SOLUTIONS TO CLEARING BLOCKED HEATERS

[partyanimallighting]

Hi all you wizards, I was wondering if anyone has any semi-foolproof methods for clearing blocked heaters in fog machines? Most times these blockages occur deep inside the fluid coil windings so there's no way to clear them. Here's my method list and I was wondering if anyone had any other methods that they would be willing to add to this list.

1. I would normally first try probing inside both ends of the heater block to see if the clog is reachable with a piece of wire. Failing that I'll normally try some guitar string to see how far I can get it into the coils of the tube then run the pump reconnected to the heater to see if the blockage was at least partially cleared. Unfortunately I've had guitar wires stuck inside the coils, never to be removed again. Heated dumped.

2. I'd use a syringe with acetic acid or very diluted muriatic acid to try to get into the coil by positioning the heater upright, leaving it overnight and hope that gravity takes effect and the acid finds it's way down to the blockage. I actually have had success with this method and next day there would be a small puddle of crud on the output end of the heater block. After that clearing was simply a matter of flushing thoroughly.

3. I've tried connecting the pump directly to the heater and running the pump to see it the pump pressure clears the blockage. I normally try this at both ends of the heater and I have a collection of adapters/connectors to fit various heater types. If this doesn't work, while the pump is pressuring the heater I would connect the heater directly to an AC source, let it heat up a bit and hit the heater block so lusty blows with a hammer in the hopes of dislodging the blockage. I've also had some success with this method.

4. Failing all of the above, I would connect the heater to an air compressor using my collection of connectors/adapters, and apply some serious PSI to the heater block. Again, with some lusty blows with a hammer, and then try again with the heater connected to AC and heated up. This method has also worked for me.

I have had success with these methods with a variety of brands but unfortunately manufacturers have now moved away from a heater core with a removable spiral to a long aluminum or stainless steel spiraled tube encased in a solidblock of molten aluminium with the thermocouple and heating element encased inside the block, totally non-removable and totally non-repairable and my success rate has dropped with these newer models. And let's not mention the cost of a replacement heater from the manufacturer.

Any hints or ideas or solutions that might help?

 

[ImagineerTom]

Proper preventative maintenance and cleaning cycles. Using the correct fluid for the machine, using a high quality machine with servicing and long life usage built into the design.

[partyanimallighting]

ImagineerTom, I've had issues with even the better brands such as Martin actually. I believe I have two Martin MP-2000's packed away for a few years because of faulty mainboards/remote controls. My best luck however has been with Antari (especially the smaller Z1200 II model) as higher end units like Rosco, Le Maitre, Look Solutions etc have never been within my budget range. The priciest units I've ever had in my inventory would be those MP-2000's and Antari M5's and even these M5's were problematic at times. A truly great feature of the Antari Z-1200 II's is that the heater block could be completely disassembled and the inner spiral tube could be removed, cleaned and the heater reassembled. All of the newer models of the cheaper DJ brands seem to now carry a solid aluminium heater core with the element and the thermocouple cast into the mold. I totally agree with you, proper maintenance is a must along with a good flush regularly. And good fluid. The best fluid I've ever used would be Martin Pro Smoke. I used to order this by the 55 gallon drum and never had issues with any of my machines with this fluid whereas  I've had machines brought in with output problems and when I inquired, the users made a simple mixture of distilled water and over the counter pharmacy glycerine and used this with "great success" and then wondered why the units clogged after a few uses. None of my de-clogging solutions listed above ever saved these clogged machines. The post was really to see if there were other ideas floating around out there to add to my de-clogging list of treatments but nothing has popped up as yet but thanks for your comments.

[ImagineerTom]

It's not just "high quality" fluid - it's choosing the right fluid; different machines are calibrated/designed for different temperatures which will effect how it evaporates / blockages. Running at 110v is also problematic - almost every smoke machine on the planet was designed for 220/240v operation and then reverse engineered to create a 110v version so heaters are never quite as powerful, pump ratios are never quite the same and parts can be harder to find. You might have more success with machines designed and manufactured specifically for the US / 110v markets rather than machines designed for both as they will, by definition, be better suited to that power and so be less prone to problems.

A cast "one piece" block heater/heat exchange is the proper way to make a smoke machine and leads to more dependable smoke production and better operational efficiency.

Other than a mild acid flush there really isn't any other recommended way to retroactively deal with blocked heaters. Guitar wire may work but risks getting jammed (as you have found) and can also cause scratches inside which change the surface area or even create a weak spot. Compressed air is rarely a good idea as the system was never designed to be pressurised and, since blockages in smoke machines are almost always caused by a gradual build up there's not anywhere for the blockage to be blown.

[sunray]

In 1990's I worked for a small nightclub install company very much glued to Martin. One of my jobs for Martin was to collect a pallet of failed smokes and strip/clean/test/repair/swap bits around to convert them into 'B stock'. In those days they were a brass tube containing the heater and spiral with a pair of wires brazed to the tube to act as thermocouple.

At the time their correct fluid didn't block the heater unless it was running cool, if that was the case the blockage was yellow and could be cleared by gently heating and pumping a strong solution of soda crystals.

Any other fluid caused blockage quickly and a different colour, they very rarely worked again.

 

Out of a pallet of say 50 I'd usually get about 5 B stock and 10 second hand. Depending on the condition of the cases thay may have supplied replacement parts but the acidic fluid usually damaged the plastic coating beyond economical repair.

