Compressor choice-Brand name vs tank size - Page 2 - 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
  #16 (permalink)  
Old 06-07-2011, 06:39 AM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
Brad that IR is at TSC has a couple of problems that we simply can't overlook because too many people ask about compressors here. First they are just flat out lying about that 18+ CFM rating which is just unrealistic for that single stage pump/motor combo and recently some places have started rating it at a more believable 15+ CFM.

Same IR compressor that TSC sells but a full time compressor outfit rates it more realistically

http://www.aircompressorsdirect.com/...ssor/p689.html.


Second they have a terrible reliability record and are notorious for burning out motors, we had a thread here not long ago with four owners of the darn things complaining about burned out motor problems in just that one thread! The IR at TSC is not an industrial USA built Ingersol Rand that the IR name is built on it is a Chinese import and unfortunately has earned a not so good track record. Also your example of hot air from a 20 gallon tank vs an 80 gallon may be valid but not so much for the 60 vs 80 with the differences being slight and even the little tank may not be as bad as it might seem. Because of space limitations we built quite a few high CFM small tank combinations for service trucks, some as much as 40 CFM with a 25-30 gallon "bumper" tank to save space (the rear bumper served double duty as a very heavy walled tank) plus various other combos of small tanks with high CFM and they did get hot but only under very high demand.


Honestly the heat difference between a 60 vs 80 gallon is going to be negligible for the same reason over-all air (in CFM) remains the same, the same amount of air enters the tank carrying the same amount of latent energy (heat) with only a small difference in cooling due to slightly more surface area of the tank, the amount of air flow through the tank is the same regardless. You are correct in your thinking and the extra cooling effect is real but just like the other advantages, energy savings and pump/motor life, the advantages are slight and not worth passing up better performance in the form of CFM and/or better quality. I have in the past harped a great deal on tank size because it is such a mis-understood factor when selecting a compressor. I in no way mean to say that a bigger tank is not better and usually it is but not always and not for the reasons most seem to think. It is useful in that it saves both on power consumption and pump motor/life due to fewer high torque start cycles, this can be substantial over the life of the compressor but negligible in the short term. Making a blanket statement that the 60 vs 80 gallon makes little or no difference is because 90% or better of the compressors being discussed here are in the 10 to 15 CFM range and in that class of compressor 60 vs 80 gallons simply will make little or no noticeable difference.

The point is that many times, far too many times, someone will pass up higher performance just to get a bigger tank and that clearly is a mistake! The compressors being considered in this thread are very good examples of the 60 vs 80 gallon dilemma that comes up so often and in this case the difference between a 60 gallon vs an 80 gallon really is very slight. As CFM increases the size of the tank becomes a more important consideration but up to about 16 to 18 CFM or so 60 vs 80 gallons really is going to be a toss-up. CFM rating, Duty cycle, pump type and construction quality plus the motor AMP rating (true rating) and service factor are all more important considerations when selecting between a compressor with a 60 gallon tank vs an 80 gallon when choosing a compressor of the size being discussed here.


EDIT: Danged if I didn't do it again!! He clearly said the TWO stage IR and I took it as the single stage! I think maybe there must be something wrong with my coffee!

    Advertisement

Last edited by oldred; 06-07-2011 at 06:44 AM.
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #17 (permalink)  
Old 06-07-2011, 10:36 AM
Registered User
 
Last photo:
Join Date: Sep 2010
Location: Toronto
Posts: 360
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by oldred

EDIT: Danged if I didn't do it again!! He clearly said the TWO stage IR and I took it as the single stage! I think maybe there must be something wrong with my coffee!
hahaha.. I started reading your post and was thinking "Uh oh, there he goes again!"..
Reply With Quote Quick reply to this message
  #18 (permalink)  
Old 06-07-2011, 04:42 PM
Registered User
 
Last photo:
Join Date: Mar 2011
Location: Columbus, IN
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I think there is something wrong with your coffee. Besides the single vs 2 stage, I also stated that 60-80 gallon difference is hardly a difference and that I was talking more theoretical than specific to this thread.

