Diluting grey paint with white - proportions?

[RrogerD]

I can't seem to get my head around this. I'm hoping someone who knows exactly what they're doing, can help me...

I've mixed 1:1 white to grey. The result is too dark (lets call it Light grey1)

I've taken this Light grey1 and mixed an equal portion of white, but it's still too dark (Lets call this Light grey2). Presumably this Light grey2 is now 1 part grey and 3 parts white?

So, I've now taken this Light grey2 and mixed an equal portion of white again to give me say (Light grey3). This seems about right. Am I correct that this Light grey3 is 1 part grey to 7 parts white? In other words 1:7 and NOT 1:8?

I need to be able to mix this from scratch each time.

Thanks

 

[JohnD]

Let's suppose you started with 1 litre of white paint and one litre of gey.

When you say "one part" do you mean another 1 litre?

Or do you mean an equal amount to what was already in the pot?

if you started with 1 litre, how many litres do you have now?

 

[RrogerD]

Let's suppose you started with 1 litre of white paint and one litre of gey.

When you say "one part" do you mean another 1 litre?

Or do you mean an equal amount to what was already in the pot?

if you started with 1 litre, how many litres do you have now?

Good point.
I basically take a cup full of this new mix and mix it with another cup full of white. Equal amounts each time.

 

[RrogerD]

And just to really complicate things, how to I use a 1:4 mix to make a 1:7 mix (if this is what I'm after based on the above). I'd been playing around with things this morning and mixed the wrong ratio. I really don't want to throw it all away

 

[JohnD]

I have a feeling you need to mix up again

get an empty 5 litre pot

put 100ml of grey in it

add white, 100ml at a time, until it approximates the colour you want

then add it in smaller quantities

then you will know the mix you want is (e.g.) 100ml grey plus 525ml white

For a perfect match, even of paint from the same supplier, you need to "box the paint" in a large pail, so I doubt you will get a perfect match if you keep mixing new batches. Google "boxing paint." It is enough to have it match in any one room, and not to change half-way along a wall.

And use your existing mixture as a first coat somewhere that will need two coats (e.g. a door or skirting board). Or in a different room or something where a slight colour mismach will not be noticed (e.g. an alcove beside a chimney breast, or a windowboard) due to the angle of the light falling on it.

I think you will need a mechanical mixer to ensure it is mixed absolutely evenly.

 

[Chivas69]

Start with the white and add grey to it. You'll hardly need any grey. Don't start with grey and add white because you'll end up using so much white!

 

[RrogerD]

Thanks for your replies and suggestions. Howver, unfortunately no one has answered actually my initial query as to what the ratio is.

Update: I've finally managed to work it out, it is a 1:7 ratio. With the 1:4 mix I simply added another 3 parts white to make my 1:7. Wall us now painted. Happy days!

Answering my own query; to convert the 1:4 mix to a 1:7 mix I simply add another 0.6 volume of white to the volume of the mix taken.
Eg: current 1:4 mix is made up of 5 parts (1 grey and 4 white) so, if I draw off 1litre it contains 200ml of grey and 800ml of white. For my 1:7 mix the white needs to be 7x the grey amount so 1400ml. It already contains 800ml of white in it so I simply add another 600ml of white.

Simples!

 

[Chivas69]

Am I watching Die Hard 3?

 

[RrogerD]

Am I watching Die Hard 3?

 

[opps]

I understand why people end up "mixing" their own paints but it can be a false economy. I did it myself years ago. All was fine until I ran out. I ended up having to get my local supplier to "colour match" it. It goes without saying that it wasn't quite the same colour, so I ended up repainting the whole room with two coats.

When I factor in my "labour costs" it would have been far cheaper to bin the original "not quite the right colour" paint. Possibly, self mixing just so that i could find a colour I liked and then getting that scanned.

 

[Bosswhite]

Its a waste of time , effort and money to try and mix your own colour of paint for painting large areas , it dosent work .