General air compressor questions

[Dino1147]

Hey all, I recently picked up a Big Red air compressor with a 5 hp motor, K30 2 stage pump, and 80 gallon tank. It's in good shape except the silencer housing broke so I need another or hopefully something more efficient. It's loud!
I have a modified gravity feed HF sandblasting cabinet parked next to the compressor and would like to hook it up so I get the best performance possible. The pump is getting new gaskets. It should deliver close to 20 cfm at 90 psi. It had a 3/4 copper pipe between the pump and tank but it was damaged. I would like to install an engine oil cooler and a water separator between the pump and tank. From tank outlet to hose connection I will need a filter and regulator and whatever else you suggest. Should I not keep all the connections, lines, and hoses as big as possible so I can get as much cfm to the sandblasting cabinet as possible? Would it not lose a lot with 1/2" tubing and 3/8" hose or is that alright? Thanks for any and all advice.

 

[The Cobbler]

silencer housing, you mean air filter? they are usually pipe thread sizes, so easily replaceable
3/4 copper should be easily obtainable too, as well as fittings.
engine oil cooler, with water separator . the air needs to be cooled for the separator to work efficiently . not sure if an oil cooler will cool it enough for a water separator work well when close together
the regulator is probably the most restricted point . then fittings, then size and length of air hose.
what's the cfm requirements of the blaster ?

 

[Dino1147]

From what I can tell looking around online, at 20 cfm I would still have to stop blasting every few minutes to let the compressor catch up. I'm sure I can blast at anything above 10 cfm but not for very long.
I have watched a few Youtube videos where people installed an engine oil cooler and the inlet temp would be well above 200 degrees whereas outlet would be in the 70-90 range.
I would like to run a splitter with a 1/4" coupling for light duty work, and 3/8" straight to the blaster.
Could I use 3/4" soft copper so I can bend it or bad idea?

 

[The Cobbler]

soft copper will be fine

 

[Dino1147]

From what I can tell looking around online, at 20 cfm I would still have to stop blasting every few minutes to let the compressor catch up. I'm sure I can blast at anything above 10 cfm but not for very long.
I have watched a few Youtube videos where people installed an engine oil cooler and the inlet temp would be well above 200 degrees whereas outlet would be in the 70-90 range.
I would like to run a splitter with a 1/4" coupling for light duty work, and 3/8" straight to the blaster.
Could I use 3/4" soft copper so I can bend it or bad idea?

soft copper will be fine

Great, thanks!

 

[Citation]

Since you need to get a new filter housing I would suggest getting one that looks like an old style automotive air filter housing. The big pan looking thing with a handle on the side. Something like this (disclaimer, I only picked this link for the picture, the product in the link could be ****)

Robot or human?

^smells like a robot....

Slide a section of rubber or vinyl tubing over the intake port. Something perhaps 3ft long. I've done something similar on my smaller 120V belt drive compressor and it works impressively well. This guy did something similar but added some car mufflers as well

I got the idea to try the tubing from my California Air Tools compressor (not my belt drive compressor). They typically come with something that looks like a Solberg intake housing with a bit of cheap tubing stuck in the intake. Well when I first fired up my CAT compressor I thought it wasn't as quiet as I recall. Then I put the air filter on... well that helped. Then I put that stupid looking tube that I would have pitched if I hadn't looked at the instructions... yeah it actually makes a noticeable difference. So long as you have to replace the intake, try to get a quiet one. For me with my larger compressor it was enough to not worry about trying to isolate the thing in my tiny garage.

 

[nadogail]

A bigger or additional air storage tank, won't give you more air; but could help keep your blaster running a bit longer.

 

[sonoronos]

I would not go smaller than 1/2" ID hose for blasting air.

I used to run a fairly large blasting cabinet with Clemco BNP guns. There was a very big difference in effectiveness between 3/8 and 1/2 ID hose, a much bigger difference than I would have expected.

 

[NakeDiesel]

This is how I quieted down my compressor room. In the summer I pull fresh air from outside through the 2" line to a filter outside, in the winter I pull it from the 2 1" lines inside the room.

 

[Firstram]

I used a Haden 1299 dual pass oil cooler on my 7.5 hp dual stage compressor that’s shrouded and fan cooled. With heavy use the inlet temperature is well over 250f, the outlet is close to room temperature! The water is filtered out before the tank.

https://www.amazon.com/dp/B000HEADLK/?tag=atomicindus08-20

 

[kbs2244]

the inlet noise fix is either a muffler or air filter from a small car
the muffler will be easier to plumb

 

[CraigStu]

When figuring out how to do the plumbing go to Lowes or HD and look at all the different types of tube fittings. Flare, compression, etc. I did that recently and was appalled at how the ID varied so much for the different types when I was looking at all of them in the same nominal size.

 

[racecougar]

I would not go smaller than 1/2" ID hose for blasting air.

I used to run a fairly large blasting cabinet with Clemco BNP guns. There was a very big difference in effectiveness between 3/8 and 1/2 ID hose, a much bigger difference than I would have expected.

AGREED! A 3/8" hose/line will pose a notable restriction to your blast cabinet, OP.

 

[Dino1147]

Thanks for all the great information guys! I really appreciate it!

 

[theoldwizard1]

engine oil cooler, with water separator . the air needs to be cooled for the separator to work efficiently . not sure if an oil cooler will cool it enough for a water separator work well when close together er ?

There is basically no difference in coolers that dissipate heat to the air as long as they are designed for the fluid (output air from the compressor) operating pressure. The issue is sizing and if there will be any external air flow (fan). Bigger is better. Forced air flow is better.

 

[Dino1147]

I used a Haden 1299 dual pass oil cooler on my 7.5 hp dual stage compressor that’s shrouded and fan cooled. With heavy use the inlet temperature is well over 250f, the outlet is close to room temperature! The water is filtered out before the tank.

https://www.amazon.com/dp/B000HEADLK/?tag=atomicindus08-20

Do you find that the cooler restricts air flow enough to make a big difference in output?

 

[Firstram]

Do you find that the cooler restricts air flow enough to make a big difference in output?

Not at all, the cooler is 3/4 in and out. I just looked it up and its rated for up to 20 gpm of oil. This cooler is probably overkill for my 23 cfm, slow speed set up. I went big to handle the full potential of my pump if I ever needed to up the horsepower.

The other things that helped me choose this cooler were the port orientations and the size was a perfect width for the compressor cage.

 

[Dino1147]

Not at all, the cooler is 3/4 in and out. I just looked it up and its rated for up to 20 gpm of oil. This cooler is probably overkill for my 23 cfm, slow speed set up. I went big to handle the full potential of my pump if I ever needed to up the horsepower.

The other things that helped me choose this cooler were the port orientations and the size was a perfect width for the compressor cage.

Excellent thanks! I'll order one and mount it on the cage. Did you use soft copper tubing to plumb it?

 

[Firstram]

I had a hookup that made teflon lined stainless hoses for me.
Had I been on my own, soft copper all the way!!!

 

[NakeDiesel]

3/4" hydraulic lines work just fine. Can get various lengths at a farm store. Been using them as flexible connections from my compressor to hard lines for almost 20 years on the original hydraulic lines.