How long can I keep PR?

[Penl8the]

Hi All,

I just started experimenting in PR casting couple nights ago. It gave me such a headache I had to stop for now. I am planning to restart it in this summer in the garage. Working is the garbage now in Calgary is not an option - it is not insulated and today temp is -10 deg C (15 deg F).

By the way, in the garage there are 2 trays of PR inside a Home Depot 5 gallon pail with the lid on. I put the pail in the garage 2 nights ago. I opened the lid this morning the smell is still strong. POTENT stuff. And they are still "soft". I can confirm one thing - it will take more then 2 days to cure PR (if at all) in temperature at -10 deg C.

I bought two cans of 32-oz Crastin' Craft clear polyester casting resin from Michael's last week - 50% off. I am planning to keep them.

• So how long can I keep an open can of PR? (I have not opened the second can)
• What is best storage method?
• And where?

Any suggestions will be appreciated. TIA.

 

[NewLondon88]

The good news is that you don't have to worry about whether or not the can
has been opened.
The bad news is that the resin is supposed to be good for six months..
that's six months from manufacture .. opened or not.
Cooler weather can extend this, warmer weather can accelerate it.
You can open a can to find the resin is already hardened. And we're not 100%
comfortable with the age of the stock at Michael's anyway.

If your resin is mixed and sitting in -10 degrees . .chances are it will never cure.
Room temp is fine for curing. As the temp gets lower, the curing time is increased.

Best storage is cool and dark.

If you need to keep the fumes outside, then here's my suggestion:
Store the resin inside. Store the molds inside. Bring everything out to the garage
to mix and pour, put them in your 5 gallon pail and put the cover on to keep
the fumes in the pail. Then, bring the pail back inside. That way, you get the
warm temps and no fumes.

 

[Penl8the]

Thank you Chuck.

As per you suggestion, I went to the garage to retrieve the Home Depot pail. I noticed I did not have the lid on tight. After hitting the with a rubber mallet. The pail is back in the workshop now. I have my wife to check the air quality in there. She approved.

So we will see if this batch will cure. If not, I will mix another small batch in the garage; seal the lid and bring the back in the workshop.

Thanks again.

The good news is that you don't have to worry about whether or not the can
has been opened.
The bad news is that the resin is supposed to be good for six months..
that's six months from manufacture .. opened or not.
Cooler weather can extend this, warmer weather can accelerate it.
You can open a can to find the resin is already hardened. And we're not 100%
comfortable with the age of the stock at Michael's anyway.

If your resin is mixed and sitting in -10 degrees . .chances are it will never cure.
Room temp is fine for curing. As the temp gets lower, the curing time is increased.

Best storage is cool and dark.

If you need to keep the fumes outside, then here's my suggestion:
Store the resin inside. Store the molds inside. Bring everything out to the garage
to mix and pour, put them in your 5 gallon pail and put the cover on to keep
the fumes in the pail. Then, bring the pail back inside. That way, you get the
warm temps and no fumes.

 

[holmqer]

This doen't address the main question of your post, but for curing in cold environments, I use a heated floor mat designed for shop use. The mat stays around 135F, and a small one (2'x3') draws 100W. I just put the pot on it to cure the stuff inside.

I also use a small piece of 1/4" masonite as a curing rack and just put it on the mat as well. That way I can use any glue I want, spread them around on the masonite and just set the whole thing on the mat.

 

[Daniel]

Branden, You do not necessarily need to heat the garage or shop, just the resin. a small box setting on a heating mat will work. a box with a light in it will also. I would think you want the fumes to escape some how. How to get those fumes where they will not make you sick is another problem. I am not sure but there may be a problem if the resin freezes.