Deposit at bottom of bubbler tube - can it be eliminated?

Update, I found out the material in the tube is methylene chloride so my guess is we are seeing a chloride salt precipitating?  Has anyone tried reversing this by leaving the bulb on under the tube for a long period  for example?  Other ideas?  

Nope, the "deposits" you see at the bottom are supposed to be there, and help to create the bubbling effect.

You often read here of these bubble tubes, that they either work slowly or not at all, even with the factory included light bulb. It is the heat generated from the light bulb that causes the fluid to "boil." I have found that giving a very gentle tap on the tube - after it has been on for a few minutes, will quickly cause the bubbling effect to take place.

Here's a video to learn even more....

Deposits are probably there to give the solvent a surface to induce bubble formation from the heat source.

GReat video. That is good to know- saved me a ton of time fooling around with that.  I guess I need to raise the voltage or get a bit more scientific on what is going on- why no bubbles?  

When I am going to show guests my accessories  that use those tubes, I remove them not long before we go down to the layout and shake them vigorously. They bubble in a fraction of the time after that. Or, after it's heating a bit, shake them then.....but that doesn't look right when your guests think you've got to shake these things up every time you show them. 

Roger

Heat is the magic ingredient, a bit more heat and the bubbles usually happen.  I've seen that with bubble lights as well.

I had a similar experience/wondering with some Christmas bubble lights.

In my case, it's the same 12 volt bulbs making the same contact with the tube as always, but my perception has been I thought there was more of a solid mass at the end of the tube than when they were newer (and bubbled more easily).  Obviously it's hard to adjust the heat on a string of Christmas lights.  Though in an experiment, temporarily holding the glass tube near a larger (C-7 style) bulb or a match (obviously no where near the tree!!!) causes bubbles to start.

-Dave

John,

You're absolutely, positively correct. I've found over the years that those little bitty tubes need a minimum of 12v to function but work better with 14v at full power. In years past I always provided those type of accessories with their own dedicated power source. I always purchased bulbs by the box. It worked for me.

Two comments....

First, support for dialing up the bulb voltage to get the bubbling started.  Our (LHS) display layout derrick w/bubbler (no longer in use) started best at 16v.  Once bubbling it could be dialed down to 13-14v.

Second...  One of our customers, having multiple oil derricks w/bubbler tubes grouped in an area of his layout swore by this trick...

Get some silicone thermal grease, apply a small dab of the grease on the top of the bulb which is closest to the bubble tube.  Push the bubble tube down into contact with the grease/bulb.  That's it!  He said (we never verified ourselves) that this grease, which is typically used to conduct heat from microprocessors/chips into the heat sink to which they're fastened, improves the light bulb heat transfer into the bubble tube.  Oh yes, he also used a 12 volt bulb.  While it may have shortened the life of the bulb, it tended to run hotter at the 12-13 volts at which he ran his accessories (buss wire).

Makes sense.  But, again, it's a matter of finding that combination of 'whatever works' that makes you happy.

FWIW,.....always.

KD

Thanks all, for the help and comments. I had a 6-12944 animated oil derrick originally and it bubbled to beat the band at 14v.  I tested the 24112 oil field at the same voltage and only two operated- that is what started me on the wild chase to figure out if I had bad tubes since all the bulbs were to spec.  Based on feedback above, I increased voltage and get 5 of the tubes bubbling at 16 volts and all bubble really well at 18 volts (which is what the Lionel manual says to operate at) .  But who reads instructions?

I plan to try that grease since I don't want to run an 18 volt line- my accessory buss is 14 volts.

Boiling does not start in a random manner, it starts with nucleation on a solid surface.  I assume the material at the bottom is equivalent to boiling chips that chemists use when they want to boil something as glass is relatively smooth and makes a poor nucleation source.  If you do not use such a surface then then boiling can start with a major bubble causing major problems.  I have a couple of the Lionel boiling tubes.  One starts boiling no problems.  The other will not start even with the voltage at cranked up.  I did determine that I could start it by placing it against a household light bulb outside of the derrick until it boils and then replacing it.  However this is absolutely not recommended as it unsafe.  I am going to try the thermal grease. 

