I thought this might help a few of you guys and girls that need some insight on paint guns.
I did some reading up on some of all this and came up with this .
Spray Gun tips
You may not need a new paint gun to get the most from your current gun to create a great paint job........ but it does give you a good reason to buy MORE tools !!!!
Every one wants to turn out the best paint job possiable and whats the key to a successful job?
It takes the correct spray gun for an outstanding paint job.
But a spray gun is like any other tool, it has to be matched to the job .
( and not to mention that its almost impossable with out proper surface preparation !
How many guns do you need?
whether the gun is several years old or brand new , you have to consider what material your spraying to choose the correct spray gun.
since the advent of VOC laws the material you spray has changed too,so its evenmore critical to choose spray gun based on what you’ll spray with it .
There are guns designed for primers and other heavy bodied materials.
many painter have several guns for applying Primers and surfacers, one for base coats, one for clearcoats.
If you can afford 3 guns thats great but if not I will try and give you some information on maybe choosing one that will work for all 3 .
Choosing Nozzle setups
You will actually achieve the best results by refering to the manufacturers technical data sheets, for the particular product your spraying.
They have spent many hours and money testing their products and found the best Needle / nozzle combination.
A general rule of thumb is :
* Heavy Bodied primers and primer surfacers work best when you use a fluid nozzle size of 1.7-2.2
*Basecoats should be sprayed with a 1.4-1.6 fluid nozzle
*Clearcoats should use a 1.3-1.7 fluid nozzle
*Sealers and single stage uerathanes should be sprayed with a 1.4-1.6 fluid nozzle.
This is a general rule but some guys go against the rules and can still get out -standing jobs with different sizes , but they know their gun and product.
The higher solids clearcoats and single stage uerathanes , you should go down in size so the paint gets broken into smaller particles to get a smoother finish.
Some gun manufacturers go againt the norm , so make sure you check your gun manufacturers settings also .
Primer surfacers require a much larger fluid nozzle as they are thick in body so bigger size is need for correct application, as too small of fluid nozzle will give you a dry application and will have poor adhesion when paint is applied.
Air Errors
Looking at your Air compressor is another factor to look into.
You ask what this has to do with painting?
You may not have air to run that new paint gun.
You say my compressor puts out 150PSI how much air do I need?
the fact is PSI doesnt matter.
The air consumption of a paint gun is measured in CFM.
Air requirements for a paint gun can range from 2-3 CFM for a small touch-up gun, to to as much as 18 CFM for some Gravity-feed or Siphon feed guns.
the average is 12 for most of the populr brands of guns.
Check the out put for most 5 -hp compressors and its around 14 CFM max.
Even though you gun only uses 30psi of air , it may exceed the CFM capasity or your compressor.
Other considerations are your hose and air fittings, as these can hamper the spraying of paint.
The minimum air hose should be 3/8 ths in. ID air hose and High-flow air fittings and couplers.
This dramitacally will improve air flow and efficiency.
Clean UP
This is key !!!
Most gun manufacturers come with a cleaning kit.
You should remove the air cap and fluid nozzle as well as the needle and throughly clean them. Plus flush the gun body and inside fluid passages well.
Nothing is worse then having a chunck of dried color or clear end up in your fresh paint job !
Never clean your air cap, fluid nozzle or needle with a knife paper clip, or any other hard metal object as these will damage them.
Create a Uniform Pattern
Gun Manufacturers suggest you use a uniform pattern overlap ( Thats the next gun pass over each other )when spraying.
It used to be 50% but now days the industery suggests a lager overlap 75%, this makes for coverage in fewer coats , a more even application and better durabilitythrough consistant mil, build.
Consistant gun passes will reduce or eliminate stripes and mottling as well.
Gun Technique is whats separates the great painters from the average.
Adjusting the gun each time, testing the pattern, keeping a consistant distance, maintaining the exact overlap and remaining perfectly parallel to the surface make for great paint jobs. They even take less time. If you know your overlap and spray distance are consistant, you know your coating thickness is too. You will reach hiding and mininum mil. build quicker if you casually wave the gun at the panel again and again.
Hope this will help some of you guys wanting to try your hand at painting your rod !
SprayTech
