Fixing a leaking compressor gasket?

Well, I finally took the head off this morning and inspected the o-ring and the gasket that seals the head pressure chamber to the part that caps the cylinder. Both looked OK, so I tried applying some thick grease to both as it was suggested earlier. That sure helped a lot and the compressor now shuts itself off again after running for a few seconds. Nice!
There's still a little bit of air coming out the one side, so I might try the silicone I had ordered on the gasket to see if that fully stops the leak. Since there are no moving parts I figure it won't do any harm.

Again, thanks to everyone giving feedback!

El Taino

I ask because this compressor you show in the pictures is literally a carbon copy of my Paschee D500

I've been using a similar design from Badger (under the Testors label) for more than 10 years and I wanted to add a second unit so I bought the one above. For the second time it has been replaced no questions asked by Paasche. They are a good cheap alternative only for short AB sessions. Once you push these to a 10-15 minutes painting session, they over heat. After that, you will notice that it wont start automatically. One can hear the motor making a humming noise but it wont start until all remaining air pressure is depleted.

I opened mine and there is not much in there, I found lots of particles from the gasket. Everything was cleaned and re assembled but the problem remains. Both, the 1st one I bought and the replacement Paasche sent have failed after a longer than the brief AB session.

An airbrush compressor that overheats in 10-15 minutes and refuses to restart is defective. If it does the same thing after 3 samples, I will ask for a complete refund.

I have a Paasche DA400. I can force it to run continuously up to half an hour, the output pressure wil not change and the cylinder head is barely warm to the touch. But it was their older, made-in-Taiwan model. It seems to me that the quality of the Paasche compressor took a head first dive after they switch supplier.

Most of the little airbrush compressors are oilless piston units that relies on a thin telfon coating on the cylinder, the moving part, to provide seal and keeps the heat and noise down. I suspect that the particles that you saw may not be from the stationary gasket, but from the moving piston. If the precision of the piston to cylinder wall is not manufactured properly, it gets the results that you saw, particles, heat etc.

So, it is important to get a good quality compressor made by a reliable supplier.

The old Badger was made by Thomas and use the diaphragm type head. It has less leak or precision problem to worry about. But the diaphragm design limits the airflow and makes it more prone to pulsation. Don Wheeler mentioned that Badger has switched compressor supplier to a Taiwan factory. It seems still to be the diaphragm type.

Wow Gonzo, seems like that one was boxed at the end of the shift on a Friday

I wonder how much they are paying for them if they send new ones no questions asked.

HawkeyeHobbies

[...]Did you try tightening the head bolts?

Hi Gerald,
thanks for the info. I actually went out and bought a set of metric hex-wrenches to tighten the head down, but that didn't help. I'll take it apart this weekend and see what I need to fix it. Won't try silicone now, that's for sure.
Thanks to Matt and his manual I shot the guys at Harbor Freight an email and they already replied asking which parts I might need, so that's looking pretty good already.

El Taino

[...]Enjoy yours and have them send you a new one every time it breaks down. The cost involved in sending replacements will give them a spoon of the soup they have been giving us.

You bet!
It does sound like yours has a leak somewhere if it keeps turning itself on. I hope that you can locate it eventually.

Here's a picture of the new compressor that they had sent me. A bit out of focus, but you can clearly see right through it. Yikes! I've sent this to their customer service and asked them if that's considered "normal".

I don't know if you experience this, but mine out of the box keeps turning on every 5 to 6 seconds. You know, they are supposed to start when you start airbrushing. Well, it does work, but if you stop airbrushing for a short while, it starts by itself. That mean there is an air leak and the compressor starts by itself at the lack of pressure. I took everything off of mine and sealed the outlet, the air leak is on the inside. Man, I've beating the heck out of my cheapo looking (well, it was actually cheap) Badger all these years

Enjoy yours and have them send you a new one every time it breaks down. The cost involved in sending replacements will give them a spoon of the soup they have been giving us.

Have a great day mate.

Never use silicone to seal a compressor head gasket! You'll only achieve another failure.

Most compressor head gaskets are made of a paper fiber material, phenolic or metal composite. You simple place the gasket and torque the head bolts to spec. The use of any sealers potentially will be drawn into the piston cylinder as the piston cycles to suck in air.

Did you try tightening the head bolts?

Hi El Taino,
that does sound like pretty bad customer service. The folks at tcpglobal (where I had bought mine from) were at least nice, didn't ask me to send the old one back, and I had a replacement the next day on my door step. Can't complain there. That replacement looks almost like the old one but is a bit different. And it has a big gap where the head gasket sits on the housing, so I don't even know how this can build up pressure, but it does. At least for now. If it fails too I'll just gonna have them replace it again while under warranty.
But they sure help to get a taste of airbrushing and to get back into a hobby that's not cheap after all is said and done.  

Thanks for taking the time Gonzo. Now I have concluded that these are not worth the effort. I won't be returning mine at my expense for a replacement that will end up with the same problem. Funny story, when I bought it at my local Hobby Town, I've got this model:

I sent it after calling Paasche customer service at my expense, happy when I saw the box at my doorstep. When I opened the box, there it was, the same compressor went on a leisure trip to Chicago. They kind of didn't believe me, I was sure it was the same one, it had the zip tie I used for the cable. So they sent a new one and told me to keep the old one (which doesn't work). The one they sent was the D500 from my previous post. I sent them an email letting them know how disappointed with their customer support I was.