It is important to use the correct bulb with bubbler accessories. Postwar Lionel 455 oil derricks called for a GE 363 bulb. It is hotter than a 53 or 1445.

The same issue can arise with the 394 beacon. Many of the past reproduction bulbs do not get hot enough. That includes the brass based bulbs that came out of Madison Hardware. As I understand it, the Madison bulb were 1455 bulbs to which they added the dimple. (I don't know how they did it). Genuine factory made bulbs had the dimple cast in as part of the mold (source: Charlie Clark). The GE factory part number was 461, They are stamped.

I posted a method above that I use to get these things to bubble quickly. Doesn't seem like it got read. I shake the tubes. So, I just went downstairs to do a test. My basement is at 64 degrees right now, so the tubes are cold. I have an MTH derrick and another derrick related accessory next to it with it's own tube. I took the tube in the derrick out and shook it vigorously for 10 seconds and replaced it. Did nothing to the other tube. Turned on the power. The derrick tube instantly started a stream of bubbles up the center and was bubbling vigorously at 30 seconds. The other tube "popped" on (as they tend to do) at 1 minute 40 seconds.      So, bottom line, if your tubes are easily removable (as the ones in the derrick are......try it.

Roger

Thanks for the "shaking" tip.  However, my oil field will not be easily accessible and I really don't want to shake all those tubes each time I decide to turn it on.  Shaking one or two that are within reach is pretty easy....shaking a whole field of them plus a couple of derricks makes for longer time-to-play scenario.

I like the grease idea...going to try that!

I wonder if anyone has automated this using low-cost electronic component modules off eBay (e.g., timer, relay, voltage regulator).  So it would be like automatic vs. manual transmission in a car automatically shifting gears (lowering voltage) once the car (bubbling) gets rolling.  Ought to help with bulb-life if you only drive it hard for the first minute of an operating session.

But the silicone grease idea seems the simplest solution.  The stuff used to cost a fortune at Radio Shack and come in a messy hard-to-use tube but now I see the computer stores carry 30g easy-to-apply syringes for a couple bucks.  Presumably these bulbs don't get too hot whereby the thermal gradient on glass can break them.  I remember the hot bulbs used for overhead/slide projectors and even modern halogen lamp bulbs warn not to get even a fingerprint on them for that reason.  That is, the thermal grease will pull heat from one side of the bulb and "stretch" the glass.

Those are indeed 'boiling chips' - as White Pine has said - an old chemistry trick to increase the surface area and provide nucleation sites.  My experience with these tubes - gained mainly through the one to three strings of 'bubble lights' on the annual Xmas tree - is the variability in performance is mainly due to how well heat is transferred from the light bulb to the bottom of the tube.  Even then, there are some lights that respond well to being 'thumped' with your finger. 

Though thermal grease sounds like it might work - I wonder if a) it won't slump or pull away at the temperatures of the lightbulb - especially of there is a big gap between the bulb and the bottom of the boiling tube and b) whether having something in contact with the glass lightbulb will shorten its life or stress the glass shell.

It might be worth trying to see if you can reduce the spacing between the bulb and the bottom of the tube without making contact (I really don't know whether contact is a bad thing...).  Another thing that might be worth trying is to loosely wrap the bulb and the tube bottom with something like aluminum foil - being careful not to make contact with anything electrical (!) - and then start with a lower voltage that you might normally use just to see if you can achieve better heat transfer without melting something...

As an aside, it is my impression* that current versions of the 'boiling tubes' don't have methylene chloride (more properly, dichloromethane or dcm) in them - which may be another reason they don't work as well.  DCM has a boiling point of just above 100 F - temperatures easily reached (usually) by the light bulbs in question (one case where switching to LED's is a bad idea).  On the other hand, its not good stuff to be in contact with should a tube break - both an inhalation and dermal exposure risk.  To be fair, not a huge risk - but enough so that there are OSHA exposure limits, etc. (I don't think it is banned in the US)...

