I need info about Grumpy's compressor linking

chromebumpers

solid fixture here in the forum
Staff member
I understand there is information on hooking together 2 air-compressors to increase output. I'm asking this as I'm most likely going to try my hand at soda blasting an entire car and I don't think my 30 gal. (4 cfm @ 90 psi) and (6 cfm @ 40 psi), 155 max psi, 1.5 running Hp Husky can pull it off. I have a pancake ac rated at 3.5 SCFM @ 90 PSI (150 psi 1.5 hp.)
I do have available 220 outlet next to 115 outlets. I would love to have something quiet but I am not going to put 5K to get it.

What is the difference in performanbetweeneen screw drive and piston compressors?
 
Just an advice like this, forget about sand blasting with those compressor.
even my 60 gal 11.2cfm@90 psi compressor is not big enough for this.
At a minimum you need those 5k$ compressor in the 23cfm range or 2x60 gallon lower end compressor that are under 1000$ (btw mine is pretty quiet for a low end compressor)and i think you need full 1/2inch line for media blasting.
Dont think you will make it under 2000$ except if you can get a good deal on used compressor.

To link 2 compressor together you need 2 compressor that are the same model i think. anyway 30 gallon linked to whatever will not work just telling you before you spend $ and time into doing this because it will not work.
these 2 compressor together will put about 7.5cfm thats very underrated they would not work for hvlp painting (my hvlp gun take 11cfm@40psi) and for media blasting you need lotta more cfm.
 
Wow - I need that much? I thought I could do most things with a min. 10 cfm @ 90 psi. Eastwood's has their large soda blaster at 10cfm/90psi. Same with a HVLP sprayer - I didn't know they need that much. Guess I better start looking on CL!
 

I don't see a problem connecting two compressor of different sizes, as long as both tanks are qualified to hold the max pressure possible. I am assuming you are NOT talking about connecting the output of one compressor to in the input of the other compressor. That is totally different than connecting the two outputs together.

Your 6 cfm compressor at 40 psi is only going to be able to supply maybe 1/2 that rating at 90 psi. So you might have available about 9 cfm. I would have to agree with mathd that you are going to come up short or doing alot of waiting.

I've never heard of a small shop ever using a screw compressor, but if $4k is Ok, then Northern Tool has a Quincy compressor rated at 16.6 cfm at 150 psi, so at 90 psi you should be good. It also has a 100% duty cycle. It should be alot quieter than an piston type compressor.

Do you have 8-71 blower setting around that you can connect to a big electric motor??? :D

You might find this interesting if you want to connect compressor together.
http://www.woodweb.com/knowledge_base/T ... ssors.html

 
viewtopic.php?f=27&t=24

viewtopic.php?f=59&t=6246&hilit=franzinator

adding a oil cooler type radiator , or even several to the hot air lines leaving the compressor output , will allow you to cool and separate a great deal of the moisture from the compressed air
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1963SS;3373681 said:
Does this happen to anyone else? Just a small compressor mishap. My compressor exploded and took out a wall between the woodworking side of the garage and the greasy side. I was about 10 feet away and I thought a Claymore mine had went off. The compressor left the floor, blew out the windows, broke the fluorescent tubes in the lights and tore up a plywood wall and studs it was beside.

There were things flying all over the garage from the force of the blow and the concussion......I guess. Never has anything like this happen in my last 71 years and I hope it doesn't happen again.

It appears that 30 years of moisture had made the bottom of the tank thinner (rust) than the rest of the tank and at 125 psi just ........ BOOM. Picture dynamite or popping the worlds biggest balloon. Geesh,.......time for an underwear change.

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yes it not only happens occasionally, but its one of the major reasons that,
its strongly suggested you drain your compressor tanks before and after each use.
and use some method of separating out moisture from the compressed air before it enters the storage tanks, a heat ex-changer like a salvaged air conditioner evaporator radiator plumbed into the air lime between the compressor and air storage tank will help.
below you see what one guy fabricated, a high pressure radiator type oil cooler or air conditioning component heat ex-changer like a salvaged air conditioner evaporator radiator plumbed into the air lime between the compressor and air storage tank will help.
obviously adding a moisture drain valve will also help here
you can plumb in a heat exchanger like this from an older air conditioner,between the compressor and storage tank, mounted high on a wall so it does not take up floor space, wire the fan to come on when the compressor runs, adding a cheap fan helps condense the moisture,and allow it to drop out of the air mass before reaching the storage tank (s).
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https://jniolon.classicpickup.com/compressorwatertrap/aircompressorwatertrap.htm
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http://www.homedepot.com/Tools-Hardware ... Qs6Dmf6k1A

