Wednesday, April 17, 2013

Getting Your Spray On Part One: The Parts

Spray Guns don't harm cabinets...Bad finishers do!

Wouldn't all those Charlie's Angels poses done at Girl's Night, Bachelorette and Wedding Parties be way more interesting if they were holding spray guns?

After 16 years of a cabinetry business and 10 years of teaching cabinetry, the only thing that gets people's hands to really shake is the thought of using a spray system.  Unfortunately this fear keeps many from enjoying an easy way to deliver a higher quality finish, save on product, and spend less time hand painting and sanding.  With the right instruction and a spray system that you feel comfortable with, anyone can produce factory finished furniture grade cabinets...or spray tans.

(Warner Bros.)
Obviously not done by a trained professional-probably a pageant mom with a paint roller.
I use a HVLP system which means High Volume/Low Pressure Sprayer.  This is different then an airless system which uses a compressor.  Each system has pluses and minuses and it really depends on what and how you spray.  If you have a commission business that involves lots of wall and trim painting then an airless system is a fast way to cover a lot of surface.  It also helps to have a large space with good ventilation to spray.  Because you may run tubing to the compressor and separate tubing to your paint, you can work with large amounts of paint or topcoats which saves time having to fill a gun.  Of course there are several cup guns that will also work with a compressor.
A big concern for the faux finisher that wants to spray cabinets is controlling the process. Meaning they want to direct the product with the least amount of over spray or drips. This is where a HVLP system can be a more manageable choice.  HVLP sprays high volume at pressure that is generally less then 10 pounds per square inch compared to 80-90 pounds in a traditional set-up.  Your transfer efficiency is higher at 65%-90%.  But, in general, you have to go slower and refill your cup gun more often.  You may also need more coats because you have to thin the product you are spraying.
Most HVLP spray systems work the same-the difference is in the details and the price.  I've seen cheap systems that work OK and very expensive ones that are too much machine and not user friendly.  I am so picky about what I want in a gun after all these years, Bruce had a system built for me so I would stop coming home with dented cup guns...because I had thrown it. That is the system I sell at Surfaces. There is nothing wrong with other systems and this blog will give you good info regardless of  what brand/type you have. Just make sure that wherever you buy can give you tech support and replacement parts (a problem with buying used systems sometimes).

And yes a spray system is an investment.  But it is one that will pay for itself in one cabinet job.
Many finishers like a turbine system that is compact and easy to carry or place on scaffolding. The turbine is the motor/fan assembly and comes in different stages. Stages indicate the number of fans.  More fans mean more stages which equals increased airflow and increased airflow in the gun.  A 2stage-4stage is usually enough power for most faux finishers. My system is a 3-stage.  Just enough to spray heavier products like crackle while still maintaining an airspeed I can control in a home.
My system has no speed control-I control it with the lever on the hose.  Other systems have a dial where you can control the speed from 1-10.  I lessen my speed when I am precision spraying a piece such as a table base and want as little over spray as possible. 
The turbine is about as loud as a vacuum cleaner.  The tubing length should allow you to move easily around a room and to place the turbine outside of small rooms such as powder rooms while you spray.

The above gun is a siphon gun-it sucks.  No really, that is not a judgment call, that is how to works. The advantage to this cup gun is it tends to be larger and hold more product-you have to refill it less.  Some people find having the cup underneath makes it easier to see what they are working on. Others find it heavy on the wrist. 

This is a gravity feed cup gun-it blows.  Literally the air blows down from the top.  In my usage a gravity feed cup gun clogs less with thicker product because gravity is working with you.  Plus the smaller size fatigues my hand/wrist less.  You do have to refill this size of gun more often. It holds a quart of product and I can spray about 25-30 pieces with a single coat of thinned product before refilling the gun.

The above gun is metal but you can also get them in plastic.

The plastic gun is a little bit lighter and does allow you to see your product as you are spraying giving an indication of when you are running low.  The lid of this particular gun is easy to screw on but the hole at the top that allows air to enter the cup could be a little larger.

One of the things to look for in a gun is the exposure of the fluid needle.  In both the siphon gun and the plastic gun, the fluid needle can be seen between the trigger and the air cap.

In the second gun, I've removed the fluid needle so you can see the gap.  Again there is nothing wrong with the design but this is a place where people have leaks.  Make sure your needle is fully engaged before loading your product. The upper gun needle loads from the back while the lower gun needle loads from the front.  For the lower gun I place the needle in and then gently press the needle against a solid surface to make the needle fully clicks into place.  When you pull the trigger, you should see the needle move.

The gun I use the most has the needle loaded in the back and is fully enclosed in the gun barrel. There is no leaking between the trigger and the fluid needle.

Above are the gun parts that stay the same regardless of what you are spraying.  Below are the parts that change based on the thickness of what you spray:

Start with selecting you Fluid Needle.  The larger needle is for thicker products such as basecoat. The thinner needle is for thinner products such as topcoats.  I keep it simple with 2 sizes. 2.4 for basecoats and 1.4 for topcoats.
Next is the fluid tip which I like to call the nozzles (it just sounds fun).  As you can see the hole size is different.  The larger hole is for thicker material and the thinner hole is for thinner material. The sides are marked with 2.4 or 1.4 like the needles but you would have to wear these to see it:

 (Warner Bros.)
Actually I got a pair when I turned 45
These are the parts that need to match:

This fluid needle, fluid tip and air cap are marked 2.4 and are for basecoats/thicker materials.  In other set-ups this is marked as 6.

The above set-up of for a topcoat or thinner products like crackle size. It is marked 1.4 or a 3 in some systems.

Putting a gun together is easy because the parts makes sense once you know what they do.  The fluid needle should be put together like a pogo stick:

I had one of these as a kid-the fact that this one looks like a crutch
 is more accurate then most parents know.

Pogo stick! The spring should bounce the spacer up and down if assembled correctly. This is what moves the fluid needle back and force when your compress the spray gun trigger.

If your set-up has the spring above the spacer then your needle won't move when the trigger is pulled.

For this spray system, the needle with the spring and spacer is loaded into the gun from the back.  It is held in place by the fluid adjustment screw:

This has a larger spring.  If this spring is left out, your needle will not engage fully and product will just spill out the front of your gun.  The black screw and the gold piece work independent of one another.  The black piece may be screwed out further to allow the trigger to be pulled lighter which allows more product to come out.  If the black piece is tighter then the trigger is harder to pull and less product comes out.  The gold nut is tightened to secure the setting.

The back of the gun is ready to go with the fluid adjustment screw set at a Quarter width.  Next, you have to set-up the front.  The needle should be sticking out the front.

Select the right sized fluid tip and hand screw it over the needle.  This set-up comes with a weird looking tool-it is used to tighten the fluid tip. There is another spring (the largest) to drop in.
This works with the Air Cap.


Next is the disc that gives you the ability to turn your Air Cap.  I call it the Egg Poacher because you want the dimples in it facing down-like you are poaching eggs.

The dimples (for your eggs) fit the bumps on the under-side of the air cap.  When these are put together correctly you can turn your air cap to spray vertically, horizontally, or an the elliptical.

The Air Cap is placed on next-remember it is also marked with a size based on what you are spraying.

Then a black ring is placed over the air cap to hold it in place. By tightening or loosening this ring you control how far the fluid tip pokes out of the air cap hole. 

Now our gun is ready to spray. Next time I will show you how to make adjustments with the spray gun and simple troubleshooting solutions.

And maybe my nails will look a little better in the next set of pictures.

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