Sunburst

[bobz]

Well I`ve strung one of my first mandos up and tuned to pitch with no disasters as yet. I have`nt done a sunburst finish before and I shall be spraying a sunburst finish using a Badger air brush and an air brush compressor. Can any of you buiders out there tell me if I need to mask off the sides when spray sunbursting the top and back? And likewise mask off the top and back when sunbursting the sides? Any help here will be much appreciated.
If you thick one of the strings is missing in the photos then your correct. One of the D strings broke when tuning up.

[Chris Baird]

I propped the mandolins up against a fan that was drawing air away from the mandolins as I airbrused them. I didn't have any overspray trouble except on the sides where the mandolin was sitting on the bench top where the tailpiece would be. I guess the overspray couldn't escape well there.

[Michael Lewis]

Bob, a lot of folks just spray away at it and scrape the bindings clean after it is all done. Let me recommend that you carefully mask all the bindings and face of the headstock before you spray the color. I always put a good sealer coat of clear down before the color goes on, that way if the job goes wrong it can be easily sanded off and re done. Seal the color coat with a clear coat BEFORE you handle the instrument, then remove the masking and clean up the binding before more clear coats.

[TNMANDO]

Hey Bobz,
I built a make shift spray booth out of a large box. I duct taped a good air conditioner return filter to the back of the fan, then cut a hole in the back of the booth(cardboard box) to fit the size of the filter. By facing the fan away from the inside of the spray booth it creates a nice vacuum to pull out any atomized particles in the air.
Good luck,
Will

[TNMANDO]

Some photos of my 15 dollar spray booth #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[TNMANDO]

and the back

[TNMANDO]

DOH! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[sunburst]

Well, I sort of feel a need to say something in a thread called "sunburst".

http://www.mandolincafe.net/iB_html/non-cgi/emoticons/cool.gif

Fact is, I don't spray sunbursts very often. I usually hand rub them on instruments that I build, and only spray them if I need to match a sprayed sunburst on restoration work. I don't seal first, I've done so many that I've figured out how to correct a lot of mistakes without having to start over, I guess. There is a definite difference in the look of rubbed and sprayed 'bursts.

Anyway, I've never masked the sides when spraying the top and back, and never masked the top and back when spraying the sides, and have never had a problem with overspray. I just spray at a slight angle so that the overspray goes away from the instrument.
Don't forget to stuff something in the "F" holes. They do need to be masked.

BTW, I hope you like your Badger air brush better than I like mine...

[HoGo]

I just airbrushed my next mandolin yesterday. All went well but remember you may have trouble getting color in the small spaces like inside of the scroll and even at the neck joint the air flow breaks tends to miss the very edge... experiment with the air pressure and flow of stain to get the best results.
Back to the original question... you dont need to mask sides when spraying top or vice versa. On the next one, however, I will mask scrolls and spray the inside before bursting the top.
Good luck.
Adrian

[bobz]

Thanks for info guys. sunburst, HoGo, thats what I wanted to hear. I did`nt fancy messing about with masking anyway. I shall mask off as much binding as practical with 3/16" and 1/8" masking tape. Saves some work scraping. TNMANDO, like your spray booth. I would make one myself, but I would`nt know where to source the fan as there`s not much call for air conditioning here in the UK. Thanks again. BTW, the mando sounds great. I don`t play mandolin, ( I enjoy playing my own made classical guitar ), but after hearing this instrument I just might take it up. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif

[Michael Lewis]

TNMANDO, Is that an "explosion proof" motor on your spray set up? You had better hope it is, but I'm guessing that it is not. I'm sure you are aware of the possibilities regarding atomized VOCs and electric arcs. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

[Luthier Vandross]

Nothing like a flash fire, nothing.

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M

[TNMANDO]

Are water based stains flammable? Last time I checked they are not. Please enlighten me if they are. I'm not planning on using the booth to spray lacquer or anything. I'm doing a hand applied varnish and french polish finish.

[Michael Lewis]

I would test whatever you are going to spray, as atomized materials can be very combustable. If you are just spraying water based stains and no other materials you are probably safe, but test it out carefully just to be safe. I don't want to hear how you lost your eyebrows, or worse. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif

[TNMANDO]

Thanks for the tip.

[thistle3585]

I'd like to throw my two cents in. One, water based products aren't going to explode. However, the more material that gets in the motor ends up oveheating the motor, regardless of the type of material. So, you risk getting zapped or starting an electrical fire. Two, even a spray booth isn't designed to divert the overspray, but mostly the fumes. If you have that much overspray, you should look at your spray technique or setup. Just my opinion.

[Luthier Vandross]

Agreed, agreed, lmao, agreed.


M

[TNMANDO]

Anybody else want to tell me how to improve my spraybooth. That's not what this thread is about. I was simply showing Mandoplyr a different way to use a fan. I'm not concerned about overspray. I use it to keep the fumes from filling my garage. I don't use any combustable prducts and I don't stick my fingers in the fan either. (my mommy taught me that one)Thanks for all the help but let's try to get back on topic, and answer Bobz'question.???

[TommyK]

"...I would make one myself, but I would`nt know where to source the fan as there`s not much call for air conditioning here in the UK..."
Bobz,
Take another look at the back side. Surely, you Brits have breeze box fans? That's not an A/C part, just a cheap floor fan. We yanks get them at WalMart for about $15.00. The filter, while used on whole house A/C units is also used on furnaces. I've always called 'em furnace filters, not being able to afford whole house A/C.
As for the fan motor... maybe a baffle of cardboard on the backside of the motor (between it and the filter) would keep the brown stuff from gumming up the brushes. Explosion? not likely, but be on the safe side and do it in a well ventilated area and keep a fire extinguisher handy. Maybe set the whole affair up so the exhaust blows out a window. Your dog may love you for it.
Make sure you remove the window screen, or you'll have a ring of brown in the middle of your screen.... I speak from experience! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif
http://www.mandolincafe.net/iB_html/non-cgi/emoticons/coffee.gif http://www.mandolincafe.net/iB_html/non-cgi/emoticons/coffee.gif

[bobz]

I`ve just been on the Guild of American Luthiers site to see when I can expect the next journal issue to hit my door mat. It will shipping in October but I want it now. I`ll most probably get it early November, the reason I want it now is below. Oh well, I`ll just make balls up sunbursting my mandos now, and find out how it`s done in November. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

We have finally arrived at the last episode of our five-part mandolin construction series. This one is all about sunburst finishing. We follow Don MacRostie as he sprays a stain burst on one of his F-5s, then Peggy Stuart does a full non-toxic burst on her A model with padded-on water stain and shellac.