Intercooled Air Compressor

[Timberwolf]

So since moving to FL I've had a big probelm with mositure in the air compressor. The gulf is about 200 yards away so it typically stays pretty humid. Finally got around to putting the the intercooler on the compressor. Having some problems brazing copper to aluminum but I may just order some 1/2" aluminum fuel line and tig it to the cooler. I still also need to find a fan to mount on the cooler. For the bracket I was originally going to buy some aluminum and fab it up. However with a 1x1x1/8"x8' stick of 6063 at $23 a piece, I decided to use some scrap steel angle I had laying around. Just need to paint it all up now, but I had to get it together quick since function trumps asthetics and I needed the compressor. O well, here's what I've got so far

[geezer]

If you need to join copper to aluminum etc. then you should try Durafix , watch the video's at this website : http://durafix.com/ and you will see it could be the answer to your problem.

There are little motors complete with fans off of the better old fridges, that could be mounted underneath your radiator and improve it's efficiency, have used them for other projects, they are terrific little motors can run for ever and don't draw much juice. The price is right as they can be salvaged from the old fridges.

I don't have much humidity where I am so I can imagine how much you have. water in the compressor is always a problem

[Timberwolf]

I tried some of the hobart brazing rods which i tried initially and got all buy 2 small holes filled on the outlet side. Using the most unorthodox method of a torch and TIG to make it stick. I have a fan that is pretty much useless for anything around the house but is almost too big for this. I may end up fabbing something up to use it....aint really decided just yet. I'd go to a junkyard but there aren't any close to me. Makes me miss home haha

[jakeru]

That's pretty cool. I'm interested to hear how much it helps with keeping water out of your air tools. Water in air tools is quite a nuisance.

I'd probably do the same thing to my 115V compressor, if I were more committed to keeping it longer term, but for now I feel like I am kind of just putting up with it.

I put a drop of air tool oil into my die grinders air inlets before each use each day, and try to drain the water every so often. It seems to be working - I haven't had to service the die grinder in quite a while, and its still running strong. I realize south-eastern humidity may be a completely different story though! The die grinder is the main air tool I use with my medium/small size compressor.

Is the blue canister looking thing a water trap?

[Timberwolf]

ya the blue thing is a filter and water trap. Glad I got it done...should save my consumables from all that moisture. I'm still adding a filter to the output side of it too just in case

[jakeru]

My air compressor (a cheapie, and noisy vertical harbor freight 120V unit) went down the other day from an electrical switch failure, so I went to giving it some long needed attention today. I previously added an electric cooling fan that I turn on whenever the compressor gets hot. This fan allowed the compressor to run at 100% duty cycle, but had a separate cord I had to manually plug in. Now I hooked it up to the compressor's power cable. Whenever the compressor is plugged in, the electric fan is on. One fewer cord to have to manage... sweet.

But even better, I tried getting rid of an inline air regulator /filer/moisture trap I had previously hooked up "permanently" to the air outlet (originally thinking I'd use it to adjust pressure as needed.) It was not a very large unit, it just had 1/4" NPT inlet and outlet ports. Well man, that was the source of pressure drop I've been looking for so long to get rid of! All the sudden my air tools have *way* more power now. They used to spin up briefly, then settle down to a lower RPM. Now they just run like a scalded cat. I can use a 3" sanding disc on my die grinder now, usefully. Before all I had the torque to spin were the smaller 2" discs. I wonder if I might even be able to use my 3" metal cut-off wheel now, that I never could get working satisfactorily now. Maybe my impact wrench will finally be useful too! I'm totally happy, it's like I just got a new more powerful compressor! (It is still noisy though, but at least its working!)

By the way, the electrical switch failure was easily remedied by a minor re-wiring of the switch. The switch was a dual pole switch, I think so it can handle switching 240V motors. Switching the neutral of the 120V circuit just seemed unnecessary, so I hard wired the neutral and just left the switch to switch the hot (black) lead. So that was a fairly straightforward fix too!

[Haywire]

You removed the regulator? I'd be wary of that. I know my little compressor generates 150psi in the tank. My angle grinder is only rated for 90psi. If I removed my regulator, it would be running at 66% over max pressure. I know a guy that's blind in one eye from an angle grinder coming apart on him.

Ian

[Timberwolf]

never touched the regulator....that's still on the tank and blowoff valve. It's sitting right there with the 2 gauges on it.

