The rest of the can looks like it has set up into one big blank:rolleyes:. Does this stuff have a shelf life after opening? So I didn't get to try the mold out but I can say it sure looks nice.:biggrin:
Click to expand...
Click to expand...
 
nsfr1206 said:
Problem is, I don't think I would use a gallon very quickly. I guess they do sell quarts though...
Click to expand...

Well, you won't pay that much more for a gallon of Silmar than a quart of
CastnCraft.. besides, you'll get hooked soon enough. :tongue:

The thing about the CastnCraft is that it is sold in stores that are often
staffed by people who don't cast. They don't care how old it is. And I doubt
they rotate stock. Maybe they just spin the can around and call it 'rotated'.

FWIW.. I've found Silmar 41 in my shop that I know I bought over a year
earlier, and it was a bit thicker, but still cured and turned fine. (wouldn't
trust old catalyst, though)
 
Any MEKP that is left-over or old should be disposed of properly. It is an explosive and becomes less stable as it ages. If it catches fire, it can't be quenched, as it creates it's own oxygen. And keep it out of your eyes!! It can cause instant blindness.

It's hard to believe people start messing with this stuff without knowing what it is they are messing with.:eek::confused:
 
And the Hobby Lobby I got my stuff from is pretty flat. It was right in line in Tuscaloosa. Guess I should order. BTW NewLondon88, do I need to put release on that mold?
 
release is always a good idea. I use a mix of Vaseline and mineral spirits.
Drop a glob in a jar, fill with spirits and shake it up. Brush it on, spray it on..
whatever works for you. Let the spirits flash off before you pour. The
Vaseline will provide a barrier between the resin and the silicone.
 
Yep, you are quite correct. I was trying to keep the explaination simple, but giving the correct information is much better. Thanks for setting me straignt.:wink:
Do a good turn daily!
Don


DozerMite said:
There is no catalyst in the resin. It is promoted with accelerators such as cobalt napthanate and dimethylanaline.
The MEKP (catalyst) that is added when pouring helps begin the polymerization. It will cure without adding the catalyst.
Casting resin is considered slow-promoted resin.



its_virgil said:
I think you just found the answer to your question.:biggrin: The answer is yes, there is a shelf life. Not from when you purchased it but from when it was packaged...6 months is the time I've been told by one supplier I use. The polyester resin we use is prepromoted which means catalyst is added when it is manufactured and packaged. So, it starts setting up as soon as it is in the can....but slowly. The catalyst we add then completes the process. Purchasing Castin' Craft or other polyresins at hobby stores is no guarantee it is fresh. It may have been on the shelf for months before you purchased it. Those of us who seriously cast purchase from suppliers that sell lots of polyresin so what we get it fresh.
Do a good turn daily!
Don

nsfr1206 said:
I received a mold today from London88 and was gonna try it out. Put a couple of label blanks in it and picked up my can of CC. Had poured two blanks out of it maybe nine months ago. The rest of the can looks like it has set up into one big blank:rolleyes:. Does this stuff have a shelf life after opening? So I didn't get to try the mold out but I can say it sure looks nice.:biggrin:
Click to expand...
Click to expand...
Click to expand...
 
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