Just curious, what COULD happen when overfilling a (lionel) smoke unit?

Well, I can't see how it could clog the gearbox, I think that's a pretty slim possibility.  The biggest issue is it makes a mess!  I know that smoke fluid will eventually make some wiring insulation brittle, that's a significant issue.  While I've seen boards soaked in fluid, I've never actually lost one, I just hose them off with alcohol and they're good as new.

Once it's wiped up, I can't see how it jumps up and does anything to the boards.

I have a Railking RS-3 that's PS3. The gasket was off on the smoke tube where you add smoke fluid. It wasn't smoking well so I took it apart and the smoke fluid was everywhere including on the PS3 electronics. I wiped it all down, installed a new wick, fixed the gasket and put it back together. That was well over a year ago, probably more like two years and the engine is still running just fine. Sure made a big mess though.

I agree 100% with GRJ and RTR12 - I have seen fluid get into the fan motor on the smoke unit (I am guessing via the bearings or mounting holes) and damage the fan motor.  It is not common, but can happen.

There are 2 types of smoke fluids I have encountered, one water based, one oil based.  The water based fluid can damage electronics.  Some starter sets have water based fluid (safety reasons); however Lionel Premium fluid is oil based.  This is why Lionel highly suggests using Lionel Premium smoke fluid in the Legacy locos.  The oil based fluid does not cause electronics damage; at least I have never seen that happen.

SantaFeFan posted:

The oil based fluid does not cause electronics damage; at least I have never seen that happen.

Unfortunately my VL Big Boy and a trip to Lionel customer service says differently. 

I had a mid 90's production Santa Fe 2-6-4 that had no seal at the top of the smoke unit.  The fluid went back along the wiring and kept shorting the reverse board.  Took a long time to clean and cook it all off to make the loco work decently again.

Turn the engine upside down and leave it on a towel overnight to empty out the unit.

Thank you for your responses everyone! Now I will know what to do if smoke fluid leaks everywhere inside an engine!

SantaFeFan posted:

There are 2 types of smoke fluids I have encountered, one water based, one oil based.  The water based fluid can damage electronics.  Some starter sets have water based fluid (safety reasons); however Lionel Premium fluid is oil based.  This is why Lionel highly suggests using Lionel Premium smoke fluid in the Legacy locos.  The oil based fluid does not cause electronics damage; at least I have never seen that happen.

So, if a smoke fluid is oil based, no matter what manufacturer, would it be OK? Thanks,

Santa Fe 3751

I think it is rare that the overfill alone would get the board damaged.  But anything is possible.  Clearly it can kill the fan motor, followed by over heating and damaging the smoke unit and element.  That can take the Lionel RCMC boards out as seen recently in an engine I am working on.  G

I can tell you when the fan motor gets loose and stops the impeller that it can not only burn up the smoke unit, but also take out the R2LC!  Don't ask me how I know this!

Wonder if it might be a good idea to place a couple hundred milliamp fuse in line with smoke unit motors?  Probably not worth doing to a new engine, but for one that is already apart for something else, it might be cheap insurance for more expensive boards?  

JGL

It couldn't hurt, OTOH sometimes the motors stop rotating and aren't drawing excessive current.  For older stuff powered by the LM78L05, you'll never get that kind of current out of the regulator, the motor will just stall and the regulator shuts down.

How do you think Menards got the idea for this?

This thread got me thinking! I only have a Christmas layout with MTH engines ,proto 3. When I fill the smoke units I get smoke but around the engines, not out of the stack, diesel or locos. If I blow into the stack, it suddenly works correctly! Am I doing something wrong? I'm very careful about overfilling!

play trains posted:

This thread got me thinking! I only have a Christmas layout with MTH engines ,proto 3. When I fill the smoke units I get smoke but around the engines, not out of the stack, diesel or locos. If I blow into the stack, it suddenly works correctly! Am I doing something wrong? I'm very careful about overfilling!

When you add smoke fluid, it can create a bubble of fluid blocking the smoke from exiting properly.  This is caused by the surface tension of the oil and is affected by how narrow the tube is, the narrower the more it likely will happen.  Blowing down the smoke stack is a good way of breaking this bubble.  I believe most Legacy engines now come with a funnel to use when adding smoke fluid to help prevent this.  You can also use items small enough to fit down the smoke stack to pop the bubble, like a toothpick, small straw, screwdriver, etc. just stop when feeling any resistance.

Thank you for answering and giving me suggestions! It was annoying but I don't think it bothered the engines, they all work fine, even better now that I know more! thanks again!

I routinely give a "puff" down the stack after adding fluid, it's a common issue.

Handle it like a man.Do it right.If somebody really went overboard and you have a huge mess on your hands,pull the shell off and clean everything up.Take the top off the smoke unit and inspect.This may be a good time to re pack the unit and replace the resistor.Many good tutorials on you tube if you are new at this.Many guys on here eager to help with advice and instruction.Nick