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Spray equipment for Polyester?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=21436		 Page 1 of 1
Author:  Alain Desforges [ Thu Mar 12, 2009 3:28 pm ]
Post subject:  Spray equipment for Polyester?
Members of the board, I am in the process of moving to catalyzed polyester finishes on my guitars.

I've shopped around a bit but all the information gets confusing as everyone is dissing the other in an attempt to sell their wares.

I was originally thinking of getting a Fuji HVLP mini mite 3 but then I upgraded to the 4 because I'm that kind of guy. Then someone told me that HVLP couldn't lay down as good a finish as with a classic compressor/gun combo... Then another chimed in claiming ultimate superiority with a Kremlin pump that is an Air Assisted Airless sytem that is as cool as it is expensive.

The Kremlin, although tempting, is out of the question. I have it narrowed down to the Fuji (780 CAD) or a 5HP compressor with a Devilbiss FLG3 (1100 CAD).

Any thoughts or personal experiences would be welcome.

TIA
Author:  TonyKarol [ Thu Mar 12, 2009 3:50 pm ]
Post subject:  Re: Spray equipment for Polyester?
Alain .. I would call Mario Proulx or Mike Collins (the Cdn one in Keswick) and ask what they are using .. they are both shooting polyester
Author:  Rod True [ Thu Mar 12, 2009 3:53 pm ]
Post subject:  Re: Spray equipment for Polyester?
Al buddy,

James Orr just purchased a new gun based on spraying Cat PE. He's been talking with Rick Turner as well as Joe white.

Here's his thread about it viewtopic.php?f=10101&t=21346 and the price was pretty reasonable.

Shoot him a PM too as you and him are in the same boat.
Author:  Flori F. [ Thu Mar 12, 2009 4:05 pm ]
Post subject:  Re: Spray equipment for Polyester?
Alain Desforges wrote:
Then someone told me that HVLP couldn't lay down as good a finish as with a classic compressor/gun combo...

I would be extremely suspicious of this claim. The problem is most likely the person spraying, not the gun.
Author:  Michael Dale Payne [ Thu Mar 12, 2009 4:09 pm ]
Post subject:  Re: Spray equipment for Polyester?
Flori F. wrote:
Alain Desforges wrote:
Then someone told me that HVLP couldn't lay down as good a finish as with a classic compressor/gun combo...

I would be extremely suspicious of this claim. The problem is most likely the person spraying, not the gun.


it is a knowing how issue, those that have gone through the process of mastering HVLP can lay down super films. those new to them have a hard time because they are two totaly differnt creatures
Author:  WaddyThomson [ Thu Mar 12, 2009 4:20 pm ]
Post subject:  Re: Spray equipment for Polyester?
Those air assisted airless systems are really nice, but they are expensive. My son uses one of those for finishing cabinets in his shop, where he has to apply lots of specialty finishes. They might be overkill for a guitar shop, though, they are very good for uneven surfaces, like cabinet doors, because the control is so good.
Author:  James Orr [ Thu Mar 12, 2009 4:47 pm ]
Post subject:  Re: Spray equipment for Polyester?
Hey Al

I'm a newbie, and this will be my first finish not sprayed with an aerosol can. Michael PM'd with me quite a bit about the Fuji systems, but ultimately I went with an Iwata LPH-300 with 1.3 tip from tcpglobal.com (ordered through phone, great customer service) and a 20 gallon Lowe's brand compressor that had a decent 6 SCFM rate at 40 PSI. Joe and Rick were both really enthusiastic with my gun choice, so the next step is to learn to use it. Rod and I were PMing about that, too.

I know you're asking about another system, but my tax return bought...

From TCPGlobal.com
Iwata LPH-300 w/o cup
Tyvek suit
Chemical-rated respirator with replaceable cartridges
Regulator for the gun
Filter/Dryer
Adapter for the 3M PPS system

From rockler.com
3M PPS mini starter kit. Mini is the perfect size for one guitar.
3M PPS mini refill kit

From micro-tools.com
2 CC glass syringe for measuring the cobalt and MEKP
25 gauge blunt needle

From jamestowndistributors.com
2 oz. MEKP liquid hardener (wasn't sure how to find this locally)
Author:  Rod True [ Thu Mar 12, 2009 5:09 pm ]
Post subject:  Re: Spray equipment for Polyester?
Hey James,

It would be great if you won't mind even putting ball park $$$ in your details, just to see where that set up stands (money wise)

Al, I think it would be most beneficial to get your stuff out of the US, even with the crappy exchange right now as well as the shipping etc... I think you'd still be paying less than the massive up charge from a Canadian supplier.
Author:  James Orr [ Thu Mar 12, 2009 7:21 pm ]
Post subject:  Re: Spray equipment for Polyester?
That's a great idea. I'd post direct links if I knew how to without displaying the long url. Keep in mind that even the consumables will last through many many finish jobs. I forgot to order a tyvek hood and gloves, but I can get those locally for $2 dollars or so. I see now that I also could've ordered the MEKP from TCP Global for the same price and saved on shipping, but we learn as we go. The PPS system is also a must as far as I'm concerned since this finish requires some measuring. It's a disposable cup system that makes cleanup easy, but it also has graduations like a measuring cup to make mixing the finish much easier.

