Looks like I won’t have the time to get to a couple of projects until March or April, job issues. I have a couple of gallons of poly laminating resin [UV] and a gallon of poly gloss resin that will be in storage for five or six months. I read the MSDS information sheet and it only recommends storage below 100 degrees F [38 C] and to store no longer than six months. I’ve probably had the resins for a month already. Here are my questions:
[1] Will the resins be any good in April? Maybe I should sell them and buy new later?
[2] Can I/should I store the resins in a cold garage [probably going below 0 C for a while]?
[3] Should I store the resins in a more temperate climate [in the house/basement]?
Store resins around 55°F, say in a cellar, and they will hold up okay for a year or so anyhow if in an unopened sealed container. Colder than that and you may have some crystallisation and lumps in there, in any event I’d use one of those paper and mesh painter’s funnel/strainer gizmos to make sure you don’t have any surprises. Dunno why it crystallises, the chemistry and physics of it is something I haven’t thought about.
In the gloss/sanding resin the wax may come to the top over time, so you might want to turn the container over a few times before use, once a day, to re-incorporate that into the resin.Like you’d do with some paint you’d had for a while. The crystallisation I have seen in the past could well be the wax that has risen to the top. I’d suspect it freezes in colder temps and, being wax, rises to the top and gums stuff up. Probably less wax in it means it’d harden incorrectly as well.
Catalyst- my experience has been that it’s okay in a ‘cool, dark place’. Light/UV seems to kill it off more than anything else. I suspect the UV breaks apart the peroxide. If you’re in doubt next spring, pitch it and get more. The nice thing is is that while resin for surfboards is kinda specialised stuff, MEKP is MEKP, it just varies a little in strength, depending on vendor and intended use.
Uhmm- for what it’s worth, resin prices will very probably be going up all winter, so it may be worth the gamble to hang on to what you have, strain it and go with it.
The polyester materials, both resin and MEK-P will degrade over time. If you keep the material in storage I would discourage exposing them to extreme temperatures. Then in the spring, I would do a test of the materials before committing to a full surfboard project. The materials are pretty resilient, and if stored properly, should last. Check again with your material product sheets. The MSDS (Material Safety Data Sheets) will only tell you what safety precautions and PPE to use when working with the materials.
Thanks for the tips! I think I’ll clear out a shelf or two in the basement where there is no natural light and very consistent temperature/humidity. I’ll also lam a test piece of foam to see how the stuff is working in the spring [eastern US].