compressor for sailing

[Isaac-1]

Ok, here goes all in one big lump:

On the engine mounting issue my unit is mounted backwards from the illustrations in the manual (looking at the front of the unit the compressor is on the left not on the right), this confused me a bit a couple of times last night also, if I were to use a Briggs and Stratton then I would have the exhaust pointed at he compressor, regardless of which one I use I will have to use some sort of mounting plate due to the spacing of the slots in the base, and to raise the shaft height about .5 inch to match the location of the electric motor shaft and therefore also the belt cover.

On the topic of the filters, the plastic on the old filter was very brittle and ended up cracking and splitting during the course of removal, the "new" one is still in good shape however. Its hard to tell due to the glare in the photo, but the interior volume of the brass cannister is about 2 inches longer than the supplied filter, I don't know if this means it might be possible to use a longer filter stack, or if the area above the bottom plate should be reserved for excess condensation. (this also did not match the engineering drawings) The drawings in the manual show shaft like a soda straw along the edge of the interior of the canister, mine seems to have a solid flat bottom (I assume there is some sort of lip around the edge for HP air. My goal is to get things up and going as soon as possible (engine first then filtration) So I think I will look for a drop in filter first then look towards upgrading later.

I will check the pressure on the valves and adjust , the blow off is set a bit too high for my comfort (around 3450 psi) I will check the filter stack when get the gasoline engine in.

Pescador775: I took the photos with my digital camera and uploaded them to some web space provided by my local community freenet (there are assorted places that offer free web space, but many require activity within 30-90 days or else they delete the files)

Oxyhacker: I suspect that this unit may have had higher pressure ratings since its original use was to fill SCBA tanks for firefighters (its been a bit too long since I dealt with those, but it seems they are rated at either 3,300 or 3,500 psi)


Thanks for everyones help, I am ordering a engine now, hopefully it will be here in a few days and I can go from there.

Ike

 

[pescador775]

I would not tamper with the relief valve but if you must here is how it is done. Small adjustments of a few hundred psi can be made by loosening the lock nut and turning the stem screw CLOCKWISE to LOWER pressure. Larger adjustments can be made but it may be necessary to change the adjustment of the main spring pressure plate. Turn this COUNTERCLOCKWISE to LOWER pressure. Turn the stem screw clockwise an equal amount. If the plate is to be removed for some reason take care to observe the number and positioning of the wave springs (washers) inside. Before any of the above procedures are done note that the dust cap must be removed. This is held with two screws. All screws use German straight slot design. Purchase a set of gun smith's screwdrivers to work on a Bauer.
Pesky

 

[pescador775]

The plastic housing cracked because of the synthetic oil which is a solvent. Personally, I would not change the length of the filter cartridge. There is nothing wrong with the design of the one you have in spares. Unless it is definitely vacuum sealed it will be necessary to remove the contents. Replace with a 2 1/2 inch column of Vaporshell 13X and a 2 inch column of charcoal. Never mind the hopcalite found in commercial cartridges. However, you should obtain a plastic hose about 6-10 feet in length as an intake. Raise the hose a few feet and route upwind when operating.

 

[pescador775]

The 'shaft' alongside the interior of the canister is called an 'inlet tube' and serves as a jet venturi to accellerate the incoming air and to prevent condensate from back flowing into the hp tubing leading to the canister. Not all filter canisters have this.

 

[Isaac-1]

This is just a quick update on my project, the 4 HP Honda came in yesterday, it fits inside the frame ok, I am having a machinest I I know make an adapter plate for it to bolt to the original belt adjustment slots (hopefully he will get that done by early next week). Also Bauer still makes filters for this unit and I have found a reasonably priced source ($20 each), I bought 2 they came in today and are marked with a 4th Qtr 2005 exp. date. According to the place I bought them from they have activated charcoal and a desicant in the filter and a 1 year / 120 hours useful life. While this may not be as good as their current Triplex filter, I hope its good enough, the place I bought the filters from has the 12 inch long triplex filters for $49 just in case anyone is interested.

Ike

For those keeping up my investment so far in this compressor project is:

$250 for the Mako Purus with 220 Volt motor
$175 for a surplus new 4 HP honda GC series gas engine
$40 in new filters
$28 for new 3/4 inch 2.2 inch pulley
$115.84 in gasoline to drive 1,568 miles round trip to pick up the compressor

value to get to fill my own tanks on my boat priceless

 

[pescador775]

The filters will be fine. As with all gas portables take care not to allow exhaust to be sucked into the compressor intake. Don't fill tanks anywhere near the LA freeway. Clean air is not black magic so take sensible precautions, relax and jam tanks. The filters have a limited life when kept inside the wet condensator. It is impossible to expel all water from these things and the interior humidity will slowly degrade the filter. (That applies to the 'triplex' too). To extend filter life, place the cartridge inside two plastic bags when a long down period is in the offing. Expect to change the cartridge after 40 fills. Forget 120 hours, ain't gonna happen. You can save $18 per cartridge by taking 5 minutes to repack yourself. There is an initial cost for the bulk chemicals but shelf life is forever if kept in sealed containers. In a pinch the dessicant can be heated and restored. See mfgr. With a new compressor and est. $40 ctgs the savings can be in the thousands of dollars over lifetime of the unit.

