will this air compressor plan work? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Garage - Tools
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 10-06-2009, 07:24 AM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: WI
Posts: 131
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
will this air compressor plan work?

I am working on building the air compressor system in my garage. I have two air compressors currently and need to see if my plan will work. The first air compressor is off a pneumatic controls system in a hospital. I don't know any info about the compressor except it appears to be a dual piston and has a 220v 1.5 hp motor powering it. It also came with a 20-30 gallon tank, not sure of the exact size. A picture of the compressor can be seen below.


The second compressor is the "wheel borrow" style. I has an 8hp Kohler engine and the compressor is a 2 stage but I do not know the specifics of it since the tag is worn off. When I looked online at compressor with an 8hp engine the minimum cfm at 100psi I saw was 16.2. A picture of it can be seen below.


My plan is to take the first compressor and the tank and mount it in the attic area of my garage. I was thinking this would work well for the everyday uses of air. I thought then I could have a connection that the other compressor could be hooked into for days I needed a lot more air (such as sand blasting or painting or a lot of sanding). I figure I can just set it out side the garage and let it go to town. I would guess then my total system cfm would be between 20 to 25 at 100psi. I had thought about buying a motor for the gasoline powered compressor but I like the idea of still having a gasoline powered compressor.

I don't have any money tied up in either of them. The first one came out of a hospital I work at and they were going to throw away. There is nothing wrong with it. The second one my dad had at his business and they never use it any. It was kind of payment for some work I did on a tractor of his.

I am cleaning the carb now on the engine and I am sure it will fire right up. The compressor can't have that much time on it because they don't have that much use for a compressor like that. All they would use it for is pressurizing pipe on a job site but now they just use electric ones.

Will my plan work? any advice is welcome? How far away from where I am sandblasting should the air compressor be?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 10-06-2009, 08:34 AM
bobjob's Avatar
Registered User
 
Last photo:
Join Date: Apr 2009
Location: florence az.
Age: 60
Posts: 295
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
you need a lot more tank.the more air in tank you have,the less times you have to fill it to keep a constant pressure..
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 10-06-2009, 08:51 AM
Registered User
 
Last wiki edit: General Motors transmissions Last photo:
Join Date: Mar 2006
Location: near Yellowstone park
Posts: 4,312
Wiki Edits: 27

Thanks: 12
Thanked 254 Times in 238 Posts
air system

gasoline compressors usually have an unloader that allows the engine to continue to run when the high pressure setting is reached, it doesn't pump air until the low preset is reached, you would probably want to set the electric one below the gasoline. at a factory that I worked at they had 3 compressors tied into the system. I knew a guy that got a 100 gallon tank from a commercial system that was being junked. he used a compressor like your little one to fill it to have enough air to paint a complete car. used systems should be carefully inspected and pressure tested,
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 10-06-2009, 09:18 AM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: WI
Posts: 131
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
The total between the little compressors tank and the gasoline powered tank is going to be 30 to 40 gallons. I would love to add another 30 gallon tank if I can find one. I don't have room for a 100 gallon tank but that would be nice. I will start looking for another tank to add to the system.

You are correct, the gasoline powered unit has a system that will set the engine at idle when max pressure is reached and it appears to blow out the excess air as to not over pressurize. My plan was to set the little compressor to come on at a lower pressure because I didn't want it to run constantly. If I am doing a high air requirement job my guess is the gasoline powered one will do all the required work unless it can't keep up.

I will go over it with a fine tooth comb. I feel a little better since I have an idea of the history of the compressors. I know where they came from.
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 10-06-2009, 12:49 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Quote:
Originally Posted by bobjob
you need a lot more tank.the more air in tank you have,the less times you have to fill it to keep a constant pressure..
He needs more tank but not a lot more.


Quote:
Originally Posted by snorulz
The total between the little compressors tank and the gasoline powered tank is going to be 30 to 40 gallons. I would love to add another 30 gallon tank if I can find one. I don't have room for a 100 gallon tank but that would be nice. I will start looking for another tank to add to the system..
Don't get carried away with the tank on this system, as has been said repeatedly A BIG TANK DOES NOT MAKE A BIG COMPRESSOR!!! With what you have there 40 gallons would work just fine but with the CFM you are going to have (from what I see there you are going to have about 20 CFM) 60 gallons would work better but don't go over 80, with a split system like that you would almost certainly be better off with a 60 gallon tank. This has been covered in detail many times before but going too big on the tank is a mistake and it will NOT make for better performance in spite of popular belief, remember it is the compressor that makes the air and the tank can only put out what the pump puts in. The common thinking behind the bigger tank is "more reserve air" but this is very misleading and it is a trade-off because any extra run time gained will be lost to the extra recharge time so you gain exactly nothing. You can in fact actually lose performance with too big of a tank because of excessively long run times causing heating which in turn leads to reduced efficiency. Keep the tank capacity within reason and resist the temptation to go huge, keep it balanced with the CFM capacity of the system and you will be much happier with it, otherwise it will get to be a PITA waiting on it to recharge.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 10-06-2009, 03:11 PM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: WI
Posts: 131
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
Ok, so if I add this 22 gallon tank i found on craigslist, I should be about perfect for overall volume of the system. If that tank in the ad is 22 gallons, I am starting to think the tank from the little compressor is more like 30 gallons so I should be right around 60 total. I will have a regulator on the gasoline compressor because I believe it runs the pressure up to 175psi but I will have to confirm that. The craigslist tank is only rated at 125psi and I believe the other tank is in the same ball park so 175 would be to much. I will make sure I include a safety blow off in case the regulator or something else fails. It sounds like my plan should work then?

