The beginnings of a highly over-engineered Air system

[mkmuch]

I am putting the finishing touches on my shops air system.

As with most things in my life the Engineer comes out.

The air system is no different. Building this airplane may be scary - I already see me re-enigineering several non-critical parts.

http://www.2muchflying.com/Shop.html

 

[Sam Buchanan]

I am putting the finishing touches on my shops air system.

As with most things in my life the Engineer comes out.

The air system is no different. Building this airplane may be scary - I already see me re-enigineering several non-critical parts.

http://www.2muchflying.com/Shop.html

I would not use an oiler in the shop air system. Oil will contaminate any lines/fittings you may wish to use for painting. Keep a little squeeze bottle of Marvel Mystery Oil on the bench and put a couple of drops in your tools before each work session.

It is very handy to have two air supplies in your system. One runs through the regulator for supplying the rivet gun and/or a primer spray gun. The other comes straight off the compressor at 90-125 psi for an air drill and die grinder. Just mark the lines clearly so you won't connect the rivet gun to the high pressure side. I used different color hoses for each side.

 

[RVAddict]

As with most things in my life the Engineer comes out.

The air system is no different. Building this airplane may be scary - I already see me re-enigineering several non-critical parts.

Quote from Paul Dye in the new RVATOR.... He's an engineer too.

One of my guiding engineering principles has always
been “Perfection in design does not come when
there is no longer anything to add – but when nothing
can be taken away.”

 

[mkmuch]

I would not use an oiler in the shop air system. Oil will contaminate any lines/fittings you may wish to use for painting. Keep a little squeeze bottle of Marvel Mystery Oil on the bench and put a couple of drops in your tools before each work session.

It is very handy to have two air supplies in your system. One runs through the regulator for supplying the rivet gun and/or a primer spray gun. The other comes straight off the compressor at 90-125 psi for an air drill and die grinder. Just mark the lines clearly so you won't connect the rivet gun to the high pressure side. I used different color hoses for each side.

Great points...

That was the plan re: the oil. I will use the filter/regulator/oiler combo without oil (they work great but don't want to contaminate the airlines). I usually use a couple drops as you described. When I bought the compressor they threw in the oiler/regulator/filter combo (which was nice - just won't run oil).

Once completed the different color air hoses as well as some large signs by each source should minimize my gaps in memory.

 

[DanH]

For a shop that nice I'd suggest an iron pipe air system rather than plastic tubing. The trick is to cool the air so the water vapor condenses, then give the liquid water someplace to go. Iron pipe gets the job done, in particular in a big shop where you have lots of distance to run.



See the 3/4" pipe running along the ceiling? That's the main air line, about 70 feet total. Drops are tee'd at regular intervals, and 1/2" risers tee off the drops with a Milton quick connect at the end. There's a ball valve near the floor at the bottom of each drop; that's where you drain water from time to time. The first drop will need regular draining, the next won't collect much, the next even less, and I never get any from the other drops.

The bead blast cabinet requires a high volume of perfectly dry air; it's at about 60 feet. The last drop is where I pull air for paint.

Connect your compressor with a 1" flex line, and a ball valve so you can shut off the system. Fit a 1/2" ball valve in the compressor tank drain, and connect it to some plastic line out through the wall. Makes it real easy to drain the tank with no mess.

 

[mkmuch]

prefer aluminum to black iron (my opinion)

For a shop that nice I'd suggest an iron pipe air system rather than plastic tubing. The trick is to cool the air so the water vapor condenses, then give the liquid water someplace to go. Iron pipe gets the job done, in particular in a big shop where you have lots of distance to run.

Nice pipe set up in your shop... I agree with you on the temp control and black iron but there are some disadvantages to black iron.

I have used iron pipe in the past in a couple shops but now prefer aluminum mains (not shown in the shop) - it's much easier to install and you don't have any rust issues like iron and frankly iron is way to time consuming to install. (IMO).

My inner shop is aluminum mains 3/4 inch. The workshop inside the shop is only 20ft from the compressor with a 3/4 inch aluminum main line feeding it.

