DIY RSU resistance soldering

[Boyan Silyavski]

Hi there,

recently have been visiting a model making club so it got into my head to build a resistant soldering unit.

Here are some instructions how to do it and some info :

DIY Cold Heat soldering iron

http://www.nmia.com/~vrbass/models/solderer.pdf

Resistance Soldering


Basically what it does is heat a graphite stick, while shorting a 5-12v 3-10A transformer. It does not matter if its AC or DC. It works both ways.
So what i did was source an old not working car charger from a boot sale. Usually apart from the fuse the only thing that can burn there is the rectifier. I payed 5 eur and it happened such was the case. I liked the unit as it had graduated steps of power and also 6 -12 v switch.

After throwing the rectifier to the garbage , the fuse if on the 6-12v side should be isolated, cause later will blow and heat!

I decided to make 2 handles which hold 3mm and 1/4 inch graphite. Just for the sake of experiment and as discovered later can serve different purpose.
Threaded bar goes through the handle and screws on aluminium heat sink. At the other side of the heat sink goes the graphite. The heat sinks i fashioned seem to work very well with the purpose of not heating so much the threaded shaft. In the future will make a base plate with some fixtures and tweeters if needed