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Electroforming from scraps? Answered

I was reading the Electroforming 'ible https://www.instructables.com/id/Electroforming-an-Iris-Seed-Pod/ and I have a couple of questions:

1)  It says you need an 18 amp digital rectifier. However in step 13 it says "Check the amp and voltage setting, they should both be at or below 1".  Why do you need an 18 amp rectifier if you only need less than 1 volt and 1 amp?

2)  Is it possible to build some sort of a suitable rectifier from scrapped microwaves?  I know people wind a 10 gauge secondary into the MW transformer to make welders, so can it be done for electroplating too?




Best Answer 6 years ago

1)  I read her ible and comments. 
The current she used WAS 0.9A at 0.85Volts.
She did point out if you use silver you will need more current and voltage.

2)  Yes it is.  If you own an amp meter you can adjust current with a series
resistor and turns count ( use 16 gauge ) on a transformer.


How would I know what current and voltage I need?
Is there a way to calculate the surface current density for different sizes and different metals?

It is current that you adjust because current is the transport mechanism, the voltage will self adjust.  You select the current by observing the copper deposit action ie when you get rapid granular build up.  The words are Trial and Error.


Current depends on the size of the piece, so you look at surface current density - it may be for her iris pods, 1A is all you need. You will still only need a very low voltage to achieve that current density, so rewiring MOTs is a complete waste of effort.