From TCPGlobal.com
Iwata LPH-300 w/o cup: 310.00
Tyvek suit: 14.61
SAS respirator with replaceable cartridges: 47.00
Devilbiss HAV-501 regulator: 20.00
Filter/Dryer item# TCP AF8039: 29.95
Adapter for the 3M PPS system: 10.00

From rockler.com
3M PPS mini size starter kit: 23
3M PPS mini refill kit: 23.99

From micro-tools.com
2 CC glass syringe: 14.95
25 gauge blunt needle: 2.95

From jamestowndistributors.com
2 oz. MEKP liquid hardener (wasn't sure how to find this locally): 5.75

From Lowes
17 gallon Kobalt compressor, 6 SCFM @ 40 PSI: 299
Author:  Alain Desforges [ Fri Mar 13, 2009 1:48 pm ]
Post subject:  Re: Spray equipment for Polyester?
Thanks a lot guys!

Waddy, indeed those Kremlins are mint! They gave me a demonstration and I sure wish they hadn't. Very silent and the atomization off those MXV guns is something to behold. But then there's the 2.5K price tag! So instead of having a 400$ paper-weight if something goes wrong, you have a 2500$ one! Just the gun is around 700 bones. If I were spraying every day, I might consider it, but for my very sporadic usage, I can't justify such an expense.

James, thanks a lot for those facts and figures. I had never heard of the Iwatas. Then again, I hadn't heard of the Walcoms and Kremlins either, until I started doing some research. I'll be looking those up for sure. The compressor I was looking at was the Omega PK-5020. It has 7.8 actual FAD-CFM's at 40 PSI and 6.4 at 90. The only thing bugging me is the price. They list at close to 1k, but now there's a special going on and I can have one for 750. I'm sure you'll agree that this is a lot of squeela, especially considering that I already own two compressors! Ha!

The Devilbiss gun I was looking at looks very well made and has the valve right at the gun too. That was hovering around the 300$ mark as well. The Walcoms seem like a well rated and reviewed gun as well... Decisions, decisions...

I'm also leaning towards having a compressor/gun combo. At least I'd have a decent compressor for other chores and I can always just change the gun if I don't like the performance. Although, I'm sure that just learning to use any quality tool will go a very long way towards achieving the desired results.
Author:  Skeet UK [ Fri Mar 13, 2009 3:16 pm ]
Post subject:  Re: Spray equipment for Polyester?
Hi there.

I am new to Guitar building, certainly to Acoustics, but I may be able to offer some advice regarding spraying material.

I am used to spraying Urethane 2K clear coats (House of Kolor UC35..the best)

The first thing you should consider, is that you do not need or want, a gun that has a large fluid tip and therefore a large "Fan".

You are spraying a Guitar, not a truck!

This will allow you to use a Mini Jet type gun, or detail gun, preferably Gravity Fed (requires less air) with a tip size of between 1-1.2mm.
I use 1.3 for Primer, 0.8-1mm for colour and 1.2 for Clear. You could go for the little known LVLP as opposed to the HVLP and achieve great results, with only 3-6 CFM. If you get a suitable compressor, you may be able to run an Airfed hood off of it, at the same time, to save your health and negate the need for replacing expensive filter cartridges.
You also want to look at drying your air, as a water trap is not sufficient.

Compressors create water and the water will be expelled down the air line at times. A water trap will catch the condensed water, but teh air itself will be at 50-100% humidity.

This is very bad! I see you are aware of TCP Global. There is a product called an Air Guardian, which is an in-line desiccant dryer and will remove most of this moisture.

I take the advice given by Jon Kosmoski; one of, if not THE finest custom painters in the world.

He suggests, that when spraying small items, to use a setup that delivers an even pattern 4 inches wide, 4 inches from the surface to be sprayed. Quite literally, adjust the gun using a tape, to get that even pattern, 4 inches wide, 4 inches from the surface (as measured from the tip, between the horns).

He also recommends doing something he refers to as "paralleling" the air cap (not sure if he intended to create a continuous verb there!).

This means that you should keep the gun parallel to the surface, while following the curves, like a missile hugging the ground.

This method, along with starting and stopping spraying OFF of the surface, will prevent irregular building of the material layer.

When spraying the clear, overlap each pass by 50%. When you look at a sample spray of a given fan setup, you will notice that the best coverage, is in the centre 50% of the pattern. By overlapping, you will get consistent, even coverage of material.

Guns wise.

