+ Reply to Thread
Page 2 of 2 FirstFirst 1 2
Results 11 to 14 of 14

Thread: Bauer Junior filtering vs. Coltri MCH 6 filtering if Coltri gets a PMV

  1. #11
    RBW Member cb1 is an unknown quantity at this point cb1's Avatar
    Join Date
    Aug 2009
    Location
    ireland
    Posts
    190
    rEvo iii

    Re: Bauer Junior filtering vs. Coltri MCH 6 filtering if Coltri gets a PMV

    Apologies for the thread hijack, but any recommendations for a timer for the Coltri MCH6? I ask as I just change the filter annually.

  2. #12
    RBW Member rjack will become famous soon enough rjack will become famous soon enough rjack will become famous soon enough rjack's Avatar
    Join Date
    Jan 2007
    Location
    Seattle
    Posts
    405
    Meg

    Re: Bauer Junior filtering vs. Coltri MCH 6 filtering if Coltri gets a PMV

    Quote Originally Posted by CCRWannabe123  View Original Post
    This is why I'm asking...IF (and if only!) they are roughly the same capacity...is it only the PMV that's making the difference or something else?
    its only the PMV although condenser design and efficiency may help one or the other slightly.


    The coltri's rated capacity is ridiculously high for some reason (probably marketing)


    On my Alkin, which uses the same basic filter size, I get 10hrs of use in summer and 22hrs in winter before relative humidity exceeds 10-20% and I change the filter. There's rapid breakthrough of water vapor on these small filters.

  3. #13
    RBW Member iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm has a brilliant future iain-hsm's Avatar
    Join Date
    Mar 2005
    Location
    Loughborough England uk
    Posts
    439

    Re: Bauer Junior filtering vs. Coltri MCH 6 filtering if Coltri gets a PMV

    Quote Originally Posted by CCRWannabe123  View Original Post
    This is why I'm asking...IF (and if only!) they are roughly the same capacity...is it only the PMV that's making the difference or something else?
    Your comparing two machines, the Coltri MCH6 and the Bauer Junior 2 that are both quite possibly the two worst examples of the level with which a compressor manufacturer has to stoop to in order to achieve sales to the inept recreational diving industry.

    And if that were not bad enough most other “scuba” brands in the same size bracket are even worse.

    You need realise that you are comparing two brands that in order to achieve sales to divers the engineers are required to re work every component to the cheapest possible method of construction and tender in order to meet the demand of the scuba markets ignorant obsession with cheep tat.

    The difference between the two companies is easier to explain if you look at the product range offered by each. Coltri sits on the porch with only lightweight scuba dive shop junk while Bauer offers are larger more industrial range of higher quality more advanced products while producing similar tat to Coltri to compete and gain sales and keep employed a small production team for the Junior.

    In answer to your specific question on the filter specific points you need to consider.

    Firstly not all molecular sieve chemical compounds are equal. The performance between the range of suppliers currently in use in the scuba industry is around 40% from the worst performer to the above average. The best performing molecular sieve costs 105% more than the worst.

    The typical supplied US grades are also very similar depending on the factory in China.
    Again I leave you to judge who uses the better sieve the European manufactured or the Chinese and of those which one supplies to Coltri.

    The second reason your Bauer performs slightly better than your Coltri is the piston to ring clearances and what is referred to as blow by. This affects heat and in turn reduces oil life

    The third reason is oil carry over, that is oil that makes it into your filter stack and in effect coats each molecular sieve zeolite with heavy oil film rendering it useless.

    In a nut shell the lower the RPM, the slower the piston friction speed, the tighter the clearances, the lower the oil carryover together with the purer the molecular sieve compound together with the higher the BPR setting and the more effective the interstage cooling the better the water separation the longer the filter chemical will last.

    That said filter design is also critical but for that you need to know the diameter to length ratio of the cartridge against the surface area of the chemical, the chemical diameter, the effective chemical compound to inert binding filler. Flow and back pressure capacity factor to get dwell time.

    But by now the engineer would have left making cheap tat for the scuba market and got into making for the military. I guess. Iain

  4. #14
    RBW Member CCRWannabe123 is an unknown quantity at this point CCRWannabe123's Avatar
    Join Date
    Sep 2016
    Location
    Zagreb
    Posts
    29
    Inspo

    Wink Re: Bauer Junior filtering vs. Coltri MCH 6 filtering if Coltri gets a PMV

    Quote Originally Posted by iain-hsm  View Original Post
    Your comparing two machines, the Coltri MCH6 and the Bauer Junior 2 that are both quite possibly the two worst examples of the level with which a compressor manufacturer has to stoop to in order to achieve sales to the inept recreational diving industry.

    And if that were not bad enough most other “scuba” brands in the same size bracket are even worse.

    You need realise that you are comparing two brands that in order to achieve sales to divers the engineers are required to re work every component to the cheapest possible method of construction and tender in order to meet the demand of the scuba markets ignorant obsession with cheep tat.

    The difference between the two companies is easier to explain if you look at the product range offered by each. Coltri sits on the porch with only lightweight scuba dive shop junk while Bauer offers are larger more industrial range of higher quality more advanced products while producing similar tat to Coltri to compete and gain sales and keep employed a small production team for the Junior.

    In answer to your specific question on the filter specific points you need to consider.

    Firstly not all molecular sieve chemical compounds are equal. The performance between the range of suppliers currently in use in the scuba industry is around 40% from the worst performer to the above average. The best performing molecular sieve costs 105% more than the worst.

    The typical supplied US grades are also very similar depending on the factory in China.
    Again I leave you to judge who uses the better sieve the European manufactured or the Chinese and of those which one supplies to Coltri.

    The second reason your Bauer performs slightly better than your Coltri is the piston to ring clearances and what is referred to as blow by. This affects heat and in turn reduces oil life

    The third reason is oil carry over, that is oil that makes it into your filter stack and in effect coats each molecular sieve zeolite with heavy oil film rendering it useless.

    In a nut shell the lower the RPM, the slower the piston friction speed, the tighter the clearances, the lower the oil carryover together with the purer the molecular sieve compound together with the higher the BPR setting and the more effective the interstage cooling the better the water separation the longer the filter chemical will last.

    That said filter design is also critical but for that you need to know the diameter to length ratio of the cartridge against the surface area of the chemical, the chemical diameter, the effective chemical compound to inert binding filler. Flow and back pressure capacity factor to get dwell time.

    But by now the engineer would have left making cheap tat for the scuba market and got into making for the military. I guess. Iain
    Thanks Iain

+ Reply to Thread
Page 2 of 2 FirstFirst 1 2

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts