keithbyrd
Member
I have two containers of PR -1 gal of Silmar 41 PR and 1 Qt of Castin' Craft PR. New containers - never opened - I opened them today and they are as hard as a rock or harder! What causes that?
How long does PR last in the can?
- Thread starter keithbyrd
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Heat. You need to store in a cool temp. I've had trouble after 6 months of silmar sitting on shelf.
its_virgil
Member
Keith,
Polyester resin, Silmar 41 and Castin' Craft and others are pre-promoted which means when manufacutured they are treated with cobalt naphthenate which is a curing accelerator cnd cross linker catalyst for polyester resins. When the MEKP is added the curing is kicked into high gear. Polyester resin has a nominal shelf life of 4 to 6 months from the date of manufacture, not from the date of the comsumer purchase.
This is the reason I purchase from vendors who I know move a lot of product and I am confident it has not sat on the local big box craft store shelf for several months. Freshness is essential. Storing in warm temps is also not a good idea.
Saying all of that I have had Silmar 41 last for several months with no problem and I have had it to start curing after just two or three months. Curing in the can, fortunately for me, has not happened often.
Do a good turn daily!
Don
keithbyrd
Member
Thanks for the info - shame on me for not knowing this! I will get a new, small can!
Gary Beasley
Member
I have extended the life of my polyresin by storing it in the fridge. Not sure how it would react to the freezer but have doubts it would hurt it as long as you dont get condensation in the can.