# Spraying recommendations



## aaronhl (Jun 2, 2011)

I would like to buy a compressor and gun to spray stain and polyurethane. I would also like to spray gelcoat and paint. Since I haven't done this before, I will be practicing a lot at first.

The projects I have are not big, but have many side and angle where it would take just too much to roll or brush on. So what gun and spray would you recommend? How about some specification recommendations at least? Thinking of going with something at Harbor Freight.

Aaron


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## texas1960 (Jan 6, 2012)

Sounds like a HVLP rig would be a less costly way to go unless you have other uses for a compressor. It takes a large amount of CFM's to use a standard cup gun. I have both and rarely use the compressor to paint, stain, lacquer items. If they are all small you can get away with a touch up gun and a smaller compressor.


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## Steve Neul (Sep 2, 2011)

Buy as big of a compressor as you can afford but you could finish something the size of a chair with one of these little smudgepot compressors. Bigger projects you would have to stop from time to time and let the compressor catch up and too big of a project would burn it up. I prefer a siphon sprayer and use the #97855 sprayer from Harbor Freight. They work really well for me. 

One note about air compressors, oiless compressors are very noisy and may get on your nerves. I've thrown away working compressors because I couldn't stand the sound. If you get one with the motor and pump seperate it should run a lot quieter.


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## Sawdustguy (Dec 30, 2008)

Sorry to hijack this topic.

Steve,

Would you recommendedthat gun for spraying water base dye stains? What would you say the CFM requirement be? I have a small PC compressor in the basement and a larger one in the garage. I am not sure of the CFM of either one at the moment.

Thanks

Now back to regularly scheduled responses.

George


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## Steve Neul (Sep 2, 2011)

George G said:


> Sorry to hijack this topic.
> 
> Steve,
> 
> ...


To tell you the truth I've never paid any attention to CFM. I just put the finish in a sprayer and it sprays it or it doesn't. I don't use a great deal of water based dye but the principle is the same. I use Mohawk Ultra Penetrating Stain. It's an alcohol based dye. Any sprayer and either compressor should spray a dye stain though. You spray it at low pressure so the air demand is small. Now if you were spraying dye on a eight foot long cabinet common sense would tell you a little compressor would run out of air before you could get to the other side. If you were attentive enough to tell where you stopped you should be able to resume spraying the dye after the compressor caught up. Dyes are just difficult for folks to spray. It goes on like nothing and dries quick so if you end up spraying two coats on a spot waiting for the compressor to catch up it will have a dark streak there. You have to just lay on a uniform coat and ignore the appearance of it as you are working it.


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## aaronhl (Jun 2, 2011)

Thanks for the information- that helps a lot as you can already tell I don't know anything about compressors or spraying.

If I were to the get #97855 sprayer and a compressor, I should be able to stain, polyurethane (ultra gloss Miniwax), and even paint?

I like how you referenced a chair and a full stretch cabinet. How many gallons and psi would you recommend to stain and poly a dining room chair for example? Or are you really sure any setup would work?


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## cabinetman (Jul 5, 2007)

If you are using a 2hp-3hp oil lubed compressor, with at least 20g-25g tank, and a siphon conventional gun, your air pressure should be about 55psi-60psi to the gun for most film finishes including waterbased polyurethane. This will allow a higher CFM.
I would try to disuade you from spraying oil base poly as its very tricky. It's heavy bodied and will run very easily...as it dries so slowly.

I also suggest you mount on the handle of the gun a small regulator and air gauge, and a bulb type disposable filter.

















.


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## aaronhl (Jun 2, 2011)

And should I pay attention to air delivery specs/ flow rate?


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## aaronhl (Jun 2, 2011)

I am having difficulty finding a clear finish for an intricate wood project. I don't want to roll and brush. I have heard people say epoxy isn't a good seal and that polyurethane (not fiberglass resin) is difficult too. Since this piece will see water and in some cases be under water for several minutes at a time, I need something durable that will be easy to apply.


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## cabinetman (Jul 5, 2007)

aaronhl said:


> And should I pay attention to air delivery specs/ flow rate?


