mrsonchus wrote:Can you give a little detail re the amount/s of potassium-acetate and copper-sulphate, also 'how it's combined' into the mounting mix?
My starting materials were chemical powders, residues of old chemical supplies. PVA and the acetate are very water-soluble so easy to prepare. Pure PVA white powder, MW around 50,000. To 4g of the powder I added 8g DW in a 20ml capped glass vial. After some swirling and intensive shaking (by hand; I do not have a stirrer or bottle roller), and 15min immersion of the vial in a small pot of boiling water, it dissolved to form a fairly clear syrup. In a separate vial, I added about 8g potassium acetate to 5g DW. Shaking and swirling gave a clear solution within minutes. To this solution I added 10-20 tiny grains of anhydrous copper sulfate. Left overnight, it dissolved completely and tinted the solution very pale blue. 3 drops of the solution was added to 10ml of the syrup, swirled until complete mixing by the eye.
THE CORRECT protocol, that I recommend is somewhat different, as follows:
1. Prepare a 50% solution of potassium acetate in DW. No need to heat for dissolution.
2. Add a few grains (per 10ml, say) of copper sulfate, mix. Ubiquitous copper sulfate (not anhydrous) is in the form of blue crystals, these will dissolve rapidly.
Note:
by "grain" I mean a tiny particle, not the "Grain (unit), a unit of mass equal to 64.79891 milligrams, 1⁄7,000 of an avoirdupois pound" (Wikipedia).
3. Place 5ml (say) of the solution in a capped vial (or beaker, depending on your mixing facilities). Gradually, add the PVA while heating at 80-90C and stirring; or repeat my shortcut, add the full amount, cap the vial, place in a boiling water bath, swirl occasionally, until the syrup emerges.
The best mixer to make syrups AFAIK is an array of two cylindrical rollers in parallel, nearby each other. The rollers are rotated (electric motor) in opposite directions - one CW, the other CCW - such that a bottle or vial that lies between them (along the space between them) slowly rotates around its long axis. IF I had this device, could lay the vial on top , turn rotation on and go away, the mixing would be complete within hours.
P.S I cannot guarantee that the above syrups are totally free from minute particles. They look colloid-like. Can be filtered, not very easy with a syringe and a syringe filter, under mechanical pressure.
Edit:
Just discovered a stupid mistake in the "CORRECT" protocol above - the aim is 2-3% acetate in the final syrup, not 25%. So After step 2, dilute the acetate-copper mixture ten-fold, and in the dilute solution dissolve the PVA. Also, less PVA can be taken - say 3g PVA per 10ml of dilute acetate-copper solution, to get a final syrup that is more fluid so easier to apply for mounting.
