Dealing with a 3/8" Air Outlet on Compressor

[3sonsresto]

Hi All,

First post here, but long-time reader. Would appreciate your input on a question I can't find many answers to:

I've recently purchased a 60-gallon compressor that (unfortunately) came with a 3/8" air outlet on the side of it. I plan to use the comp for both sand-blasting and powder coating. I'll run at least 25' (but no more than 50') of copper tubing in order to allow for air cooling/moisture relief.

Ideally, my copper tubing will be 3/4", as I'd appreciate the extra air "storage" with that over 1/2", and have read several other posters stating they wished they would have gone larger after having installed 1/2".

I do not want to mess with removing/replacing the bung on the comp. Besides, I've read some theory that enlarging the bung doesn't really do much, anyway. Rather, I'm interested in how to best move QUICKLY from the comp to 3/4" line. I already have on hand a 3/4" hydraulic flex hose to go from the comp to the hard line, and a full-port 3/4" ball valve with one male end, one female end on it.

Does anyone make a 3/8 male to 3/4 female reducer for this purpose? I'm having a hard time finding one. Is using one even advisable in this scenario? Or, do I need to find a way to go 3/8 -> 1/2 -> 3/4? Or, am I simply overthinking everything and should I just go 3/8 -> 1/2 and keep all lines at 1/2?

Thanks!

 

[cvairwerks]

Look for a 3/8 NPT male to 3/4 NPT female adapter. Lots of places to find them. Pulling the the reducer out of the tank fitting is actually the best idea. Any time you choke down a flow path, it doesn't help if you are looking to maximize flow at a particular pressure.

 

[brewchief]

3/8 Male x3/4 female shows as available from fastenal and others, it may be pricey.
A 3/8 short ****** and a 3/8x3/4 reducing coupling would be easier to source.

The id of whatever 3/8 fitting will be the biggest restriction, a steel ****** may be better than a brass one, either one might be improved slightly with a drill bit, just don't go to far and make it prone to breaking.

Sent from my SM-G965U using Tapatalk

 

[MattT]

A 3/4">3/8" reducing ****** and a 3/4" coupling is gonna be easiest/cheapest option. Or reducing ****** and female female ball valve would look a little cleaner if you want to throw an extra $10 at it.

 

[claymont]

They make reducing ******* in the sizes you're looking to use. We used them at the refinery I worked at quite often. There's also reducing couplings available in the those sizes. Any commercial plumbing supply would have them. You could also drill and tap the bushing/bung to the size you want.

 

[bad_idea]

Yeah... 1/2" is plenty for what you are doing. The compressor will be the hindrance, not the diameter of the distribution piping. The manufacturer is hinting at the capability of the compressor with that size of an outlet. I recommend an actual dryer over a bunch of copper pipe.

 

[Citation]

I would agree with those who say this compressor is probably not sufficient for the tasks you have in mind but I may be wrong.

I think the typical side of tank setup is a pipe bushing with a 3/4" thread on the inside. I would presume the 3/8” is threaded into that 3/4" bushing id. A picture may help.

 

[3sonsresto]

Yeah... 1/2" is plenty for what you are doing. The compressor will be the hindrance, not the diameter of the distribution piping. The manufacturer is hinting at the capability of the compressor with that size of an outlet. I recommend an actual dryer over a bunch of copper pipe.

Thanks for your reply. Agree that 1/2" is plenty for the actual work, but thought that 3/4" would give me more storage ability so the compressor workload would be reduced.

Money was the reason for purchasing the comp I did, so an air dryer (even a cheap one from HF) isn't feasible right now, esp if I have the copper already laying around. I'm just going to blast very small parts, and have the patience to wait if needed. Thanks for your thoughts!

 

[3sonsresto]

They make reducing ******* in the sizes you're looking to use. We used them at the refinery I worked at quite often. There's also reducing couplings available in the those sizes. Any commercial plumbing supply would have them. You could also drill and tap the bushing/bung to the size you want.

Thank you for this suggestion! I might look into that if it's feasible.

