Postcrete: still soft after 2+ days

Dilisk

Recently, I used some postcrete in my back garden to anchor the groundspike
of a clothesline. Almost 3 days later, the postcrete is still soft: if I
poke the top with a little stick, there is almost no resistance. Will the
postcrete ever harden, and if so, when?

(For those who may not know: postcrete is a type of concrete used for jobs
such as fixing posts. The product I used is Kilsaran's Post 10 (which has a
web page at <http://www.kilsaran.ie/build/product/post-10/>).)

To assist anyone diagnosing this problem, I will give some details about
what I did.

I dug a hole in the back garden, stamped down the bottom, inserted the
groundspike a little way into the bottom, poured in some water, and poured
in the postcrete from the bag, attempting to put the postcrete evenly around
the groundspike. The water seemed to fizz a little as I was pouring in the
postcrete.

You're supposed to set the water level so that the postcrete comes up to the
top of the water, but I got this wrong: even when I had poured out the
entire bag, the postcrete was still below the level of the water.

I waited roughly 45 minutes, then decided to scoop away the surplus water
with a tin can. Not long after I had completed this, the postcrete had
absorbed the remaining water and gave the appearance of being hard (though
as noted above, it actually isn't hard).

One fact worth noting: there were some small cuts on the bag of postcrete
before I opened it. Presumably, these left it exposed to air, and perhaps
humidity.

Calahonda52

looks like you didn't make the hole the right size, its supposed to set in 10 minutes so my guess is that is was gone off.

Flag the issue with the the place u bought it but wait a week or so, it may set

Steve

If it's still soft after 2 days, I'd dig it out and get a fresh bag. If you leave it, it'll never be right.

TopTec

Yep, agree that its gone off. The wetness doesn't matter as eventually that will seep away or evaporate. As a comparison I was using a cement based aggregate adhesive recently and it was still soft after 24 hours when it should be hard after 2. It was an old bag. Bought some fresh a couple of days ago, same process and its rock hard after 3 hours.

Skim, bonder, tile adhesive among many ,all have a shelf life.

TT

Safehands

Dilisk wrote: »

Recently, I used some postcrete in my back garden to anchor the groundspike
of a clothesline. Almost 3 days later, the postcrete is still soft: if I
poke the top with a little stick, there is almost no resistance. Will the
postcrete ever harden, and if so, when?

(For those who may not know: postcrete is a type of concrete used for jobs
such as fixing posts. The product I used is Kilsaran's Post 10 (which has a
web page at <http://www.kilsaran.ie/build/product/post-10/>).)

To assist anyone diagnosing this problem, I will give some details about
what I did.

I dug a hole in the back garden, stamped down the bottom, inserted the
groundspike a little way into the bottom, poured in some water, and poured
in the postcrete from the bag, attempting to put the postcrete evenly around
the groundspike. The water seemed to fizz a little as I was pouring in the
postcrete.

You're supposed to set the water level so that the postcrete comes up to the
top of the water, but I got this wrong: even when I had poured out the
entire bag, the postcrete was still below the level of the water.

I waited roughly 45 minutes, then decided to scoop away the surplus water
with a tin can. Not long after I had completed this, the postcrete had
absorbed the remaining water and gave the appearance of being hard (though
as noted above, it actually isn't hard).

One fact worth noting: there were some small cuts on the bag of postcrete
before I opened it. Presumably, these left it exposed to air, and perhaps
humidity.

Not necessarily gone off. If it was, I suspect the product would be hard. It was not so its safe to assume it was not gone off. I think the problem here is that you had far too much water, so the water/cement ratio was wrong. I don't think it is an underwater product and effectively, that is what you were doing. Dig it out, do it again and reduce the water you were using.

Dilisk

It turns out that the postcrete is satisfactory.

About 4 days after using the postcrete, I tried to pull out the groundspike,
and discovered that it was stuck, even though the top of the postcrete was
still soft. I then decided to put the clothesline into the groundspike and
see if the groundspike would hold.

Since then, the clothesline has handled a load of washing and there is no
sign that the stability of the groundspike has been affected.

Presumably, the lower layers of the postcrete have hardened enough to keep
the groundspike secure.

Safehands

Dilisk wrote: »

It turns out that the postcrete is satisfactory.

About 4 days after using the postcrete, I tried to pull out the groundspike,
and discovered that it was stuck, even though the top of the postcrete was
still soft. I then decided to put the clothesline into the groundspike and
see if the groundspike would hold.

Since then, the clothesline has handled a load of washing and there is no
sign that the stability of the groundspike has been affected.

Presumably, the lower layers of the postcrete have hardened enough to keep
the groundspike secure.

Yes, it is wise to remember, the greatest enemy of all cement based materials is excess water. It really messes up the expected performance.