Tips are vital for a good paint job. Here are some guidelines for them.
Don’t think that tips don’t wear out. As your tips have paint pass through them and
they begin to wear, the pattern will go from a long rectangular shape to a
round shape. The paint will not be
nearly as evenly applied to the fence, but maybe more importantly, you will see
an increase in paint usage. This is
normally not an issue for individual farms, but is a huge concern for
commercial contractors. We do have some
contractors (especially ones who price jobs with paint included) who change
tips after only 10-20 drums have been sprayed.
I don’t think its necessary to change tips this often, but they think it
keeps their paint usage to a minimum and thus increases their earnings.
Tip choice, like many things in life, is a simple trade
off. Bigger tips mean faster speeds and
fewer tip clogs while smaller tips mean slower speeds, and less paint wastage
in the form of overspray. There are some
limitations to this rule. The tips must
not be too big for the equipment being used (see fence paint equipment blog) or
you will get what we call gapping. If
the tips are too small you will see too many clogs which slows the process and
leads to more paint wastage. Each
different product has its own minimum tip size.
Check the recommendation for the product you plan to use before
purchasing tips.
There is a standard terminology used by most, if not all,
tip manufacturers. Tips have a three
numbers associated with them. These
numbers will normally be clearly marked on any packaging material and will also
be stamped somewhere on the actual tip.
On dirty tips these numbers may be hard to find but will be
somewhere. These three numbers ARE NOT
RANDOM. Let’s use the tip size 325 and
look at what each number represents. The
first number (3 in our case) is an indication of the spray pattern size. Double this number (6 in our case) and this
means the spray pattern will be 6 inches wide one foot away from the tip. This is the most common spray pattern used
with fence paint. The normal fence board
is 6 inches wide. If you use a smaller
tip pattern, the entire board will be hard to cover without holding the tip too
far from the fence. A larger size will
lead to more overspray and paint usage.
Larger size tips, 4, 5 or 6 have 8, 10 or 12 inch patterns. These would be more favorable on barns and
barn roofs. The second and the third
number represent the orifice size in thousandths of an inch (.025 inches in our
case). The orifice size determines how
much paint will pass through the tip at a given pressure. This number should be chosen with several
factors in mind. There is a minimum size
for each individual product. Make sure
you are larger than this number or you may have clogging problems. As you get larger than the minimum size,
painting speeds will increase pretty fast.
Consider the experience of the person using the tip. Less experienced painters may find smaller
tip and slower painting speeds easier to keep up with. Larger tip sizes also tend to lead to more
overspray and paint wastage. Again, it’s
a tradeoff. Do you want speed or is
paint efficiency more important?
There are two primary types of tips. I would always STRONGLY
recommend reversible type tips. These
tips are designed so the user can spin the tip to a position where paint passes
through in the opposite direction from the spraying position. This allows clogs to be blown out backwards
and the tip returned to the normal spray position. The vast majority (all that I know of) of reversible
tips are a universal size. Graco tips
can be used in titan housings etc. The
other type of tips are commonly referred to as flat tips. There is no easy, safe way to clean these
tips. I say safe because common paint
spraying equipment is capable of high enough pressures to inject paint into and
through the skin. This is a very
dangerous situation. If this ever
happens to you or anyone working with you, immediately drop the job and head to
medical attention (THIS IS VERY DANGEROUS).
Reversible tips have a guard to reduce to possibility of paint
injection, but flat tips do not.
Great Tips, Great Article.
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