Airbrush problems

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Airbrush problems

Joined: January 16th, 2005, 5:53 pm

January 17th, 2005, 12:10 pm #1

I've posted this in the braille scale section aswell.

I have a new Tamiya HG superfine airbrush and...

This is my trouble: I can not spray a fine line (1-2mm) for more than about 2-10 seconds before the needle clogs and the paint flow stops. (two days to paint a NATO patten on a leopard tank.)

This is what I've tried: Tamiya acrylic, Vallejo model air and Humbrol super enamal all thinned with their respective branded thinner (I've also tried other suitable thinners for each). I've done tests with 10%, 20%, 30%, 40% and 50% paint (acuratly measured) and tried air pressures between 8-40 PSI with each paint mix. So far I reckon I've spent at least 15 hours testing. I clean my air brush with very expensive cleaner (any sugestions for a cheap effective cleaner) with no change in the above pattern.

I'm getting desperate this is the scenario: as having just cleaned the nozzle not 10 seconds ago (for the umptenth time this hour) the paint flow is dieing I pull back just a little more on the trigger, the jam clears and a great big blob of paint ruins 3 hours work!


Thanks in advance,

Jason
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Joined: November 6th, 2003, 6:56 pm

January 17th, 2005, 1:25 pm #2

to clean your airbrush. I generally use Windex with a little amonia added
to it this also helps to cut thru the paint.

Hope this helps.

K
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jack fisher
jack fisher

January 17th, 2005, 6:42 pm #3

I've posted this in the braille scale section aswell.

I have a new Tamiya HG superfine airbrush and...

This is my trouble: I can not spray a fine line (1-2mm) for more than about 2-10 seconds before the needle clogs and the paint flow stops. (two days to paint a NATO patten on a leopard tank.)

This is what I've tried: Tamiya acrylic, Vallejo model air and Humbrol super enamal all thinned with their respective branded thinner (I've also tried other suitable thinners for each). I've done tests with 10%, 20%, 30%, 40% and 50% paint (acuratly measured) and tried air pressures between 8-40 PSI with each paint mix. So far I reckon I've spent at least 15 hours testing. I clean my air brush with very expensive cleaner (any sugestions for a cheap effective cleaner) with no change in the above pattern.

I'm getting desperate this is the scenario: as having just cleaned the nozzle not 10 seconds ago (for the umptenth time this hour) the paint flow is dieing I pull back just a little more on the trigger, the jam clears and a great big blob of paint ruins 3 hours work!


Thanks in advance,

Jason
I have an Iwata mb and I use tamiya acrylics diluted at least one to one with tamiya acrylic thinner and sometimes when doing the tiny lines I dilute even more at 25 psi. Clean up with windex as stated before and occasionally clean the brush with ammonia (careful with the fumes).
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Johan Detruyer
Johan Detruyer

January 17th, 2005, 7:18 pm #4

I've posted this in the braille scale section aswell.

I have a new Tamiya HG superfine airbrush and...

This is my trouble: I can not spray a fine line (1-2mm) for more than about 2-10 seconds before the needle clogs and the paint flow stops. (two days to paint a NATO patten on a leopard tank.)

This is what I've tried: Tamiya acrylic, Vallejo model air and Humbrol super enamal all thinned with their respective branded thinner (I've also tried other suitable thinners for each). I've done tests with 10%, 20%, 30%, 40% and 50% paint (acuratly measured) and tried air pressures between 8-40 PSI with each paint mix. So far I reckon I've spent at least 15 hours testing. I clean my air brush with very expensive cleaner (any sugestions for a cheap effective cleaner) with no change in the above pattern.

I'm getting desperate this is the scenario: as having just cleaned the nozzle not 10 seconds ago (for the umptenth time this hour) the paint flow is dieing I pull back just a little more on the trigger, the jam clears and a great big blob of paint ruins 3 hours work!


Thanks in advance,

Jason
Did you clean the needle thoroughly after each airbrushsession ? Seems to me that your needletip is catching paint that dries of course very quickly !
It could also be that your needle is bent on the tip and hence catching all the paint, but I suppose that should be visible.
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Joined: January 16th, 2005, 5:53 pm

January 17th, 2005, 9:50 pm #5

Thanks for all the responses and keep em come'n, I'm sure we'll get to the bottom of this sooner or latter.

I'm asuming that this is not a normal thing and airbrushes should spray for at least a minute or 2 before clogging? Can others please advise.

The needle looks fine even under a magnifying glass but i think you're on the right track.
This is my cleaning procedure, i think it's thorough but let me know if I'm wrong:
After each colour I...
1. Tip out remaining paint
2. Add cleaner and clean inside the cup with a paint brush, tip this out.
3. Add more cleaner and spray through.
4. Repeat 2.
5. Carefully take out the needle and gently clean with a cloth dipped in cleaner.
6. Clean boddy and nozzle with cloth soaked in cleaner then re-assemble.
7. Spray 1 cup of clean water.

