Bill,

>Does anyone know if the WLS primer can be applied with a
>roller? If so, what type of roller?

i have used WLS with rollers and by spraying.  i prefer the
spray technique because i can keep building up layers in the low areas
by adding up to 5 spray coats.  with the roller it is harder to build up.

i found i made much faster progress after i got the spray setup.

when i say build up i mean oh, maybe 5 mils. low spots deepeer than
that should be corrected with micro to save weight. or just
left low if weight is more important to you than finish
quality.

i dont seem to have any pinholes in the WLS coats, but that may be
because i filled the weave with micro and a squeegee, then
sanded with a very straight sanding board (several times)

i sand the primer with the sanding board as well.

when you can sand and area with the board and not sand through
anywhere, but also not leave any spot unsanded, then you
are done.

i have a few small areas where i needed to make a 1/8 inch correction.  
ouch. there I overcoated the micro with a sheet of glass cloth to prevent
the micro from cracking.

one more thing.  i tried automotive urathane hi-build primer and
hated it.  too soft. ended up sanding it all off.  I like WLS.  hard but
flexible.
 
good luck.

-Jeff Peterson
N273CK (lnc2 90%)