(DIY) Adding a tank to compressor.

[Amra]

Alright, I am pretty sure this is probably the final update.

Finally received my 1/8 pressure safety valve in the mail, so I went and picked up the short union and tee!

Once I finished mounting all that together, I disassembled the compressor from the tank and removed the pressure switch, moving the pressure switch to the remaining port on the TEE, tightening everything down, and then reassembling the compressor.

I also finally bolted the compressor down to the frame of the tank. Inspired slightly by Andre's compressor with its high-rise compressor mounting, I bought some 2 1/2" bolts, then used my propane torch to get them red hot, and bend the ends about 1/2 an inch behind the head cap. (see my MSPaint diagram in the previous post for a basic description of this design) Then I pushed on some rubber spacers and pushed them past the bend, so they would absorb vibration from the compressor. I then mounted them and put on additional 3/4 rubber bushings to absorb more vibration. They press into the foam, causing it to warp, but they will sit flat after I stretch the foam some (if not, I will disassemble, and glue the foam down, so it doesn't move).

With that, this build is essentially complete. Everything works better than I expected, its quiet, holds plenty of air for what I do, and fills up plenty fast. When it turns on using the HP-CS, I can continue airbrushing non-stop and it will still be able to fill up and shut off, so it more than keeps up with the air usage of that brush. The compressor heads get warm to the touch after about 30min of airbrushing, and hot to the touch, but not so hot that I can't hold it, after about an hour of constant airbrushing.

All in all I am very pleased with the performance of this compressor, and having used it several times I will say, Yes, all of the issues that I was having without a tank have been solved.

Lastly, I thought it funny... look what I saw at Home Depot today, when I went to get the last couple fittings.

A 1HP twin compressor motor, with a 4.6 gallon tank, and supposed to be pretty silent.... for only $139USD. It took everything I had to not buy it.

 

[AndreZA]

Your machine is looking really good but that Home Depot one is a steal. Motor noise is on par with yours but can handle long paint sessions much better.

 

[Amra]

@AndreZA I thought about it overnight, and while I have a nice compressor for airbrushing now, I figured I could use a portable one for all the double duty stuff. Something that can go up to 125psi, whether for filling up tires or nailing things outside where the big compressor won't reach. There are enough reasons, and the price was good enough, that it makes sense to have the extra compressor for around the house jobs. Like you said, if I am going to have an extra long painting session, it might be worthwhile to use this one for those sessions, provided the sound is comparable to the one I made, which is pretty quiet. I'd say the one I made is 40-50 db, you can have a conversation with it running and not need to raise your voice at all, haven't tested this one, but so long as its pretty close to that we should be golden!

 

[AndreZA]

@Amra, I did this to my inlet. It quietens it down a bit much. It's just a thin dish rag wrapped over the opening. Thin enough not to obstruct airflow.

 

[Amra]

Nice, Ill give that a try. It is pretty quite, but noticeably louder than my smaller compressor, probably 50-60 db, still not bad but every little bit will help!

 

[Amra]

Downloaded a Sound Meter program for my phone to see what the DB level of my compressors are. My room, when quiet and empty is 39-41 db. The DB rating of the one I built in this worklog is ~48-52 db, and the one I purchased runs ~64-68db as is from the factory. I might see what I can do to get that down, but its not bad for now.

 

[RebelAir]

40 Db on a quiet empty room? check that meter or stop breathing close to the mic LOL but 50db ain't to bad but when theres no background noise and its constantly kicking in I reckon your next project will be a sound proof box LOL..But better than the factory effort ..65 Db ain't very "silent" at all

 

[Amra]

40db is about the same as a quiet library, according to most charts I've seen, I'd thats pretty quiet. Could have been windy outside too though, or a heater in the background, who knows.

That said, the app probably wasn't calibrated for my phone either (not sure if it can be, ill have to check). I suppose the more important takeaway is that the compressor I made is only about 10bd louder than the ambient sound level in my room, while the larger compressor is about 25db louder than the ambient sound in my room (this difference should be consistant regardless what the ambient sound in the room is, so if its actually 30db in my quiet room than the compressor is only 40db, but if it's 40db in my room the compressor is 50db, etc etc)

 

[AndreZA]

(this difference should be consistant regardless what the ambient sound in the room is, so if its actually 30db in my quiet room than the compressor is only 40db, but if it's 40db in my room the compressor is 50db, etc etc)

Not actually. Sound is sound, it does not get piled up on what is already in the room. My clock radio on 1 is almost too loud for me at 2 in the morning and I can hardly hear it at mid day. The ambient noise is increasing and actually getting as much as the radio's.

 

[Amra]

Not actually. Sound is sound, it does not get piled up on what is already in the room. My clock radio on 1 is almost too loud for me at 2 in the morning and I can hardly hear it at mid day. The ambient noise is increasing and actually getting as much as the radio's.

Sorry I probably didn't explain that properly and as a result made it sound confusing.

What I meant is that the numerical values of the measurement I took are largely irrelevant in the sense that the device I used is not necessarily calibrated and might not be accurate with respect to 0db. When I gave different numbers I was speculating on how far out of calibration the device could be, not how loud it was in the room, it was, as far as I could tell, essentially silent in the room.

So, the measurement I took was late at night in a quiet room with noone else in the house and little to no background sound as far as I could tell. So, at that specific point of time when the room was silent to my ears, the values the device gave me are essentially irrelevant. At that specific moment, there was a 10db increase in sound when the compressor turned on.

Naturally, different conditions (tv in background, kids playing outside, cars passing down the road etc) would absolutely increase the ambient db, making the db increase when the compressor turned on *less* than 10db, and if the ambient sound level were higher than the db of the compressor, there would be no change in the meter.

I didn't mean to imply that the compressor would always be 10db more than ambient regardless of what the ambient level was. Sorry if that is what it sounded like I was implying. I know that would be silly!