Balling cement in mixer

[onionsa]

Can someone advise me on why cement would ball up like this in a mixer and how to avoid it?

Thanks.

 

[EddieM]

Can someone advise me on why cement would ball up like this in a mixer and how to avoid it?

Thanks.

How old is the cement?

 

[onionsa]

I've had it a couple of weeks but its a fresh opened bag every few mixes.

 

[EddieM]

Hmm, check the bag, should have a date on it, are you putting water in first?

 

[onionsa]

I'll check the bag later. Its defo not old stuff. My usual method has been to add a small amount of water, half the sand, half the cement, bit of water, add the rest of the sand and then rest of cement and then water to dampen the mix.

 

[noseall]

Nothing to do with the cement and everything to do with the addition of materials into the drum.

Never add to a dry drum.

Always add water before drying it up again with the cement.

If the mix is too wet, just add more dust (cement) and sand.

 

[EddieM]

What with your wobbly patio slabs I'm suspicious of your cement.

 

[onionsa]

I'll try starting with more water today and see how I get on.

 

[noseall]

I'll try starting with more water today and see how I get on.

If you can gauge the total amount of water and put it in at the beginning then you will fare better. Otherwise just add water BEFORE adding more material into the drum. If you intend leaving the muck in the drum for a long period, then leave it wet. Add more gear prior to tipping it out if you need to.

 

[onionsa]

I'm scooping it out as needed to make carrying it easier, so it is left in there, but not for more than 20mins say at the most.

 

[onionsa]

What with your wobbly patio slabs I'm suspicious of your cement.

I've just been to check the cement bags for a date but can't see anything - what would you consider to be old?

 

[EddieM]

I've just been to check the cement bags for a date but can't see anything - what would you consider to be old?

Depends on how it's stored of course recommended by Lafarge is 4-6 weeks, 2 months max

 

[onionsa]

Oh ok, didn't think it was that short of a shelf life. It's just stacked in its plastic bags like it would be on a pallet.

 

[noseall]

I've just been to check the cement bags for a date but can't see anything - what would you consider to be old?

It aint the cement bud. Concrete sand is notorious for allowing the balling up of the cement when mixed in the wrong sequence. Amateurs who have attempted floor screeding (dryish mix) are testament to that.