You could, but it may be very close. For continuous output you would need to match the CFM of the tool to the CFM output from the compressor. But, you won't likely be spraying like that.

















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## bradford (Jun 14, 2014)

cabinetman said:


> I would try to disuade you from spraying oil base poly as its very tricky. It's heavy bodied and will run very easily...as it dries so slowly.


I second cabinetman on spraying oil based poly. It is very hard to get a consistent coat without runs and takes to long to dry. I have the #68843 it works fine. I don't have any reason to not recommend it.


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## aaronhl (Jun 2, 2011)

Great information I hope it can educate many other besides myself.

What is the difference between the container on top v. container on bottom? And why would I use either or?

So if I set the compressor to release 60psi then I should turn a knob on the gun to let the 60psi out the tip? How would I be able to match it? It seems like the guns need about 10cfm but the compressors are only like 6cfm.


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## Al B Thayer (Dec 10, 2011)

aaronhl said:


> I would like to buy a compressor and gun to spray stain and polyurethane. I would also like to spray gelcoat and paint. Since I haven't done this before, I will be practicing a lot at first.
> 
> The projects I have are not big, but have many side and angle where it would take just too much to roll or brush on. So what gun and spray would you recommend? How about some specification recommendations at least? Thinking of going with something at Harbor Freight.
> 
> Aaron


Check into the Earlex 5500. It's a turbine HVLP capable of spraying thick material like gelcoat. Under $300 for the whole unit. I have one and used it so much I burnt up the turbine. I called them and they sent me a new unit no questions asked. I was really pushing it and they said its not supposed to happen. It's easy to adjust and the gun is pretty well made. 

I also have a not so expensive $65 HVLP gun I run off a 1-1/2hp Emglo compressor. I'm spraying lacquer like a mad man and getting good results. 

Your going to need different tips for different materials. Start with good step by step instructions on adjusting the gun. Then practice on brown cardboard.

Al


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## Steve Neul (Sep 2, 2011)

aaronhl said:


> Great information I hope it can educate many other besides myself.
> 
> What is the difference between the container on top v. container on bottom? And why would I use either or?
> 
> So if I set the compressor to release 60psi then I should turn a knob on the gun to let the 60psi out the tip? How would I be able to match it? It seems like the guns need about 10cfm but the compressors are only like 6cfm.


The sprayer with the container on top allows you to use every drop of paint. If you are working with most wood finishes this isn't important, you can just add more finish to the cup. When you use some automotive finishes like urethanes they are catalyzed and you mix the catalyst with the paint as you use it. The paint is also expensive like $200.00 a gallon. If you are using this kind of paint where you can't save the paint left over it gets more important to use every drop. The sprayer with the cup underneath needs a couple of ounces just to get it to spray. 

Personally I don't care for a sprayer with the cup on top. If you are spraying something out in the open like a car it's alright. If you are spraying something like a chair or a cabinet where you need to get the sprayer in and around the parts the cup on top is too cumbersom. Also a lot of finishes seperate and need to be stirred frequetly. With the cup on the bottom the paint all settles in the cup and you can just stir it. With the cup on top the solids settle in the nozzle so you need to take this kind of paint out of the sprayer right away and put it in a different container so you can stir it.


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## aaronhl (Jun 2, 2011)

So the tip is changed for the thickness of material?

What type of lacquer are you spraying?


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## Steve Neul (Sep 2, 2011)

aaronhl said:


> Thanks for the information- that helps a lot as you can already tell I don't know anything about compressors or spraying.
> 
> If I were to the get #97855 sprayer and a compressor, I should be able to stain, polyurethane (ultra gloss Miniwax), and even paint?
> 
> I like how you referenced a chair and a full stretch cabinet. How many gallons and psi would you recommend to stain and poly a dining room chair for example? Or are you really sure any setup would work?


