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Woody GRM+ Memberand MegaDork
9/29/12 7:28 p.m.

A few days ago, I picked up a small jeweler's bead blaster off of Craigslist. I asked the seller why he was getting rid of it and he told me that he bought it at an auction, and only because he wanted the small air compressor that came with it. When he showed me the compressor, I immediately understood why. It was a Jun-Air. I had only seen one other Jun-Air. That one was a single cylinder that a friend of mine found in a storage unit. It was small, but impressive.

So got the blaster home and set it up beside my big noisy Craftsman compressor. It's a really perfect little blasting cabinet. I started thinking about how nice it would have been to have gotten the original compressor with it.

Jun-Airs are made in Denmark. They are often used by dentists and tattoo artists. If you've never heard one operating, you may have been standing right next to it.When my friend found his, we plugged it in and thought that the motor was seized or burnt out. Then we noticed that the pressure gauge was going up...

A quick check of Craigslist (via SearchTempest) turned up of couple of really expensive ones. And one that was about an hour away for $70. I think you can see where I am going with this...

As luck would have it, the seller was actually visiting family not too far from me and he agreed to bring it with him. And now, it's mine.


It's a two cylinder, 8 Bar (116 psi) with a 45 liter tank. Made in 1985. It needs a little cleaning but I plugged it in and, for a moment, thought that the motor might be burnt out. Until I saw that pressure gauge going up....

Grtechguy UltimaDork
9/29/12 8:13 p.m.

Congrats, I love mine (a Freebie). I agree with how quiet, especially if you have the case designed for them. Mine will reach 150psi in under 20 seconds.

You will notice the compressors are all rubber mounted as well.

If anyone is ever looking for one, start asking your dentist where they get theirs. I believe they can only run them for a set number of hours.

Woody GRM+ Memberand MegaDork
9/30/12 10:21 p.m.

I learned two things about these today.

-The pistons do not have rings, just incredibly tight tolerences.

-Jun-Air synthetic oil is crazy expensive.

dculberson SuperDork
10/1/12 10:38 a.m.

Wow, nice score! They look a lot like refrigerator compressors.

benzbaronDaryn Dork
10/1/12 12:12 p.m.

My dad got me one for free from his work, they threw it away. The oil was something like 75$ a quart and if anything breaks you are basically SOL as far as parts and service. I couldn't get it working and sold it for parts. The guy who bought it got a european model which wouldn't work on US electricity. I actually contacted Jun air and they were of no use to find parts, the closest service center was down in L.A.

Good luck and hopefully nothing breaks!

Woody GRM+ Memberand MegaDork
10/1/12 12:22 p.m.

They have a distributor about 20 minutes from me, but the oil is expensive.

Woody GRM+ Memberand MegaDork
10/2/12 3:56 p.m.



Enyar Reader
10/3/12 8:13 a.m.

Good to know!

Woody GRM+ Memberand MegaDork
10/3/12 8:20 a.m.

Think gas is expensive?



...per pint! Good thing I didn't need much.

Apexcarver UberDork
10/3/12 8:23 a.m.

I have purchased more expensive! (but it was for vac pumps I used in my nanotech research internship)

Woody GRM+ Memberand MegaDork
10/3/12 8:48 a.m.

That's why I have vowed to avoid nanotech research.

benzbaronDaryn Dork
10/3/12 1:10 p.m.

Check out the price for high vac seal grease, my dad gets me stuff throw out at his work, a little tube is something like 180$.

Looks like a sweet setup!

Woody GRM+ Memberand MegaDork
10/3/12 1:21 p.m.

Eye drops are where the money is. I got a bottle of prescription drops one time that held 0.5 ml. I figure out that it cost something like $112,000 per gallon.

Woody GRM+ Memberand MegaDork
11/27/12 6:04 p.m.

One of my compressors wasn't working, so I removed it, plugged the lines and set it up to operate as a single compressor pump. For the past month or so, I have used it as a handy air station in my garage.


Today, I decided to take another look at the bad compressor. I wasn't sure if the problem was electrical or mechanical. I swapped control units from the good pump to the bad one, and it still wouldn't work. I opened it up and found that the piston was seized. I was able to free it with a few whacks with a poly mallet and I was able to turn the crank through about 2/3 of the piston's stroke.



I suspected that it had been sitting for a while with moisture in the cylinder and that the bore was corroded. I removed the head, and, sure enough, there was a chunk of rust that had been keeping the piston from moving. I used a wire brush in my Dremel to clean up the bore, vacuumed it out, added a few drops of gun oil and now it moves nice and smoothly.



I still need to find a new head gasket for it. I'm not sure if I'll be able to salvage enough of the old one to make a pattern and, even if I can, it would be a PITA to make a new one as it has thin sides and a bunch of small holes in it. Fortunately, there is a Jun Air distributor not far from me and these things didn't change much through the years. I should be up and running on twin pumps in a couple of days.

friedgreencorrado PowerDork
11/27/12 6:36 p.m.

In reply to Woody:

Note to self..remember that gun oil works on metal, and doesn't care that it's not on a gun.

Thanks for the tip, dude!

Woody GRM+ Memberand MegaDork
11/27/12 6:46 p.m.

I chose gun oil because it was within reach and had a handy little spout.

Dr. Hess
Dr. Hess UltimaDork
11/27/12 7:26 p.m.


Woody GRM+ Memberand MegaDork
11/27/12 7:29 p.m.

I'll have to take a look. It's not enough to power a full size sandblaster, but I bought a small Gesswein jewelers bead blaster that was powered by a similar unit. I've been using the noisy compressor for the high CFM stuff.


spitfirebill PowerDork
5/11/15 7:47 a.m.

Do I need one of your compressors in my canoe?

Dusterbd13 SuperDork
5/11/15 7:54 a.m.

Dunno if canoe or not.

But I do know that woody never did update his compressor rebuild. Three years later, im wondering if he found a head gasket.

DrBoost UltimaDork
5/11/15 8:52 a.m.

Yeah, cummon Woody.

clutchsmoke Dork
5/11/15 10:18 a.m.

I got a free pony keg size Jun air from work. I really only use it to fill tires.

Woody GRM+ Memberand MegaDork
5/11/15 10:47 a.m.

In reply to Dusterbd13:


I made my own head gasket. I have photos somewhere. But there's some kind of electrical issue with that motor. I never looked into it further, but I just set that compressor up to run off a single motor. I use it in my basement when I'm doing bicycle repairs. These things are silent and perfect for basement work. However, my friend who found the original JunAir that got me interested in these things had a fire at his office recently, which inspired a whole bunch of house cleaning. He has offered me that original compressor, which he says has a leak. I may fix the leak or just swap the motor into the other one.

My life takes many twists and turns...

Slippery GRM+ Memberand Dork
5/11/15 4:38 p.m.

Woody, if you dont have any use for that extra compressor I'd love to mess with it. Let me know how much you want for it.

Woody GRM+ Memberand MegaDork
5/11/15 4:46 p.m.

In reply to Slippery:

Sorry, it's a keeper.

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