Devilbiss, SATA, Iwata etc are all very good guns. Devilbiss do a "Finishline" series, which are excellent value. They also do a Filter regulator for your air system in that range "The Big Red One". The FLG5, is a very good gun. The Tyvek suit is a must, for yourself and the quality of finish.

http://www.tcpglobal.com/spraygundepot/sgair.aspx

This CamAir/Devilbiss unit, will remove oil and other contaminants as well as dry your air, all in one go! Brilliant!

Elsewhere on TCP, there are 2 or 3 gun kits by Devilbiss "Starting Line" 1.3 and 1mm units are available.

I hope this helps in some way.

Gary
Author:  Barry Daniels [ Fri Mar 13, 2009 5:19 pm ]
Post subject:  Re: Spray equipment for Polyester?
Gary,
That is helpful to me. I am switching from nitrocellulous to 2k urethane. I have not heard of reducing the fan down to 4", but it makes sense for a guitar. Also the parallel path idea is useful, although I kind of already did that intuitively. Thanks again,
Barry
Author:  Skeet UK [ Fri Mar 13, 2009 5:28 pm ]
Post subject:  Re: Spray equipment for Polyester?
Barry Daniels wrote:
Gary,
That is helpful to me. I am switching from nitrocellulous to 2k urethane. I have not heard of reducing the fan down to 4", but it makes sense for a guitar. Also the parallel path idea is useful, although I kind of already did that intuitively. Thanks again,
Barry


Glad to be of assistance.

Yeah, simply dial the pattern down to a 4 inch width, then adjust the air pressure and fluid delivery until you get a nice pattern, on a full trigger pull, that covers at the speed that you can control the gun.

You may need to add some more reducer (thinners) to allow it to flow nicely from the smaller tip, but that is no problem.
Author:  Barry Daniels [ Sat Mar 14, 2009 9:04 am ]
Post subject:  Re: Spray equipment for Polyester?
James, Do you already have a spray booth? I hope so.
Author:  Skeet UK [ Sat Mar 14, 2009 9:12 am ]
Post subject:  Re: Spray equipment for Polyester?
Barry Daniels wrote:
James, Do you already have a spray booth? I hope so.


I would be interested to hear/see what peoples spray booth's are like and what equipment they use in them (extraction and filtration etc).
Author:  Alain Desforges [ Sat Mar 14, 2009 10:50 am ]
Post subject:  Re: Spray equipment for Polyester?
Gary, thanks a lot! Great info and advice. I had heard about keeping the gun at a constant distance from the piece being sprayed.

I know Walcom have a smaller gun, I think it's the EGO HVLP that has a smaller cup and is considered a 'touch-up' gun. Would 125CC's contain enough to spray a guitar?

As for a booth, I'm still shopping around for options. Booths in Ottawa are crazy expensive. A 5ft wide benchtop, open-ended model will run you 5K. And that's without the exhaust stack! (add another 1K+) I've seen comparable models on ebay for under 1K.
Author:  Skeet UK [ Sat Mar 14, 2009 11:34 am ]
Post subject:  Re: Spray equipment for Polyester?
125cc is certainly enough to be getting on with. You have to consider the "pot life" of your mixed 2k. Normally a couple of hours or so, after which it will set up in your gun!

You will have to let each coat flash off before applying another, which gives you time out or away from the booth, to mix up more if you need it.

Try spilling 125cc of milk on a surface and spread it out, goes a long way does it not?:D

You can probably construct your own booth, that will fit your requirements quite easily, as long as you observe certain factors.
I have some links that may be of use that I can put up, if you are interested.
Author:  Rod True [ Sat Mar 14, 2009 11:40 am ]
Post subject:  Re: Spray equipment for Polyester?
Gary, I think those links you have for spray booth design/construction would be helpful to many. I'd love to see them if you don't mind (although I already have a booth set up).
Author:  Skeet UK [ Sat Mar 14, 2009 12:16 pm ]
Post subject:  Re: Spray equipment for Polyester?
Rod True wrote:
Gary, I think those links you have for spray booth design/construction would be helpful to many. I'd love to see them if you don't mind (although I already have a booth set up).


A downdraft (or semi at least) seems to be the best way to go. It also requires the lowest Feet Per Minute flow rate, around 50.

I personally have a 900CFM fan for mine, which helps to ensure that solvents are diluted below Explosive levels. If you are only spraying 8cfm with your gun, and pulling 6-900, you should be OK:D

Andrea Concertina Filters are available on Ebay and work very well.

http://www.briansmodelcars.com/tutorials/tutorial.asp?TutorialID=23&CurPage=1

Also something on using IR heaters (such as external patio heaters) for curing paint. Very efficient as they do not heat the air, just the item.

http://www.infrared-heater-radiant-electric-gas-kerosene.co.uk/paint%20drying%20infrared%20heater%20.htm
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