Good compressor for infrequent use?

[iain/hsm]

Re the cost increase:
Counting out 600 seal rings from the same batch and compound number into a bag for a single military customer takes an hour to wrap bag seal and sign off.

By contrast counting out 400 rings to a hundred individual recreational customers four at a time into 400 bags with 400 sign offs and each paying by 400 credit card transactions reciepts takes a week.

 

[iain/hsm]

If you purchase the standard maintenance kit, as of Dec 2018 for the SA6 it is $1201. In 2006, it was $665, so parts have come up quite a bit in the last decade unfortunately. Don't know what the SA3 is, but I imagine it is about the same. In 2018, that does include $350 worth of the Krytox grease and the inlet filter which I would argue you don't need to buy, and that's up from $200 in 2006. Figure add in a grand of "just in case" and you're good, or adding a filter tower etc.

Good point and this is a throw back to the USN military kit assembly and component list. The Krytox is enough to last you 10 years and the filter we have discussed before being way over spec for a recreational application.
Blocked flow design, polyester micronc element and non replaceable filter element all way overkill for the retail market. However we are not in agreement entirely with the Solburg size for flow discussed in prevoius posts.
The Europe military kit gets a 5 gram tube of Christo-lube MCG111 cost is £7.50 GBP and we understand is used once then thrown away. All other pricing is still reflective of each item being suitable for military procurement and a QA that would make your eyes water.

 

[iain/hsm]

I am proud to own a RIX. But they can be a little tedious to maintain in top performance. For example, moisture in the air combines with teflon dust from the wearing of the teflon rings. This gradually gums up the ring expansion and diminishes the seal... So a few months after you have it running at a full 3.0 cfm, it might be running from 2-2.5 cfm. I've found that the teflon rings can be "refreshed" by taking out the pistons and washing them (with the rings) in Dawn detergent. You can see and feel the rings ability to compress and expand being restored as the gunk is cleaned off. Dry everything thoroughly before re-assembly.

- As for O-Rings... Don't be like me. I got impatient and just wanted to get it back together and fill tanks. Hardware store O-Rings fit fine and seemed to run fine. But they really didn't. They either extrude or melt and cause leaks.The manual specs Viton 90 for the heads and I bought a lifetime supply of these (correct O-rings) for pennies from the O-Ring Store.

But as T-bone said, RIX were built for the military. Money is no object there. Rix are easy to take apart and re-assemble. Military can just replace all of the O-rings and teflon rings and the thing runs like new again. It's quick and easy when you have new parts and you've done it a few times.

I would add that replacing the 90 shore 0-ring more often on the piston will extend piston ring life even longer. A fair proportion of the stuff "gumming up" the rings is Viton material "scuffed" off by the ring itself outboard and the bronze piston rod inboard in the rapid expantion and contraction of the 0-ring in the piston bore.

The only kicker is the labour time/cost 20 minutes against the benifit of just changing out all the polymer junk 0-rings and compression rings rider ring etc while you have the part out and in your hands.

Incedently the 2 rider rings will last twice the life of the 4 compression rings but for the $14 price its hardly worth the effort as the cost of scuffing the metal piston itself is a huge incentive just to change them out also. Call it an insurance cost to protect the metal parts.

Agree again on some of the costs not required for sports divers. Another example is on the 3rd stage piston 0-ring on the SA-6. For example the mil-spec IPP we have for the RAF calls for a small yellow dot to be marked on the outside edge and when fitting you place this yellow dot marked side up side in the head. As well as the USN requirement for it also on the 3rd stage head 0-rings at $2.36 each. Go figure.
It shows also that its a Viton 90 shore hardness O-ring but also to an aircraft quality grade. That is the dimension tolerance is much tighter than that of a standard industrial static or dynamic 90 shore viton ring. Further the polymer must be from Dupont and the compound used is also specific in specification. Also the compound cure date is known and hardness tested and recorded. The yellow "Dot" and the corrsponding QA required with it costs more than the ring itself and the shortened shelf life from the cure date also causes waste.

By contrast the typical commercial retail compressors suggested use rings that can be 10 years old before being sold to the varoius vendors from unknown compounds, from unknown suppliers, with unknown performance. Made from tooling worn out to a point of being outside of any tolerance performance requirements from suppliers that are happy to supply to the hydraulics to farming impliment industries regardless. Buyer beware I guess.

 

[iain/hsm]

Went back and looked at the quote from RIX in 2012 for the SA-3. Without the grease and filter it was around $700 - must have gotten some of the rebuild parts when I bought the compressor. Sorry to hear it's gone up so much, wish I'd bought the SA-6 parts at the same time...

Still, how does this compare to what it takes to rebuild a similar capacity Bauer/Coltri/etc?

Interesting question. Look forward to others answering say the piston head and liner cost for say the 2nd stage Rix Sa-6 against the Bauer Capitano or the SA-3 against the Coltri MCH-6.

One thing to note is Rix publish the spares price upfront as a pdf price list and have done for the last decade or more while for some others you will have a job getting a quote as the price is on a one to one quoted basis, priced depending on who you are or where your from and in all cases wanting to know the serial number of the pump to assess if you are genuine retail customer from new in which case you are referened to you local or original dealer, or in the event you have a second hand unit surplus your get the "jack the cost hosed special price" Lol Just saying,

 

[SurfLung]

I would add that replacing the 90 shore 0-ring more often on the piston will extend piston ring life even longer. A fair proportion of the stuff "gumming up" the rings is Viton material "scuffed" off by the ring itself outboard and the bronze piston rod inboard in the rapid expantion and contraction of the 0-ring in the piston bore.

For the RIX newby... The "compression spring" for a teflon piston ring is provided by an O-ring that's underneath the teflon ring.

Thanks for the tip, Ian. I will add "replace O-ring" to my ring refresh service.

 

[abnfrog]

infrequent use is a killer with the Bauer/jordair ....when mine was rebuilt at the factory , they told me not to let it sit around as its a killer, dont know about the rix .....some said use some one elses ...I think that good advice ...........I run mine every 30 days even in winter when I don't need it ......its why I have always left some capacity in the storage tanks