Mixing of powder chemicals

[Bateleur]

Hello All,

While mixing a batch of my standard brew, Ilford ID-11, last night I noticed a residue of dust in the packaging. This is common and I have always ignored the waste as being negligible.

Perhaps the question is purely academic as I experience consistent results and am satisfied with the density of my negatives, but I was wondering if anyone has conducted tests to see where the threshold of accurate chemical mixing lies?

 

[MikeSeb]

The question is purely academic.

Most people will see far more inconsistency from poor temp regulation or careless agitation than from a few micrograms of unmixed powder.

 

[bdial]

If you have any doubts, just rinse the package with some of the water you're mixing with.

 

[Rich Ullsmith]

My greatest concern when mixing developers is minimizing oxygen, which basically means mixing and pouring with as little turbulence as possible. Less turbulence, less surface area for gas exchange, less oxygen in the mix, longer shelf life. I think this (and the temp/agitation as mentioned) matters more than the dust remaining in the package.

 

[fotch]

Well, when you think on how often and how long this is been going on, it may mean Zillions of $$ being wasted.

 

[vedmak]

I do not think it will make a difference, for example while mixing Xtol I found that it has over 1.5 g over the weight stated on the package, I do not think that when you mix a gallon of solution tiny amounts of powder will make difference either way.

 

[Bateleur]

Thanks guys for the input, yes it is academic, and no I don't want to think about the cumulative effect of the residue.

My greatest concern when mixing developers is minimizing oxygen, which basically means mixing and pouring with as little turbulence as possible. Less turbulence, less surface area for gas exchange, less oxygen in the mix, longer shelf life. I think this (and the temp/agitation as mentioned) matters more than the dust remaining in the package.

Interesting point, Rich and Michael. As a newbee I was pretty aggressive about mixing. Now I relax and enjoy the ride.

 

[Ian Grant]

My greatest concern when mixing developers is minimizing oxygen,

Well many older books actually acknowledge this and suggest using boiled water to make up developers, this drives off the dissolved oxygen.

Ian