How often do you add Smoke Fluid?

As needed.  Your milages may vary.

Whenever the locomotive stops smoking, I add more fluid.

My non-tinplate steam locomotives run from early postwar to about 1990.  None of them have ever suffered any ill effects from running dry.  I can't speak for the new fan-driven units, because I don't have any.

When the smoke volume drops significantly, it's time to add more fluid.  If you allow most smoke units to run dry, they will cook the wick and then you have to open them up and replace it.  I go through a lot of wick for repairs here, most smoke units that come in the door are needy.

i always add a little to every locomotive that I intend to run at the start of every running session, so as to ensure that none are dry. I then fill each locomotive up as needed.

I'm in the "add more when the volume of smoke output drops" camp. On my MTH locomotive it's very noticeable since the smoke output on that engine is truly prolific - almost to a fault!

You can turn the smoke volume down under DCS.

I try to add some when the output gets fairly low. I then add about 2 squirts from a needle tip bottle I have from JT's Mega Steam. Nice little bottles, kind of like the oil bottles only with an angled tip.

However I have one Railking diesel that the smoke output dropped on and I added my usual amount. It didn't increase the smoke output, so after running for a while I added some more. Did this at least 2-3 more times (anything worth doing is worth over doing). A few days later the bottom of the engine was a bit oily. Wiped it down and it has not been oily since. Think I may have over done that one a bit.

Now thinking it may have needed a new wick or something instead of being low on smoke fluid? It was still working when we moved last fall, haven't had it back out since then. Hope I don't need some new boards for it when I do get it back out.

I add smoke every running session.  I am one of those that has waited too long to add more smoke fluid resulting the wick to burn up.  I have replaced the wicking several times and even had to replace a smoke unit.  However, I have read on one of threads on the forum that Mike Reagan recommends you don't add fluid until the engine has run for some time in order to allow the smoke unit to warm up.  I have followed his advise.  

My guess is you just need a new wick in the smoke unit, a common issue.

That's encouraging. I'm hoping it's just the wick, I think I can fix that myself.  I was really worried about the smoke fluid getting on the electronics.  I have never had one apart like you guys have, don't know how it's laid out inside. It ran just fine for a few months after the incident, but the smoke was never again as good as when new. It's a UP SD70ACE from a starter set. Forgot to add it's PS2

The signs that is time to add more smoke fluid are rather obvious with diminishing smoke volume.

if any of you have seen the live pictures of our club layout, we have to add smoke fluid after about one trip around the layout.

Two of my MTH PS-1 locomotives I bought (used) came soaked in smoke fluid.  I cleaned them up, put a new wick in, and they smoke just fine now.  And by cleaned them up I mean I wiped them off with a paper towel.

I monitor mine closely as I managed to burn out one unit.  When I notice that there is little smoke I add some...no further issues...

Ditto. By far the simplest and most reliable method.

I usually add a few drops every other time I run an engine unless it's been sitting for a while, in which case I add a little more.

A good fireman with good coal under average conditions yielded little or essentially

no smoke anyway. Oil burners tended to be smokier. So a little smoke on a model

can look quite prototypical. On my RR the firemen are extraordinary and the coal

is always top notch, so we're talking whiffs, usually.  

Of course when starting a train, or really, really working, or making "fake" smoke

for the fans on an excursion (I really hate that), there could be quite a bit of the

smoky stuff produced. 

I run mostly diesels. But they are carefully tuned to the highest Russian standards, so as to achieve billowing clouds of smoke at all times.  

Years ago, my young son complained of an earache, so I popped him up on the kitchen counter and laid him down on his side to put some ear drops in his ear. When my wife got home, he told her I had put smoke fluid in his ear and it made hime feel better. So add smoke fluid only when your ear starts to hurt.

As others have said, when you notice the smoke fluid output diminishing, that's when you need to refill.

You have received lots of good advice here, the most important being never let the unit run dry.

My procedure to prevent that is when I am about to run the engine, I add 8 drops of fluid. When I am ready to park it for a while, I add 8 drops before shutting it down.

Also, not a good thing to add fluid when the unit is on. Shut it off first and then back on.

The puffers make a mess, add it sparingly, 2-3 drops and more often.

How much depends on the type of unit.  A mechanical puffer will take 6-8 drops, while a modern fan-powered unit will need a full dropper-full. 

I like to re-smoke my units at the end of the operating session.  It gives the fluid time to settle into the wicking and for any meniscus to drop away.

Jon

Re-filling at shut down sounds like a good idea, think I will start trying that. Never thought of that, but it makes sense!

As Jon does, I usually refill at the end of a session to allow the fluid to truly have time to wick completely through the batting.

However, how long before that fresh smoke fluid begins to evaporate or dry up in the smoke unit?? Sometimes I may not run an engine for months.