 

[TRWham]

If your main reason for running 3/4 is storage, you should run the math on the volume of air in 50' of 3/4" vs 50' of 1/2" pipe. I think you'll find the gain is not worth the effort. Yes, it's twice the volume, but 2 flea farts of air is not much more useful than one. You would need to run over 300' of 3/4" to store even 1 cubic foot of air.

 

[3sonsresto]

I would agree with those who say this compressor is probably not sufficient for the tasks you have in mind but I may be wrong.

I think the typical side of tank setup is a pipe bushing with a 3/4" thread on the inside. I would presume the 3/8” is threaded into that 3/4" bushing id. A picture may help.

Thanks!

Here's a link to the compressor on HD's website. A picture of the bushing is on the left.

 

[3sonsresto]

If your main reason for running 3/4 is storage, you should run the math on the volume of air in 50' of 3/4" vs 50' of 1/2" pipe. I think you'll find the gain is not worth the effort. Yes, it's twice the volume, but 2 flea farts of air is not much more useful than one. You would need to run over 300' of 3/4" to store even 1 cubic foot of air.

Hmmm. Well, I might need to do some math, then. Thanks for this. Perhaps using 1/2" is a better idea then.

 

[TRWham]

So apparently that's a 2" to 3/8" bushing, so it should be easy to replace that with a bushing to go from 2" straight to whatever size you want. 1/2" pipe is more than enough for that compressor.

 

[Citation]

Thanks!

Here's a link to the compressor on HD's website. A picture of the bushing is on the left.

That picture shows a 3/4” pipe bushing on the side.

 

[Lucid Moments]

Just an odd note. I bought what looks to be the same compressor except mine is Husky branded. But the same 3.7HP and 11.5 scfm and it has a 3/4 inch bung in it.

 

[3sonsresto]

Just an odd note. I bought what looks to be the same compressor except mine is Husky branded. But the same 3.7HP and 11.5 scfm and it has a 3/4 inch bung in it.

It's my understanding that the same compressor motor is made for several different brands, including PowerMate, DeWalt, PorterCable, etc. Many of these companies all use the same basic motor and just strap it to their own unique tank once it arrives in the U.S..

I was initially under the impression that the compressor I bought also had a 3/4" bung. I won't know for absolute certain until it's delivered Tuesday, but when I click on the instruction manual linked to this model on the HD site, it says it's 3/8". Amazon's listing for this comp also has folks mentioning in the Q/A that it's 3/8". Hence, my initial question and issue.

 

[Lucid Moments]

It's my understanding that the same compressor motor is made for several different brands, including PowerMate, DeWalt, PorterCable, etc. Many of these companies all use the same basic motor and just strap it to their own unique tank once it arrives in the U.S..

I have no doubt that is true. I wouldn't bet much money that they even change the tank. Just a different paint job on it, and different fittings.

I was initially under the impression that the compressor I bought also had a 3/4" bung. I won't know for absolute certain until it's delivered Tuesday, but when I click on the instruction manual linked to this model on the HD site, it says it's 3/8". Amazon's listing for this comp also has folks mentioning in the Q/A that it's 3/8". Hence, my initial question and issue.

I'm sure you are right, and that it does have a 3/8" outlet. Just out of curiosity if you want the larger pipe why do you not want to just replace the bung? A big pipe wrench and some thread sealant and it should be a 5 minute job.

 

[Marctrees]

3sons - Rather than your copper pipe cooler idea check out Motorguard "Toilet paper" filter.

I humid TX it works great for blasting w my 16 cfm 5 hp.

I have it plug in installed at entrance to pressure pot.

Marc

 

[MattT]

Thanks for your reply. Agree that 1/2" is plenty for the actual work, but thought that 3/4" would give me more storage ability so the compressor workload would be reduced.

Money was the reason for purchasing the comp I did, so an air dryer (even a cheap one from HF) isn't feasible right now, esp if I have the copper already laying around.

3/4" isn't going to add much storage. You might gain one gallon if you run the full 50'. But it will do a better job of cooling/moisture removal so you may as well run the 3/4" since you already have the material.

 

[3sonsresto]

I'm sure you are right, and that it does have a 3/8" outlet. Just out of curiosity if you want the larger pipe why do you not want to just replace the bung? A big pipe wrench and some thread sealant and it should be a 5 minute job.

