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For certain reasons I am interested in constructing low power circuits using wood instead of PCB/Protoboard as a surface upon which to place and join components. Although many might find this silly, I still want these circuits to be high quality, rugged, efficient, and just as functional as a circuit not laid on top of wood.

A simple method to achieve this in my mind would be to place screws as junction points, then solder the component wires to these. The solder connection should be sufficient to hold light components. Heavier components I plan to investigate fixing to the board with fasteners.

My question is this: Will any commonly available screws (zinc, stainless steel, ...) have sufficient conductivity to produce an efficient circuit. If so would a certain common material/conductor be preferable? I assume size will effect the resistance/conductivity? Should I measure the resistance of the screws to get a good experimental idea of their resistance/conductivity? Is there a certain range that I should be looking for?

If commonly available screws are not sufficient, my next idea was to look into hammering solder header pins to the wood, however I am worried they could come loose from the wood over time.

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    \$\begingroup\$ flickr.com/photos/jeanbaptisteparis/sets/72157624604071700 \$\endgroup\$ Jul 23, 2022 at 13:26
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    \$\begingroup\$ @TonyStewartEE75 Wow that is absolutely amazing (and very aesthetically pleasing as well)! One of the motivating factors of this was trying to reduce the use of non-biodegradable materials so this is a very interesting option to look into! Thanks! \$\endgroup\$
    – sasukenebe
    Jul 23, 2022 at 14:45
  • \$\begingroup\$ the screws do not need to be part of the circuit \$\endgroup\$
    – jsotola
    Jul 23, 2022 at 14:50
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    \$\begingroup\$ another option is to buy a short length of solid power cable, extract the conductors, and make copper "nails" ... pre drill the board for easy insertion \$\endgroup\$
    – jsotola
    Jul 23, 2022 at 15:45
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    \$\begingroup\$ hackaday.com/2017/02/03/… The book described here was my introduction to electronics in the early 1970s and probably had a profound effect on the way I built circuits from that day to this. \$\endgroup\$
    – Frog
    Jul 26, 2022 at 1:27

5 Answers 5

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Wood does not really like soldering temperatures, so you may want to minimize the conduction to the wood. You could consider ordinary sewing pins, which are generally made from steel but with a plating that is solderable, at least some are. The steel will have poor thermal conductivity and the pins are reasonably small (0.65mm in the sample I liberated from my wife's storage). This is similar to the construction of many component leads (plated steel) however the leads are made from soft steel and the pins are stiff so they can be driven into a soft wood like pine easily.

enter image description here

This is actually pretty robust mechanically. For heavy things or things that go off the board you could use standoffs (you can even get 4-40 threaded wood inserts to do things really nicely- they have a wood screw thread on the outside and an internal thread that accepts a machine screw threaded standoff etc.)

You can also get solid brass escutcheon pins (dome-headed nails- the sort of thing you'd use to fasten the hinges on a jewelry box) but they are much larger diameter so they'll carry and hold a lot of heat. Also, more expensive.

As far as electrical characteristics go, there is a fair bit of (generally old) information on wood. Dielectric constant of dry wood can be lower than epoxy-glass, conductivity is highly variable. For ordinary (up to 1M\$\Omega\$ resistors and not high precision where there are high impedances) probably you won't have to worry much for dry wood kept indoors and especially if you varnish it.

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  • \$\begingroup\$ Stout component leads could also be used like this, directly; components often use plated steel (check with a magnet!), or brass pins/header stock could be used (sharp buggers, watch your fingers around em -- will go into wood easily!) Downside of non-headed nail substitutes, you'll have to grip it carefully yet firmly with pliers, and push hard enough to embed it. Diagonal cutters leave a wicked sharp wedge on the cut piece, use this to your advantage! \$\endgroup\$ Jul 23, 2022 at 20:03
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    \$\begingroup\$ Sewing-like pins are usually available in hobby/handicraft stores, and can work amazing for this. They solder very well and I had no problems with them. The end results can look very nice too! \$\endgroup\$
    – Uncle Dino
    Jul 25, 2022 at 21:43
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These might meet your requirements. Screw it down to the wood, bend the tab up.

enter image description here

Or, there are phenolic strips with multiple solder lugs and an L bracket to screw them down (normally to a metal chassis). Some early TVs were wired this way, point-to-point, no PWBs!

enter image description here

Both from Amazon.

