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Posted: Fri Mar 15, 2013 1:57 pm
by ringi
Sorry for the very basic question. I find that whenever I try to create a dry mix of concrete or mortar, it does not mix well and a lot sticks to the side/back of the dram, what am I doing wrong?
My sand is damp as it is in bulk bags so get rain on, if that is an issue.
Posted: Fri Mar 15, 2013 2:08 pm
by GB_Groundworks
You should always cover your materials keep them dry, there are a few reasons for sticking to the side I've found
Drum isn't cleaned and has mortar already stuck to it
Drum is at the wrong angle (more on bigger site mixers)
Overloading the drum (very common)
Are you starting with your cement first?
I always like to start with a little water coat the drum
But a clean drum is the key hate it when the lads don't clean the drums out I often spend an hour nesting a barrow of stuck stuff of our big site mixer runs so much better when clean
What mix are you using?
Posted: Fri Mar 15, 2013 2:30 pm
by ringi
Thanks,
I think my issue may be the drum not being clean; there is a bit of a build-up on the paddles. What the best way to clean an old drum?
Is the Belle Concrete Dissolver Spray any good?
Posted: Fri Mar 15, 2013 3:38 pm
by msh paving
chuck half a borrow of gravel in it and some water ,let it spin for a hour and tip it out MSH 
Posted: Sat Mar 16, 2013 12:22 am
by KLS
If you want it really clean we put about 1ltr of brick acid in with a 25kg bag of 10mm gravel, comes out looking like new. Just leave it mixing for about 20-30 mins.
I find to help stop the mix sticking to get it in quick and almost as soon as you have got it in trickle it over the rim of the mixer into a barrow, consistent mix every time, then every 10 mixes or so get in the mixer quick with a pointing trowel to make sure you don't get a massive build up.
Posted: Sat Mar 16, 2013 1:43 am
by lutonlagerlout
what we call a *dry* mix always has an element of water in it
water first (say 2 litres) then if doing say leanmix I would pour the cement on to the aggregate and shovel it in as one
then you need to tip the mixer forward over the barrow just to the point that the gear is starting to come out and hold it there for 5 minutes
this change in angle allows it to mix better
LLL
Posted: Sat Mar 16, 2013 7:57 am
by seanandruby
ringi wrote:Thanks,
I think my issue may be the drum not being clean; there is a bit of a build-up on the paddles. What the best way to clean an old drum?
Is the Belle Concrete Dissolver Spray any good?
As in everything, prevention is better than the cure. Always clean the mixer after use, throw in a couple or three half bats with water and keep mixer running, tip it out then throw clean water in until spotless. As LLL says: always there should always be water added to a mix.