Epoxy paint and photo chems?

[Dave Martiny]

I'd like to tighten up my temperature control during film processing by placing all my chemicals (instead of just the developer) in separate containers in a large water bath. I'd like to use metal cans as they would facilitate temperature equalization more readily than either glass or plastic containers.

I have some soup and nut cans that would work well for this, but I was unhappy to find that if water is left in them for a period of time, the will begin to rust. I'd like to coat the inside of the cans with epoxy paint to try to solve this problem, but I'm concerned about the possible incompatibility of the paint with any of the chemicals, which will include high pH developers like Rodinal, acid stop bath, acid fixer, hypo clear, and photo flo. Before doing my own experimentation on this, does anyone if painting the cans would be likely to work, and if so, can you recommend a specific paint? If not, any alternative suggestions?

Thanks and best regards,

Dave

 

[AgX]

I have no idea what soup and nut cans are, but does the advantage of having good warmth conductive characteristics really weigh up against that corrosion issue, lack of scaling and transparency, lack of pouring feature (I guess)?

 

[fschifano]

I don't know man. This sounds like way to much trouble to me. I simply use cast off plastic soda pop bottles for that task. Works well. Conducts heat readily. Completely non-reactive. What's not to like? But getting back to epoxy paints, sure that will work.

 

[MattKing]

I'd go to a largish paint store and seek their advice. They might have empty cans designed for samples that would work.

 

[Roger Thoms]

Dave, why not collect a few stainless steel tanks, the type that are used for spiral film reels. Depending were you live these can be had for next to nothing on Craigslist. You should also be able to find them here on APUG on the classified section. You could also post a WTB request in the APUG classified.

As soon as you coat the nut cans with epoxy you will create a thermal break which will at least partially defeat the purpose of using metal.

If you want to go the epoxy route check out West Systems. http://www.westsystem.com/ss/

Roger

 

[Allen Friday]

Glass?

 

[CBG]

I used to put glass storage jugs into a big plastic tub / tempering bath. A bit of hot water from the faucet into the tub got temps where I wanted them in short order. The epoxy / nut can idea would work, but would entail extra effort. The shiny surfaces of the cans would need to be thoroughly cleaned and abraded to give the epoxy a good grip. Plus, cured epoxy tends to be a bit brittle without reinforcement, so your finish will probably chip off at some point, leading you back to the corrosion you seek to avoid. Just put your storage bottles in a bath a bit prior to use and it will work like a charm.

 

[mts]

I use a big plastic pan--one I was given in a hospital stay a few years ago, intended originally for use as a barf pan. It served its purpose well then and continues to do so as a convenient tempering bath for C-41 and E-6. I do not suggest that you make hospital stay to get one yourself. Instead use a plastic washpan that you can find at most big box stores.

 

[hrst]

And, what has not been mentioned yet, is a fact that after you coat the metal with epoxy (plastic), you lose the temperature advantage of metal jar over plastic! So, just use a plastic bottles, they are readily available - HDPE or PET work. PET beverage bottles can be very thin with manageable heat transfer, as good as your epoxy coated metal jars would be.

 

[Roger Thoms]

And, what has not been mentioned yet, is a fact that after you coat the metal with epoxy (plastic), you lose the temperature advantage of metal jar over plastic! So, just use a plastic bottles, they are readily available - HDPE or PET work. PET beverage bottles can be very thin with manageable heat transfer, as good as your epoxy coated metal jars would be.

Actually I did mention that in my previous post. I also did a quick search on thermal conductivity and stainless steel is much higher than glass (which has also been suggested). Pretty hard to beat stainless steel although in actual practice I'm sure Pyrex beakers would work very well.

Roger

 

[Dave Martiny]

Many thanks to all of you for the replies. I think at this point I've been rightly dissuaded from the epoxy approach. Stainless steel tanks are the best solution for what I'm after, perhaps followed by capped beverage bottles left floating in the water bath like logs.

Thanks again and best regards,

Dave