Official Luthiers Forum!

Anyone! help! I fired up my new Fuji Q4 HVLP sprayer and went at the mando I was re-doing. I like it so far but seem to be having a hard time getting a wet coat unless I realy lay it on...then I get orange peel. The peel levels out but I realize I must be doing something wrong...any suggestions? I did try thinning the nitro with some butyl cellusolve about 10 percent. But not any noticable change. I am using Behlens Master stringed instrument nitro. TIA

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

DId you use retarder and what is the setting of the sprayer. You should have some adjustments. Flow and air . I think you have too much air for the amout of paint you are flowing
john ahll

have you tried adjusting the valve on the end of the hose? That controls
the amount of air flow. Between that, the needle size (the q4 std needle
is plenty big enough for nitro), and the other gun adjustments you should
have no problems laying on a nice even and thin coat.

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John Mayes
http://www.mayesluthier.com

Set your air pressure to about 45 lbs., mixture about 40% laquer and 60% reducer...no retarder needed unless you're shooting in a humid atmosphere and set the spread for about a 4" wide spray pattern. Hold your gun about 12" from the surface and keep a smooth constant flow. As you are spraying, keep the reflection from a light where you are spraying where you can see it at all times. When you see the lacquer start to shine move along slowly to keep it constant. Move from left to right, and right to left across the guitar in a continuous motion. Overlap your spray pattern just a bit as to not have dry streaks. I always spray the corners and edges first then come back with the flat surfaces in a constant pattern. Spray 3 coats in 1 hour intervals. Let dry overnight (24 hours), wet sand and do it again. Don't get frustrated...finishing is one of the toughest parts and takes the most time of the building process.Brazilwood38588.9019675926

[QUOTE=Brazilwood] Set your air pressure to about 45 lbs., mixture
about 40% laquer and 60% reducer..[/QUOTE]

that is really way more thinner/reducer than you need when using the fuji
gun. I never thinned my nitro at all except for the final two coats where I
would thin it 20% or so to help a nice flow out and make final wet sanding
easier and it laid down great. I usually had to add some retarder here in
the oklahoma summer, but no thinner. I think he is really just dealing
with a set-up adjustment.

One more thing .. call Fuji. The couple times I had questions I called
them and they were very helpful, and of course free to talk to.

_________________
John Mayes
http://www.mayesluthier.com

Thanks for the responses. I will definitely turn back the air. I have it full blast at the moment. Behlen recommends spraying full strength without any dillution. I have been dilluting about 10% because it is so hummid here in fla. THANKS AGAIN GUYS!

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Dave...if you are finishing with Nitro in Florida in August..I would say you definitely would require a retarder. When you spray lacquer in a humid, non controlled environment, humidity (moisture) will enter into the laquer as it passes through the air (from your gun to the guitar surface). When the nitro starts to seal (within 10 to 15 minutes) this moisture will get trapped in the lacquer which will cause a clouding effect in your finish. (Water and Nitro are not a good mix) Retarder will slow the sealing process and allow time for the moisture to evaporate before the lacquer seals. Thus avoiding a potential problem. Believe me..when you get "Blushing" in the finish, the only real solution is to completely sand off the finish and start again. I've been through this several times and it didn't take long to realize I wanted to avoid it at all costs. There are some products out there (blush remover was available thru Stew Mac) that if you catch it fast enough will take out the blush. But, it's not 100%. I've used it on occasion to save the day but, could still see the blushing effect a little if I looked at it in the sunlight or outdoors. The best solution to a problem is a good prevention. Gibson actually moved their acoustic division from Tennessee (where humidity was a big problem in the summer) to Montana (where there are more months without humidity issues)due to finishing problems. So, imagine the difference in Sunny - Hot - Humid Florida. Good luck..

Dave, did you really go at a Mando without testing the gun? YIKES! Anyway, I think lowering your pressure will help a great deal. When I was in AZ spraying was hard for me as the air was so dry and hot that the paint was drying before it hit the surface. I lowered the pressure WAY down and (had to) thin it a bit to get it to flow out of the gun right. 40%/60% seams pretty high to me as well. Seams like you would not really be putting much paint on but mostly solvent. Find the mixture that works in your environment and to your gun.
Oh, and yes, retarder will most likely save you lots of frustration in the future.

There were reasons I used a 40%/60% mixture. First and foremost was to reduce the amount of Lacquer being applied to the body. I always felt that a heavy finish does smother (dampen) the sound of the box. And your analogy was correct PWoolson, you're not putting much finish on the body...my intended result. Just enough finish to give the cosmetic result you are after without killing the sound. Plus it makes the finish flow better. I don't have a lot of photos of my finish work as most of my pictures were taken with a 35mm (before my digital days) but, here is one that I scanned and the reflection should show you my results.

Wow! that's a beautiful inlay Jeff! Is that Stevie?

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Dave Rector
Rector Guitars

That's Stevie..this was a custom model I made for a guy who was a huge "Stevie Ray Vaughn" fan. The "teardrop shape design" represented the great sadness and loss, the rest was sort of a last curtain call theme. I did it all out of different woods with the exception of the shirt which was "mother of pearl". Thanks for the compliments. This guitar got a lot of attention at the Nashville shows.

Ok I am going to show my age. While I am young enough to ave been one of Stevie's big time fans (with us for way too short of a time ) My first thought was it's Gary P. Nunn.

