Choosing the correct airless paint spray tip for your application can be a difficult one. This choice can affect the operation and effectiveness of the entire airless spray system.

The manufacture will have recommendations for the max airless tip size. This is the best place to start, but this tip size will reflect the capabilities of a new machine.

I believe it is best to use a smaller airless tip size than the manufacture recommends. This will allow the pump to work less and give you more control. An example would be a maximum tip size of 517, use a 515 instead.

The type of material being sprayed will determine the airless spray tip size. Varnish and oil base enamels are light, or thin, coatings and exterior Acrylic/Latex paints are thicker and require larger tips.

Recommended Spray Tip Orifice Diameter

Thin Coatings

Spray Material — Tip Size(s)
Wiping Stains — 009-011
Dyes — 007-009
Exterior Stains — 011-013
Varnish — 011-013
Lacquer — 011-013
Acrylic Urethanes — 011-013
Oil Base Paints — 011-013
Enamels — 011-015

Thick Coatings

Spray Material — Tip Size(s)
Acrylic/Latex Paints — 015-017
Emulsions — 015-019
Elastomeric — 021-029
Epoxy — 019-021
Block Fill — 019-023
Exterior Acrylic Primer — 015-019
Exterior Oil Based Primer — 013-015
PVA Primer — 015-017

These are examples and reflect a range of different materials. Every paint manufacture will have products that are thicker or thinner than there competitors. Always look to the airless pump manufacture and your paint supplier for suggestions.

Ideas and Basic Considerations

The 3 numbers used to describe a tip size, example 517, refers to the fan size and the orifice size. The fan size of a 517 is 10 inches wide, one foot from the surface being sprayed. The first number is always 1/2 the actual fan width. The last 2 numbers refer to the actual size of the orifice. These numbers represent thousandths of an inch, example 517 is .017 inches.

With a constant fan width, a larger orifice size will apply more paint. Another example is a 515, it has an orifice of .015 inches and a 517 has an orifice of .017. the 517 applies more paint in the same amount of time. Remember the smaller the orifice the less material will be applied.

Airless paint spray tips wear out with use and this will change the fan width and orifice size. The fan will become more round and smaller as the tip wears out.A 515 could become a 617 after 50 gallons or less of material sprayed. If you need to spray your entire house and your tip is already a little worn, it would be best to buy a new airless spray tip. A worn tip can be used for primer or finish coats that will be back rolled.

Recommendations

Consider the width of the surface to be sprayed. Deck railings are thin, 4 inches or less so there is no need for a wide fan. A 211 tip applying exterior deck stain will have a fan of 4 inches and give you great control. Another consideration is the type. 2 types of airless spray tips exist, these are flat tips and reversible tips.

• Flat tips do a good job and are the cheapest. These are available in many sizes, but require the use of a special airless tip housing and cannot be reversed to clear a clog. A needle can be used to clear most clogs.
• Reversible tips are the currant standard for professional airless paint sprayers. When these clog turning the tip 180 degrees and pulling the trigger can easily clear them. The clogging material is forced out by the pressure contained within he paint gun.

A good combination of airless spray tips for general use would be a 311 for fine finishing and a 515 for production work.