There is an issue with the emerson motor on the IR unit. My research has shown that these motors will last when wired properly and given enough juice. They are very sensitive to resistance, and specifically if too small wiring is used they will burn out. I was recommended to go with a 10 gauge wire, which is drastically too small for the load. If most go with the recommendation, there is the issue. I ended up using 6 gauge IIRC, which is the wire actually rated for the amp draw.
Reply With Quote Quick reply to this message
  #19 (permalink)  
Old 06-07-2011, 05:48 PM
Registered User
 
Last photo:
Join Date: Sep 2010
Location: Toronto
Posts: 360
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
10 gauge is plenty sufficient for a 5 hp motor, which will draw 22-23 amps at load. 6 gauge is almost ridiculous, unless you have a 7.5hp motor. Not sure I agree with whomever gave you your information. I'm a little skeptical on resistance burning out the motor.
Reply With Quote Quick reply to this message
  #20 (permalink)  
Old 06-07-2011, 06:04 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
You said you didn't agree with the blanket statement that the 60 vs 80 gallon didn't make a difference and I simply explained what I meant, that it was not a "blanket statement" that it made no difference at all. As far as the 60 gallon vs 80 making a difference while painting that can be a toss up also, you run a bit longer but then you also wait longer IF the compressor has to catch up, if it doesn't have to catch up and can keep up with the spray equipment then it makes no difference. The idea that an 80 gallon tank is going to provide cooler air than a 60 gallon is something you seemed to be saying and that is simply not going to be an issue since it is the amount of time the pump runs in a given work period that will cause the hotter air, when running that sandblaster for 15 minutes (or any tool for more than one run cycle) the pump will run the same amount of time regardless which tank you have and THAT is what heats the air. Having an 80 gallon tank instead of a 60 gallon does not mean the pump will run less during any given work period and it would be the same even with the 20 gallon you mention. You said that with a 20 gallon tank when painting you would have the same issue as you do when sandblasting with the bigger tank but that's not so, when sand blasting the compressor runs almost continuously and accumulates a heck of a lot more run time during the work period than when painting for the same work period. the frequent and short start/stop cycles of the smaller tank would cause some cooling problem but not for the same reasons as sandblasting with the bigger tank nor would the problem be as severe. If you paint for 30 minutes then the compressor will run the same amount of time whether has a 60 gallon tank or an 80 gallon or a 20 gallon for that matter.
Reply With Quote Quick reply to this message
  #21 (permalink)  
Old 06-07-2011, 06:16 PM
Registered User
 
Last photo:
Join Date: Mar 2011
Location: Columbus, IN
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
It doesn't matter who built the motor; if it does not receive the juice it requires it will shorten the life. The issue with these emerson motors is well known and I did a lot of research before buying the IR compressor because of this. Reading about this online and talking with IR, this conclusion makes pretty good sense to me...haven't seen too many failures from those running a thicker gauge wire. I know that a 5hp motor typically uses approx 25 amps under load and uses a 40 amp breaker. I was specifically told to use an 6 gauge because of my distance from the box to the compressor, but shorter distances can use 8. I don't know of a reason for this as I didn't get that far into it, quite possibly these motors have a very high initial amp kick. We use slow-blow breakers that will take considerably more amps for a short amount of time, so this wouldn't be instantly noticeable to anyone, but if the wire (power supply into the building, wherever the weak link is) can't handle the high amp draw, the motor will not get the amps it wants on the initial kick.

It has been a few years since I installed mine so all of the numbers are a bit fuzzy, but I believe the initial amp draw was near 100. I was also researching the 7.5hp versions as well, so that number may be for it. In any case, it was over the current carry capacity of a 10 gauge.
Reply With Quote Quick reply to this message
  #22 (permalink)  
Old 06-07-2011, 06:33 PM
Registered User
 
Last photo:
Join Date: Mar 2011
Location: Columbus, IN
Posts: 32
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
If you paint for 30 minutes then the compressor will run the same amount of time whether has a 60 gallon tank or an 80 gallon or a 20 gallon for that matter.
That is correct, it will run the same amount of time. CFM is CFM no matter where it comes from. If I had a 20 gallon tank the compressor would run more often, but shorter times. On my 80, it runs longer, just not as often. From the way I time my coats, the compressor runs once per approx 30 minutes. My air temp after the piping is just a few degrees above ambient with the compressor off and tends to jump about 15 degrees with the compressor running, and cools off pretty quick. I have forced air ventilation around the compressor helping it stay cool.

I understand the theory that pumping X amount of air creates Y amount of heat, whether that is done at once or over a period of time. My gun takes 13cfm (15cfm compressor) and I can get an entire coat on a full size pickup before it kicks back on. Add in flash time between coats, and the compressor sits idle for a good long while. If the compressor kicked on 4 times during the coat, I could not keep the air nearly as cool. 15 degrees isn't much of a difference, but in high humidity, there is quite a difference on how fast my desiccant dryer is used up. When the compressor runs continuously for long periods, I can get a 50 degree jump.

