Stumbled across an unopened pack of epoxy tubes today, big starburst on the back — “The rocket-age adhesive!” Hmmmmm, pretty old stuff, no? Probably will toss that one out, but what about epoxy that’s maybe 4 or 5 years old? If it still squeezes out of the tube, is it OK? I’ve got the Titebond date-code thing down, but know nada about epoxy shelf-life.
forestgirl — you can take the girl out of the forest, but you can’t take the forest out of the girl 😉
Replies
Forestgirl
Just try mixing a little and see if it hardens as it should. If so then it is ok. If one of the componets has formed crystals in it just heat it to about 120 and they should dissolve. FWIW you should mix the epoxy and let it cure before you dispose of it, that way it is no longer hazardous waste.
Rich
The Professional Termite
From what I have read about epoxy is it is supposed to last forever.
Well, I buy the stuff in pint cans (A+B = quart) and usually don't get a year out of it in Florida. The white part always gets lumpy and stiff and becomes and very hard to mix. I toss it and buy new 'cause it aint worth screwing around with the glop. I should probably mix up more when it's good and fill more holes with it. There's always holes that need fillin somewhere . . .
Boatman, I wonder if you filled up the vacant air space in the can mightn't the epoxy last longer... You could try the inflated balloon trick and see what happens (insert an appropriately inflated balloon into the can before sealing).forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Hello Forestgirl'
I've read and heard the same thing as Pat S - epoxy shelf life is unlimited.
Regards
SA
Woodnymph, I bought a dozen packs of epoxy cement almost 12 years ago Can't remember the brand, but I finally used the last of them last year. No problem, when ever I started on a new pack, I mixed a 'test' lump on a piece of plate glass and 24 hrs tough as nails. Stein
The epoxy manufacturers say that the hardener has a shelf life of a couple years or so, depending on the storage conditions, but the resin has an indefinite shelf life. In reality, the hardener takes on a darker color and gets more viscous as it ages, but still seems to work fine. I used a gallon of System Three epoxy that was more than 10 years old on a wooden kayak project, and it was fine except that the hardener was a little thicker and had a darker amber tint to it.
As Rich said, mix the two parts and let the stuff harden if you are going to dispose of it. The hardener is especially nasty to the environment. Just remember that it's going to give off heat as it cures, so take precautions if you have a large amount.
Rick
I let everything that has solvents in it dry out before disposal. Sometimes it's a pain, but that's life. Actually, the modern landfills are quite well sealed (my sweety's an environmental engineer and has designed and reclamined more than a few), but still I like to get down to solids before disposal.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
FG: I let everything that has solvents in it dry out before disposal.
This isn't meant as a specific criticism of Forestgirl, since not all things are equal, but I've read that when things with (all/most?) volatile solvents are used, they have to go somewhere; if they're buried, they poison he ground/water, and if they're allowed to "dry out", they poison the atmosphere. Pollution occurs in either case, only the location is different. As I said, I don't know if this is the case with all solvents, since I've read about it mostly in the case of oil-based paints and varnishes. Some people use this as a reason for avoiding all finishes with organic solvents in them, though I haven't personally gotten to that point yet.". . .and only the stump or fishy part of him remained."
Green Gables: A Contemplative Companion to Fujino Township
Norm, you are correct. Although the county hazardous waste people tell us to open the cans and let them dry out, then put them in the garbage, that evaporative stuff goes right into the atmosphere and accumulates along with the big industrial stuff. My main approach to lessening my contribution is to re-use solvents as much as I can (e.g., when cleaning brushes), take much better care of any paint I have in cans, and not buy gallons unless I'm pretty sure I'm going to eventually use the whole thing (even if quarts are mega-expensive ounce-wise).
Back to the landfill design thing: As I mentioned, landfills these days are extremely well-sealed so that they don't leak junk into the ground and groundwater. I had to clean up a few old cans of paint, stains and solvents last week, and I did the following (will check with the engineer when he gets home this weekend): I half-filled a heavy plastic bucket with cheap kitty litter. Then I dumped the Minwax, Danish, or thinner into the litter. I'll let it sit for a week or so, then take it to the transfer station (our dump option on the island).