Yes that would work however I would recommend you buy one sprayer for stain and paint and another for clear finishes. It seems like no matter how well you clean and maintain the sprayer some of it hides somewhere in the sprayer. I had one gun one time that I used for enamel paint and when that job was over I cleaned the gun and used it for clear finishes from then on. Then 10 years later I was spraying a table top and it spit out a speck of the enamel I had used the gun for. Now I consider a gun ruined for clear finishes if it has had anything else but clear finishes used in it. The Harbor Freight sprayer will work better with 40psi. pressure. Any higher pressure it will atomize the paint too much. As far as the amount of finish you should be able to finish a couple of chairs with a quart of oil based polyurethane. Poly dries slow so be sure you have a fairly clean environment. I wouldn't spray it in your shop. The finish will drift through the air and settle on everything and stick. At least corner off a space with some polyethylene plastic. 

Now the reference to paint, yes you can use any solvent based paint with that sprayer. Latex paint doesn't work. You have to thin it so much to get it to spray its more colored water than paint. Latex paint needs to be sprayed in an airless sprayer or a siphon sprayer equipped with a pressure pot. It takes the pressure to get it to spray right.


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## Al B Thayer (Dec 10, 2011)

aaronhl said:


> So the tip is changed for the thickness of material?
> 
> What type of lacquer are you spraying?


Viscosity is to be taken in to consideration for tip size. I'm spraying pre cat lacquer with a 1.4 tip. My supplier tells me it's the type he sells the most of, I was surprised. I use it because it's a tougher finish than nitro lacquer and it's very very easy to use and get right. Im not experienced with spraying stain. The brands I use are Mohawk and Gemini. I used to use Sherwin Williams. Good product but $60 a gal was the best price I could find. The Mowawk and Gemini are $23. And I believe the Mohawk is a better finish. 

Al


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## Al B Thayer (Dec 10, 2011)

Steve Neul said:


> Now the reference to paint, yes you can use any solvent based paint with that sprayer. Latex paint doesn't work. You have to thin it so much to get it to spray its more colored water than paint. Latex paint needs to be sprayed in an airless sprayer or a siphon sprayer equipped with a pressure pot. It takes the pressure to get it to spray right.


The Earlex 5500 sprays latex with ease. It almost has too much power. This is probably its strong suit. It used to be not as powerful.

Al


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## Steve Neul (Sep 2, 2011)

I've never really researched it but I think the Harbor Freight sprayer only has the 1.8mm tip available. I'm able to spray most finishes alright with it. The only one I had trouble with is Omni automotive metal flake base coat with that gun.


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## aaronhl (Jun 2, 2011)

I have learned so much in the last 1 hour, thanks again for the info...What clear coat would be good for a piece of wood that will have contact with water? And can I paint over it?


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## Al B Thayer (Dec 10, 2011)

aaronhl said:


> I have learned so much in the last 1 hour, thanks again for the info...What clear coat would be good for a piece of wood that will have contact with water? And can I paint over it?


You mean like a canoe paddle? The only thing I recommend is West System. Yes you can paint over it. 

Al


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## aaronhl (Jun 2, 2011)

Something like that- it is actually a remote controlled boat. It will be in the water for about 10 minutes at a time

Have you sprayed west system resin?


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## Steve Neul (Sep 2, 2011)

Just 10 minutes any film finish would work. It would be better to use a marine grade spar varnish though.


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## aaronhl (Jun 2, 2011)

Ah cool I guess I will try to spray that- thanks for all the help so far


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## HowardAcheson (Nov 25, 2011)

>>>> Thanks for the information- that helps a lot as you can already tell I don't know anything about compressors or spraying.

Being a beginner let me strongly suggest you buy a book titled Spray Finish by Andy Charron. Amazon will have it. The book will give you all the info you need to determine the type of equipment you need, how to set it up and adjust it and then, how to use it properly. For example, applying oil based finishes with a sprayer is problematic. Oil based finishes dry very slowly and the over-spray is in the form of liquid droplets. The over-spray will float in the air and where ever it lands it will end up drying to a crust. To spray oil based finishes, you will need a efficient spray booth or be able to spray out doors.

Finally, as you mention, you must learn and practice you spraying technique. There is more to it than just pulling the trigger. In many cases, you will find things go better if you do your spraying before you do certain assemblies.


