How to quiet down air compressor

[rayra]

I built a cabinet for my noise machine. Skirted, backed and topped with pegboard. It gets a little warm, but I rarely use it hard. If I'm running a high volume tool, I'll usually leave the door open somewhat. The hinge faces the street, so it still blocks / redirects most of the noise.

I still need to put some egg-crate / sound-absorbing foam in it.

 

[Gamble]

Mine runs all the time for my cnc plasma and will be running more once the cnc mill is up and running
kind of why i want to avoid and enclosure on top of not having enough room

 

[clawman]

A few have mentioned that Harbor Freight compressors are noisy. Is that stmt true of ALL HF compressors or only oil free units?

 

[eastbaysubaru]

Probably just the oil-free units. I have this one and it's about half as loud as my old Craftsman oil-free unit:

https://www.harborfreight.com/29-gal-2-HP-150-PSI-Cast-Iron-Vertical-Air-Compressor-61489.html

-Brian

 

[Gamble]

Probably just the oil-free units. I have this one and it's about half as loud as my old Craftsman oil-free unit:

https://www.harborfreight.com/29-gal-2-HP-150-PSI-Cast-Iron-Vertical-Air-Compressor-61489.html

-Brian

That's mine but that one looks slightly different (mine is 4 years old)
Saw this in the store. the feet are wider, the foot bracket to move it around, it's also shorter and fatter.

hockey pucks and dynmat (generic) showed up. I will play around tonight if I get a chance to buy some longer bolts

 

[Gamble]

Soo umm? not sure WTF happened

So put a few pieces of the sound deadening on the back.
Got some longer bolts and put 4 hockey pucks under the pump then another 4 under the motor. After that the only thing I did was check the other bolts..on the cage..all tight... on the head maybe 1/16th of a turn on one. On the big flywheel on the pump..turned it..came loose, reverse threaded, tighten it back up and done. Plugged it in and it was crazy quiet. 83db.

Sounded like it wasn't spinning at the normal speed. So I let it run. and turned it on/off a few times. It was really weird like the speed would drop then pick up and a few times it didn't want to start up. So scratching my head at this like WTF. Loosened that flywheel bolt again and tightened it just not as tight..pretty much the same story after that.
I thought maybe belt tension but the pump doesn't have slotted holes and I only took out 2 bolts. The motor has slotted holes for adjusted and I put it back to where it was which is as tight as it can go, but still seems loose. If you watch it you can see it go up/down when not around the pulley.
Drained the tank completely and some brown oil came out...this happens a few times here and there. Turned it on and it took 5min 30sec to fill up to 110psi. Wish I timed this before so not sure if that's normal, but anyway this time it's down hovering around 85db. High 84.x to low 86.x.

It's for sure not as loud as it was before but I'm really confused on why or what happened that it wouldn't spin as fast. Unless it's just dumb luck that it's crapping out when I am working on it.
I will order some oil and get that done next but after that I give up

 

[Gamble]

Started to troubleshoot this tonight. Not the motor for sure. It's the pump.
So it struggles to do anything but if I unbolt the exhaust it seems to run normal. So wondering if there is a block in the tube, maybe?

 

[lakelandcat]

Already have the intake silencer.

have you tried taking off the intake silencer?

 

[Gamble]

have you tried taking off the intake silencer?

Yep
Didn’t change anything

 

[lakelandcat]

did you say it took almost 5 min to pump up your tank? Thats along time. You said you had some gunk come out of your tank? Not good. If your motor runs fine when you disconnect your exhaust, you have released some pressure on the comp side, now your back to square one. 1 how long does it take to fill the tank? Is there any excess gunk? Check the slack in your belt.

 

[Denwood]

Due to the volume of noise, you have two choices.

1. Enclose it. We built a complete wheeled enclosure for a small compressor at work. It cuts noise down by half.

2. Remove them. I did this in the home shop (moved two compressors to a shed beside the garage) which honestly was my best mod ever. It freed up precious floor space, removed the risk of explosion, and made them pretty much silent. I shut them down when leaving the shop via breaker..but otherwise I don't hear them at all.

This is all you see in the shop:

With the sliding door closed, the reel is high and dry

 

[SGKent]

if it is a ******** type compressor that is the problem. Those things are very slow and loud. Need a piston and cylinder compressor. I keep my two in the shed and put a fan on them when I will be using air continuously - beading, painting etc..