After I left there, but still did some casual work for them, Martin combined with another (might have been Jem) and suddenly Jem fluid 'became acceptable' for use in Martin products, however the composition changed which a lot of people didn't believe.

[themadhippy]

Diluted white vinegar has done the job for me  many  times,dont try pushing it through with a syringe,use the machine to heat it   and pump it through, and best do it outside.

[partyanimallighting]

Hey guys, thanks for all the responses. ImagineerTom, we're 120VAC locally so 99% of the machines used are 120V. The idea that the guitar wire could cause scratches inside the tubing and create an abrasive surface that could create further blockages seems quite sound actually. Contrary to your doubts about compressed air I have used this method with success and there's normally a loud expulsion of pressurized air once the blockage gives up resistance and blows out the other end. After that a good flush is all that's needed ....... and the compressed air won't cause scratches on the inside of the coil.

sunray, great bit of "back in the day history" there. A couple questions though. What would cause the heater to run cool? A faulty/failing heating element? A faulty thermocouple? And flushing with soda crystals?? Can you define and describe this? Are we talking bicarbonate of soda here diluted in water I presume?

themadhippy, this method also works but most times not on an absolute blockage but on the type of blockage where there's still a "dribble" of output from the other end of the heater. My "heating and whacking" method normally works with these partial blockages.

Based on all the comments received on the post, it seems that the one surefire way to resolve the problem is to buy a new heater block 😁😁 Thanks all!!!

[sunray]

On 8/30/2023 at 1:36 AM, partyanimallighting said:

Hey guys, thanks for all the responses. ImagineerTom, we're 120VAC locally so 99% of the machines used are 120V. The idea that the guitar wire could cause scratches inside the tubing and create an abrasive surface that could create further blockages seems quite sound actually. Contrary to your doubts about compressed air I have used this method with success and there's normally a loud expulsion of pressurized air once the blockage gives up resistance and blows out the other end. After that a good flush is all that's needed ....... and the compressed air won't cause scratches on the inside of the coil.

sunray, great bit of "back in the day history" there. A couple questions though. What would cause the heater to run cool? A faulty/failing heating element? A faulty thermocouple? And flushing with soda crystals?? Can you define and describe this? Are we talking bicarbonate of soda here diluted in water I presume?

themadhippy, this method also works but most times not on an absolute blockage but on the type of blockage where there's still a "dribble" of output from the other end of the heater. My "heating and whacking" method normally works with these partial blockages.

Based on all the comments received on the post, it seems that the one surefire way to resolve the problem is to buy a new heater block 😁😁 Thanks all!!!

From my school days I seem to remember soda for cleaning is soda carbonate rather than bicarbonate (what the difference is disappeared from my head 50 years ago😟) and more alkaline than bicarb other than that I'll have to go to google.  This sort of thing:

Yes I used to mix it really strong, literally keep pouring it into warm distilled water until it stopped dissolving in a plastic pressure vessel (home made out of high pressure plastic pipe), attach to the heater in place of the pump and add pressure to about 25PSI with a bicycle pump. Turn temp down to minimum (see below) that would make the brass heater body a bit too hot to touch.

The smokes had a pot on the PCB to control the temp, I'm convinced movement used to affect it as the static machines used daily used to stay correct whereas the mobile DJ's machines were always coming back complaining the smoke output was low.

 

I don't know what modern machines are like (having only been inside one in the last 27 years) I was used to windscreen washer pumps but back in the day I came across several which had been damaged with too high pressure from a compressor.

 

WARNING: DON'T USE SODA CRYSTALS IF THERE IS ANY CHANCE THE PIPE IS ALUMINIUM, IT WILL BE DISSOLVED

 

Edited August 31, 2023 by sunray

[sunray]

Interestingly MadHippy is suggesting acidic vinegar whereas soda is alkaline.

[alistermorton]

25 minutes ago, sunray said:

From my school days I seem to remember soda for cleaning is soda carbonate

The soda crystals that are really corrosive (and attack aluminium) and are also used to clear blocked drains (because they convert fat into soap, effectively) are sodium hydroxide.

Really nasty stuff if you get it on your skin (you can feel the fat in your skin becoming soapy) and you always add the crystals to water slowly a little at a time, never pour water onto the crystals or just dump a load of crystals straight into water as there is a lot of heat given out when they dissolve and the water can boil, spitting corrosive liquid. Gloves and eye protection are a really, really good idea. 

Edited August 31, 2023 by alistermorton

[partyanimallighting]

Well, I certainly learnt something today. I've never come across soda crystals as far as I can recall but you have to remember I'm in a small island in the West Indies so that says something. Based on what's stated above, even if I source these crystals, I doubt that it can be used on the newer models of fog machine because the tubing is very thin and it seems to be made out of either aluminium or stainless steel but I'm more inclined to believe it's stainless steel because of the temperatures involved. Even the Antari M5's carry an aluminium block (one smaller cylinder welded inside a larger outer cylinder) with a heater rod inserted in the middle so these crystals would corrode the block itself. The Martin MP-2000's do however carry copper tubing but these Martin heaters rarely clog or develop any sort of blockages.

[musht]

Washing Soda is sodium carbonate, Baking Soda is sodium bicarbonate and Caustic Soda is sodium hydroxide.

[sunray]

On 8/31/2023 at 5:57 PM, musht said:

Washing Soda is sodium carbonate, Baking Soda is sodium bicarbonate and Caustic Soda is sodium hydroxide.

My goodness I can't believe I got that so right after >50 years👍🍺