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## Maylar (Sep 3, 2013)

aaronhl said:


> And should I pay attention to air delivery specs/ flow rate?


Yes... depending on what you're spraying. Any gun / compressor combination will work for very small projects, but spraying large panels will consume air quickly and the compressor can run out of air before you get a coat laid down if the tank is too small. The CFM rating of the compressor will determine how quickly the tank fills back up. The best scenario is when the compressor is rated for more CFM than the gun needs, so that even if the tank runs low the compressor itself will keep up with the demand.

There are 3 different kinds of spray gun technologies. HVLP uses low pressure and high air flow to atomize. The big benefit is the transfer efficiency, which by definition (and EPA rules) must be 65% or better with 10 psi at the air cap. "Conventional" guns like the HF siphon feed you guys are talking about use high pressure - typically about 65psi - to atomize paint. They atomize very fine particles, but transfer effieciency is poor - some are less than 30% - which means you get a lot of overspray and waste a lot of paint. The last type is "compliant" guns, which still comply with the 65% but use more pressure than HVLP specs allow. They give the best of both worlds and are popular in paint shops getting into the new waterborne technologies.

My favorite spray gun is my Sata MiniJet, which is an HVLP "touchup" gun with an 8 oz gravity feed cup. With different tips it'll spray anything and it needs only about 4 CFM of air. My 1.5 HP 25 gal compressor has no problem keeping up. The small size makes it ideal for the kind of work I do. BTW there are very few bottom feed HVLP guns, there's not enough air pressure to pull the paint out of the cup.

The current hot item these days for small guns is the DeVilbiss SRi Pro detail gun, or if you're on a budget their Finishline or StartingLine are pretty good.

Another thing to note about air delivery - the pressure you get at the gun with trigger pulled is always lower than what's at the tank. Just like voltage loss in elecrical wiring, when air flows through the hose pressure drops at the load. That HF gun needs 10.5 CFM at 60 psi so with say 25 ft of 3/8" hose you'll need to set the tank regulator way higher than that. As Steve mentioned, you should always have a pressure gage right at the gun (and an inline filter).


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## aaronhl (Jun 2, 2011)

Thanks for the replies

Is a regular necessary? I was looking at the instruction manual for a HF compressor and it said to put one inline.


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## cabinetman (Jul 5, 2007)

aaronhl said:


> Thanks for the replies
> 
> Is a regular necessary? I was looking at the instruction manual for a HF compressor and it said to put one inline.


I'm all for it. I don't mount a filter or regulator on the tank for the airline out. I try to get it as far from the tank as possible. It's under full pressure there. If you're in a small space, you could run some piping initially to get some cooler air, trap moisture, and provide an efficient regulator/filter.
.


























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## Al B Thayer (Dec 10, 2011)

aaronhl said:


> Something like that- it is actually a remote controlled boat. It will be in the water for about 10 minutes at a time
> 
> Have you sprayed west system resin?


No I haven't sprayed it. But I built a small boat with it. Not sure anyone that uses it sprays it.

Al


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## Maylar (Sep 3, 2013)

aaronhl said:


> Thanks for the replies
> 
> Is a regular necessary? I was looking at the instruction manual for a HF compressor and it said to put one inline.


Yes, you must have a regulator. And every compressor I've seen has one and a gage. When using a spray gun, you should also have an inline regulator like one of these, right at the gun:

http://www.amazon.com/3M-16573-Accu...404403018&sr=8-1&keywords=spray+gun+regulator

And an inline filter right before the regulator:

http://www.harborfreight.com/disposable-inline-moisture-filter-68224.html

A water trap is also important. Compressed air contains water vapor that will cause fisheyes if it gets into the finish.


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## aaronhl (Jun 2, 2011)

I am getting somewhere guys!! Thanks for all the help. I am going to HF soon just to touch some of these items to get a better idea of everything.

For now I am going to try to perfect spraying with the Preval sprayer.