http://madison.craigslist.org/for/1384392657.html

I will also include a ball valve on the extra tank so the little compressor does not have to fill it up all the time. I know the little compressor can handle the other tank because that is the tank it was designed for.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 10-06-2009, 05:30 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Whatever else you do do not use that little CH tank at 175 PSI! Make sure that any tank you use is rated at the pressure the system will be capable of. The Two stage compressor could be de-rated to 125 PSI in order to use the other tank but that would defeat the purpose of adding the extra tank in the first place since the higher pressure is just another way of storing more volume, the higher pressure would allow you to have as much cubic feet of air in a small tank as you might have in a larger tank at lower pressure. If you use a tank that is rated for less than maximum system pressure it would have to be down-stream of the main pressure regulator since if it became pressurized to 175 PSI even momentarily it could result in a violent, and possibly deadly, explosion. If your system storage total now is around 40 gallons you might want to try that first since it may work better than you might think and this would give you a workable system until you can locate another tank. Depending on your needs 40 gallons may work out quite well and the recharge time would be much shorter than with a larger tank, either way the compressor will keep up with your tools the same regardless of the tank size it is just going to be a matter of how much it runs vs how much time is spent recharging. With a small storage you will get more frequent but shorter run cycles while with a larger tank you will get fewer but longer run cycles, either way the actual time the compressor is going to be available is going to be the same. If the tank is too small it will be cycling at an annoying rate but if it is too large it will require an annoyingly long recharge time so I would suggest trying what you have now and adjust it from there.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 10-06-2009, 08:41 PM
Registered User
 
Last photo:
Join Date: Sep 2009
Location: WI
Posts: 131
Wiki Edits: 0

Thanks: 0
Thanked 1 Time in 1 Post
I was not planning on running the CH tank up to 175. My plan was to have a regulator directly on the gasoline powered compressor so only its tanks went to its rated pressure (what ever the factory level is). I don't think the 30 gallon tank I currently have will take the same pressure as the gasoline powered compressor. As a safety measure I will include several blow off's so if the regulator on the gasoline compressor failed I would have a back up. Also as a safety in case the switch that shuts off the compressor fails. If I can get the little tank for $20 I think I will. I will most likely wait to install it though and see if it is really needed. The price just seems to good to pass up. Plus it will be easy to install in the attic.

I will try to draw up a plan so it is clear what I want to do.

Thanks for all the tips and advice.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 10-07-2009, 09:50 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Quote:
Originally Posted by snorulz
I was not planning on running the CH tank up to 175. My plan was to have a regulator directly on the gasoline powered compressor so only its tanks went to its rated pressure (what ever the factory level is).

That will work, also if you add that small tank downstream at just before the water separator (you do have a separator don't you? ) you will get the added bonus of having much dryer air. I have seen, and used, small tanks set up in that location just for moisture collection and it works quite well, we called them "thump" tanks. If you don't have a separator then these tanks plumbed inline at the finial air take-off point will still help a lot, sometimes even to the point of making a separator unnecessary unless the set-up is used for painting or sandblasting.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 10-09-2009, 09:07 AM
Registered User
 
Join Date: Sep 2009
Location: Gonzales, LA
Posts: 23
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
will this air compressor plan work?

I hope you don't mind me jumping in but, I am using a blast cabinet utilizing a 2 stage compressor with an 80 tank probably 30 feet from the cabinet. Even though I have a moisture trap I still am not satisified with the performance. I know filling that large tank creates a lot of heat and consequently a lot of moisture especially with 85-90% humidity. I have an old 20 gal tank I could install inline right next to the cabinet as a "thumper tank" as y'all refered to them. From what I'm reading, this would definitely be a benefit correct.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 10-09-2009, 04:30 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Quote:
Originally Posted by 64Bird
I hope you don't mind me jumping in but, I am using a blast cabinet utilizing a 2 stage compressor with an 80 tank probably 30 feet from the cabinet. Even though I have a moisture trap I still am not satisified with the performance. I know filling that large tank creates a lot of heat and consequently a lot of moisture especially with 85-90% humidity. I have an old 20 gal tank I could install inline right next to the cabinet as a "thumper tank" as y'all refered to them. From what I'm reading, this would definitely be a benefit correct.

