[pcm81]

One of my hobbies is playing with coatings. Black iron oxide or phosphate are some of the porous coatings i can apply at home. Usually oil is used in conjunction with these coatings to function as a rust preventive. I fund it very beneficial to use a vacuum chamber to enhance and speed up penetration of oil into the coatings.

I am now trying to develop a dry to touch coating and need your help with choice of the solute. I will be using Propylene Glycol as solvent, because it does not evaporate at room temperature even near vacuum, which is needed property to allow me to use the vacuum technique. I will then heat the treated object to 100-200 degrees F an return to vacuum chamber allowing the trace amounts of Propylene Glycol to evaporate, leaving the solid solute deposited in iron oxide matrix.

I need your help selecting an organic compound that is very viscous or even solid at low temperatures, is soluble in Propylene Glycol and is not crazy difficult to get. I was thinking of greases or waxes, polystyrene also comes to mind, but wanted to get yall's opinion and ideas first.

Thanks ahead

[Enthalpy]

Hi pcm81,

the solids you cite are all non-polar, which makes sense to keep moisture away. For them, I'd use a non-polar solvent, heavy enough to evaporate slowly at room temperature. Approximately a mobile lubrication oil, you have some choice among them.

Dissolution of solids or pastes in a thick solvent may take time, but you can heat. Powders dissolve more quickly. You might also add a light solvent which will evaporate first, possibly before applying the solution.

[pcm81]

Hi pcm81,

the solids you cite are all non-polar, which makes sense to keep moisture away. For them, I'd use a non-polar solvent, heavy enough to evaporate slowly at room temperature. Approximately a mobile lubrication oil, you have some choice among them.

Dissolution of solids or pastes in a thick solvent may take time, but you can heat. Powders dissolve more quickly. You might also add a light solvent which will evaporate first, possibly before applying the solution.

Hi Enthlapy,
I agree with everything you said above, however it is the opposite of my question. My solvent is Propylene Glycol and i need a recommendation for solute that fits the physical properties i outlined in original post.

[pcm81]

What do you think about taking acrylic or polyurethane lacquer, adding PPG and using that as the coating. Would PPG keep it liquid after the oem solvent evaporates under vacuum at low temperatures?