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## Steve Neul (Sep 2, 2011)

aaronhl said:


> I am getting somewhere guys!! Thanks for all the help. I am going to HF soon just to touch some of these items to get a better idea of everything.
> 
> For now I am going to try to perfect spraying with the Preval sprayer.


Do you have all your free stuff coupons? :laughing:


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## Quickstep (Apr 10, 2012)

Great thread - I hope I'm not hijacking...

I have a regular compressor and a good (Devilbiss) HVLP conversion gun. It runs at about 26 psi. Even at what is relatively low pressure for a gun that runs off of a compressor, it seems like I get a lot of overspray and bounce back. Would overspray and bounce back be greatly reduced with a turbine gun? Also, is there a turbine gun with a gravity cup?


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## Quickstep (Apr 10, 2012)

aaronhl said:


> Ah cool I guess I will try to spray that- thanks for all the help so far


I agree that spar varnish is the right thing, but spar varnish really isn't meant to be sprayed. It's thick gooey stuff that's designed to build a thick but soft protective finish. It dries slowly and levels pretty well without spraying. Epifanes spar varnish seems to be the popular choice. 


I think the same goes for spraying west system epoxy. I've been using low viscosity epoxy thinned about 5% with denatured alcohol and it levels beautifully. I apply it with a high density foam roller.
I think by the time you get epoxy thin enough to spray with an atomizer gun you might have modified its properties. Also, if it "kicks" in your gun before you can clean up, you're gun will be ruined. 
Side note: if you do use epoxy, you need to top coat it with varnish with UV inhibitors; epoxy can't take exposure to sun.


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## Steve Neul (Sep 2, 2011)

Quickstep said:


> Great thread - I hope I'm not hijacking...
> 
> I have a regular compressor and a good (Devilbiss) HVLP conversion gun. It runs at about 26 psi. Even at what is relatively low pressure for a gun that runs off of a compressor, it seems like I get a lot of overspray and bounce back. Would overspray and bounce back be greatly reduced with a turbine gun? Also, is there a turbine gun with a gravity cup?


If you mean bounce back like when you spray inside of a cabinet where one plane meets another then no the turbine won't help. You need less atomization. This can be done with an airless but I prefer to use a siphon sprayer connected to a pressure pot.


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## cabinetman (Jul 5, 2007)

I just use a conventional siphon cup/gun. I have no problem with spraying inside of a cabinet, and no need for a pressure pot. I would use a pressure pot for daily use of a top coat, or sealer if I were to use one. I don't find much advantage other than having more than 1 qt at a time. If the output is more, it's not worth the maintenance of keeping a pot and hoses clean. 


















.


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## cabinetman (Jul 5, 2007)

aaronhl said:


> I am getting somewhere guys!! Thanks for all the help. I am going to HF soon just to touch some of these items to get a better idea of everything.
> 
> For now I am going to try to perfect spraying with the Preval sprayer.


A Preval setup will not satisfy your general finishing. The output is similar to a spray can. It's good for small projects and touch-ups on site.


















.


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## Quickstep (Apr 10, 2012)

Steve Neul said:


> If you mean bounce back like when you spray inside of a cabinet where one plane meets another then no the turbine won't help. You need less atomization. This can be done with an airless but I prefer to use a siphon sprayer connected to a pressure pot.


Steve,

When you say I need less atomization, can you put that in terms of what gun adjustments I should make? Smaller tip/larger tip? Less material? My gun only offered one air cap, so no opportunity for adjustment there. The manual for the gun recommends 26 psi. Should I be using less?


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## Al B Thayer (Dec 10, 2011)

Quickstep said:


> Great thread - I hope I'm not hijacking...
> 
> I have a regular compressor and a good (Devilbiss) HVLP conversion gun. It runs at about 26 psi. Even at what is relatively low pressure for a gun that runs off of a compressor, it seems like I get a lot of overspray and bounce back. Would overspray and bounce back be greatly reduced with a turbine gun? Also, is there a turbine gun with a gravity cup?


Hey lucky you. You have an excellent gun. There should be many tips available for it. Getting the right tip is the best place to start. I would say if you are experiencing a high level of bounce back you do need to make some adjustments. The beauty of HVLP is low bounce back and more transfer of material to the surface.

