Chemistry - solution strengths?

[julianf]

I've run out of a cleaning fluid that i use, and have been looking at the safety sheet.

This is listed as the active components -

Im thinking that its probably the Potassium Hydroxide thats doing a lot / most of the work in that lot?

....and i happen to have about 20kg of KOH in the garage.


I reckon the Glycols are, maybe, more of a convenient thickener / binder than much of a working agent?

(the stuff is to clean mesh thats stretched across alloy frames - so its probably a moderately good idea not to have the KOH running over the alloy in excess)


Anyway, is anyone much familiar with the "other stuff" in it, and what its there for?

Again, its a cleaning fluid to disolve ink residues, which, in my case, are epoxy resin based, rather than just 1k solvent based.

Im wondering if i just do 300g of KOH in 700ml and dont bother with the other stuff, if that will get me somthing usable, even if it is a whole load more fluid?


Boots "value" cough medicine used to be pure glycerol, which i figured could sub in for the propylene glycol, but, it seems that they have started puting flavorings in it now, which might complicate things.


Anyway, my prior retailer has put up their price to a whopping £80+vat for 5ltrs, and, again, ive got a whole drum full of KOH in the garage, so you can see my interest!


Thank you.

 

[Screwdriver]

Be careful. Worth checking for any known reactions with that cocktail of additives:

https://grok.com/share/bGVnYWN5LWNvcHk_aeca4ecf-4b0a-4abc-a011-684c27fdd5cb

I imagine there would be a specific process to avoid any adverse reactions while you're mixing it up. I guess you already know the obvious ones if you have that much KOH lying around...

 

[Misterg]

Im thinking that its probably the Potassium Hydroxide thats doing a lot / most of the work in that lot?

There are several decent solvents in there too, which I think would be significant.

 

[Ross365]

I can understand your wish to use the KOH you have, but I think it's worth asking yourself the question "what price do you put on your time".

If that existing product works really well for you, how much time do you want to risk doing experiments?

When you look at a commercial product like that cleaner, with all of it's constituents, and it's significant price, you have to think that someone put some time and effort in to developing it to the point where they had a really good product (they eventually "hit the sweet spot"). That said, it's the old question about whether you'd accept a product that was 80% as good, coming at 20% of the price?

 

[julianf]

I can understand your wish to use the KOH you have, but I think it's worth asking yourself the question "what price do you put on your time".

If that existing product works really well for you, how much time do you want to risk doing experiments?

When you look at a commercial product like that cleaner, with all of it's constituents, and it's significant price, you have to think that someone put some time and effort in to developing it to the point where they had a really good product (they eventually "hit the sweet spot"). That said, it's the old question about whether you'd accept a product that was 80% as good, coming at 20% of the price?

It's shipped across from America.

 

[Dapph2]

If you have one have you tries a pure steam generator to get it off . Again if you have one have you tried it with the lightly caustic Vehicle Body Wash as a pre soak to soften things up a bit. ?

 

[SustWel]

Out of curiosity what is the cleaning chemical for? Only stuff I really see propylene glycol used for these days is some kind of antifreeze…

 

[julianf]

Out of curiosity what is the cleaning chemical for? Only stuff I really see propylene glycol used for these days is some kind of antifreeze…

They're for removing ink residue / haze from the meshes used in screen printing.

The emulsion can, under odd circumstances, also become insoluble, and the product breaks the bonds in that also.

 

[julianf]

If you have one have you tries a pure steam generator to get it off . Again if you have one have you tried it with the lightly caustic Vehicle Body Wash as a pre soak to soften things up a bit. ?

The mesh itself is some sort of synthetic fiber, so I could, basically, dip that in caustic, and there would be no issue.

It is, however, tensioned and bonded to a alloy frame. Eating though the "glue" would render the item useless. As would dissolving the alloy that the glue is bonded to.

So I've got to be a little careful. I can't just make a vat of the stuff and put it in for a long soak.

With the propitiatory product, I've applied it and then wrapped the whole thing in cling, which has seemed to work.

I have, however, done exactly the same with other propitiatory products, that are supposed to work, but have not AND have delaminated the mesh.


The small screens are cheap enough that it's worth some experimentation. The larger ones are £50 or £60 a hit, so I can move onto them if I get something that works.


I guess my main concerns are -

Mixing up the KOH too strong and it killing everything and

Finding a "binder" of some sort to keep it in one place.

 

[Erie Fred]

I am no chemist.

However, just because there is a list of ingredients, does not necessarily mean you can just dump
all of those into a container and BOOM, you've got your stuff.

Might be some need reacting under heat and or pressure with others to make some intermediates, and maybe a catalyst is used as well.

Might need cooling as they are slowly mixed together, to avoid runaway.

 

[Erie Fred]

It's shipped across from America.

Is it "Simple Green" ? (maybe not)

https://cdn.simplegreen.com/downloads/SDS_EN-US_SimpleGreenIndustrialCleanerDegreaser.pdf?_gl=1*1h4ykhq*_gcl_au*NTc4MjQyMjk3LjE3NzAyNTM5Mzg.

 

[Screwdriver]

I have found the methylcellulose is often used as a sort of thickening agent. Helps keep things in place.

 

[Ross365]

I once worked on a mixture where a very fine solid powder (fumed silica) was mixed in to a liquid. Mostly, I think you'd expect that sprinkling the powder in to the liquid while stirring was the way to go, and that forms a gel. However, that gel was very, very corrosive, but we knew that it shouldn't be corrosive.

Turned out that if you poured the liquid in to the powder, that also formed a gel, but hardly detectable corrosion. We spent a lot of time finding that out.

 

[Turbo]

There is up to 42% alcohol in that mix and I should think that is what is doing most of the work dissolving the dried ink.

 

[Gareth J]

I don't know what you are using but maybe it's worth trying a few different proprietary screen cleaners and studying their data sheets. See if you can infer anything from the differences/similarities. Either which ingredients to include or avoid.

The shops my wife uses stock speedball speed clean.

 

[Agroshield]

Mixing up the KOH too strong and it killing everything

Have you a screen you can sacrifice in the name of science?

Mix up a known concentration and do some controlled experiments: concentration, immersion time, quality of result. Then you will find the sweet spot.

How many failed lightbulbs did Edison make?

 

[badabec]

How many failed lightbulbs did Edison make?

Not as many as Sir Joseph Swan

 

[badabec]

If you include the time and effort in making your own, trying it and tweaking the formula, paying up cheerfully for a known, working product seems a better plan.

 

[julianf]

If you include the time and effort in making your own, trying it and tweaking the formula, paying up cheerfully for a known, working product seems a better plan.

In the short term, probably. But maybe only in the short term.

 

[Pete.]

I am no chemist.

However, just because there is a list of ingredients, does not necessarily mean you can just dump
all of those into a container and BOOM, you've got your stuff.

Might be some need reacting under heat and or pressure with others to make some intermediates, and maybe a catalyst is used as well.

Might need cooling as they are slowly mixed together, to avoid runaway.

A valid point. I just bought some concentrated synthetic coolant that needs mixing 1:20-1:30 with water. The instructions warn you to mix one into the other, not the other way round or you risk creating a 'reverse emulsion'.