My first smoke fluids that I used with my A.F. Loco were unsatisfactory, so I bought several kinds of "super-smokes" smoke fluids, which cloged my wick always fast up - see the 1. photo under this text !

This started me to think about this problem, because to change every 6 months a wick is bad for the loco and smoke unit.

Smoke fluids need some chemicals which are making smoke (of course!) , so there will be always some residue, but the goal is to have as less as possible!
Personal, I think, this is well achieved with my -Clean Steam- Formula.

During my research and testing of my smoke fluid -Clean Steam- I made the discovery, that if the heating windings are wound with a bit of space on the glas wick, so that there is only little contact to the glass surface - it's possible to burn the wick free!
Like with cars the exhaust...

The Eternal Wick:

--Every use of this explanation is on your own risk!--

Make sure that the active lenght of the wire has max. 25 Ohms and not less then 23 Ohms. (Try to get 25 precise)
The wire must be wound around the wick in such a manner, that you can easily push the wire on the glass-wick around.

I made it that way, that I wound it first around the glass-wick in the normal way, which means full contact to the wick.
Then I measured and put the Ohms of the wire to 25 (active lenght!).

Then I retwisted the wire in the counter direction, that it was wound the first place. This removes the wires off the glass-wick surface, so that there is only little surface contact.
Take care, that you also have enough space between your windings, that it can't short out!
After this you can proceed like with a normal wick change...

Important!:
Make sure that you have as less wire contact to the glass-wick fibres as possible!
If you have much contact (normal wound wire) , the wire will burn the glass surface black!

25 Ohms, are in the case for S Gauge Gilbert A.F. Smoke-Units, low enough to burn residues away and high enough not damage the wire.
This is at least what I've found out in my own tests!

Also, this was achieved with the use of Clean Steam ONLY.

How to burn the wick free:
Let your loco run, and after a while you will notice, that the normally odorless smoke becomes smellable.
If you followed well my explanations, then nothing bad can happen to the heating wires. Let it run dry till you can't really see any smoke and thats it!

Hint:
For longer Smoke time, it's better to seal around the bottom of your smoke-unit, as it looses with the paper gaskets always some fluid.
I made this whit nail varnish.
Simply draw the line on the side.
Easilly removed with acetone...

If your wick is working fine, you can see fluid -around- the single windings, like in the last photo!

Have fun!
Long live the Gilbert A.F. Trains!
For me the best analog classic modell trains (1950's).

Best wishes,
Gereon