On bags of addy/grout it usually says something along the lines, 4 parts powder to 1 part water (or similar). Does that mean i can go by volume rather than weight? Say 2L of powder, to .5L of water etc?

I've never measured adhesive just mix it to when it feels right, go by volume as it says on the bag

Originally Posted by whitebeam

I've never measured adhesive just mix it to when it feels right, go by volume as it says on the bag

Yeah cheers whitebeam. I guess it'll be a while before i can do it it by feel; so far every adhesive i try feels different!?!

The "feel" is different between different adhesives. As such, it's good to mix according to the instructions the first few times, before you learn to recognize the correct consistency for the specific adhesive you're using. Grout is a different story. Try to mix according the instructions as much as possible, as grout tends to be more sensitive than adhesive.

And yeah. 4 parts powder to 1 part water refers to the volume, ie 4 litres of powder + 1litre of water.

Most adhesives and grouts list the density of the powder as well. 1300g/dm3 means that 1 litre powder weighs 1.3kg. 1 litre of water, generally speaking, weighs 1 kilo.

So if it says "5 parts powder to 1 part water" on a 25kg bag that says "1300g/dm3", that means 25kg powder is roughly 19.2litres (25kg/1,3kg/dm3). If you want to mix the entire bag, you add 3,8l water (19,2l powder/5parts). 19,2+3,8 = 5+1 parts. Good to know imo.

Thanks sWe, that's really useful to know.

Originally Posted by sWe

The "feel" is different between different adhesives. As such, it's good to mix according to the instructions the first few times, before you learn to recognize the correct consistency for the specific adhesive you're using. Grout is a different story. Try to mix according the instructions as much as possible, as grout tends to be more sensitive than adhesive.

And yeah. 4 parts powder to 1 part water refers to the volume, ie 4 litres of powder + 1litre of water.

Most adhesives and grouts list the density of the powder as well. 1300g/dm3 means that 1 litre powder weighs 1.3kg. 1 litre of water, generally speaking, weighs 1 kilo.

So if it says "5 parts powder to 1 part water" on a 25kg bag that says "1300g/dm3", that means 25kg powder is roughly 19.2litres (25kg/1,3kg/dm3). If you want to mix the entire bag, you add 3,8l water (19,2l powder/5parts). 19,2+3,8 = 5+1 parts. Good to know imo.

I don't think he was expecting that sWe, well done mate, as always.

Maths is usefull ya know

I always carry a pocket calculator when out working. Good for calculating layouts, amounts, etc etc... At £4 it's a good investment, and gives you more control.

Originally Posted by Dan

I don't think he was expecting that sWe, well done mate, as always.

You're right there!! hehe! Didn't help too much today though, as neither of the 2 small bags of grout i used had that info on them. Doh! I'll keep the info for next time though.

I bought 2 bags of grout, as i mixed the 1st bag in direct sunlight and it went off straight away...

Another question for ya:

On the Bal grout it said to add powder slowly to the water, but didn't mention it on the Granfix grout. I did anyway, just to be on the safe side, but was it necessary?

It saves you getting a lumpy mix

Originally Posted by whitebeam

It saves you getting a lumpy mix

I did wonder, but i seem to remember reading somewhere that you can over-mix it too!?! So much to learn....... Luckily there's no rush!

Originally Posted by beanz

I did wonder, but i seem to remember reading somewhere that you can over-mix it too!?! So much to learn....... Luckily there's no rush!

Not overmixing per see, but if you've got an ill-suited mixer, ie one that has a too high rpm, or an ill-suited paddle, you can mix too much air into the mix, which is bad, for a number of reasons.

A good way of avoiding lumps is to not add all the water at once. If the mix is "stiffish", the paddle more easily dissolves lumps. If you add half or two thirds of the final amount of water, and then mix to a homogenous consistency, and then add the rest of the water, you'll have minimized the risk of lumps.

Originally Posted by sWe

Not overmixing per see, but if you've got an ill-suited mixer, ie one that has a too high rpm, or an ill-suited paddle, you can mix too much air into the mix, which is bad, for a number of reasons.

A good way of avoiding lumps is to not add all the water at once. If the mix is "stiffish", the paddle more easily dissolves lumps. If you add half or two thirds of the final amount of water, and then mix to a homogenous consistency, and then add the rest of the water, you'll have minimized the risk of lumps.

Cheers sWe. I've been using the same paddle on my mixer, as i use for the addy. What qualifies as a suitable paddle!?!

The labourer

Originally Posted by bighen

The labourer

I can't afford me, let alone a labourer!!