I like the high pressure tubing for short runs off the mains to allow for custom install locations - if you look at the flow numbers it flows better than equivalent black iron pipe but with no rust issues (particularly if you take the 90ty's out of it) - I agree if you have long runs high pressure tubing is not the way to go (to small) - hence the aluminum mains.

Materials for modern air systems have advanced (do not use PVC) - not to say there is anything wrong with traditional "black iron" (besides rust & long install & now cost) - in my opinion there are now much better alternatives.

Mathematically the system will flow more cfm than the current compressor can deliver (IR model SS3L3) - even with the high pressure tubing.

 

[az_gila]

But Paul forgot to add...

Quote from Paul Dye in the new RVATOR.... He's an engineer too.

Quote:
One of my guiding engineering principles has always
been ?Perfection in design does not come when
there is no longer anything to add ? but when nothing
can be taken away.?
---------------------

"...after approval by at least a dozen committees that are only referred to by their initials".

There is a Whitworth bolt sitting on the moon that was accidently placed in a design by a freshly imported English engineer (it wasn't me......).
It was easier to make a new drawing for that specific bolt and have it machined and heat treated from a solid piece than it was to go through Houston to get the approvals to change the drawing.

I'm sure that aspect of NASA space hardware has not changed since the 70's....

 

[PCHunt]

Must be True

.......... There is a Whitworth bolt sitting on the moon that was accidently placed in a design by a freshly imported English engineer (it wasn't me......).
It was easier to make a new drawing for that specific bolt and have it machined and heat treated from a solid piece than it was to go through Houston to get the approvals to change the drawing.......

Now that is an absolute HOOT !! Only in a Gov't Bureaucracy.

 

[IowaRV9Dreamer]

Whitworth Bolts

There is a Whitworth bolt sitting on the moon ...

I hadn't thought of Whitworth bolts in a long time.... my "old" MG had a few mixed in. Loads of fun.

To the OP - nice shop and good to see another Hawkeye builder. Never come to my shop... the air system consists of a Harbor Freight regulator/dryer that hasn't removed 1 drop of water in 4 years and a flexible hose on the floor.

 

[DanH]

<<My inner shop is aluminum mains 3/4 inch. >>

You're right, certainly superior to black iron. I would still want at least one hard pipe drop/drain rather than depending entirely on bowl-type water separators at the end of flex lines. If the inner shop is kept cool in the summer, you should be able to get a lot of condensing done with as little as 20-30 feet of aluminum main run through the cool area. Another advantage to aluminum.

Nice shop!

 

[mkmuch]

Good Suggestion...

The interior of the workshop is cooled in the summer...

I will extend the main aluminum run and add a dedicated drain at the end (inside).

I originally planned this at the end of the outside but giving the cooling aspect more consideration - your suggestion to move that inside the temp controlled area (summer) is a superior plan.

Thanks...

 

[BrentHumphreys]

I have the rapidair system in my small shop, without the hard piping. I do get a lot of condensation, and will eventually hard pipe most of my runs.

On the rapidair, I must have gotten a bad batch of ball valves, and had a heck of a time getting the system to seal. They shipped out a new set of ball valves, and they worked fine.

 

[Jerry Cochran]

Whitworth

I hadn't thought of Whitworth bolts in a long time.... my "old" MG had a few mixed in. Loads of fun.

To the OP - nice shop and good to see another Hawkeye builder. Never come to my shop... the air system consists of a Harbor Freight regulator/dryer that hasn't removed 1 drop of water in 4 years and a flexible hose on the floor.

I still have a complete set of Snap-on Whitworth end wrenches and sockets I had to buy for my then new 1968 Triumph bike. Guess I should put 'em on eebay sometime... That bike taught me how to isolate vibration from an air cooled engine... and fight oil leaks..

Jerry

 

[Ironflight]

Quote:
One of my guiding engineering principles has always
been ?Perfection in design does not come when
there is no longer anything to add ? but when nothing
can be taken away.?
---------------------

"...after approval by at least a dozen committees that are only referred to by their initials".

