Dull misty dry coat

The Achilles' Heel of Luthiery
Ben-Had
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Dull misty dry coat

Post by Ben-Had »

I sprayed a color coat that came out dry and somewhat gritty. Will it smooth out after a clear top coat is applied? This has not happened to me before, I guess the heat and humidity are to high tonight in NC.

Tim B
Tim Benware
tippie53
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Re: Dull misty dry coat

Post by tippie53 »

nitro?
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Ben-Had
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Joined: Fri Sep 03, 2010 2:14 pm
Location: Creedmoor, NC

Re: Dull misty dry coat

Post by Ben-Had »

tippie53 wrote:nitro?
Yes.
Tim Benware
Tony_in_NYC
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Re: Dull misty dry coat

Post by Tony_in_NYC »

And?
kencierp

Re: Dull misty dry coat

Post by kencierp »

Is this a sunburst or something else. If its just a solid color you really should level it and re-spray a wet coat. I assume this is from cans? If its from a compressor the air mixture was wrong -- what I am really saying is more information required to make a logical assesment. Just laying on more coats of nitro will not necessarily level the surface -- actually most likely it will not. And if you have not already, go out and buy the best thinner you can afford -- it will not evaporate as fast and will prevent some other problems as well.
Ben-Had
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Joined: Fri Sep 03, 2010 2:14 pm
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Re: Dull misty dry coat

Post by Ben-Had »

kencierp wrote:Is this a sunburst or something else. If its just a solid color you really should level it and re-spray a wet coat. I assume this is from cans? If its from a compressor the air mixture was wrong -- what I am really saying is more information required to make a logical assesment. Just laying on more coats of nitro will not necessarily level the surface -- actually most likely it will not. And if you have not already, go out and buy the best thinner you can afford -- it will not evaporate as fast and will prevent some other problems as well.
Not a sunburst, solid dark red mahogany (double strength mix, stewmac color tone). Shot with compressor at 35 psi (adjusted at the gun), 1.4 mm tip (I have a 1.8 mm as well). Mohawk nitro 80%, Mohawk reducer 20%. Thanks for replies and any further help.

Tim B
Tim Benware
kencierp

Re: Dull misty dry coat

Post by kencierp »

To me it sounds like a simple air / fluid mix adjustment. Do you have a Zahn cup to check vicosity from batch to batch? Also, if not in a controlled area results can differ from day to day. I have a stack of cardboard I use to test my spray pattern, coat thickness and flow out etc. Since the gun is disassmebled after each use for cleaning there is no other way I can determine the mixture tweaks from the previous session.
tippie53
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Re: Dull misty dry coat

Post by tippie53 »

I agree with ken Spray adjusting can be finiky. If you get too much are you start drying before it hits the wood.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Ben-Had
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Joined: Fri Sep 03, 2010 2:14 pm
Location: Creedmoor, NC

Re: Dull misty dry coat

Post by Ben-Had »

Thanks John and Ken - I lowered air and increased the fluid and it came out much smoother.

Tim B
Tim Benware
tippie53
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Re: Dull misty dry coat

Post by tippie53 »

play with the knobs, it is what we do . You can learn alot. once adjusted mark the knobs for your settings , it gets you roughed in pretty well.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
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