[jakeru]

If you have dual gauges, pull the trigger on an air tool while watching the gauge that's after the regulator, and see if it drops. Then do the same except this time while watching the pre-regulator gauge. If the regulator gauge is dropping when the air tool goes "wide open throttle", but the pre-regulator gauge is holding relatively steady, you have a significantly pressure / flow restriction in your regulator. Regulator "droop" is the word for it.

On my regulator even when I had it "cranked up all the way" (which is 100-120 psi on my compressor), after the regulator would drop from tank pressure down to about 60-80 psi when I pulled the trigger wide open on my die grinder. The regulator was definitely the restriction.

I don't have an air angle grinder, as I always thought my compressor was far underpowered to drive one of those. So far, no problems with my die grinder regulating the needed power at the air valve. I'm looking forward to trying the newfound power with my other air tools.

I think the "rated pressure" of the air tool is the pressure it should be getting at its air inlet *while under use*, which could be significantly lower than the tank pressure, or the static (no-flow) max pressure. Maybe my regulator was jacked (maybe some junk got stuck in it?), maybe it was undersized, I don't know. I figure if I need a regulator (like for spraying paint) I'll add one inline as needed. So far, it's been a good riddance!

I had a friend who had access to a shop with a dual stage, 200+psi compressor. I remember he said the dual stage air really woke up his dual action sander.

[Timberwolf]

you're right jake, that is a big choke point in things. If you're running larger air tools that require a lot of CFM, then that bottle neck can put a big hurt on the air flowing out. Pull the trigger on an impact and you will notice it sounds really powerful for a second then drop and remain constant. That first surge is from the 120+ psi then the pressure drops and you get the 80-90 PSI. Of course a lot of people also try to run them with standard 3/8 hose and QD's when in reality they should be using 1/2" hose and Hi flow QD fittings. I don't run air tools for hours on end so I generally just run the regular QD's and 1/2" hose, though the normal quick disconnects will still be a choke point... Plus the plasma requires only a small amount of air so I'm not affecting it at all. But the dry air makes a huge difference

[jakeru]

Before figuring out the regulator restriction, I tried all kinds of things in desperation to try and get my air tools working better (I especially wanted to make my 3" cutoff wheel work which was just a horrible performer...) I replaced the restrictive looking shut-off valve with a 1/4" full port ball valve. I replaced the quick disconnect fittings with those high-flow versions. I didn't go to 1/2" hose I took a good look and it just seemed overkill, however I certainly tried using the shortest length 3/8" hose with the least restrictive looking 1/4" fittings on it I could find. Even after all that, before I ditched the regulator... I just "couldn't get no satisfaction". I figure that regulator was sapping / drooping / leeching away 1/3 of my usable air power!

I also certainly used to get the "whee!-oahhhhhhhhhhhhhhhhhhhh....." sound out of the die grinder. Now it goes "wheeeeeeeeeeeeeeeeeeeeeeee!!" (unless I throttle it back.)

[Haywire]

Oh, I misunderstood. When you said you got rid of the regulator, I thought you had gotten rid of the regulator.

But even better, I tried getting rid of an inline air regulator/filter/moisture trap

[everlastsupport]

Timberwolf,

Where did you find/buy your radiator? Did you ever get a fan mounted on it? How is it working?

I am a lot further from the water here in Florida (10+ miles), seem it is in the air Might build up something like that if it works. The desiccants filter work very well at the end of the hoses, but they are not free either. Like to get them to last a little longer. I would never stop using them, it is night and day when plasma cutting.

[Timberwolf]

Hey Mike, the radiator is a tranny cooler from autozone. 6 pass tube and fin for $42 out the door. The water seperator is from HF and usually is $60 but was on sale closeout for $12. I also bought an inline filter and luber for $11 since they were changing suppliers for a lot of the air tool supplies and I couldnt pass it up for that price. The only thing I need to change is instead of soldering the copper to the aluminum, I either need to get aluminum fuel line and weld it, or get compression fittings for it all. There's no really good process out there it seems to braze/solder copper and aluminum that's cheap. I'm actually ordering 1/2" fuel line from summit racing to replumb it and get rid of some pinhole leaks. I haven't added a fan yet as I've noticed I really haven't needed to. There's only been one time so far when I put a fan blowing on it and that worked out great. You'd really be surprise how much heat that little radiator will dissapate just by convection.

Overall for the money it was a worthwhile investment for me. I still plan on using one more filter on the output side and then using the small dessicant filter on the plasma machine itself before that filter unit.

