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NEW UPDATE 02/15 What to use in place of lacquer thinner


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I have the absolute worst luck with airbrushes. I am stil having issues. Painting bodies has been the biggest obstacle for me and it is pretty much the reason i don't finish builds. 

 

I have a Grex Tritium TG airbrush. I was told by the Grex rep that I can spray lacquer thinner through it without issue. This isn't true. The packing seal o ring, the tiny o ring deep inside the body, starts to deteriorate and swell. This allows air/paint blowback to get past the needle seal and I am having a really hard time laying down nice paint. I'm sure this isn't the sole issue, but this needs to get fixed before I can move onto figuring out what else I can do to improve. I have 2 uses since I did a complete teardown and rebuild with all new seals and o rings. The o ring is swelling and coming apart already. 

What will clean lacquers that I can use instead of lacquer thinner? Isopropyl Alcohol is not working, at least on the Gravity Colors I was using tonight. I am honestly ready to just sell all my BLAH_BLAH_BLAH_BLAH an move on. I enjoy building more than actually finishing, but I would like to finish a model here and there. 

I would honestly just buy another airbrush, but I already started getting arthritis and cramps in my hands and this airbrush makes a massive difference, since it has the pistol grip. 

Edited by Quick GMC
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Do you still have any "good" o-rings? If you do you can measure them up and go to McMaster Carr and order better ones that will work with laquer thinner. If you can't measure them accurately enough get the size from your airbrush guy.

http://www.mcmaster.com/#o-rings/=10yqxsl

Mark

Edited by astroracer
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I had the same issue w/my Grex Tritium TG. Once I replaced my O-ring (and bought spares), I began to take better care of it. First I make sure the needle always comes out of the airbrush and is inserted back into the airbrush from back to front, so the blunt cut-off end never goes through that O-ring first. Second, I always use the blue needle lubricant applied to the needle in the general area it goes through the O-ring. This helps to protect the O-ring from the solvents and from the friction of the needle itself going through the O-ring.

I have had zero issues since replacing that first O-ring, but I'm also careful. If it becomes an issue again, I'll have to source better O-rings. So far, not necessary, and I use the brush a lot.

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Grex uses O-rings?  Hmmmm, I guess they are off my list.  I have a Badger, and several Tamiya/Iwata brushes and guns and they all have Teflon seals.  No problem with lacquers. Does Grex make a Teflon replacement?  Most companies do.  You might try that first.  Call Coast Air Brush in Anaheim. http://www.coastairbrush.com/  They would know for sure. Very helpful and knowledgeable when you need help with air brushes.  

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If you really love your airbrush and the manufacturer doesn't supply a solvent-resistant O-ring, you can try a little re-engineering yourself. Teflon (PTFE) O-rings (and other solvent-resistant compounds) are available from a variety of sources. Here's one, with some good information.

NOTE: Some industrial suppliers will still give you samples in small numbers for "evaluation". And while some industrial suppliers have minimum orders, others will happily sell you just one. 

http://www.coorstek.com/resource-library/library/8510-1182_teflon_o-rings.pdf

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You are not soaking in lacquer thinner are you?  You should be able to shoot through the gun though.  I have Iwata air brushes and use their Medea cleaner for actual cleaning.

Not soaking. Putting it in the cup to spray through after finishing with a color, or when I am done using it. I spray it through, then disassemble the airbrush to wipe down what I cant

Do you still have any "good" o-rings? If you do you can measure them up and go to McMaster Carr and order better ones that will work with laquer thinner. If you can't measure them accurately enough get the size from your airbrush guy.

http://www.mcmaster.com/#o-rings/=10yqxsl

Mark

I have one left. I can measure it. i will check that out, thank you

you can clean your airbrush with lacquer thinner, BUT be sure u remove all the O rings..lacquer will swell them..

