Rebuild Silent Compressor?

[Skids]

I have a Sil-Air silent compressor, and it's just worn out i think. does anyone know of resources for parts? tips for rebuilding or troubleshooting? I'm a DIY kind of guy ya know!

[AirDave]

any local compressor rebuild shop can repair.

but, you hit upon the biggest setback.
parts availability.
it seems that parts are hard to come by (for these silent compressors)

recommendation:
1. buy another compressor
2. send the broken one in for repairs and wait as long as it takes
(then keep 2, or sell one)
3. keep the broken one, start hunting for parts, learn how to fix it yourself
(not that hard)
4. remove the compressor/motor from the unit and replace it with a fridge
compressor.

My very first compressor (lasted about 4 years) I built.
Consisted of an old bullet tank, a couple of tank gauges, some copper lines and fittings, a check valve, a one way valve, a compressor regulating switch
and...a refridgerator compressor

Fridge compressors are used for silent compressors, but they have no lubrication system for the motor, so they have to add a sump.
A/C compressors pump refridgerant gas through pipes. An oil is added to that gas, and as it is pumped thru the compressor, the oil lubricates everything.
Silent air compressors have the casings filled with oil to create lubrication.

Once you pull a fridge compressor and open the lines, the oil is lost with the freon. You can drill a hole in the top of the case and fill with oil (but some will leak), or as I did, just run it till it seizes (about 2 years) then replace the compressor again.

Just remember to run the newly home built compressor for a while, in the beginning, to pump out any oil residue from the system.

[bean]

i was told these sil-airs are not rebuilt, when they wear uot they must be replaced.

[Skids]

AirDave, i'm VERY interested in doing that mod to my silent compressor! actually i have a big ol fridge on my back porch i'm not using and it's begging to be donated to the cause and free-up some room out there......

If the general consensus is that this is a common problem and worth the effort, i'd be happy to document it and take some heavy photos of dubious quality provided i'm given the proper guidance in the interum........you game?

man, i have a small portable that sounds like a dirtbike with the throttle stuck wide-open, and a big portable that's not much better, but will power the Iwata lph-300 and air tools....but i DO miss that silent compressor, and really don't work as much because of it........OKAY.....I'M a CHEAP BASTARDO and resent paying that much for something i can't work on !!

[AirDave]

[You want to swap out the compressors?
And you want me to take part?
You nuts??!!

yeah...okay...I guess

seriously...not sure what help I can offer,
but its all yours (I think?).

first, you got the right kind of compressor?
second, do you know what you are doing?
third, are you prepared to break the law?

first...will the compressor fit the application? fit your casing or mounting frame or will you have to adapt that also?
second...mechanical skill? knowledge of a/c systems?
third...does the fridge system still have refrigerant in it? if it hasn't already somehow leaked out, then it has to be drained. I can't advise you to do that by just bleeding from the fill valve or breaking open a line, etc...because there are laws about venting refrigerant gases into the air.

So, to cover my ass, I must advise, if you are unfamiliar with refrigerant systems and to avoid any legal issues, you should have the refrigerant gases drained by a qualified technician.

[Skids]

HA! you're a GAS, Dave.

I'll be back home on tues., and i'll drag that thang out and have a look see. I need a silent compressor more than an extra fridge anyway.

i'm guessing it's the right kind of compressor....what's the wrong kind?? oh ya, i anticipate the adaptor plate, i can swing that no probs, i've spent my whole life rigging things to do things they ain't supposed too do, so this'll be a snap.

i still have a couple bottles of oil made for the application, so that won't be a problem......definately gotta do a frankenstein paint job on it before she goes on there, eh?

I hereby release AirDave from any responsability in whole or part concerning any proceedings on my part in retro-fitting any type of refrigerator motor onto any compressor base hitherforto refered to as "the THANG" and realize that any advice given to me whether implied or infered is followed at my own risk. I take it upon myself to see that no laws are broken in my quest for good quiet air supply, be them federal, state, or local, and also release AirDave from any responsability for the silliness that might come from artwork done late at night under the influence of...whatever, because i'll once again be able to paint without waking up everyone for a 3 block radius

well....I feel better!!!....heheheeee

[AirDave]

Well alrighty then....

punch a hole in that sucker,

let that gas run free (as nature intended)

and lets git er dun!

[AirDave]

Heres the deal.

The compressors are lubricated by the oil that is added to the refrigerant.
When the compressor is empty of refrigerant, there is no internal lubrication.
(Actually it will take a little while to pump out all the oil, but I think its good oil for bonding Createx to fabric!)

Now, it is possible to drill the outer casing and create an "oil fill" and half fill the casing with a lubricating oil (as is used in the silent airbrush compressors)

but I cannot guarantee a proper casing seal to avoid oil leakage.

(Note: Oil in any engine has a primary purpose....cooling. Lubrication is a secondary purpose. Heat is the enemy of anything with moving parts and airbrushers!)

Personally, I viewed mine as a disposable compressor, and ran it without oil.
I seized the motor at least a dozen times...cool 'er down...bashed it around a bit and got it started again (each time)!!

[Skids]

hehehee...well, i'd like to have some oil in it. on the old one, there's just a plastic plug on the oil fill, no threads...is that under pressure then? seems to be just a hole in the casing with an extention, but i'll have to take it apart to refresh meself on that.

something you said on the earlier post got me thinking...what are the odds of taking the guts out of the "new" compressor and drop them down in the old housing?...hmmmm...lots of food for thought here. twood be nice to have the oil fill window and everything in place, eh?

gots to get some sleep here, then i'm off...see ya back tuesday!!

