Tuesday, August 1, 2017

Fence Paint Tips


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. 
  

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