What's funny is I've found listings on Ebay for this comp saying it's a 1/2" outlet, review pages stating it's 3/4", pictures showing it's 3/4", and an "official" manual that says it's 3/8." I'd call the company directly but they're closed, and with all the variation, I'm not sure I'd be confident in their answer anyway.

It's frustrating to think that potentially there are a few different variations of this same exact model floating around out there, under various trade names. If that's true, makes me think that these manufacturers really DON'T know what they're doing when cobbling these things together, as someone else suggested in this thread. Or, maybe they just figure anything 3/8" and over is just fine for the general hobbyist.

I'm very hesitant to change out the bung. I've read several horror stories of guys destroying their tanks doing it (on this forum and others), or worrying about the integrity of their units afterwards.....especially when using heat. Besides, I don't own a pipe wrench, so I'd have to buy or rent one. I have no doubt if I could get it out that I could get a replacement back in...it's just the getting it out part that concerns me.

Additionally, I've read from several sources that a small restriction out of the tank really doesn't matter if one reduces the amount of other restrictions in the line, and that changing out the bung is simply not worth it. I don't want to compromise my unit if the end product isn't even worth it.

Regardless, if it ends up being 3/4", great. I'll proceed. If it's 3/8", I think I'll take the suggestions here and just get a ****** up to 1/2" right out of the outlet and do 1/2" hard lines.

Thanks everyone for your input and suggestions!

 

[3sonsresto]

3sons - Rather than your copper pipe cooler idea check out Motorguard "Toilet paper" filter.

I humid TX it works great for blasting w my 16 cfm 5 hp.

I have it plug in installed at entrance to pressure pot.

Marc

Thanks! I've heard of these, but was under the impression these were more often used to get rid of any oil in the lines, and not necessarily water, too. If I used one, agree that I'd most definitely put it at the end of the line, though. I see way too many guys putting filters right next to the compressor where they do next to nothing.

In your setup, did you use any hard lines at all, then? Are you putting this filter at the end of a long flexible hose? How have you configured things?

 

[Marctrees]

Plugged into tank 50' 1/2" hose w the large Milton quick connects.. sorry don't know part # then Motorgard direct at sand tank.

true 5 hp 60 gal about 16 cfm.

Had constant wet sand plugging problems... Motorguard TOTALLY eliminated them.

Probably have 100 + hours experience w this setup... on an IR T30.

One of those things where you set it up as best you can and then after bunch o blasting upgrade whatever needed.

But that simple system works great for me.

Not to be an *******, but how much did you pay and is it tooo late to return ?

Marc

 

[Marctrees]

These connectors -

https://www.northerntool.com/shop/t...MIwMWxsfr94gIVAYbICh1MPA4tEAQYBiABEgJoq_D_BwE

 

[Marctrees]

on my tank is nippled a 1/2" ball valve, then regulator, then one of these big Miltons.

Then I made an adapter w large milton in and regular smaller milton out to use for everyday stuff.

When I sandblast, I remove that adaptor and plug my big 1'2" hose big milton to big milton.

Lotsa miltons.

Marc

 

[3sonsresto]

One of those things where you set it up as best you can and then after bunch o blasting upgrade whatever needed.

Not to be an *******, but how much did you pay and is it tooo late to return ?

Marc

I like this idea. Why not buy the filter, see if it works, then do hard lines if needed? Especially if we don't really deal with humidity here. Really appreciate your insight. Might go this route.

I paid ~$200 for it, as I had a gift card I used for the rest. Total was $610 shipped. I'm brand new to sandblasting and powder coating, and the biggest compressor I've owned prior to this was a 5-gallon. As long as this thing doesn't **** out in a year or two, I'm ok with this level and did not want to spend more. I'm reminded of the adage, the guy with 40CFM always tells the 20CFM guy to upgrade, who tells the 10CFM guy to upgrade, etc.

I'm aware that there are better comps for blasting out there, but also think, given what I've read, that I can make do with this one, as other guys have done just fine with similar specs. I'm not restoring cars or large parts....just small toys, tools, and whatever else I find to keep my kids busy and myself entertained. Doubt I'd turn the unit on more than once a month....kids keep me too busy and I can't risk too many noise complaints in an HOA community anyway.

