Introduction: Trash Soldering

About: I'm an applied physicist by training(phd Yale 2006, BA Berkeley 1998, math and physics), and have done physics research in the federal government and product development in the private sector, starting two of …

I want to be able to fabricate circuits using only trash in a way that can be both scaled up and automated. This is my first attempt to get rid of my soldering iron using a flame, based partly on some other people's great posts on here.


a bunch of bricks and shards of brick or whatever you can find

aluminum beverage can

candle, lighter

scissors, knife, fork, solder

parts, electronic trash

Cans can be found lying around pretty much anywhere. Bricks can be found by going up and down alleys and looking for brick shard piles that often exist behind very old brick buildings.

flux core solder

This is yet another instructable that is part of a much larger network of instructables that I'm putting together into a system. So without it's subsets and supersets it may not make entire sense at this stage, but I have to publish all these first as I go, then come back and connect them all together with hyperlinks which will hopefully make the path much clearer.

Step 1: Harvest the Can

Cut with knife, then cut out with scissors as shown to make one big flat slab. Flatten the slab out and remove burrs if you can with the scissors. Be very careful of the edge, it is very easy to get cut. Wash in sink.

Step 2: Build Furnace

Stack bricks, with aluminum surface in between as shown. Cut a candle down to a small size to fit in here, melt wax inside to make a joint between candle and ground/cement/pavement/bricks.

Step 3: Parts Salvage(optional)

This hotplate is great for salvaging parts from old surface mount boards. I would normally use tweezers for this but have recently lost my tweezers in my trash piles so I used a fork to just push it over. The fork worked great.

Step 4: Solder!

This is pretty much like soldering on a hot plate because that's exactly what it is! Solder your parts together by placing them where you want, pushing them around as needed with the fork, then using a role of flux core solder to get solder where you want, blow out the candle, LET IT COOL, and take it out and clean it up. One of the photos shows how I remove the harmless soot from the resistor. Soot from a dirty candle flame full of burning beer like this is certain to be full of a gallimaufry of every possible carbon nanostructure. So we now have a ton of material for making nonlinear nano-devices up from scratch as well as our finished circuit made from capitalist components.

Step 5: Decorate, Document

I like using the color codes: black = ground, red = positive voltage supply, blue is output to the coil, and yellow is the input from the digital circuits. A colorful circuit is an easy to understand circuit, hopefully easy enough that future users can fix, edit and upgrade easily.

Step 6: Use Naked Flame for Coil Connections

For free wires out away from the components, I use a naked flame. I had to go inside because it got dark so this is my standard coffee table setup with a brick. This is a higher resistance coil than shown in my other trash coil instructable, because it's for a new project which will be for higher supply voltages(24 VDC).

Perhaps it is not immediately obvious that this is scalable and can be automated using only trash robots. However I think that it can scale continuously. Suppose I want to make 10 of these at a time. I could line them up along an edge and move the flame along on a track, which is not hard to automate. A single simple manipulator that rolls out solder can then make all the joints, with some supervision by a human probe handler. This could probably make 100 in a leisurely afternoon in 10-20 unit batches. But if each line like that only needs intermittent attention as they all move pretty slowly, you might be able to manage as many as 10 lines like this, making a daily output of 1000 units even in a very mellow afternoon with many breaks possible. Multiply by a few people hanging around a camp sight for a week, with some people drifting through to help during certain times of day it's not hard to see making millions of units.