Removing coating from photoplate aluminum.

[misterNNL]

I need a dependable method for removing the blue coating that comes on aluminum photo plate.i have tried oven cleaner which doesn't begin to touch it.Sanding tends to wrinkle/bend the thin stuff so what's left to try?

Thankks in advance for the help I know is coming!

[Ace-Garageguy]

Are you using the "low odor" oven cleaner, or the baddass lye-based (sodium hydroxide) oven cleaner?

If the coating is anodized, a sodium-hydroxide or potassium-hydroxide product will take it off, though you may have to bag it to keep it wet for a while.

Edited February 25, 2016 by Ace-Garageguy

[misterNNL]

I am using Easy Off brand oven cleaner.It has been my go to chrome and paint removal product for decades.I tried that and some generic BLAH_BLAH_BLAH_BLAH with no fumes and no results.Neither had any effect on this coating.

Is there some brand name product that contains the compounds you mentioned?Thanks again!

[Ace-Garageguy]

Easy-Off makes an Easy-Off branded product that's low-odor and won't do much of anything, but I'm sure you know that.

Drain cleaner contains one or the other, but it's really hard on the aluminum too.

Do you know what your "blue coating" is specifically?

Is this "photoplate" made specifically for an acid-resist photo-etch process?

Have you tried any other solvents?

If it's a lacquer coating, even the harshest oven cleaner won't have much effect either.

 

[misterNNL]

I plan on stopping today at the printing business where I obtained this plate last year and asking for their help.the original packaging is heavy gauge black plastic which made me think the coating might possibly be light sensitive.I laid some sample sheets in direct sunlight for several days with no effect at all.

The sheets are also separated with sheets of thick sheets of tissue paper for scratch avodance which told me the coating could be removed by abrading with sand paper.that is very time consuming.I was hoping to produce a polished surface with a whole lot less effort.Several attempts using sanding have resulted in parts with unplanned folds in bad places,kinked corners and uneven shine from all the different grades of sanding materials used.

[talon63]

Sounds like an emulsion plate used in contact printing. Depending on the type, it might be removed with very hot water instead of chemicals. glycol ethers and isopropyl alcohol may do the trick as well. Alkaline cleaners should dissolve it, but acid/emulsion cleaners don’t  or take a lot.