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    \$\begingroup\$ The lugs are especially nice because the screw heatsinks it for a while, keeping heat away from the wood. \$\endgroup\$ Jul 23, 2022 at 19:59
  • \$\begingroup\$ While in the development stage, OP may want to consider using Fahnestock clips, which do not require soldering. They worked well for me in the 1950s. \$\endgroup\$ Jul 25, 2022 at 19:44
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When I was really young, just getting into electronics, my Mother gave me a wooden board, some screws, and a bunch of these:

enter image description here

I got that picture from this supplier: allfasteners.com

They are called "countersunk washers", and can be used with regular countersunk wood screws to pinch down onto multiple wires or component leads, connecting them together.

Perhaps that's an option for you.

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  • \$\begingroup\$ I recall doing something similar in school in the early 90s. Another term is "cup washers" \$\endgroup\$
    – Chris H
    Jul 25, 2022 at 7:59
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    \$\begingroup\$ The excellent ladybird book Making a transistor radio is the reason I have had a 40+ year career in electronics and software. These screw cup based connections were the basic method used in the project. \$\endgroup\$
    – uɐɪ
    Jul 25, 2022 at 13:49
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Steel will not accept common electronic solder. So you'd need screws made from solderable material, like copper or brass. I mean, not steel with a coating that makes it look like it's copper.

Brass will probably be cheaper and look more steampunk. It solders easily with an electronics soldering iron, but if there's a large chunk of it, it'll take more power to heat it.

However, once the screw head is full of solder, it'll be impossible to remove. So you could use brass nails or tacks instead. These should not be varnished.

If the goal is aesthetics, you should protect the wood while soldering, otherwise it'll be full of flux stains. You could use a mylar sheet ("laser projection sheet") with the schematic printed on it, then rip it off, or maybe just paper. Or varnish the wood first. This would need some experimentation.

Current leakage through the wood should be higher than FR4 and depend on ambient humidity.

You could also make a PCB and glue thin wood veneer on it, then re-drill the holes...

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  • \$\begingroup\$ Thanks very much for this information. Regarding making a PCB with a wood veneer: One of the main reasons I am looking to make wood breadboards is to reduce the use of non-bio-degradable substances such as are found in PCB thus this is not appealing to me. Another reason is to reduce cost. Cosmetics are not a concern as the items I am looking to make at this time will hold the breadboard inside a case, though I am now wondering if I should treat the wood to help avoid decay from moisture. Wow I wouldnt have thought of current leakage through wood, that stinks, I will need to look into that. \$\endgroup\$
    – sasukenebe
    Jul 23, 2022 at 14:39
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    \$\begingroup\$ Stainless steel will not accept common solder (acid flux is needed) -- however, clean, plain steel can be tinned with rosin, with moderate difficulty. Tin-plated fasteners would be ideal, if you can find them. Nickel plating is difficult to tin (worse than plain steel, I would say). Galvanize (zinc plate) can be tinned easily, but it dissolves in solder, leaving a drossy joint: YMMV. \$\endgroup\$ Jul 23, 2022 at 19:58
  • \$\begingroup\$ Brass woodscrews are easy enough to get, easier than steel in really small sizes. If you don't screw them all the way down you can get them out with pliers, even if the head is ruined. But you could easily enough clear a slot in a screw head by getting it hot enough to melt the solder, then using your screwdriver. Varnish would show burn marks from solder drips worse than wood; I'd use cardboard or thick paper as a protector. \$\endgroup\$
    – Chris H
    Jul 25, 2022 at 8:03
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Why screws? @SpehroPefhany has already suggested sewing pins, but (at least in the UK) there's an even easier alternative---copper panel pins, which solder very nicely, have a low enough thermal mass to solder with an 18 W antek iron, and are readily available at every DIY/hardware shop/screwfix/amazon.

If you print the circuit diagram and glue it to the board below, and then drive pins at the junctions, you can solder the components directly between, following the layout of the diagram. I've seen this used for teaching in amateur radio clubs, and has the advantage that not only can one follow the schematic very easily, one can hook a probe at any point (either to lead or to nail).

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