The rep told me 2 times, without a doubt, I can safely use lacquer thinner through the brush

I had the same issue w/my Grex Tritium TG. Once I replaced my O-ring (and bought spares), I began to take better care of it. First I make sure the needle always comes out of the airbrush and is inserted back into the airbrush from back to front, so the blunt cut-off end never goes through that O-ring first. Second, I always use the blue needle lubricant applied to the needle in the general area it goes through the O-ring. This helps to protect the O-ring from the solvents and from the friction of the needle itself going through the O-ring.

I have had zero issues since replacing that first O-ring, but I'm also careful. If it becomes an issue again, I'll have to source better O-rings. So far, not necessary, and I use the brush a lot.

I had a massive improvement after replacing the o ring the first time. But I have replaced it 2 times since then and only have one left. I use the blue Iwata lube. I pull the trigger back and apply the lube through the side directly into that packing screw, then slide the needle through, just like you described. I apply the lube every other time I use the brush. 

Grex uses O-rings?  Hmmmm, I guess they are off my list.  I have a Badger, and several Tamiya/Iwata brushes and guns and they all have Teflon seals.  No problem with lacquers. Does Grex make a Teflon replacement?  Most companies do.  You might try that first.  Call Coast Air Brush in Anaheim. http://www.coastairbrush.com/  They would know for sure. Very helpful and knowledgeable when you need help with air brushes.  

There is a nylon washer in the body, then a packing screw with an o ring on the end of it. The other o rings are out of harm's way

If you really love your airbrush and the manufacturer doesn't supply a solvent-resistant O-ring, you can try a little re-engineering yourself. Teflon (PTFE) O-rings (and other solvent-resistant compounds) are available from a variety of sources. Here's one, with some good information.

NOTE: Some industrial suppliers will still give you samples in small numbers for "evaluation". And while some industrial suppliers have minimum orders, others will happily sell you just one. 

http://www.coorstek.com/resource-library/library/8510-1182_teflon_o-rings.pdf

I will check them out, thank you 

 

Here is a picture of the o rings. On the left is the unused new one. On the bottom is the one that has seen no more than 2-3 sessions. On the right is one that was used for half a dozen or more sessions. The only thing i put through my airbrush is Klean Strip lacquer thinner from Home Depot, Vallejo acrylic thinner and 91% Isopropyl Alcohol. 

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You could try "Mr. Color Thinner" for lacquer.  It is mostly Isobutyl Alcohol I believe.

Anyway it is in a plastic bottle if that tells you anything.

I have only used it once as a test to find a good airbrushable primer.

Used to thin Mr. Surfacer 1000, 2 to 1 and it worked a treat.

Next I'm going to try it with some Model Masters enamel.

They also have a slower "leveling" version I'd like to try.

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Ok, so I have learned a lot about lacquer thinner in the last few days. I knew there were different brands that would vary, but I never knew that there were different "speeds." Nobody has every mentioned this before, until I talked to the Grex rep.

First of all, Grex rep talked to me for 45 minutes on the phone and it was one of the most incredible customer service experiences I have ever had. He was very interested in finding a solution to the problem. Turns out he uses the same brand and same can of lacquer thinner as I do. He insisted I ship my airbrush to him for a thorough inspection and rebuild. He ended up not replacing anything except the o ring and one other sliding part that I didn't know I was supposed to put grease on. Other than that he said it was in great shape. If anyone is considering Grex, I would highly recommend it because of their customer service alone. I shipped the brush to them on Thursday, they called me Friday morning and had it apart and put back together already. 

This particular seal I am having trouble with is made of Viton. I was informed that Viton is fine with most solvents, except Acetone, which will definitely destroy it. It was also pointed out to me that the Klean Strip thinner from Home Depot is a fast thinner, or has a high concentration of Acetone. I will now try and slow thinner that has much less, or no acetone. This will supposedly solve the problem. 

I bought a second Grex Tritium after shipping my airbrush to them as a backup/second setup. They have a new fan tip I want to use for bodies. Normally wouldn't be the smartest thing to double down on my issues before I find a solution, but I know there is a solution, I just have to find it. 