Correct. If done properly (standing the tank vertically helps some) then this can indeed help remove moisture. What are you using for your pipping system from the tank to the separator? Is it sloped properly and no sags anywhere along it's length? Proper plumbing between the tank and the separator can make a huge difference in the amount of moisture that shows up in your lines and as you already know that is very important for blasting.
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 10-10-2009, 04:37 AM
Registered User
 
Join Date: Sep 2009
Location: Gonzales, LA
Posts: 23
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
will this air compressor plan work

I haven't done the plumbing for the additional tank but honestly I did not know that the slope of the plumbing had any importance at all. Can you suggest any reading material so that I can educate myself before making any obvious mistakes.

I know I'm preaching to the choir but the amount of knowledge shared on these forums is truly incredible. Thanks
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 10-10-2009, 04:29 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Just use the search button at the upper part of the page to search "air system" and you should find about everything you need to know. There are several ways to plumb a system but basically what you want to do is to use the plumbing to cool the air as much as possible before it reaches the water separator. This is necessary so that moisture contained as vapor in the hot air will be cooled and thus condensed into liquid water that can be more easily removed by the separator, plus a lot of it will be trapped in the pipping where it can be drained. A good plumbing system is extremely important to having dry air but it does not have to be overly complicated nor terribly expensive. One especially nice system for a home shop that was designed and built by one of the members can be seen here,

Water Problem with Air Compressor


The system does not even have to be this elaborate but for what that system cost and the ease at which it can be built I think it is an excellent design.

I will list a few things you might need to consider then after you research it a bit I am sure someone here can answer any questions you might still have.


First thing is DON'T even consider using PVC pipe for your plumbing because in addition to the fact it is very dangerous, in spite of what some may have told you, it is about the worst choice you could make for moisture control. This is because of it's insulating properties so Copper pipe, black iron or galvanized pipe are far better in this respect with the Copper being the best choice IMO.


You will need to try to use about 50' of pipe from the compressor to the take-off point for best performance but this is not always practical and there are other ways of doing it


You don't want to have any sags in the line ANYWHERE that can allow water to condense and collect without having a "drop" or collector pipe with a drain.


The water separator must be located at the farthest point possible from the compressor because it will do a very poor job of removing water vapor from hot air which is what you will have right at the tank, a separator located at the compressor tank will do next to nothing.


This may sound a bit complicated but actually it is not and taking the time to plumb that compressor right will save you a lot of frustration later and if you are doing any painting it will likely save you some money too!
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 10-30-2009, 11:44 PM
Registered User
 
Last photo:
Join Date: Jan 2009
Location: Springfield, MO
Age: 29
Posts: 1,107
Wiki Edits: 0

Thanks: 5
Thanked 0 Times in 0 Posts
I have not read all the replies to this post but I've read a few. That blue pump looks to me like it has the head unloaders that are used for constant run applications (gas engine powered). I can see that it is now on an electric motor. I think that it was switched in the past. I myself would use the blue pump, the silver one looks like a cheap Chinese knockoff pump and with an 8hp motor i don't think you're going to see 16 cfm. I have a Saylor Beall 705 that is needing a 12-13hp gas engine to make 17.3 cfm @ 175psi. It is a 2 stage 2 cyl.

The blue pump looks kinda like a quincy? If thats the case it is certainly the better pump.
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 05-07-2012, 09:06 AM
Registered User
 
Join Date: May 2012
Posts: 1
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Air Compressor Recommendations

I have a recommendation for this system. Call these guys, they helped me solve many problems...The owner has been in the business his whole life. The business itself has been opened for over 50 years. ************************************************** *******

Last edited by OneMoreTime; 05-07-2012 at 12:08 PM. Reason: Advertising. Please see: commercial posting guidelines.
Reply With Quote Quick reply to this message

Recent Garage - Tools posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
larger compressor gburgess2002 Garage - Tools 13 07-19-2009 09:36 AM
one giant orange peel flamedfordbronco Body - Exterior 14 06-20-2007 09:04 PM
air compressor maintenance CaPrI_MaN Garage - Tools 8 10-04-2006 10:14 PM
Air cleaner advice. ScreamingEagle General Rodding Tech 2 09-18-2006 10:59 AM
shooting clear vinvango73 Body - Exterior 3 10-28-2005 11:24 PM


All times are GMT -6. The time now is 02:35 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.