I bought two of these compressors, one was not enough to keep up with the flow required in my shop,I found that was the least expensive route to get a 120 gallon storage capacity and two compressors, be aware that one compressor will always tend to kick in a bit before the other one and the second compressor will kick in a couple psi lower no mater how you adjust the two.each compressor supports about 8cfm at 120 psi, keep in mind you'll want to install and AIR drier or any painting or sand blasting will quickly have moisture in the lines, you'll need to run a moisture separator, I fabricated mine for 4 air conditioning condensers so each compressor feeds a manifold that feeds all four condensers then returns to a manifold that feeds both 60 gallon storage tanks, the condensers have a electric fan to remove heat, read the link I supplied
each tank has a cut-off valve and separate drain, so it can be used isolated from the other if required.
the twin 60 gallon tanks act as a cushion, and having twin compressors helps also. but you'll obviously need two 220 volt circuits that each handle 15-20 amps MINIMUM.
remember the flow out of each compressor will be several hundred degrees (F) so you feed that into a shared manifold and that manifold feeds the condenser radiators, the fan, cools and condenses the moisture, the common manifold feeds the franzinator drain pipe assembly the franzinator acts as a moisture trap, which then allows dry air to be routed to the distribution pipe where you can use flex hose to the tools but even the air pipe should be arranged so any moisture will tend to run to a few multiple moisture drain points. as any moisture in the compressed air flow,will quickly cause problems with tools, or painting, or sand blasting jobs.

read thru these links
 
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I see HF has a unit that has a 60 gal tank, and it's 16 cfm @ 90 psi or 13.5 cfm @ 165 PSI fo $800 - That's still not enough?
 
that should be plenty, but having two separate compressors and 120 gallon storage capacity in the combined tanks seemed to be a better option to me at the time.
and keep in mind you need DRY AIR, not just pressure!
I chose to use two compressors, simply because if you have two compressors and one failed you still have a functioning compressor set-up in the shop, with a 120 gallon storage tank capacity
 
First see the spec of the soda gun you want to buy, if it need only 10cfm@90 psi you will be fine with the 16 cfm@90psi compressor(is it a quality unit?, always air for quality). Your 2 compressor together will not work except if you want to wait ALOT then it will do the job.. but it will be noisy take lots of electrical power and your gonna use up your compressor head its gonna make some heat and run almost non-stop, this kind of setup do not last for very long and it will NOT work for hvlp painting because of excessive heat and humidity in the air and probably lack of cfm too. I know some people do it locally here, but they have to paint a car in 2-3-4 step...Not something i want to do, and i bet once you have the good setup for soda blast you will want to spray too :)

I would not use a 10cfm@90psi compressor for HVLP spraying, i do it with my 11.2cfm@90psi and i almost wish it was bigger.. Am using a devilbiss FLG-3 with the #3 cap and it need 13cfm@23psi. my compressor put our 13.4cfm@40psi... that make for a small margin, less that ideal but works fine since am not spraying every day of the year.
buying a compressor is a long term and expensive project so avoid going "a little too small", and go "a little too big" so forget about anything under 60 gallon and 12-13 cfm@90psi for that soda blast gun, just an advice like that.

Also about air dryer, people around here tend to use long copper tubing to cool the charge before the air dryer.
compressor tank>long copper tubing>air dryer>pressure regulator>flexible hose>air tool :).

If you get that soda blast gun that take 10cfm@90psi let us know how it work. I feel like some people would start soda blasting around lol.
 
It's so close between what a shop charges and what I would spend getting my own stuff. I sold my trailer at Mecums last week so that makes things a little pita. Shop wants $1200 for media blasting. I think I'll watch out for a commercial/industrial equipment auction and try for a deal there. I have seen some big compressors at auction and they don't bring the big money because the of their limited market.
 
chromebumpers said:
It's so close between what a shop charges and what I would spend getting my own stuff. I sold my trailer at Mecums last week so that makes things a little pita. Shop wants $1200 for media blasting. I think I'll watch out for a commercial/industrial equipment auction and try for a deal there. I have seen some big compressors at auction and they don't bring the big money because the of their limited market.

I am not sure if its practical but maybe keep an eye out for a Used Industrial portable air compressor like the kind used with Air powered Jack Hammers you see the highway department & demolition guys use.
If it will power a Jackhammer, should be plenty of CFM for Soda Blasting & Psi required.
With construction off season( winter now), poor economy for all contractors to work in(no Work), you may be able to score a Portable 4cylinder diesel engine Roots Supercharger Twin Screw Air Compressor for $300 to $500. It will be on single axle wheels to pull behind your pickup truck or if like me a GMC Suburban 4X4.
I have been asked to repair these portable air compressors & they are built like a tank. Caterpillar, John Deere, or Kubota brand diesel engines.
Some are pretty quiet in operation too. Depends if steel frame enclosure is insulated or not.

My boss had one of these portable industrial air compressors out in his iron scrap pile for 2 years.
In my spare time I got it running for fun.
Must have been a 30 year old unit.
Caterpillar 4-cylinder diesel.
Twin Screw Roots Supercharger( about a 6-71 GMC Detroit Diesel Blower) for an air compressor head.
Should have bought it or just hooked on & brought it home.
He sold it for scrap iron junk to a Junk guy that comes around for $50 bucks.
When I found out, I shook my head & asked why.
Farmers in my area like my boss do strange things that make no sense sometimes.

Brian R.
 
The only issue using 1 of these portable industrial Twin Screw air compressors is that they have 3/4" to 1 inch" outlet lines.
At least on flexible rubber lines.
Have to step down to typical 3/8" rubber hose for auto & lite truck air powered tools.

Lots of air volume. Should handle any task guys like us can dream of overcoming.

A few old models have gasoline 4 cylinder engines.
Be 1970's & earlier.
Just have to look around your area.

BR
 
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