This is just a quick update on my project, the 4 HP Honda came in yesterday, it fits inside the frame ok, I am having a machinest I I know make an adapter plate for it to bolt to the original belt adjustment slots (hopefully he will get that done by early next week). Also Bauer still makes filters for this unit and I have found a reasonably priced source ($20 each), I bought 2 they came in today and are marked with a 4th Qtr 2005 exp. date. According to the place I bought them from they have activated charcoal and a desicant in the filter and a 1 year / 120 hours useful life. While this may not be as good as their current Triplex filter, I hope its good enough, the place I bought the filters from has the 12 inch long triplex filters for $49 just in case anyone is interested.

Ike

For those keeping up my investment so far in this compressor project is:

$250 for the Mako Purus with 220 Volt motor
$175 for a surplus new 4 HP honda GC series gas engine
$40 in new filters
$28 for new 3/4 inch 2.2 inch pulley
$115.84 in gasoline to drive 1,568 miles round trip to pick up the compressor

value to get to fill my own tanks on my boat priceless

 

[pescador775]

I have now confirmed that the latest specification for the Kidde compressor is MIL PRF 23699. I came about this info after examining a brand new, late model Kidde. There is a metal tag wired to the compressor with bold print: USE TURBO OIL MIL L 23699. This oil is commonly known as JET II and is readily available from aircraft parts dealers. As I have said, the common misconception is that oils like Chemlube 201 are spec'ed for these compressors. Aircraft instrument oil, like Chemlube and others, are only intended for aircraft installed compressors subject to sub zero temps. The viscosity is too low for general use, IMO. After talks with Megget Airdynamics, the current manufacturer of this compressor, the info was subsequently confimed by E Mail.

For those who might be concerned about the slight toxicity of Mobil Jet II there is an advanced, non toxic product, Mobil Jet 291.

Well, it looks like many are out there gathering dust. Still, I know of some intrepid souls, besides myself, who use these machines. The key to long term reliability is the correct oil. Lately, I've begun some introspection on this subject. The military uses 'aircraft instrument oil' in the Kidde and Stewart Warner pumps. This oil is applicable in mechanisms which have high rotational speeds such as gyro bearings and high speed compressors. However, the crucial characteristic of this oil which appeals to the Air Force is the low viscosity allowing startup of the pump in temps down to -40 deg, typical for aircraft at high altitude and in arctic conditions. It appears to me that this low viscosity (less than 5W) may not be as advantageous for SCUBA compressor use (except maybe in Canada or Sweden). Another item for consideration is the flash point of instrument oil which is 430 deg, fairly high but not as high as some commercial oils. After a literature search, I found that certain aircraft turbine oils might be suitable. Like instrument oil, these oils are synthetic and have higher flash point (475 deg), a 10W viscosity (ISO 32), but lack the corrosion inhibiters so necessary for compressor oils. I then discovered that the military had recently requested the manufacturers to produce an inhibited oil. I obtained a quantity of this oil for testing. The tests are going well and I will report later if there is any interest. A note about the chemistry of these oils. They are listed as 'toxic'. However, a review of toxicology test results indicates otherwise. It turns out that test animals, fed the equivalent of a water glass of oil 5 days/week for 10 weeks, developed paralysis. The chemical which causes this is dubbed tricresyl phosphate. Reading these reports carefully, it turns out that the oil is considered safe at Grade E levels (5 mg/M3). Thus, the air produced by a good filtration system should be safe to breath. Personally, I cannot detect any oil odor coming from the test compressor's outlet or from tanks filled by this compressor. Anyone should be able to detect 5mg/M3 of oil which has been hammered and heated by a compressor, that is if the oil vapor is actually present. I doubt that I will actually have the air tested because I already know the results for the system. I just wanted to know if any unusual odors would be getting through the filtrants. The turbine oil is sometimes available through E bay for much less than the price of instrument oil. The spec is MIL PRF 23699F, Type C/I (corrosion inhibited).

 

[pescador775]

TRUE GRIT
I see that the current manufacturer of the four stage Kidde pump is finally listing its actual performance and not that which is measured at 20,000 feet altitude. Meggitt Airdynamics lists the sealevel output at 4.7 CFM which agrees with my tests reported on this thread a year ago. These little four stage compressors are absolutely amazing. It is little wonder that it takes a 5.5 HP gas engine to drive the pump at max RPM.

http://www.noa-fan.com/Applications.htm

Everything I do is with an eye to beauty, so, in my compressor assemblies, to match the height, profile and color of the Kidde I still use the low slung, black, old style Briggs and Stratton 5 HP. It will drive the Kidde at a reduced 3300 RPM and 4.2 CFM. The latest model sports a black frame, black pump, black engine, black condensator, looks good, runs like a bat out of h*ll.

 

[The Curly One]

And it really ran pretty good. Noisy as all get out but it worked good. Then I found about 6 more supposedly good ones and none of them were good. I still have one that may be salvagable. The problem with them is they are hard to find parts for, hard to work on and noisy. They do put out a lot of performance in a small lightweight package though and supposedly some have lasted quite well. Curly

 

[Mverick]

And it really ran pretty good. Noisy as all get out but it worked good. Then I found about 6 more supposedly good ones and none of them were good. I still have one that may be salvagable. The problem with them is they are hard to find parts for, hard to work on and noisy. They do put out a lot of performance in a small lightweight package though and supposedly some have lasted quite well. Curly

And, It's still Runnin Strong.... In my Garage....

Thanks Curly. I was wondering why you quit selling them. I guess now I know.

And no. I don't wanna sell it. Actually, I have another good compressor. That needs to be put together. Haven't had the time. I also bought a Larger one. For the garage. But the little demon is still sweet to bring with.

Oh, I've been using it for my AirGuns though. I still haven't found a filter for it. Anybody have one? Cheap?