Fiberglass and Print-Thru

I have an 35-year-old f'glss sweetheart that needs hull paint. It's
white now, and I lean to a darkish color like a flag blue. But one
paint guy has warned me about the possibility of print-thru on dark
colors.

Can anyone shed some light on this? How real is that possibility?
What causes it? Any experiences?

Arnold Shore
Annapolis, MD

The term 'print through' generally refers to the coarse woven-roving
fabric used in a hull lamination lay-up being visible on the outside
of the hull. This is why - when hand laminating a hull - a layer of
mat is laid first into the gel-coat; the mat 'hides' the weave of the
subsequent woven fabric.

In a chopper gun lay-up, where a slurry of chopped fibers is 'sprayed'
onto the gel-coat, any "holidays" by the operator might allow the
woven fabric to 'print-through' , meaning that on close inspection of
the finished hull you'd see a 'small waffle' pattern in the finish.

Dark coloroed hulls do require a higher level of finish that do light
(white) hulls. This has something to do with the mechanics of our
eyes ( a subject way beyond my ken). Anyway, if you're going to paint
her, a dark color shouldn't be a problem, even *if* your hull has
print-through (which it may not - one can see print-through even on
white hulls with careful inspection) PROVIDED you can commit to
thorough preparation of the hull surface.

If your Sweetheart really wants to shine, the best choice is a two
part LPU, the final finish of which has been preceded with filling /
fairing and a couple of coats of epoxy primer.

This may sound daunting, but isn't too bad. Interlux has a cool on-
line video that shows the whole process for thier 'Perfection'
product, generally applicable to Awlgrip, etc.

MW