Selecting Airless Tip Size and Proper Filter for Zip Tips and Big Barrel Tips


The selection charts below provide a  guideline which should help you decide which Lemmer tip size and filter is most appropriate for the product you are spraying. Viscosity was measured using a Lemmer viscosity cup. Tip wear can only be estimated because materials in paint vary to suit each application the paint is designed for. These paint materials may be highly abrasive or require higher spraying pressures which each contribute in a greater or lesser degree to tip life.


Coating Viscosity
(seconds)
Fan Size (measured at 1 foot)
2"

4"

6"

8"

10" 12"
Lacquer, varnish, furniture stain 15-35 * 2-09 F 3-09 F 4-11 F 5-11 F 6-11F
Industrial enamels, stain, colored lacquer 25-50 1-09 F 2-11 F 3-11 F 4-13 F 5-13 F 6-15 M
Shop primer, solid stain, oil base, latex 40-100 1-11 F 2-13 F 3-13 F 4-15 M 5-15 M 6-17 C
Flat oil base, latex 60-150 1-13 M 2-15 M 3-15 M 4-17 C 5-17 C 6-19 C
Thick latex, prepared block filler 150-200 1-15 C 2-17 C 3-17 C 4-19 C 5-19 C 6-21 *
Most block fillers n/a 1-17 C 2-19 C 3-19 C 4-21 * 5-21 * 6-23 *

Explanation of tip and filter sizing
eg: ( 4 - 15 M )
4 = half of the fan width (8" @ 1 foot away from wall) 
15 = orifice size in thousands of an inch (0.015) 
M = (M)edium filter

Filter Selection:
F
= fine screen red filter (180 mesh) 
M = medium screen yellow filter (100 mesh) 
C = coarse white filter (50 mesh) 
* = not recommended


Tip volume at various pressures
---Gallons per minute--- 
Results are based on water, heavier viscosities will produce less volume. This is especially noticeable with large tips and very heavy coatings.
Tip size

500 PSI

1000 PSI

1500 PSI

2000 PSI

.007

.028 .040 .049 .057
.009 .039 .055 .067 .078
.011 .060 .080 .10 .12
.013 .090 .12 .15 .18
.015 .12 .16 .20 .23
.017 .16 .23 .27 .32
.019 .20 .27 .33 .39
.021 .24 ..33 .41 .47
.023 .28 .40 .49 .57
.025 .33 .47 .58 .68
.027 .37 .52 .64 .76
.029 .47 .65 .79 .98
.031 .53 .75 .91 1.1
.035 .69 .90 1.0 1.2
.043 1.1 1.5 1.8 2.1
.053 1.5 2.2 2.9 3.4
.057 1.8 2.5 3.1 3.5
.063 2.2 3.1 3.9 4.4

Pump maximum tip size

Pump Absolute Max To allow for  tip wear
L-1095 .017 .015
DC-3100 .021 .019
DC-5500 .025 0.23 (2x.015)
DC-7700 .031 0.29 (2x.021)
HP-9500 .045 0.43 (3x.025)

Very approximate wear values comparing tungsten tip size and paint type (Gallons)

New Tip Size .015 .017 .019 .027
Tip Worn to .017 .019 .021 .029
Lacquer 400 - - -
Latex 75 150 250 -
Block filler - - 75 250
Road paint 2 20 50 200

The two most important things to remember about tip wear...

1) Low pressure equals longer life, for tips and the pump. Less overspray too!
2) Worn tips waste paint and overwork the pump, causing premature pump wear. The maximum tip for a pump is the largest tip that will deliver a proper pressure for spraying without overworking or overloading. When a tip is used for some period of time, it can wear beyond the maximum size recommended for the pump, which will cause low pressure and a poor spray pattern. 
  • Stains and thick latex products often cause the most rapid wear of the tip, while clear lacquers and varnishes cause the least wear. Thus tip life can vary from as little as 50 gallons to as much as 200 or more, depending on the product being sprayed and the pressure used.
  • Filter screen mesh for the gun or pump are picked not because of the type of paint being used, but to protect a given size of tip from plugging. Pick the tip for the type of paint and job being done and then choose the correct filter to protect the tip.