I have a very old stationary engine of unknown make that has wire wick oilers. As it is a non runner I have never tried them but they looked original so left them as is. If it had been a runner I may have thought "what idiot put those in" and changed them to cord. We live and learn. I subscribe to Robs channel and he does expel quite a few myths on brazing, casting and a few other things. He also builds engines from scratch.
Does a bare wire work as a wick ???? I have my doubts.
Most full size steam engines use the same arrangement but the wire is wound with sheeps wool. The wool is what is used as the wicking material and the wire as a support and used to push the wick down the hole.
When oiling a steam engine, it is good practice to remove the wick each time and dip in the oil to ensure that it is completely wet and replace it in the oiler hole.
The wick works like a syphon hose to lift the oil over the top of the pipe in the oiler and drain it to bottom. If the wick is dry, it may not work. (a hose will not syphen water (or other) if you don't remove all of the air and place the discharge end at a lower level)
Synthetic wool does not have the capilliary properties of real wool.
Does a bare wire work as a wick ???? I have my doubts.
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There's no point saying it doesn't work, it plainly does, what we need to know is how. Capillary rise doesn't need a tube.
I am given to understand that once the wire is wetted surface tension drags the oil down the wire. A bit like pulling a string the end will always follow. regards
Pleased to know that i wasnt the olnly one never to have heard about these. I will be conducting a few trials in the near future to determine flow rates etc.
A sensible & practical answer Paul! Referencing several of my 'old steam' books, have not come across any mention of plain wire oilers – always tend to the copperwire with pure lambswool twisted in.
I'm sure if plain wire worked properly it would have been used widely. However, it does seem that it was used in several types of machine etc as mentioned in earlier posts – so there's a bit of an enigma!
I've played with old machines, portable steam engines and traction engines for 20 years and have never seen plain wire oilers (not to say that they don't exist) but they have mostly been twisted copper wire and lanbs wool.
If oil will flow uo the side of a piece if plain wire, why would it not flow up the side of a piece of flat plate. If it could, why does'nt a can of oil empty itself if you leave the cap off ?
I've not had any practical experience of wire oilers, but from the OP's video it looks like it's a syphon action (or combination of capillary and syphon) caused by the narrow central tube. So to set things going, the reservoir would need to be 'over-filled' and then the drips would continue until the supply was exhausted. Possibly this is why Paul's experiment didn't show any results for the plain wire – there was no oils already in place to start the flow, nor the relatively narrow tube to keep the syphon effect going.
Rob
Edited By Grindstone Cowboy on 20/01/2022 10:00:14
Just managed to get in before SOD
Edited By Grindstone Cowboy on 20/01/2022 10:01:44
I think two forces are involved: lifting by capillary action and syphoning.
I suspect the syphon is broken because the two wire examples touch the container lip. It isn't broken in the multi-strand wicks because the outer threads are lifted over the edge. If so, the single wires might work if they were held by a firm base that hooked them clean over the lip.
Possibly the viscosity, weight and how well the oil sticks to the wire matter too. Could be a lighter oil on a different surface would be OK. I've no idea what effect galvanising would have, but I'd expect the rough porous surface caused by rust to destroy capillary action.
Paul's experimental setup is different in that there isn't an oil filled down pipe. The original link mentions having to splash oil over the down pipe. I'm suspecting that a film (diaphragm?), and a combination of surface tension and syphoning does the rest. If I'm right, filling the container and then inserting the wire wouldn't work.
Is it a strand of solid wire or a very small tube that siphons, started by capilliary action ? Worstead trimmings were used in locomotives, where by the capilliary action fed oil to a bearing surface from a resovoir. That it does not entrain grit is a very good point I had not thought of. Noel.
I made wicks from copper wire from an old transformer or charger, and worsted wool for my 4CD, and they work a treat. There is a tube up into the body of the oilers. I found out that worsted wool is combed out more than ordinary wool, so the fibres are all aligned, and presumably syphon better. Lambs wool would naturally be the same, with the fibres in line. I made a loop of copper wire, pulled it into a double strand, then wound the wire round a pencil making a copper coil or spring, and fed the wool down the middle and then tightened the coil around the wool. The wick can be tailored to fit the tube bore.
I did a couple of other experiments to test some of the theories that were posted.
Lifting by capillary action and syphoning.
I suspect the syphon is broken because the two wire examples touch the container lip. It isn't broken in the multi-strand wicks because the outer threads are lifted over the edge. If so, the single wires might work if they were held by a firm base that hooked them clean over the lip.
Possibly the viscosity, weight and how well the oil sticks to the wire matter too. Could be a lighter oil on a different surface would be OK
My test does not use a tube on the inside of the oil pot and I don't believe it is a syphon action that lifts the oil. On some large engines the tube is 1/8"-1/4" diameter and 2"-3" high and open to air at the top. Somehow, the oil has to be raised by the wick on the outside of the tube
The test below has the wicks held at the base and hooked over the lip without touching the cup. The 1st is solid copper wire, the second plain steel with no coating on its surface and the 3rd is multi strand copper wire (from electrical cable).
Lighter (hydraulic) oil was used this time for the test and each wire coated with it to wet its surface.
Sfter 12 hours nothing happened.
In this test the first wick used a solid steel wire wrapped tightly with wool yarn..
We don't have worsted wool in Australia and I used a local lambs wool knitting yarn. ( Worsted is a high-quality type of wool yarn. It is named after the small English village of Worstead, in the county of Norfolk)
The second wick is one strand of the copper electrical wire, bent in half to make a small loop and twisted together. The wool passed thru the loop and roughly wound around the twisted copper wire. (this is how I make wicks for our full size traction engines)