So using my brand new out of the box airbrush, i had the same problem, which is what I suspected would happen. After 2 uses, the seal wen bad again, which is actually what prompted the response above, from Grex, about the acetone. 

I decided to do a test. I normally use Scale Finishes lacquer base coat, which is what I did here. Then I used a 2 part urethane clear for the first time. I have heard these can be a problem too. So I found a o ring from Grex made of the same Viton that I didn't need and cut it into 3 pieces. 

Then I mixed up some clear the same way I did when I sprayed the body, lacquer thinner in a cup and some Scale Finishes paint in a cup. 

I let them sit 10 minutes, then pulled them out. Paint did not have any effect. The clear may have had a slight affect, probably due to the part of thinner that was added. The Lacquer Thinner is clearly the culprit. 

here in the same order, the piece in the thinner is easily twice the size that it started out as

 

So there it is. I don't blame Grex. It is what it is, and they say they have had a very small amount of people with o ring issues. The seal should be replaced every 6-12 months they say, which is perfectly acceptable to me. When not having o ring issues, the airbrush works incredibly well. 

I will be ordering a slow speed thinner and I will report back. 

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Cameron, you certainly did your homework on this issue. 

What that Acetone did to the o-ring is not a surprise to me, it is nasty stuff.

The fact that it is in part what makes up regular cheap Lacquer thinner / stripper

has me wondering just what a good "slow" thinner is?

Did the guy from Grex give you any ideas of what thinners to try specifically?

Again, thanx for the information and the follow up.


 

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I am actually very happy you posted this. No offense, but it means I will never own a Grex airbrush. I have tried them at shows and thought them to be solid pieces of equipment. Knowing this about them takes them off my list because I use so many different lacquer paints.  I'll stick with my Iwata/Tamiyas and Badgers.

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I have been trying the local auto shops for slow thinners, but so far they are all restricted in CA, figures. I am trying to place an order for one on Amazon right now, we'll see if it goes through. 

 

Here is a good article I found that lists all the different ingredients that are used to manipulate the speed of thinners

http://news.thefinishingstore.com/index.php/understanding-solvents-part-iii-laquer-thinner/

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I placed the order on Amazon without issue, let's see if it gets kicked back or not. 

This is what I ordered: http://www.tcpglobal.com/RSP-LT85-GL.html#.VrvbgFgrLhE

I'll start with that and see what I can do from there. If that doesn't help, I'll start calling o ring companies and find a solution. Once I find the fix, I should be good. 

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Slow (or high temperature) reducers (thinners) for automotive paints have slower evaporation rate than medium- or low-temperature reducers.  The slower evaporating solvents are usually less aggressive (so probably safer for rubber o-rings).  I have a Badger model 200 airbrush and it uses Teflon gaskets for the areas which have contact with paint.  Teflon is solvent resistant.

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So I got the new thinner in. Turns out they are in San Diego, so one day shipping for me. I did the test again and the o ring got a little swollen, but nothing like before. This should make the o ring last a lot longer. I haven't used the airbrush yet, but after a few uses I will take it apart and report back. 

This is after about 10 minutes in the thinner. 

 

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  • 5 years later...

I was about to place an order for a Grex Tritium.TG but now reading this I think I'll pass.

Are the Grex airbrushes still being made with the rubber o-rings or have they switched to teflon seals?

Edited by crowe-t
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Nitrile or nitrite

On 2/9/2016 at 12:31 PM, Quick GMC said:

Ok, so I have learned a lot about lacquer thinner in the last few days. I knew there were different brands that would vary, but I never knew that there were different "speeds." Nobody has every mentioned this before, until I talked to the Grex rep.