[AirDave]

There are a number of different compressor designs.
If the cases are similiar in size and shape,
why not look into the idea of changing the guts?
I have never done that so I can't help you there.

Although, to possibly help and definately answer certain questions,
you will have to get some good photos for me to see.

[blinddog 99]

LOL, good luck you guys. I wouldn't want to be in the room when you fire that thing up Skids!

[Skids]

well, i'm back! had to have some dental work done yesterday so i'm in a bit of a fog from the meds.....i'll try to get out there and get some pics of the 'new' unit as well as the insides of the ol' Sil Air. I ain't cutting anything up or plugging anything in under the influence tho-!

[Skids]

man, sorry i haven't been able to do this yet, i'm having some complications with my swold-up mouth......to be continued!

[Skids]

UPDATE......i emailed the guys at SilentAire, and they do indeed sell parts for old Sil-Air compressors. I'll see what it will cost to do it the 'right' way first and proceed from there. If anyone else has one of these, you can contact Andrew thru their website and he'll cure what ails yee!!

[Skids]

I STILL haven't done this project! and STILL need a silent compressor! I do however now have a guy who'll reclaim the gas for me. I haven't seen AIRDAVE around for a while so, anyone else out there with experience breathing new life into old silent compressors?

[Norm]

Skids, I don't have experience with that, but my solution was to pipe air into my studio from a large compressor in the garage.. keeps it silent as it removes the source of the noise to another area.... works for me.

[Skids]

thanks Norm, I've got it all worked out at the house now, I moved my 6hp into the basement.

I still want the silent one up and running tho-, it'd be great for doing events and such.

[ARTSPRAYJ4J]

these are made by werther international Italy they are freezer compressor variants if the motor is worn out then there isnt much you can do about it if the head gasket is blown then make another one out of gasket paper and sealant
if the piston or bore is shot forget it

a replacement head unit isnt going to be cost efective the better option would be to go for the highest wattge freezer unit you can rob from an old freezer

drill a hole two inches up the case weld a nut onto it then fit a bolt with a fibre washer this will be your overflow method of filling the pump with synthetic comp oil although there is always sufficiant oil left in these units when robbed off the freezer if they where in working order

use any one of the two inlet tubes to refill and as the air inlet one is usualy cut short and crimped the one you have had to cut one is the better option as it will be at the rear of the unit

the outlet is self explanitary its the one pumping the air out wireing is easy and connecting up the air supply again easy


you coud drill and tap the side and rob the site glass from your original unit but swapping internals isnt possible as the electrics are epoxy sealed and the outlet is welded to the case

wouldnt bother splitting the case WHY? when the new pops its clogs rob another one

always use synthetic comp oil
if you are envoiromentaly concerned then buy a new head unit designed for a freezer check the specifations with the supplier the higher the wattage the bigger the output
paul

[Skids]

COOOL!

That's JUST what I was needing, JFJ!

[ARTSPRAYJ4J]

its a pity you are not in the UK i have some TC5000 units for sale although not silent they are not noisy plus oil free

i buy and sell equipment all the time and was offered a bambi medical with one head unit down but as they are 0.5 HP one head unit will more than do the job for airbrushing

i also have a presscold portable unit thats 3/4 hp good old unit based on a comercial coldroom compressor it fills a ten litre reserve in seconds and other than a little induction noise cos the intake filter is missing its pretty near noise free

get yourself on Ebay go to compressors you will find local sellers that cant post out heavier units ,i always ask them for a buy it now price and most will bite for cash offers


or find longer distance sellers that havent offered postal costs and ask if they will post for a reasonable fee a lot of time they will do it for you


there is always more ways than one to skin a cat ,as my old grandad used to say

oh as for your old unit take the piston head off cheack the gasket and the reed valves ,clean the valves up with some 1500 paper check the piston and bore for wear most problems are down to head gaskets and reed valves,if the piston and or bore is /are shot i cant see it being worth the cost of repairing but check the cost first just in case a rebuild kit is available at reasonable cost

a new gasket is easily made from mechanics gasket paper and a wipe of high temp silicone sealer ,dont go mad with the sealer it only takes a wipe then let it cure for a few mins before fitting it to save it from splodging into the guts of the head
paul

[Skids]

Good info there Paul.

It's been a while since i fired this thing up, but i remember that the problem was that it would overheat and trip the thermal switch alot, but had good pressure while it was running. thanks for your help!

[ARTSPRAYJ4J]

sounds like low oil as they can run for a long time pretty hot as well ,could be a faulty overload swith

what they will do is overload if started up on high pressure as the pump will stall, it recomends decompressing before starting them if the tank is still at high pressure on units without auto start

if your one is not auto shut then run it constant but for not much more than tweny or so minutes at a time


with no reservetank and just pumping to the atmosphere i have run one of these overnight to test for oil mist but when compressing air the back pressure causes load on the motor ,the higher the pressure the higher the load

starting one with a full reserve is much like hill starting a car it takes a lot more effort and easily stalled but unlike a car engine the power cant be increased to compensate for the extra load so the load must be decreased


paul

[Skids]

this one has a reserve tank and auto stop/start. could it be a faulty valve allowing pressure back onto the piston maybe?