Building my own compressor- Need filter advice

[LakeTravis55]

Guys: I have just joined this forum after reading and re-reading the threads on setting up your own homebrew compressor. I have decided on the Stewart-Warner 3.5cfm from BargainMarge. I am getting the basic military flamethrower compressor, and am adding my own Honda 5 hp engine. I don't relish the idea of spending almost $400 for the filter housing. I understand that it has to be able to withstand 5,000 psi of pressure, but I am a pretty capable welder with lots of equipment and i would like to try and make my own final filter housing. I think I would like to start off using the Factor cartridges in it. Are there any suggestions or plans for building the housing? I have a 350 amp TIG setup and a lathe and vertical mill, so I can thread tubing etc. I don't know the inside diameter, type of metal, method of capping the cylinder or anything about it. I was hoping that someone who has dealt with this might be able to help a new recruit.

 

[Rogier]

Thank god you live far away from me!
Even the genuine Bauer filter housings have been exploding in the past...

 

[LakeTravis55]

Thank god you live far away from me!
Even the genuine Bauer filter housings have been exploding in the past...

I had not heard that filter housings were exploding. Is that true about the Bauer?

As an update, I was able to locate a used Cornelius filter housing (aluminum that weighs 4 pounds) and will either get a Lawrence Factor cartridge if they make one for it, or bulk pack it. Now I still have questions like: Should I use steel tubing to interconnect the moisture trap to the filter using compression or flare fittings, or use flexible air hose?

 

[Rogier]

Use Stainless steel tubing with a pig tail in it if there is movemet between the filter housing and the compressor. Yess I have seen a blown up housing and there has been (long time ago) a recal from Bauer.
Also remember that the mfg recommend a maximum lifetime for the water seperator after the final change due to the high stress load of (de)-pressurising all the time when running.

 

[oxyhacker]

Filteration media shouldn't come in direct contact with aluminum, so you will have to make some sort of cartridge if you can't find one to fit. Some of those little housings just don't have enough capacity to be much use - there's someone who sells one on ebay, a surplus filter housing that takes a LF cartridge, calling it a "6 mo" cartridge when according to LF it is good for about 4 tankfuls (they also sell a compressor setup without a separator which is insane!).

Lot of DIYers have built media stacks using surplus accumulators - there are some pictures in the Gallery on our website. If you are building from scratch, seamless schedule 80 SS pipe is a lot safer than aluminum since it is far more forgiving about fatigue, radii and other machining details - it is possible to build one without any threading using plugs in each end held in by cross bolts but you want to keep the diameter on the small size do the math!

 

[LakeTravis55]

Use Stainless steel tubing with a pig tail in it if there is movemet between the filter housing and the compressor. Yess I have seen a blown up housing and there has been (long time ago) a recal from Bauer.
Also remember that the mfg recommend a maximum lifetime for the water seperator after the final change due to the high stress load of (de)-pressurising all the time when running.

Thanks Rogier. I bought some Gyrolock fasteners and connectors and hope to get this thing assembled during the Christmas holidays. Thanks for the heads up on the stainless tubing. I have some tubing I think will work with the gyrolock stuff.

 

[LakeTravis55]

Filteration media shouldn't come in direct contact with aluminum, so you will have to make some sort of cartridge if you can't find one to fit. Some of those little housings just don't have enough capacity to be much use - there's someone who sells one on ebay, a surplus filter housing that takes a LF cartridge, calling it a "6 mo" cartridge when according to LF it is good for about 4 tankfuls (they also sell a compressor setup without a separator which is insane!).

Lot of DIYers have built media stacks using surplus accumulators - there are some pictures in the Gallery on our website. If you are building from scratch, seamless schedule 80 SS pipe is a lot safer than aluminum since it is far more forgiving about fatigue, radii and other machining details - it is possible to build one without any threading using plugs in each end held in by cross bolts but you want to keep the diameter on the small size do the math!

Oxyhacker: Thanks for the advice about aluminum and filter media. I had never heard that before. Is it the charcoal or the dessicant or the trapped moisture that causes the problem with the aluminum?

 

[rjack321]

13x + liquid water becomes caustic. In my limited experience humid air + 13x doesn't generate the same pH issues, it has to be saturated.

I think the repackable canister on my Alkins is aluminum and there's some minor corrosion in it. But then again it doesn't hold pressure either. LF canisters are aluminum though.

 

[Rogier]

Talking about removing moisture.
I made an aftercooler by putting a coil of Stainless steel tubing in a bucked filled with with coolant Inside a small chest freezer.
Put a water seperator behind it. And than filter the air. Cartitches last for ever!

 

[LakeTravis55]

Talking about removing moisture.
I made an aftercooler by putting a coil of Stainless steel tubing in a bucked filled with with coolant Inside a small chest freezer.
Put a water seperator behind it. And than filter the air. Cartitches last for ever!

That should be really effective at condensing the moisture out of the air. My portable compressor will be on my boat dock so I won't have access to ice everytime I use it, but I was thinking about using one of the Peltier devices to cool water in a small igloo cooler and run the condenser coil through that. They don't pull much DC current but they don't get really cold either. I was trying to think of a way to have the whole condensing chamber in the igloo. The lake water gets over 80 degrees in the summer here in Texas so I don't think that water alone would accomplish much.