On Aug 22, 7:13 am, (Doug Miller) wrote:
In article , "Mike" wrote:
A few years ago, I bought a bag of mortar mix to
make some small repairs around the house.

After using a small amount, I stored the bag on a shelf in my
garage over the winter. The bag never came in contact with
my cement garage floor. I used some the next spring, only to
discover it went bad. It mixed and applied as usual, but when
cured, it just rubbed off with my finger.

Yep -- absorbed water vapor from the air, reacted with it, and now it won't
set. Completely normal.



So last spring, I bought another bag, and again I used a small amount.
But this time time after opening the bag, I poured the remaining mix into
a clean and dry 5 gallon plastic bucket with a tight lid. This time I stored
it in my basement over the winter (heated).

I just mixed another small batch, only to discover it has gone bad again.
It was not clumped together it seemed the same as when it was in the bag
It never got hard or anything like that.
Is mortar that sensitive? I didn't notice an expiration date.
What can I do to make it last longer ?

Use a bucket with an airtight lid next time -- it seems that the lid on your
bucket isn't quite as tight as you thought it was.

Or buy it in smaller bags, since you're only using it in small amounts. It's
not like the stuff is all that expensive, you know, and it doesn't appear that
you use it often enough to be actually saving any money by buying it in bulk.



Please help me to understand about mortar mix.

Mortar, plaster, and concrete cure by chemical reaction with water. This
includes water vapor in the air. Once the reaction has taken place, it can't
take place a second time -- thus, mortar stored in moist or humid conditions
will become unusable, often in a matter of only a few weeks. The key to
preserving it is to keep it dry.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

You could also put one of those damp remover dessicant widgets in the
bucket. That's what I do with grass seed.