Making solution for submersion based deacidification
I've been reading that some folk might be attempting to wash/deacidify one of your own posters. Last night Sven discussed book keepers spray a magnesium based deacidification product. Based on my research I selected to use Calcium Hydroxide (CaOH) as a solution for deacidification. I completely soak the poster and rinse out the reactants. This is typically my first step outside of just getting the poster wet.
What you need to make it:
Measure out 2g of the powder on the scale and mix with 1 liter of deionized water. Let it sit overnight, preferably 12 hours so the solution can reach equilibrium. This one liter of solution is concentrated and will need to be diluted by another 1 liter of water. Any of the CaOH that doesn't mix with the water is basically still powder and settles at the bottom - I gently stirr up the top part of the solution but leave the particulates at the bottom. Then I gently poor the mixed solution into the new container (leaving the remaining solid at the bottom) and then add the additional 1 liter of water. After you mix the solution a bit more it is ready to use.
If you don't have fancy 1L containers you can also recycle... I had to measure 1.5 grams to use these and then I'll poor them into the sprayer with equal parts deionized...
What you need to make it:
- Scale (capable of measuring grams)
- A 1 liter container
- A 2 liter container
- Distilled/deionized water
- Stirrer
- Calcium Hydroxide Powder
Measure out 2g of the powder on the scale and mix with 1 liter of deionized water. Let it sit overnight, preferably 12 hours so the solution can reach equilibrium. This one liter of solution is concentrated and will need to be diluted by another 1 liter of water. Any of the CaOH that doesn't mix with the water is basically still powder and settles at the bottom - I gently stirr up the top part of the solution but leave the particulates at the bottom. Then I gently poor the mixed solution into the new container (leaving the remaining solid at the bottom) and then add the additional 1 liter of water. After you mix the solution a bit more it is ready to use.
If you don't have fancy 1L containers you can also recycle... I had to measure 1.5 grams to use these and then I'll poor them into the sprayer with equal parts deionized...
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Comments
After soaking in the CaOH2 solution, I need to rinse. Is it OK to use tap water for this step, or do I need to come up with large amounts of distilled/de-ionized water and some sort of pump? Not quite clear on the rinse.
Back in the photography world, we simply kept a moderate flow of tap water to rinse the chemicals out. My tap water comes a short distance from Lake Michigan and is pretty clean, but it is chlorine treated and fluoridated.
As as for those used/empty liter bottles, nice tastes Charlie, esp the Bourbon!
Here is a photo of my soaking tub after I pulled out a poster which had a lot of acids pushed out of the paper-hard to see, but the yellow in the water are the acids left behind-paper emerged in much better shape!
I am thinking I could slowly add the CaOH2 while stirring, a tablespoon at a time until there was a small amount left on the bottom, showing saturation.
Thoughts?
Just add and get rid of any that doesn't react... You probably don't have a pH reader but if you did all you would need to do is make sure the pH is not way above 9-10...