> I have never attempted a vac myself, because I keep hearing that
> they are more difficult than injected. Could someone elaborate on
> the special challenges that vac models present? Which parts of the
> building process are harder than injected? Seam filling, fit, what?
Getting message at work is great.
The biggest problem with vacs is the "sanding-out" of parts. Since
most parts will come on a sheet of plastic, you have to cut around
the parts, and sand off the thickness of the plastic. Usually when
you cut around the part, you leave anywhere from 1/4 of an inch to
one full inch of plastic sheet around it to you can tell when you're
through sanding. Another hint I've used is to take a permanent black
magic marker, and mark where the parts meet the plastic sheet. That
way it will be even easier to tell when you're through sanding.
Normally the plastic is thinner, so you tend not to use liquid
cement.
Some of the bigger vacs require some sort of bulkheads in the
fuselage (and sometime wings) so the parts won't "collapse" due to
the thinness of the plastic.
On "smaller" WW1 a/c, you have to "round" the leading edges of flying
surfaces, especially wings, since most vacs are "flat", especially
after sanding.
After all those problems, it then becomes "just another kit". You
fill the same way (if you have to - since you are sanding the parts
out, you control how much you sand away), glue the same way (sans
using liquid cement) and paint the same way.
The advantages to vacs are that flying surfaces are realistically
thin (although some of the new resins are getting quite thin) and
(especially in the past) vacs were all there were for the more
"esoteric" stuff.
I highly recommend building a vac. You definitely want to start with
something a little easier - and comes with the "smaller bits" in
plastic, resin or metal, thus avoiding the scratching that most,
older vacs required. What would be good? Hmmm... Maybe a Sierra
Scale vac? My (honest) first vac was a Phoenix (now Blue Rider) Otto
C.I Doppeldecker. I only had to worry about 6 vac parts - since it's
a boomer, and the booms are made with Contrail rod and strut. Not a
good first timer, if only for the booms and rigging.
Good luck!
Matt