Used coltri mch6 portable infos!

[RayfromTX]

Latest Developments...

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When I tried an intake hose that looked like the one in your picture, the air tasted very strongly of vinyl and I have good filtration. The hose said it was food grade but it was horrible. I replaced it with one designed for breathing air from nuvair. It is a ARH 1 1/2" suction hose with a pvc to silicone pipe connector of the appropriate size Craig Hubner helped me with it. 1-805-815-4044. Not cheap but zero taste.

 

[SurfLung]

You can also blow down your separator more often. I ignore the manual saying 15 minutes and blow down at about 5 minutes and that has helped a lot.

Thanks for the tip. I've also noticed that the "Diffuser Separator" that acts as a vortex generator is not present in my little Aero as it is in the more modern versions. Mine shoots air and moisture straight up through the accumulated liquid where it hits the bottom of the tube cap, right next to the exit port that leads to the filter tube. Gonna try something a compressor smart friend suggested and in combination with the Back Pressure Regulator I think it may solve the problem.

 

[SurfLung]

When I tried an intake hose that looked like the one in your picture, the air tasted very strongly of vinyl and I have good filtration. The hose said it was food grade but it was horrible. I replaced it with one designed for breathing air from nuvair. It is a ARH 1 1/2" suction hose with a pvc to silicone pipe connector of the appropriate size Craig Hubner helped me with it. 1-805-815-4044. Not cheap but zero taste.

Thanks for the tip. I did try it to refill half a tank while using this hose and I did not detect any funny smells... I would have used the Nuvair hose if I could have found it. I see it now and will contact Mr. Hubner if this hose doesn't work out for me.

 

[SurfLung]

Progress is Good...
- Here's a video of the AERO filling Twin 48 scuba tanks at a little over 3.2 cfm FAD. AS you can see, I got the remote intake hose and filter system up and running. My buddy Bill AntiqueDiver helped me with rigging a Vortex Generator to replace the missing one in the moisture separator. And, I now have a Back Pressure Regulator keeping the system at 1800 psi for better efficiency at Moisture condensation and filtering.

 

[SurfLung]

When I tried an intake hose that looked like the one in your picture, the air tasted very strongly of vinyl and I have good filtration.

- I am happy to report that there is no taste or smell in the air pumped through my intake hose. My buddy and I made two dives each on tanks filled from this compressor and the remote intake hose shown in pictures above. We used the Filtertechs Lawrence Factor filter with 2/3rds 13X Sieve and 1/3rd Hopcalite and Activated Charcoal. Dives were 50 minutes and 35 minutes for each of us. Also, the air was super dry... We both got dry throats!
- My buddy AntiqueDiver came up with a solution to the missing Vortex generator in the moisture separator. The new configuration seems to work VERY well.

 

[SurfLung]

Filter Efficiency...
- Before AntiqueDiver Bill showed me how to make a vortex generator for the moisture separator, I was getting 4-6 fills per filter. Now I'm estimating 12-16 fills per filter. The modern Coltri MCH-6 manual estimates 20 fills per filter. I'm think that since I'm using the "purifier" filter, I've got about 33% less 13X Sieve to absorb moisture. So, 12-16 fills per filter is probably about as good as I can get. $31 divided by 16 fills is about $2 in filter cost per fill. Not bad at all.

 

[KentB]

ive had my MCH6 electric for 2.5 years...... only issue i had was switch crapped out covered by warranty and other than that i got 120 hrs on it so far and its been fantastic!

 

[SurfLung]

A New Moisture Dissipator for my Aero...
- I don't know if I mentioned it before but, this little Aerotecnica MCH-6 compressor was made back in the 1980s. It's very similar to the current MCH-6 model but they have evolved and improved several aspects of its design. One of which is the moisture separator tower. Modern MCH-6 Separators have a very simple but efficient air inlet nozzle that points the airflow into a spinning directional flow that pools and drains condensate efficiently. On my 1980s model, the internal "dissipator" or "vortex generator" appeared to be missing. We made up a vortex generator from a repackable filter and a Chore Boy stainless dish scrubber. And it worked but not well.
- I removed our home made vortex generator from the Moisture separator tower and found it was heavily coated with gunky condensate. So I decided to take the Moisture separator tower apart and see what could be done. Fortunately, I have a nearly identical Olmeva separator tower on the filter array for my RIX compressor... (Something that works well to compare with). So I took the bottom of that one apart to compare. Below you see the broken Aerotecnica dissipator on the right and Olmeva on the left.

- The original 1980s MCH-6 dissipator was a micro screen with the air inlet below it. The design allowed for a chamber below the screen and condensate tends to accumulate in that chamber. I think the gunky oil and water condensate clogged the screen so eventually it blew out of its mounting, breaking the mounting in the process. So now, the gunky condensate pools in the chamber above the inlet and just keeps shooting up and down and pooling without ever completely draining the condensate.

- In contrast, the Olmeva dissipator vents the incoming air through small holes in a verticle tube... The holes are located above the condensate drain pool so they're not blowing air through it AND the condensate can settled and be drained more completely.

- I replaced the broken microscreen dissipator with a home made dissipator along similar lines to the Olmeva dissipator. I used a concrete floor anchor just like the one Rich (50,001 Questions) came up with for replacing a dip tube on a tank valve. You can see how the slots will dissipate the incoming air above the condensate drain pool. This allows the condensate to pool unmolested at the bottom, and drain completely when the drain is opened.

- I've used this now for four of tank fills at home and three fills at our most recent dive trip to Fortune Pond. It seems to be working VERY well.