Puff The Magic Dragon

My Feedback: (2)

Does Expoxy have a shelf life when sealed? The other day I ran out of epoxy, and went to Lowes and bought some Loctite 60 Minute Epoxy. I carefully mix my epoxy with measuring cups. After 4 days it is still rubbery. What Is the best brand of Epoxy?

TedMo

I have used various brands over the years with total success and it's never been totally sealed, just a loose cap. Right now I have Devcon that is at least a year old and works fine. I use 30 min and 6 min. I would take yours back to Lowes. In fact when I mix I just guess at amount of equal parts.

aerowoof

I have some hobby poxy that must be close to 10 years old that works just fine.

Gray Beard

My Feedback: (-1)

If it isn't mixed completely you will never see it cure. Most epoxy problems are operator malfunctions, don't ask me how I know that!!
If you can, get to a harbor freight when they are having a sale and buy a couple of bags of there acid brushes, brushes mix epoxy better then a stick and they are cheap enough to not worry about when you toss them.

ChuckW

I have bought one package of 30 minute epoxy in the last few years that was bad. When the first batch didn;t set up, I figured I made a mistake. when batch number two failed, I figured I was a real idiot and made the same mistake again. After the 3rd and 4th batches I decided to toss it out. Never ever had a problem before or since though and I always use that same brand.

bassfisher

My Feedback: (21)

I've been using the Devcon epoxy for years (5 minute and 30 minute).  In fact, if I'm in a store with my wife and see it, I always buy a couple of packs of it.  Drives her nuts!!  The twin syringe applicator makes sure that you always get the right mix and eliminates operator error. I've never had a bad batch (knock wood). 

Rodney

When you say you mixed it in measuring cups, did the cups have a wax finish?  If it did, that may be your problem, you must mix in a wax free container.

OldScaleGuy

My Feedback: (2)

Some epoxies do have a shelf life. However, in my many years of working with epoxy, typically when it is "too old" it is too thick to use and cannot be mixed at all. I have been NHP brand for the past several years with no shelf life issues.

KW_Counter

Puff,
What is the temp and humidity where you are working?
If it is to cold the epoxy will have trouble setting up.
I also believe humidity may be a factor but haven't had to deal with that.
Try putting it in the sun for awhile.
Good Luck,
KW_Counter

j.duncker

My Feedback: (2)

Moisture is bad news as well.

But I have just got some 20 min epoxy from an Albuqurke supplier which will not set. It might be old stock [ 1 year plus and stored above 60 F. ]

In the Composite production world they are very fussy about having recently maunufactured resin [ we are talking weeks ] for maximum strength lay ups.

kdc

Before you rush back to the store ensure you really did measure according to the instructions, and of course its also possible you mixed 2 lots of resin together instead of 1 resin and 1 hardner!

I had a polythene bottle of epxoy just split whilst stored in a cupboard indoors ( well above freezing and never over 90 F ) and made a sticky mess on the shelf which never hardened. Otherwise it lasts for some years but it may depend on the climate.

Steve Steinbring

I sold Epoxy products for over 35 years. Most likely what happened here is a mix ratio issue. Epoxy works a bit different than how fiberglass resins work![&o] With fiberglass you can mix it HOT to the point of combustion. With epoxies the more "B" side you add the softer the cured material will be. So if someone takes one part resin to two parts of hardner its going to be a more soft cured result. Whereas a 2 to 1 resin to hardner will be a great deal harder.

Bottomline use the products as described by the manufacturer they have for the most part figured it out for you. Playing chemist will most often endup with some unsatisfactory results unless you have the proper background to assure desired results.

carrellh

I've heard the following procedure for getting a really good mix.
Mix as thoroughly as you can in a new cup
Throw away the mixing stick
Pour the mixture into a new cup
Mix again with a new stick

It may be overkill but the theory is that you'll have a layer of unmixed glue on the cup. I have popped the cured epoxy out of a cup after a few days and found it hard on top and rubbery on the bottom.