Another option for paints: The county lady told me to mix Quickcrete concrete mix into the paint cans, mix it up and let it harden, then throw them away.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
To All;
Evaporating the solvent is akin to using the material as intended: solvent into the atmosphere! To bury hazardous liquids risks ground water contamination. Preferrable to solidify these by granulated liter box filler or cement as mentioned, thus serving to confine older hazardous pigments (lead) to insoluble status.
You might not be surprised to find that way over half the (hazardous) waste in the USA is NOT commercially processed nor deposited in secured waste sites! Nasty! We just gotta keep doing our best ... the best way. What did Grandpa say? We all live downstream!
It'll be a long time before the manufacturers can/will produce water based finishes that equal solvent based, so until then, I'm sticking with what I know best, just not wasting it.
John
"Evaporating the solvent is akin to using the material as intended: solvent into the atmosphere!" Point taken, John, but if it's being evaporated because the material is not being used as intended (e.g., it's outdated material, poorly stored so not useable, etc.) then that is solvent that didn't need to go into the atmosphere. Obviously, this type of venting is going to take place, because we're not perfect, but keeping it to a minimum is what I'm currently trying to do. I just took care of the last of some quite outdated stuff, and hopefully careful planning and conservative buying will keep my wastage to a minimum, as you do also, as cited in your post.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
The VOC in epoxy is a small amount of styrene, much less than polyester resin. When you figure boat builders use rail road tank cars full of polyester -- high in styrene -- those tiny bits we use are like a drop of water in the ocean. All else is amines and glycols (as in ethelyne glycol antifreeze), which are water soluable when uncatalized and which is why you should mix it before dumping. You don't actually have to mix it, but just combine the two parts together, that will do it eventually. Place on a piece of wood and put outside in case the exotherm wants to start a fire. Unlikely, though, but be safe.
You'd be surprised at landfills. Non-hazardous (garbage) landfills are subject to stringent double liner and leachate collection rules. Good? Well, here in the grand state of confusion (the 5th largest economy in the world), there are only a handful of double lined landfills - the hundreds of others were grandfathered in when the regulations were adopted for minimum technical requirements at solid waste landfills. In otherwords, most landfills here and elsewhere really don't protect ground water against pollutants from landfills!
Once I was an engineer, and could hold precision jet engine parts in my hand and know that I contributed to this physical thing of high-tech beauty. Now, I work for the state of confusion and spew drivel like that above all day! (although I know, in my heart, that this kind of environmental protection is important, no, vital, to our future). That's why I want the workbench I'm making to be as good as I can make it, and maybe better, even if I drill a hole into it a week after I'm done!
If you mix it to dispose (don't dispose unmixed), be careful about batch size. Epoxies are mostly exothermic - they release heat when curing. Since higher temperatures cause faster curing, the heat release speeds the cure, increases the heat release, speeds the cure even more, etc. It can get hot enough to catch fire.
Researching hazardous waste treatment operations a few years ago, I was surprised to find a number of emergency response incidents to large batches of epoxy mixed for disposal that caught fire or gave off noxious fumes!
Mix small batches, or mix and spread on some scrap plywood and leave it in the driveway until it's done curing.
A few years ago, making the stitch and glue kayak in an old finewooking (great fast boat), I used a high knap roller cover to spread epoxy since it was the only one I had in the garage. I spread the epoxy and put the roller cover on a sheet of newspaper to cure. The next morning, the epoxy in the roller had hardened and turned to discolored epoxy foam from the heat! I got lucky and it didn't catch fire.
By the way, use a low knap roller - short fibers. The darn roller probably held about $20 of west epoxy!
Epoxy goes bad. We had some stuff on the shelves for a few years (about 5). It was suggested we use it for the bring your kid to work day projects. Good thing we tried it before. It wouldn't set up at all. Nothing worse than a bunch of kids with sticky hands.
We use mixing tubes and epoxy guns so the mix was correct.
Toss it.
Len
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