 

[Marctrees]

OK, ya, it will be good enough for that no prob.

Marc

 

[Marctrees]

I don't have any hard lines... works fine for me.

Never felt the benefit of spending time and $ installing any.

Marc

 

[Marctrees]

If you get the Motorguard... REMOVE the filter if it gets wet... leave can open to dry out... re use filter.

The combo of Al filter body and the interior paint they use is not get along well w longgg term storage w wet filter inside.

Made and works beautifully otherwise.

I'm really surprised more guys don't use them.

I have two of them... one w flaky paint interior (from the wet storage) that I use for blasting, and a second like new one for spraying finishes where I can't risk a loose spec of paint coming through.

Course, I still have the little screw on tennis ball size dispo filter at gun, but anyway.

Belt and suspenders.


Marc

 

[3sonsresto]

Marctrees,

You've been extremely helpful. I really appreciate all of your time and insight.

While I have both 1/2" and 3/4" copper around, I think I'll take you up on your suggestion to try the Motor Guard first before committing to more work. I'll see if I can get one of the M-100 models and rig up a system similar to yours. If moisture is still a big issue, I can then look at copper lines.

Thanks again!

 

[Marctrees]

Note that they are all the same body... but w different size threaded in's and outs.

I believe I have the 1/2" NPT for both mine.. run full size for the blasting and reduced down for the spraying use one.

Can always reduce, can't really enlarge.

Marc

 

[Marctrees]

And really, I did most my blasting not where we live now but on the TX Gulf coast.

You will have less humidity where you are, so it will take care of your needs.

Marc

 

[MattT]

Additionally, I've read from several sources that a small restriction out of the tank really doesn't matter if one reduces the amount of other restrictions in the line, and that changing out the bung is simply not worth it. I don't want to compromise my unit if the end product isn't even worth it.

Correct. Pressure drop is per foot. At the flow rates you'll be using you're looking at a fraction of a psi per foot for 3/8" so a couple inches of fitting is a non issue.

 

[3sonsresto]

Note that they are all the same body... but w different size threaded in's and outs.

I believe I have the 1/2" NPT for both mine.. run full size for the blasting and reduced down for the spraying use one.

Can always reduce, can't really enlarge.

Marc

Agree on the 1/2". Will order one.

If it's not too much trouble, would you mind sharing a pic of your setup at your blasting cabinet and how you attached everything there? If not, no worries! Thanks again.

 

[Marctrees]

I do not have a cab... blast in open using Silica... Canvas blasting hood w forced air from dedicated tiny shop vac.

100 lb ALC pressure pot.

Marc

 

[Marctrees]

Most of my stuff is big... CJ5 frame and parts, big offset BBQ, etc.

O - A good size fan blowing on the comp pump/ motor is a must for extended jobs.

Marc

 

[3sonsresto]

Most of my stuff is big... CJ5 frame and parts, big offset BBQ, etc.

O - A good size fan blowing on the comp pump/ motor is a must for extended jobs.

Marc

Got it.

By chance, does your comp come with an aftercooler? I'm wondering if perhaps you'd had so much success with moisture because the air coming out of the tank is so much cooler already.

My compressor will not have an aftercooler unless I put one on it, so the air coming out of my tank will be very hot. Lack of humidity here or not, it will definitely need to be cooled down and/or filtered out with a Motorguard.

 

[Marctrees]

No cooler, straight out of side of tank.

Marc

 

[BillK]

Ideally, my copper tubing will be 3/4", as I'd appreciate the extra air "storage" with that over 1/2", and have read several other posters stating they wished they would have gone larger after having installed 1/2".

Just for grins I did the math. 50Ft of 1/2 is .51 gallons 50 ft of 3/4 is 1.145 gallons Not worth the trouble.

My business shop is all plumbed with 1/2" copper. Have never had a problem. Shop is 30x60 and the compressor is in the far back corner.

 

[The Cobbler]

keep in mind that 3/8 schedule 40 is almost 1/2" ID anyway,

 

[iagsxr]

Can't you just retap the bung?