There is a Whitworth bolt sitting on the moon that was accidently placed in a design by a freshly imported English engineer (it wasn't me......).
It was easier to make a new drawing for that specific bolt and have it machined and heat treated from a solid piece than it was to go through Houston to get the approvals to change the drawing.

I'm sure that aspect of NASA space hardware has not changed since the 70's....

There are way to many good stories like that Gil...and as we both know, most of the are true! Of course, I never claimed that Perfection is ever actually achieved by LARGE engineering organizations......

 

[az_gila]

Good point Paul....

There are way to many good stories like that Gil...and as we both know, most of the are true! Of course, I never claimed that Perfection is ever actually achieved by LARGE engineering organizations......

...it's always easier to come to a decision with a Committee Of One (COO)...

 

[dhall_polo]

perfect inspiration

?Perfection in design does not come when
there is no longer anything to add ? but when nothing
can be taken away.?

- Antoine de Saint-Exupery

Perfection is also when an engineer who like to write and fly is able to derive engineering inspiration from a famous writer and aviator.

That stitches everything together beautifully.

Don

 

[bhassel]

What are you using for alum pipe? I'm guessing it's more than conduit!

Thanks,

Bob

 

[rv7boy]

Aluminum versus iron piping

Bob, There are several suppliers of aluminum pipe specifically designed for compressed air systems for home workshops. I considered them for the compressed air system for my workshop I built about a year ago. The pro's are easy installation, ease of takeapart and re-installation, and a neat installation. The con's are cost, kit packaging which may lead to having to buy more than you really need, and cost. Did I say cost?

To me the aluminum was just way too expensive for the installation I planned. After seeing DanH's photo of his shop, and after considering the many carbon steel ("black iron") compressed air systems I had installed as a Facilities Engineer, I decided on carbon steel pipe.

I do have ball valve drains at each drop; for the two drops in the center of my shop, I also tee off the TOP of the main piping run and then go down for each drop; and I have a straight run to the drain valve with the regulator and ball valve in both horizontal runs. My last drop is diagonally across the workshop and I have a ball valve located about 4 feet off the floor to drain any moisture. I have an automatic moisture drain on the bottom of my tank that drains condensate each time the compressor starts (got it at Harbor Freight, and so far it's worked great!). When I leave the shop I close the main valve just downstream of the main tank, and then when I come back to the shop I open valves in a set sequence to be sure and drain any moisture that might be present. So far, I've caught very little. It sounds more complicated that it really is.

Carbon steel pipe isn't really hard to work with and the cost is reasonable, once you invest in a pipe threading die.

One other comment...we engineers tend to think a lot and not get much actual work done out in the shop. However, with a little forethought and planning, an adequate compressed air system can be installed.

I do admit to having Sch 40 PVC piping in my previous garage/workshop and after learning of the POSSIBILITY of plastic shards being propelled in all directions, I decided to take it out and not repeat it in my new shop. I don't intend to start a new pipe war; it's already been debated enough. The clincher for me was I could not find a single piping code in the U.S. that allowed PVC for compressed air, except one...and that one allowed it buried 18 inches underground. There's some concern that the small amounts of oil that inevitably come from the air compressor may cause deterioration of the PVC over time. How much time? Maybe several years. I didn't want to be a test case. Plus, if I ever sell my house, I didn't want the possible liability of a PVC air system in the shop.

More than you asked for, I know, Bob, but I was going to post anyway and just decided to include all this in one post.

Got to go get something done on my rudder out in the shop!

Don Hull, P.E.

 

[RyanM]

Has anyone ever piped their compressed air outside to cool it down? I live in ND, and its cold here most of the year, and I was wondering if that would be a good way to cool the air to condense the moisture?

 

[RScott]

With the plastic, won't you need to support it very well so you don't develop low spots that will accumulate water?

I used copper, went together easily. A 28 ft. run easily clears out all the water. I can work on the plane for several days, open the valve at the last drop and maybe get a little fog. The drop nearest the compressor gives a mist and maybe has a tablespoon of water. I get nothing at my water separator.

Re: Separate regulators & lines: I didn't think to do this, but wouldn't you then have a mess of hoses, getting tangled? OK, I guess if you have a reel for each, but my hose just lies on the floor.