An hour later I've got a phone call from Paasche. They guy at customer service was pissed because ''he delivered''. I said I didn't receive a replacement for the compressor I sent. He told me that for the holiday season ''I come across customers like you, you should send an apology email to me'' he said. WTH? After saying those words, he said that they sent a different one because the one I originally sent was discontinued. How the heck am I supposed to know it was discontinued? I got it new from my Hobby Town which he in doubt asked me which store? In short, that's no customer service. If they include a note in the box saying that the previous model was discontinued and I was getting an equivalent, it would have made a world of difference. I lost almost $150, they lost a customer.

Thanks Matt!

El Taino,
I had mine for less than 2 months. Used it to finish one model and doing a bit of testing it out, but that's about it. The quality is obviously much lower than I had hoped for. I'd seen some pretty good reviews for it on Amazon, but those folks might not have used it all that much I guess. I'm just glad that I got it for about $70 shipped with a pretty decent dual-action AB, so I didn't spent a fortune on it.
But yeah - for any kind of serious modeling you need to get something better than those. I think that replacing one is already factored into the profit margin for them - that's how cheap I think they are bought from the manufacturer. 

Question for you Gonzo. For how long have you been using this compressor?

I ask because this compressor you show in the pictures is literally a carbon copy of my Paschee D500

I've been using a similar design from Badger (under the Testors label) for more than 10 years and I wanted to add a second unit so I bought the one above. For the second time it has been replaced no questions asked by Paasche. They are a good cheap alternative only for short AB sessions. Once you push these to a 10-15 minutes painting session, they over heat. After that, you will notice that it wont start automatically. One can hear the motor making a humming noise but it wont start until all remaining air pressure is depleted.

I opened mine and there is not much in there, I found lots of particles from the gasket. Everything was cleaned and re assembled but the problem remains. Both, the 1st one I bought and the replacement Paasche sent have failed after a longer than the brief AB session.

This is the Badger/Testors I've been using for over 10 years without a glitch. As for the Paasche, it was a $109 plus shipping the defective ones to Paasche waste.

Have a good day.

Well best of luck!  Nothing worse than broken gear when your trying to have fun with a hobby. 

The best compressor I have ever used in this hobby is my Senco PC1010, 6yrs and no problems and it's still as quiet as it was on day one.  If you ever get the chance to buy one it would be very well worth it!  Heck you could use up 3-4 other compressors in the Senco's lifetime.

Anyway, just my 2 cents.

Matt-in-Cali

...in the manual..

The manual?? There's an idea. That seriously never crossed my mind.  But when I did look at it this morning I realized why - the manual that came with my compressor is about 4 pages of no information. Nothing like the one you got from Harbor Freight, with a breakdown and such. Thanks for the link to the PDF! It does say at the bottom though that those are not necessarily replacement parts that can be ordered. We'll see..

Thanks to everyone for the tips and info. I feel well prepared now to fix this puppy and have me a spare in case I need it (which I reckon might be the case sooner than later, since the dealer didn't even ask for the broken one back. hmmmm...)

Get a blank gasket sheet from a automotive supplier & RTV silicone gasket maker. Once the gasket is cut perfectly to fit the head apply a very thin coat of RTV to all mating surfaces. Upper, lower & both sides of the gasket. Allow to set for 20-30 min. and reassemble using a graduated sequence of torquing the head bolts.

Allow to set for 24 hours and operate the compressor at a low PSI. Hold and check for leaks. Ramp up the PSI and repeat until satisfied the repair holds.

The supplier should have various thicknesses of gasket material, choose one close to the original and error on the thick side.

The RTV should work instead of the O-ring. Any compressed air seal needs a 'wet' seal, as in even the original O-ring should have grease applied.

Good luck & good wrenching!

Jason

Didn't the compressor come with a replacement part list?  I have this same compressor (the 1/5hp one) and it has a list of parts in the manual that can be ordered from the manufacturer.  I did however get mine from Harbor Fright Tools, but it seems that the ones on the net are the same thing.

I don't know if this will work but here's the address for the PDF for this compressor.  You might have to copy and paste it to your browser.  Hope this can help! 

http://manuals.harborfreight.com/manuals/95000-95999/95630%20Compressor%20Kit%20Manual.pdf

Wow - thanks for the info Milairjunkie!

I was going to take the head off and take a look at the gasket this weekend. Any chance that you still might find the link to that company that sells spares?
As far as sealing goes - the only experience I have with leaking head gaskets is called "buy a rebuild engine"..
I was looking at this stuff on Amazon and was wondering if that would make a suitable sealant?

Permatex 80011 Form-A-Gasket #2 Sealant

In any case - for a cheapo compressor it obviously would have to be a cheap fix or it just wouldn't be worth it.
Thanks again for the info!

Kay.

I came across a German company retailing a comprehensive range of spares for these recently, but much as I search, I cant find it again!

Looking at a parts diagram for a similar compressor, it looks like the cylinder head plate (the black bit) has a fixed or bonded gasket on its underside & an O-ring on its upper-side. If the compressor is no longer required, I would strip the head & have a look, the lower side of the plate can most likely be sealed using a quality silicone liquid gasket material & if the upper O-ring needs replaced & bit of shopping around auto suppliers & the like should yield a replacement. If there are any pressed gaskets involved, likenesses of these could be made from thicker gasket paper (auto supply again).

If you do proceed, when you strip it down check all the sealing faces for dmage / imperfections, clean the sealing faces & wipe with a suitable solvent / degreaser & allow it to dry before closing up & bolt the head down evenly & tight - but keep in mind that the main body is die-cast. Allow the whole thing to dry & settle, & then run it up to pressure at a safe distance - just in case it decides to blow some of you handywork back out. 

It possible that the body, plate or head are warped, in which case you may find it difficult to make a seal which will last for any length of time.