[everlastsupport]

Yea, you can use the desiccant filter as an indicator of it working and still have it dry what slipped though.

Dang, $42. Well at least it's a good size, works and it was clean when you got it. Glad to hear it works well.

I think I have some O/A filler rod that will do copper and aluminum. Will check on the copper part. If it will I'll let you know and cut it shorter (easier on shipping price) and send you some if you like. It was like $52 for 1 or 2 lbs if I recall, like to see someone get my moneys worth out of it. So far I have just been giving it out for boat prop repair, the project it was for, magnesium, it did not work there.

[Timberwolf]

Is it the durafix stuff? I tried some of the hobart rods and they didn't work worth a crap so I bought some special aluminum solder and that didn't really hold to copper or aluminum. That would be sweet to save on having to but aluminum fuel line! let me know

[jakeru]

Timberwolf - I see you put your intercooler between the pump's outlet and the unloader valve. So, I imagine the unloader is venting more volume (the cooler's volume and your air-water separator canister volume) when it opens, as it switches off the motor. Do you feel like this is the best way to go, or is there a better place to put it? (It would be pretty cool if the water somehow automatically got drained as the unloader opened.) Also, do you think that having the air-water separator canister is a good way to go, or would just letting the separated water drain into the main tank (to be drained out the bottom of the tank) have merit?

I'm just brainstorming, because now that my compressor is working as well as it is, I am thinking the investment of intercooling it might be worthwhile.

[Timberwolf]

Yes it does vent a lot more air and really isn't a big deal for me. As for the canister there, I think that's the best thing because otherwise it would just be in the tank exactly where it was before. Believe it or not I still had some moisture in the tank the other day when I was running it at 100% humidity in the air. This leads me to believe a fan on the cooler is a mnust because the air isn't cooling enough to lose all of it's moisture. My other idea was to put the cooler and tank of water and just add cool water if I'm using it a lot or just the ambient temp to cool it down if using it occasionally. But I'm going to add a fan and go from there. I was also thinking of makin a fronzinator to put on the output side http://weldingweb.com/showthread.php?t=540&page=2

Any remaining moisture would hopefully fall out in there and also have another seperator/filter just outside of that. At least that's the plan for now. Hopefully I can get some pipe and get it made over the weekend and go from there. Either way, it makes a huge improvement and I would definately do this again. I would have liked to have had a bigger cooler, but none of the AC condensers I found had 1/2" pipe and didn't want to risk building up more heat in the compressor head

[jakeru]

Franzinator... interesting. I like how your current setup is portable and moves with the compressor.

I've got a 120V electric cooling fan on mine, I duct taped it to the cooling air inlet of the plastic air shroud on my air compressor. It sure keeps the heat from soaking around the cylinder head after the motor turns off. Otherwise the cylinder head can easily get too hot to the touch. I used to have the fan on its own electric cord and plug, but recently integrated its power with the air compressor's power cord, so it simply is just turned on whenever the compressor is plugged in (works pretty well actually.) It's a pretty powerful unit, I got it at Boeing surplus back in the day. "comair rotron" is the brand. About as much wind/cfm as a good hair dryer blowing on high, I'd say. I can see something like that fan working well on your setup, blowing through the intercooler. I'll see if I can get a picture for ya.

My air compressor is just a direct drive with a 3600 rpm motor. But actually, it's been holding its own ever since I removed the regulator! It has a plastic cooling shroud that ducts the airflow around the electric motor and through the cylinder head. I added some aluminum sheetmetal to direct the air flow closer to the cylinder head, so it cools the cylinder head better. One thing I like about my compressor is how it's relatively portable and doesn't take up much floor space. (Being a vertical unit... 21 gallon size.) It's air intake "filter" also actually has no filter assembly in it at all... it's just a baffle for noise reduction.

[Timberwolf]

I hate the direct drive units and ended up getting mine for $100 from some guy looking for drug money. It is hard to find a good muffin fan for a decent price. Once you get up to any CFM they are well over $50. I have a small house fan I was thinking of using and making it blow air on the intercooler then have an aluminum channel to vent it to the head. Knock out 2 birs with 1 stone. I was also going to wire it exactly how you did. Just wish I had a higher CFM fan. maybe the weekend will give me some time to work on it. O, I would also highly reccomend an air filter. It will make it quiter but it will also ensure long life. You'd be surprised what you suck in even just around the shop. I also removed the regulator today and will just be using it with quick disconnects on air tools that need it. Good idea