I have several of his bootleg (actualy early Austin sceen days self produced tapes not really bootleg)tapes and one has a pic of him from the rear walking down a dusty road in a black hat and a peasent shirt, but it was a martin on his back not a Stat.

Let's see that would have been in about Oh 69 or 70 I was 14 or 15 Please don't do the math

Thanks to everyone who responded.
Jeff, I did have some blushing when I was using a standard sprayer but I simply sprayed the next day with a light coat of butyl cellusolve and it completely disappeared. Yes it is hummid...around 90 percent on a dry day. I am spraying outside ( by the pool on the back deck) and then letting it flash off and then hanging in my shop overnite ( 40-50 % at 75 deg.) . I only spray one - two coats a day and usually hang the mando outside for 20 minutes or so to aclimate some before spraying.
Paul, yea I went at it straight away, well I sprayed some old , large cardboard sheets first, but I went at the mando after I already had the burst done and a coat or two of clear from my standard gun. The way I see it I pt so much work into this thing that If I gave it back right now he's way ahead and compared to the way it was when I got it...well forget it! It was unplayable...I completely stripped the neck and body, cleaned out over spray from interior( last person to spray didn't bother covering the f holes, put a new fretboard and frets on , new binding, plugged and re-drilled tuner holes, all new hardware. All that for a Martin "forest friendly" dread. It was for a neighbor...and yes he is peeing himself with joy. So anyway I could pretty muc tie the thing behind a truck and drag it down the street and the owner would still be happy. I know...still should have worked out the kinks first!
Just as I was writing this the mando was hanging on the back deck ( under the covered portion THANK GOD!) and we got a heavy down pour...I can probably still go spray once the rain stops because the hummidity probably won't be any higher than it was with the sun shinning!!!!

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

[QUOTE=MichaelP] Let's see that would have been in about Oh 69 or 70 I was 14 or 15 Please don't do the math [/QUOTE]

Michael, so long as I'm here, nobody needs to worry about arithmetic...

John Mayes,
Thanks for the air tip, turned it down at the hose and it is spraying on much wetter/nicer. THANK YOU !!!!

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Jeff,

I did go out after the rain stopped and sprayed a full coat on the top, back, and sides. No blush what so ever. I think it is because I am adding the butyl Cellusolve right in with the nitro. It melts on beautifully.


p.s. I still seem to be getting Orange peel. But I am lucky, I guess because it must be the B.C. that's flattening it all out? I don't know?Dave-SKG38589.7382986111

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

I Think the butyl just delays the hardneing time and keeps it open long
which ends up letting the finishsettle and flow out better. AS long as it is
flowing out it's good, but I never had a problem with any orange peel at
all. You should have the 1.4 tip right? That tip is large enough for even
thicker urethane so there should be plenty of material. So as long as the
pattern is tight enough (I normally left it almost wide open.. about a 6-8
inch flat vertical pattern) and your not spraying too far from, the surface
you should not be getting any orange peel.

_________________
John Mayes
http://www.mayesluthier.com

I have the #3 tip and #4 tip and #5 which are 1mm;1.4mm; and1.8mm. I have the 1.4mm in the gun. When you say wide open do you mean the collar in? Instructions say turning the cllar in and out changes the size of the fan. The adjustment on the rear of the gun seems to adjust the triggerwhich I suppose is the "fluid control knob". I do have the collar set to spray a flat vertical pattern. The pattern looks to be about twelve inches wide when about 12 inches from surface. How close should I be to the surface? The manual says 8" max. What do you recommend? Thanks John!

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Hi Dave
I spray all the time up here beachside New Smyrna, and use just a few drops of flash off controladded to Mohawk classic instrument laq. The butyl seems to take a long time to harden in this humidity. Although it will stop blushing, it keeps the finish soft for several days. The flash off doesn't seem to affect the finish that way.

[QUOTE=DaveF] Hi Dave
I spray all the time up here beachside New Smyrna, and use just a few drops of flash off controladded to Mohawk classic instrument laq. The butyl seems to take a long time to harden in this humidity. Although it will stop blushing, it keeps the finish soft for several days. The flash off doesn't seem to affect the finish that way.[/QUOTE]

That sounds great! Where do you buy from? Is it made by Mohawk? Thanks for chimming in!

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

O.k. I thinned what I thought was going to be my last two coats 50/50. Sprayed the neck and headstock. Got bubbles and a minor run on the headstock and Blush all over! Yikes! I think a lite coate of BC will resolve the blush but what about the bubbles? What caused that? I also assume I will have to sand those out they appear close to the surface. ANY Help is GREATLY appreciated.

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Bubbles are usually a sing of too thick of a coat. However, spraying a 50/50 mixture shouldn't do that.You may have to pop the bubbles and drop fill them, then try a very light finish coat. The blushing is because the finish is flashing off too fast, and the humudity is too high.

I think thinning it 50/50 is way to much. For final coats I thinned like 20
-30% at most. Blushing is humidity..plain and simple. Put some retarder
in the finish. I used the stuff LMI sold with great success. A cap full
worked good for a full quart. The bubbles may be solvent pop..either it is
a cause of too much thinner or there is some foreign matter in the finish.
It can also be from laying it on too thick, but with lacquer that is normally
not an issue.

_________________
John Mayes
http://www.mayesluthier.com

Thanks John! Thanks Everyone! Your help is greatly appreciated!Dave-SKG38593.3571296296

_________________
Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"