How to electroplate vias and THT holes on PCB with copper?

How can I electroplate copper into [PCB](https://en.wikipedia.org/wiki/Printed_circuit_board)'s [via](https://en.wikipedia.org/wiki/Via_(electronics))s and [THT](https://en.wikipedia.org/wiki/Through-hole_technology) holes?


I found several instructions, but they all use palladium (which is expensive), or calcium hypophosphite (which I can't get in my country), or hydrogen peroxide (which I can only get with a concentration of 8%).


Are there any alternative ways using chemicals which are easier to get?




The connection of vias in multilayer PCB's used to be done *via* (no pun intended) [electroless plating](https://www.eurocircuits.com/electroless-copper-deposition/), but that process is a bit fiddly, demanding extra precleaning and postcleaning, and use and disposal of hazardous chemicals, such as chromium compounds. You can still [buy an electroless plating kit](https://nano3dsystems.com/product/electroless-copper-kit-for-plating-on-pcb-substrates/), for US$150 and up, but the solutions have limited shelf life and contain various hazardous compounds.


Commercially, electroless deposition has largely been replaced by the [black hole process](https://www.eurocircuits.com/black-hole-process/), so-called because a thin layer of black conductive carbon is deposited in the via, then plated with copper.


An individual might find [conductive ink](https://www.thinktink.com/stack/volumes/volvi/condink.htm) an alternative method for connecting vias. This can be automated, as in [this video](https://hackaday.com/2015/11/23/easier-pcb-vias-using-conductive-drill-bit/). Conductive ink can be [found for ~US$120 for 50 grams](https://www.precisebits.com/products/chemicals/conductive_plating_ink.asp). Also, see [this paper](https://www.circuitinsight.com/pdf/nanocopper_based_paste_solder_copper_via_fill_ipc.pdf) on filling vias with conductive copper paste.


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