First of all, Grex rep talked to me for 45 minutes on the phone and it was one of the most incredible customer service experiences I have ever had. He was very interested in finding a solution to the problem. Turns out he uses the same brand and same can of lacquer thinner as I do. He insisted I ship my airbrush to him for a thorough inspection and rebuild. He ended up not replacing anything except the o ring and one other sliding part that I didn't know I was supposed to put grease on. Other than that he said it was in great shape. If anyone is considering Grex, I would highly recommend it because of their customer service alone. I shipped the brush to them on Thursday, they called me Friday morning and had it apart and put back together already. 

This particular seal I am having trouble with is made of Viton. I was informed that Viton is fine with most solvents, except Acetone, which will definitely destroy it. It was also pointed out to me that the Klean Strip thinner from Home Depot is a fast thinner, or has a high concentration of Acetone. I will now try and slow thinner that has much less, or no acetone. This will supposedly solve the problem. 

I bought a second Grex Tritium after shipping my airbrush to them as a backup/second setup. They have a new fan tip I want to use for bodies. Normally wouldn't be the smartest thing to double down on my issues before I find a solution, but I know there is a solution, I just have to find it. 

So using my brand new out of the box airbrush, i had the same problem, which is what I suspected would happen. After 2 uses, the seal wen bad again, which is actually what prompted the response above, from Grex, about the acetone. 

I decided to do a test. I normally use Scale Finishes lacquer base coat, which is what I did here. Then I used a 2 part urethane clear for the first time. I have heard these can be a problem too. So I found a o ring from Grex made of the same Viton that I didn't need and cut it into 3 pieces. 

http://i.imgur.com/GamEuoH.jpg?1

http://i.imgur.com/vvWU9yQ.jpg?1

Then I mixed up some clear the same way I did when I sprayed the body, lacquer thinner in a cup and some Scale Finishes paint in a cup. 

http://i.imgur.com/qxJSGHP.jpg?1

I let them sit 10 minutes, then pulled them out. Paint did not have any effect. The clear may have had a slight affect, probably due to the part of thinner that was added. The Lacquer Thinner is clearly the culprit. 

http://i.imgur.com/31r8feu.jpg?2

here in the same order, the piece in the thinner is easily twice the size that it started out as

http://i.imgur.com/3kltAsf.jpg?1

 

So there it is. I don't blame Grex. It is what it is, and they say they have had a very small amount of people with o ring issues. The seal should be replaced every 6-12 months they say, which is perfectly acceptable to me. When not having o ring issues, the airbrush works incredibly well. 

I will be ordering a slow speed thinner and I will report back. 

Clean Strip is a medium thinner, it says it right on the can in very fine print. Non the less at it's price point I'd be surprised if it didn't have at least some acetone in it. I usually cut it up to 50% with Xylene to slow it down a little more if I use it as thinner except in enamel paint where it's fine straight out of the can. I mostly use it as cleaner though.

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Just an FYI Kleen strip lacquer thinner as sold in California is predominantly acetone and ethanol.  The composition is spelled on the Manufacturer's Safety Data Sheet.  AKA MSDS.  Here is the web site for this product. http://www.kleanstrip.com/product/lacquer-thinner-for-california  Click on the MSDS/Data tab and then on the SDS tab.  You will see, shockingly, that this product, as sold in California can be as much as 100% Acetone!  Unlikely that it is that way, but it can be.

  This is bears out what I have said for years.  All lacquer thinners are not the same.  Automotive lacquer thinners meet a much more stringent standard and will do a better job of dissolving the solids in your paint but they are also more inclined to attack plastic such as your O-rings.  Not to mention a heck of a lot more expensive. 

 If you were able to order Restoration Shop lacquer thinner(I assume that is what your got because their HQ is in San Diego) in SoCal you were very lucky.  I tried not so long ago and they refused. Amazon also had a block on the sale.   I had to ship it to a friend in Arizona and he shipped it back.  Last time I was in Phoenix, I stopped by the PPG auto paint store and bought 2 gallons of PPG thinner.  I now have 3 gallons.  I will reserve these for paint thinning only and clean the airbrush with straight acetone. Living in SoCal has its issues. 

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