I’ve mentioned before that I have a Lionel Berkshire junior( in the form of a 2004 or 5 Polar Express engine) into which a friend placed a new smoke resistor to improve smoke output. The output did increase and this in turn revealed a new issue. Evidently the smoke piston must fit a bit loosely in its cylinder because smoke comes out of the bottom of the smoke unit as well as the stack. (It reminds me of the steam coming out a real engines cylinders.). My primary concern is that vaporized smoke fluid is also going into the shell of the engine and might in the future possibly ruin some of the electronics. I would appreciate reading your thoughts on this. Is it a problem or not?
I doubt there’ll be a problem but hedging my bets a bit I’d also add “But you never know.”
Lionel steamers of that vintage tended to be a little anemic on the smoke output to begin (mine were) with and there may have been a reason for that, like the loose piston fit you mentioned.
I don’t know, were it mine I’d do one of two things, put some electrical tape over the boards to protect them from smoke fluid residue or re-install the old resistor and live with the reduced smoke output.
If anyone else has any suggestions I’d love to hear them too.
That would hide any ‘wicking’ or corrosion, and might cause component overheating.
The definitive treatment would be Parylene coating, as is done to control boards in HVAC equipment. At present this is expensive to set up for a small or single run, but if you could assemble multiple boards on a jig or carrier and ‘split’ the expense it would provide peace of mind…
There are probably some other spray hydrophobic coatings that could be used – be careful as some of them use “forever chemicals”. To my knowledge none of them produce a conductive film. I don’t know if Home Depot or Lowe’s still stock the two-part waterproofing kit, but that ought to work nicely even on circuit boards with protruding or poorly-soldered leads.
Be careful with board-to-board conductors or contacts.
Great input! Thanks!
Thanks, guys.
Any smoke fluid you should be using in your locomotives will be mineral oil.
I don’t want to say “never” but there are few things I can imagine being more benign on a circuit board. In fact about the only thing I’d imagine being safer is one of the Dupont Fluorinert series compounds, which were specifically designed for things like immersion cooling of electronics, but mineral oil has also been used in that application.
Smoke fluid can make your track slippery, mess with traction tires, and cause general messes elsewhere. Some locomotives put the chuff trigger switch on the smoke unit lever, and I’ve seen those get saturated with smoke fluid and quit working(K-line used to send me replacements all the time)…but that’s because smoke fluid is a great insulator.
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Thanks, ben10ben. That is really good to know. I’m sure others will appreciate reading this as well.