Blocked smoke machine

[norty303 0]

I've got a smoke machine which has only been used a couple of times since new (very cheap tho and not worth sending back for warranty or anything) and very quickly reduced itself to virtually no smoke output. You could hear the pump motor straining so i thought it was probably a blockage somewhere.

 

A few weeks ago I first took off the nozzle and noticed that there appeared to be 'sand' inside the exit of the heating element. So i cleaned with a pipe cleaner and re-assembled and ran some distilled water and white vinegar through it. It didn't really seem any better.

 

Tonight i took the whole thing apart and tested that the pump worked when not connected to the element and it flowed well. I took the element out and managed to tip a small pile of this 'sand' from the element. Back together and test and the motor isn't labouring, although its not giving smoke output like it should for its size.

 

Now i know that manufacturers say that regular cleaning is necessary to prevent 'particle' build up but how could it make sand-like particles!! I thought it might be that the heating element is encased in a cinder block which has broken up but then how would it get in the pipe?

 

Anyone here repair foggers who can give some advice or know what the situation is?

[superstardeejay 0]

I've noticed the 'sand' at the bottom of built-in tanks on some machines...I can only conclude it comes with the fluid..no doubt it gets caught in the tube.

 

The capilliary tubes in cheap smoke machines are very small-bore and block very easily indeed..yet can be 12-24 inches long when uncoiled. Sometimes the only option is a new heater block & tube assembly.....not worth it if your machine is under about 100 quid.

 

Get a Jem and it should last a lifetime!

 

 

 

 

[norty303 0]

Thats the thing though, there is a very fine brass filter on the pick up tube so it must've been in the machine from new. It was very cheap as it was to make up for a late delivery of lights but it would be nice to get it running right if i could.

[otronics 0]

QUOTE

Get a Jem and it should last a lifetime!

 

Yes, but I'm not sure he needs a 1 billion watt fog machine! http://www.dj-forum.co.uk/html//emoticons/tongue.gif

 

Jem 5 litre fog fluid costs £70 or so and their machines, well £5,000+ http://www.dj-forum.co.uk/html//emoticons/fear.gif

 

Anyway, jokes aside:

 

I have never seen this problem, but have gone through a couple of foggers.

 

One was from Argos ( http://www.dj-forum.co.uk/html//emoticons/rolleyes.gif ) but a proper metal job that lasted 2/3 years (Soundlab equivilent) and it got blocked. Same as yours barr the sand, motor going but no smoke.

 

Got a cheap Soundlab that lasted a year or less. Same thing, so got an EU-Lights 700w job and its been great! No problems yet touch-wood.

 

What happens if you turn it on + heat up, press the button and give it a little bash, anything come out then? (Yes, I know this isn't good for it but worth a try) http://www.dj-forum.co.uk/html//emoticons/whistling.gif

[ChrisPointon 0]

QUOTE

Jem 5 litre fog fluid costs £70 or so and their machines, well £5,000+

 

LOL, even with the deliberate exageration you shop at the wrong places mate!. Some mail order places have genuine Jem manufactured fluid for as little £8.56 inc vat for 5 ltrs http://www.dj-forum.co.uk/html//emoticons/tongue.gif

 

Could the "sand" be fragments of ceramic from the element?

[norty303 0]

QUOTE

Could the "sand" be fragments of ceramic from the element

 

This is what i suspected but i wasn't sure if the ceramic could actually get into the smoke path within the element.

 

Thanks for the suggestions to buy a new one, i'm well aware of the options thanks, more interested in why this one might be exhibiting this problem and how to fix it (everythings fixable - just whether its affordable/worth doing is the issue).

 

BTW, Le Maitre are the daddies of foggers, kick Jem ar$e all day long! ;)

[nrgize 0]

QUOTE (superstardeejay @ May 15 2006, 10:11 PM)

Get a Jem and it should last a lifetime!

I've got a Jem Technofog which I've had for about 3/4 years now. Never had any problems with it or the output from it. But I am guilty of leaving it with its Fluid tank full up. Will this damage it ?? And also is it best to clean it out reguarly ??

 

 

 

 

 

 

 

 

 

 

Nathan

[otronics 0]

QUOTE

But I am guilty of leaving it with its Fluid tank full up. Will this damage it ??

 

Not sure. I wouldn't have thought so apart from maybe the fluid leaving residue here and there but I doubt it. Just like leaving petrol in a tank maybe http://www.dj-forum.co.uk/html//emoticons/533.gif

 

 

QUOTE

And also is it best to clean it out reguarly ??

 

Good to do, there is a guide on the forum. How often do you clean your bathroom for example (actually, don't answer that!).

