Scuba Compressor Aero Technica Coltri MCH6

[woodland]

A compressor…………… is the next level in PCP airgunning for me.

What excuses would i have this time to take such a step?

I still have my first card from the Diveshop for 20 fills for 36 euro dated 07/08/2010  4 left.
Moneywise i can never find a good argument.
Well add driving, time, dependence. Still not coming near..........
Never having 300bar with filling at the Diveshop isn't an argument too......this Coltri is limited to 250 bar.

Well my argument is independence and in these bad economical times i am not sure my  investment in my PCP hobby is that safe........meaning
Will the diveshop still be there the next year.  No air no PCP airgunning
There i have a point; do I...say yes please...   Very good thinking of me....

Seeing a bargain in the Divesection did help a lot
It was an older type Coltry for the price of a second hand R10/AA510 other new pcp what ever. There i wouldn't doubt a second so why having any hesitation with a good running second hand compressor giving the air i need.

The Coltri MCH6  can run from 200 bar to 300bar
I googled on the coltri and what came out was;
 The Coltry can run hot  when  longer then 45 minutes pumping but will be a true friend when treated well by the divers that use it.
Advertised with; “see how beautifull it runs”

And well it does just that.
The owner had it on 200 bar so i asked him to change that to 300bar but that needed a new hose with a 300 din connection and a new  safetyvalve to release on 300bar instead of lower.
In the proces of changing the owner came with adjusting the excising safetyvalve to max 250 bar. (nr 4 drawing)
So a new  safety valve was needed.
But i didn’t take a new valve.   I left it to max 250 bar.

250 bar is just fine.
Most PCP’s take 200 bar and the sweetspot of most of them is also around  170/180 bar.
And 300 bar takes longer to pump
I fill my bottle always from about 150 bar;  that means with a 5 liter  300 bar bottle this is 1500 liter half full   meaning 750 liter which should take 10/15 minutes.
Because the safetyvalve opens at 250 bar it takes just  5 minutes to refill the extra air in the 5 liter bottle. ...........which also means 5 minutes of 82 dB  noise.
I do think i will take an extra 300 bar bottle  for events we go to.

Compair  this older MCH 6 with a shoebox solution  or
The new type Coltry which can suffer from switch burning
Or the Bauer junior II which  might have a valveproblem on the long run and  is a  little to heavy in powersuse for domestic use.  I told the fuses might go out.
That is the information i found all together. Not much .......
May be i fell into a niche of a niche market so there is very little information or my searching was wrong.

This Coltry MCH 6 runs on electricity and i have a petrol engine as well in case needed.

Like most things this Coltry needs maintenance;
Filters, oil, watch the quality of the hose.

The using proces is simple;

It must have a minimium of free space.and the Coltry must be used  horizontally for good lubrication.
First things first.
Check the oildipstick and the quality of the hose every time
Release the moisture if still left any from the previous fill.
Check the other  pressure release valve if it is closed.
Watch where you hang your breather/filter hose for clean air.
Connect to bottlehose to the bottle.
Start the compressor.
Wait until the compressor  reaches 150 bar on the meter (in my case) then open the bottletap
At 250 bar  you close the bottletap and stop the compressor. You see it won’t go any further then 250 bar.
Depressurise the compressor and open the moisture valve.
Disconnect the bottle hose.

I will use a schematic for time and dates of usehours and maintenance.
I will store the lot dust free.

A child can do the laundry so to speak.

All in all I think  this older Coltry MCH 6 may be a bargain.


any remarks suggestions
What should i know more about the use / safety of this compressors

regards
Woodland

[woodland]

I did a bit of TLC  because from the moisture tap came some water and oil.
i checked the Coltri inside and it looked as new. Gave it a spray and a new beltcover.

I took  the airfilter to my mouth and compaired that with a brand new filter.
I noticed that the current air filter was harder to get air through.
I replaced it by a new filter from a carshop;  a customized Mann P715 filter.

The scubabottle was filled quicker to 260bar and this time no water and no oil from the moisturetap.

i think with a shortage of air it starts sucking oil.

I found out it is built in 87 .......very good compressor for it's age.