Is it possible to have a needle and tip that dont mate well? (Tamiya is supposed to match them in the factory before sale, or so i read) or maybe there is an alignment problem in the body of the airbrush? It has never sprayed well even right out of the box I had this problem (2 months and four 1/72nd models ago). Can others with the Superfine please let me know how their's behave.

Sorry about the longwindedness of my responses but I'm assuming the more detail i give the quicker we'll get an answer.

Jason
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jack
jack

January 18th, 2005, 4:34 am #6

I put the nozzle of the windex gun in the cup and force a few squirts thru the airbrush with the needle already out then use the spray nozzle next to the sink to flush everything out.
By the way if the little thingy at the end of your brush (the part where the needle barely sticks out) is damaged (the hole is no longer perfectly circular) then paint will come out unevenly and build up on the needle protector,
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Joined: January 16th, 2005, 5:53 pm

January 18th, 2005, 10:38 am #7

Ok I think we have an answer, here is what I've found:

Under a magnifying glass i can see that from wide open as you close the needle down it doesn't come out through the centre of the nozzle. Taking the needle out of the airbrush and looking at it under the magnifing glass I can see that the tip is straight but the whole point is machined off centre by 20-30 degrees!!
Hence in any postion other than fully closed the tip of the needle touches one side of the nozzle. I'm pretty sure this is not normal, now what to do next?

Do airbrushes come with a warranty?

Is the nozzle now ruined?

Is this the cause of the clogging?

Thanks,

Jason
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Tom Herling
Tom Herling

January 18th, 2005, 12:02 pm #8

You might try rolling the needle on a table edge or other hard surface to straighten it out. If you can't straighten it out, perhaps just purchasing a new tip and nozzle would do.

There was an article in Fine Scale Modeler a while back about tuning up airbrushes. They suggested using metal polish to better seat the tip into the nozzle. You can find metal polish in any auto parts store.

The metal polish is used as a fine grinding compound. You put some metal polish on the tip and gently twist it in the nozzle so that the tip and nozzle surfaces polish each other to match as best possible.

You might be able to find that article by looking through their website.

Also, your problem could be that paint is drying on the tip as you spray. Try wiping the tip with a soft cloth dampened with thinner every so often as you spray. I've noticed this is a problem with acrylics, since they dry so quickly.

Tom
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Tom Herling
Tom Herling

January 18th, 2005, 12:02 pm #9

Ok I think we have an answer, here is what I've found:

Under a magnifying glass i can see that from wide open as you close the needle down it doesn't come out through the centre of the nozzle. Taking the needle out of the airbrush and looking at it under the magnifing glass I can see that the tip is straight but the whole point is machined off centre by 20-30 degrees!!
Hence in any postion other than fully closed the tip of the needle touches one side of the nozzle. I'm pretty sure this is not normal, now what to do next?

Do airbrushes come with a warranty?

Is the nozzle now ruined?

Is this the cause of the clogging?

Thanks,

Jason
You might try rolling the needle on a table edge or other hard surface to straighten it out. If you can't straighten it out, perhaps just purchasing a new tip and nozzle would do.

There was an article in Fine Scale Modeler a while back about tuning up airbrushes. They suggested using metal polish to better seat the tip into the nozzle. You can find metal polish in any auto parts store.

The metal polish is used as a fine grinding compound. You put some metal polish on the tip and gently twist it in the nozzle so that the tip and nozzle surfaces polish each other to match as best possible.

You might be able to find that article by looking through their website.

Also, your problem could be that paint is drying on the tip as you spray. Try wiping the tip with a soft cloth dampened with thinner every so often as you spray. I've noticed this is a problem with acrylics, since they dry so quickly.

Tom
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Joined: January 16th, 2005, 5:53 pm

January 18th, 2005, 1:00 pm #10

You might try rolling the needle on a table edge or other hard surface to straighten it out. If you can't straighten it out, perhaps just purchasing a new tip and nozzle would do.

There was an article in Fine Scale Modeler a while back about tuning up airbrushes. They suggested using metal polish to better seat the tip into the nozzle. You can find metal polish in any auto parts store.

The metal polish is used as a fine grinding compound. You put some metal polish on the tip and gently twist it in the nozzle so that the tip and nozzle surfaces polish each other to match as best possible.

You might be able to find that article by looking through their website.

Also, your problem could be that paint is drying on the tip as you spray. Try wiping the tip with a soft cloth dampened with thinner every so often as you spray. I've noticed this is a problem with acrylics, since they dry so quickly.

Tom
Here is a rough exagerated drawing of the needle. From both side on and point on.



It seems to have been machined crooked in the factory and not bent.

Your dead right paint drying on the needle tip is definatly the problem. I reckon it might be because the needle is crooked and touches the side of the noozle deflecting the paint flow onto the needle where it builds up and blocks the flow.

The metal polish sounds like a good idea to me, after I get this sorted out I'll give it a go as I don't think it will help with the crooked needle etc..

I've been searching for a new needle and tip on the net but I can't seem to find a vendor, any sugestions?

Jason
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