I have both turbine and conversion. Earlex 5500 and a Neiko conversion. The Earlex is a work horse that will spray latex with ease. But the Neiko has a better finish which is probably due to the adjustability and slightly better tip. I recommend neither of these guns even though I have had success with them. I will buy a better gun sometime in the future. These are get by for now type tools.

Al


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## Steve Neul (Sep 2, 2011)

Quickstep said:


> Steve,
> 
> When you say I need less atomization, can you put that in terms of what gun adjustments I should make? Smaller tip/larger tip? Less material? My gun only offered one air cap, so no opportunity for adjustment there. The manual for the gun recommends 26 psi. Should I be using less?


Well atomization is the size of the droplets of paint in the fog you spray. The bigger the droplets the more paint sticks instead of blowing around. The larger the tip would atomize less. The more narrow fan pattern would also atomize less but would be more difficult to keep from having lap marks. 

Depending on the finish you are using, you may be able overcome some of this blow back and orange peal problems by thinning the paint more or in the case of lacquer use retarder thinner or water based finishes use gylcol ester. 

I prefer to use a pressure pot for spraying the inside of a cabinet because a regular sprayer is just siphoning the paint out and the volume is low. The pressure pot is pushing the paint out and puts out so much volume you have to work fast to keep from having runs in the finish. It will also spray at any angle.


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## Quickstep (Apr 10, 2012)

I have tips in 1.2, 1.3, 1.4, 1.6 and 1.8

I'm spraying General Finishes Enduro-Var. It's fairly thin, but high solids. 

When I tried the small tips, the coats were so thin that the little droplets on the surface never flowed together, kind of like a major orange peel kind of thing. 

With bigger tips, it seemed like I got sooo much material coming out I couldn't control it. I'm spraying relatively small surfaces (banjo resonator) so a couple of passes and it's all over. 

I should qualify this by saying I'm a very newbie sprayer, so any and all guidance is appreciated.


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## Steve Neul (Sep 2, 2011)

Quickstep said:


> I have tips in 1.2, 1.3, 1.4, 1.6 and 1.8
> 
> I'm spraying General Finishes Enduro-Var. It's fairly thin, but high solids.
> 
> ...


You have to think of it this way too, the little droplets start drying as soon as it comes out of the gun. The smaller the droplets the faster it dries so it may be 75% dry before it touches the wood. You either have to use a larger tip so the droplets are bigger or sometimes in hot weather use a retarder thinner so the finish isn't so dry when it reaches the wood. 

I use a cheap harbor freight sprayer. It only has a 1.8mm tip and I spray most any kind of paint with it. The only paint I really need a smaller tip for is metalic automove paint. It needs to spray a finer mist so the metalic flake goes on more uniform. Wood finishes I don't have a problem with. You want to spray a wet uniform coat anyway.


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## cabinetman (Jul 5, 2007)

Quickstep said:


> I have tips in 1.2, 1.3, 1.4, 1.6 and 1.8
> 
> I'm spraying General Finishes Enduro-Var. It's fairly thin, but high solids.
> 
> ...


Atomization is more than just the size of the droplets, or tip size. For a specific material, you would adjust your gun pressure at the tip, and the fluid control. Between those two you will get a variety of atomized material. If you are practicing with some scrap cardboard, start with plain water in the gun. As you increase the air pressure, it will push out the media harder, and by adjusting the fluid control that will mix how much fluid and air exit the tip at the same time. Along with those adjustments, you can adjust your pattern. 

A wide pattern will be less concentrated than smaller one more cylindrical in shape. Once you get some practice with those adjustments, practice the distance from the object you are spraying, and check the pattern so that you can maintain a wet overlap. Then, how fast you make your paths may be the indicator of how the material lays down and whether there will be orange peel or not.

So, you can see that it's not just the tip size that determines the finish. It's the experience you get from practicing. There's no substitute.

















.


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## Bill White 2 (Jun 23, 2012)

My HF gun has a 1.4 tip.
Came that way.
Bill


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