fan driven smoke unit rebuild question?

Good question 

If the resistor with the heating element wrapped around it does not touch the batting which is soaked with smoke fluid how does it heat the smoke fluid to produce smoke?

I have rebuilt many Lionel smoke units, post war and modern fan types, and the heating element always has to touch the batting to produce smoke. If my memory is correct, the video produced by Mike Reagan about rebuilding smoke units shows the heating element touching the batting.

I'm certainly not an expert so I would be interested in what the experts have to say.

ez mike, that was my impression also. 

I absolutely have to agree that the resistor has to be in contact with the batting, so that the fluid flows by capiliary action and wets the resistor. If not in contact the resistor would have to be nearly red hot to make smoke. Stand by with the fire extinguisher! 😱

Rod

rod, i agree with you. this person had very white thick plums of smoke comming out the stack. when I have had smoke like this it was a shure sign my resistor was going out. I thought I would ask this question here just to be sure though and settle my mind on this. you are all correct in mike regean stating in his video to put the resistor down in the batting. 

The resistor should be firmly in contact with the wick but NOT totally covered.  For MTH smoke units, normally the braided wick is sandwiched between the two resistors from the factory, and that works well.  For Lionel stuff or anything with a single resistor, I shred the wick in the bowl and then have the resistor about 1/4" off the PCB sticking straight down into the shredded wick.

What GRJ said; I made sure on my repair that the resistors contacted the batting but not buried-covered by the batting.  One test is feeling a bit of resistance-push back between the resistor and batting when mounting the PCB back to the reservoir.  Also, took Lionel's string batting and shredded it before pushing it into the reservoir per Mike Reagan's video; I used 12 inches of string per reservoir.  One last thing - make sure batting does not block the fan air channels to the reservoir.

gunrunnerjohn posted:

The resistor should be firmly in contact with the wick but NOT totally covered.  For MTH smoke units, normally the braided wick is sandwiched between the two resistors from the factory, and that works well.  For Lionel stuff or anything with a single resistor, I shred the wick in the bowl and then have the resistor about 1/4" off the PCB sticking straight down into the shredded wick.

Exactly!

Mike

thanks guys, you just reaffirmed what I suspected all along.