I also specifically stated in my first post that 60-80 gallon is negligible and any point you make in saying otherwise is utterly ridiculous. No nowhere did I state that "I didn't agree with the blanket statement that the 60 vs 80 gallon didn't make a difference" as you said. HR has a hive-mind on this subject, and while being generally correct, is just that, a general statement.

I also originally said: "If I had a 20 gallon tank while painting, I would see the same issue as I do now with the DA." My gun is 13 cfm at 26psi, compressor 15 cfm. A 20 gallon tank would empty very rapidly causing the compressor to run near constantly while spraying. I know that with my DA, which causes the compressor to run near constantly water is an issue. I could not effectively dissipate the heat from the compressor on the fly in 95 degree weather, such as today, when the compressor rarely shuts off. I can get a full coat, or nearly a full coat without the compressor kicking on with my 80 gallon. Although the air heats up when the compressor kicks on, it has plenty of time to cool back down between coats.

This isn't just for painting, but for any non-continuous use tool, impacts, air hammers, etc. There may be a time when you will impact for 20 minutes straight, but that is far and few between. There are times when I need all the cfm I can get, the blaster and DA are my only ones, but for 80% of my air usage it is intermittent.

Last edited by Brad4321; 06-07-2011 at 06:51 PM.
Reply With Quote Quick reply to this message
  #23 (permalink)  
Old 03-03-2014, 08:27 PM
Member
 
Last photo:
Join Date: Jun 2002
Location: NYC
Posts: 822
Wiki Edits: 0

Thanks: 10
Thanked 3 Times in 3 Posts
Quote:
Originally Posted by TNshadetree View Post
No, Harbor Freight still has a two stage advertised. Just got a flyer yesterday. I don't see a 80 gallon anymore, but here's the 60 gallon listed.

US General Lot #93274 5HP 60 gallon 2-stage 13.5@165 15.8@90 16.4@40 Reg $899.99 Sale $799.99
Its been "On Sale" for three years now!
Reply With Quote Quick reply to this message
  #24 (permalink)  
Old 03-10-2014, 05:15 PM
ChevelleSS_LS6's Avatar
Jeep XJ and a Javelin
 
Last wiki edit: Compression test
Last journal entry: August 9, part III
Last photo:
Join Date: Dec 2001
Location: Grand Rapids, Michigan
Age: 28
Posts: 1,610
Wiki Edits: 7

Thanks: 3
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by oldred View Post
Don't compare Apples and Oranges! The HF compressor (actually it's just a rebadged Belair) is a single stage "home shop" type compressor while the Quincy is an industrial duty two stage full time shop type compressor meant for the long haul, you just can't compare the two. The HF (Belaire) is an excellent buy for a compressor of that class but would likely come short with a sanblaster..
I didn't get the HF part number you're talking about- so there may be some USA made HF stuff (and I have seen them once in a while), but a large single stage HF compressor at a shop I worked at is IDENTICAL to the snap on compressor at a buddy's house, including the "certified by flung sum dung" plate on the tank. I think those were 80s. I didn't tell my buddy that. I'll let him live on his snap-on high. Buyer be aware.
Reply With Quote Quick reply to this message
  #25 (permalink)  
Old 03-10-2014, 07:25 PM
Member
 
Last photo:
Join Date: Jan 2003
Location: tennessee
Posts: 5,912
Wiki Edits: 0

Thanks: 0
Thanked 7 Times in 7 Posts
This thread is a bit dated now and it's been over two years since my post on the HF/Belaire compressor, the situation has changed some since then. The compressors are no longer "US General" and are now "Central/Pneumatic" with a few differences, they still look like the Belaire but now come with either a Century motor or another motor I have never heard of and can't remember the name of right now but it seems to be hit-or-miss on which one it will have at any given time. The pump looks to be the same Italian built pump but it also might, or might not, be a Chinese copy, I have not been keeping up with these things lately but it seems today with just about everything and the stinkin box it comes in being from China it's hard to say if they are still the same or not.
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
Air Compressor Choice Devilbiss vs Craftsman 67Elcamino Garage - Tools 16 04-22-2011 08:44 AM
Air compressor-opinions on CFM/brand Iwanttolearn Garage - Tools 48 08-04-2008 09:19 AM
Compressor Tank Size Morgan22 Garage - Tools 24 01-31-2008 06:06 AM
Carb size and choice KGRIFF Engine 10 07-10-2007 04:26 PM
what size and brand cam should i use? 72chevyhotrodder Engine 4 03-04-2004 09:10 AM


All times are GMT -6. The time now is 05:04 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.