*On reflection, I'm not sure where my 'impression' comes from - likely something I saw on a 'bubble light' box -  which would mean rummaging around in the attic in search of confirmation...

I was checking on the bulb details from the specs above (from CW and others)  and found that the bulbs in my unit are supposed to be 9809-300 which has a spec of 15v and 0.2A (3 watts) per trainz part page.  The bulb I have in at least one of my hard to get going bubblers on the 24112 oil field is a 15v, 0.15a (2.25 watts) labeled on it.  This is easy to miss and it appears someone replaced bulbs with a lower wattage.  

Does anyone have a link to a detailed spec page on lionel replacement bulbs?

 The instructions for the old Christmas tree bubble lights tells you to shake them, or the branch they are on, should they happen to not bubble.

Not banned at all.  In fact, Tenax adhesive probably available in your LHS for styrene and other plastics is DCM. 

A question for the experts (or chemists)....I did every suggestion and only one works, here is the list:

1) I increased the voltage, and even put the oilfield on a circuit I can jack up to 18 volts.   One or two of seven tubes begin to bubble a bit  within a few minutes.

2) I changed the bulbs to 14v, 0.3amp and no difference.

3) I bought some of the heat transfer grease used on cpu heat sinks.  No difference.

4) the only thing which consistently works is shaking after they heat up a bit....

Have I missed anything?    So... seems a logical conclusion is the bubble tubes may be this issue.  Does the the methylene chloride age or the bubble activator clog somehow?  I hate to spend $7 each for new tubes.....assuming that would solve the issue.

Methylene chloride

Making your own bubble tubes 1

Making your own bubble tubes 2 (This guy has built a DIY scanning electron microscope also for those of you out there with a scientific bent)

Jerry

Previously all tubes worked at 18V.  Now only 1 or 2? 

If the oilfield is on its own base, another hair-brained scheme is to attach a vibrator motor (a motor with an off-centered weight).  As I previously suggested you could put the higher voltage on a 2 minute timer when first turning accessory on.  Same timer could apply voltage to the vibrator motor to jostle all the tubes.  This has the additional benefit of providing your visitors what they expect - on TV shows the ground shakes as the oil well first comes up...then "there she blows!"  Or, irrespective of your opinion on fracking, the ground is essentially shaken to release more oil.

Johnny, the guy on you tube is amazing.... small fluorescent tubes must be thicker glass  than the 48 inch ones, or maybe these are european ones he is fooling with!  That video reminded me, the stuff is actually boiling so you would think it would not weaken since it is sealed up. 

Stan, Love the fracking idea and yes that is the maddening part.  I had not run it in a few weeks as you can tell from the post dates and I went backwards in performance! I just had a thought, I am measuring voltage at the transformer.  I need to see if I am getting some losses someplace.  

Vibration is the key to setting the proper reaction into motion.

Heat helps too. We also dialed up the zw for about 30 seconds and would lower it after things started happening.

Heat sink "grease" sounds like a good idea to help transfer heat.

I was recently researching bubble lights and tubes in general before this thread even started. All the bubble tube manufacturers have that same suggestion. Vibration or shaking.

 If some folks had solved this, I'm sure the other tube makers would have caught on and changed things. But the MFG. suggestion to shake, hasn't changed in over 50 years .

 My whole life I was twapping/flicking at tubes in derricks to get them started for a session. Gramps layouts always had at least one, usually 3+. Two or three quick twaps of a finger usually sets them into flowing right.

I'd never put one where I couldn't reach it easy.

 Kids have smaller finger that's how I got the flicking job.

Maybe tapping with a pencil, or wood stick would work if you have big hands?

Never tried it, but 5 year olds don't have much power in their fingers either 

 The next time the same tube may need it again, or maybe not again for months.

It may bubble like mad, or just a little.

Or start big and die off(seldom). Or not start for while, or at all....or that day.

I wouldn't replace one unless it is dead and can't be helped more often, than not.

 There are occasional lemons. But the tubes are not a perfectly operating mechanical device either. Chance can screw with the flow inside.