 

Obviously you don't need to do it as aften as that, but no harm in keeping the machine dirt free. http://www.dj-forum.co.uk/html//emoticons/smile.gif

 

[superstardeejay 0]

The Jem Technofogs / Magnums are a nice small machine, the smaller brothers of the ZR12 and 22 range which are used by most credible installers. British-built and now part of Martin Professional (Denmark). A Magnum 600 retails at around 60 quid and a technofog/Magnum 800 at around 150 quid. The superlative ZR12 starts at about 270 quid, more for the DMX version.

 

 

 

I can't see the silica from the element getting into the pipework at all. First, the element is sealed, it's like a small kettle immersion element, made from copper or a proprietary alloy (hastelloy/incalloy etc), sealed at the end with ceramic insulators, it slides with heatsink compound into a recess in the aluminium heater block. The capiliary tube is wound around and around what appears to be a giant cylinder in which is machined a spiral groove. The heater block is drilled out and the cylinder with tube is inserted into the hole in the block. One end of the tube is terminated in the jet (or sometimes just hammered over to make a spout) and appears on the nozzle end of the machine. The other end is connected to the pump...which is usually a modified 'Ulka' espresso coffee pump on UK built machines. The inlet port of the pump is connected to the PVC pipe which dips into the fluid...not all types have a filter BTW.

 

The whole heater assembly is then sealed into a lagged chamber (cheaper machines just have glass wool wrapped round them like a sleeping bag.)

 

Maybe the grainy stuff somehow crystallizes out of the fluid, maybe like limescale?? Perhaps it's impurities. I really don't know.

 

I doubt that leaving the tank full is a problem, since they're plastic and there'll be lots of fluid left in the pump/heater anyhow. The main damage you may do to a machine is leaving it running with no fluid in since the pump relies on the fluid to keep it cool & lubricated. Cheap machines don't always have a level sensor.

[norty303 0]

Well i reasembled it and started to run water/vinegar through it and after about 5 mins it reduced to zero output and straining pump again, so whatever was slightly blocking it is now solid again. Am i right in thinking that i should be able to feed a stiff enough piece of wire all the way down the tube or do the coils run quite tight to each other?

 

I think what might be happening is that the blockage is slightly porous from the gaps in the sand but gets waterlogged with fluid over time and blocks completely.

[superstardeejay 0]

Oooh I think the bore of the capilliary tube through the heater will be way too fine for you to do that. The coil has about the diameter of a thin candle, the tube itself is usually only around 3mm outside diameter on a big one, so anything thicker than cotton won't go through anyway...and they can be over two feet long compressed into a 5 inch spiral.

 

I've had moderate success with kettle descaler, but it's a corrosive acid, gives off poisonous fumes if heated and can blind you if it squirts in your eyes...and it may attack certain plastics or rubber.

 

Sometimes the pump gets scaled up, stopping it oscillating properly. It might be worth dismantling that, the Ulka ones come apart easily but the Chinese versions are usually welded together.

 

PS . Regarding vinegar and water, sometimes the pump will stop if you run this through for too long, the pumps rely on the lubricating nature of smoke fluid to keep them oscillating. They are a piston pump with very tight fitting parts!

 

 

 

[ChrisPointon 0]

Since writing the article smoke machine cleaning fluid has now appeared more widely available on the market and many manufacturers now recommend this for cleaning machines.

 

Many die hard theatre technicians still swear by the vinegar and distilled water method and I must admit to using it myself. However, as always its better to follow the manufacturers recommendations where specified.

 

And just a reminder to use white vinegar if you do choose the older method, not the stuff that goes on yer chips and to carry out the cleaning outside.

[norty303 0]

It's ok, the manufacturer recommends white vinegar and distilled water as the cleaning method. I've checked the pump separately and it gives good pressure.

 

I've also managed to get a pipe cleaner and a piece of garden wire up the tube about 4" so far. Is it likely that the bore of the tube gets smaller or would it continue at this diameter all the way?

[Andy Westcott 0]

It would get much smaller than this - it is the tight bore which causes the pressure to build up as the liquid vapourises, forcing the vapour out at high speed ensuring good atomisation.

 

I'm mystified by this 'sand'. Have you done any tests on it? Is it actually sand? Does it melt/burn? Does it dissolve in boiling water? Etc etc.

[superstardeejay 0]

Its the same all the way through, it's cut off a coil when it's made. However I think you'll have a real job getting it through. Like I said, it isn't just a straight piece of tube, it's a very long spiral coiled tightly inside the heater, about 12-24 inches long.

 

 

 

 

[norty303 0]

I'm going to have the heater out again tomorrow and clean it as well as i can. I'll see if i can test some of the 'sand' if i can get enough out this time - threw the last lot away unfortunately. If not i'll probably junk it. It's a Chauvet F-1250 by the way, with timer remote which i paid £30 for all in, new and unopened.