Carf-Models Composite-ARF Extra 330L Instruction Manual page 6

Composite-ARF Extra 330L (2 x 2m)
Occasionally customers see certain problem areas with
composite parts. But the question is: Are these real prob-
lems, or are they just a misunderstood sign of high-tech
construction, proving high-end composite technology?
Seams:
ALL composite parts have seams. They are there today,
and they will be there forever. You will have to get used
to them ... or you'll have to touch up the paint yourself !
But what is a seam? A seam on the fuselage, especially
already painted in the mould, proves that this is a vacu-
um-bagged high-tech part, made in negative moulds.
Our seams are fine and straight, no negative impression
at all ... but they are there. When possible we include
5mm wide strips of self-adhesive vinyl, painted in exact-
ly the same colour as the plane for you to cover the
seams if you want.
Paint flaws:
If a plane is painted in the moulds, you can save a lot of
weight. At least 2 lbs ... and that is worth saving !
A 'negative' paint job is very complicated to make. The
painter cannot see the design growing and developing -
he is painting 'blind'. He even cannot see little mistakes
and flaws, and even if he COULD, he could not correct
them. The maximum time to apply a designer paint
scheme in the mould is no more than 20 minutes. It is a big rush, because even if it is just few
minutes too slow then the masking cannot be removed without pulling off the paint itself ! This is
a BIG challenge, but the result is extraordinarily impressive. Even with slight flaws the general
appearance of these one-of-a-kind paint jobs is unique. In a 'positive' paint job some effects can
never be done. Just think about the shadows, peel backs, highlights, and 3D effects - and all with
a perfectly flat and uniform surface for optimum airflow and aerodynamics.
Truly hard to do, but still possible, are the paint jobs which seem so simple at first glance:
Schemes with straight lines and stripes. Quite easy with positive painting, but it's very hard
masking the lines in the negative moulds, because we cannot assemble the parts before mask-
ing. To get the stripes lining up exactly at the rudder, wing and cowling joints is therefore almost
impossible. This is why we suggest using thin vinyl trim to make sure that these stripes line up
perfectly. Sometimes it is necessary to do that, and it is definitely not a quality problem or a
"flaw". It comes back to what is possible, and what is impossible.
If you want to have a really perfect paint job, then you might decide to have a single colour ver-
sion and have it painted by yourself or your friend.
But don't forget: Consider the additional cost, consider the additional weight, consider that even
if it is painted 'positive' there will be areas you won't be happy with. Of course you won't com-
plain, because you created these flaws yourself... !
The 'Paint Job'
6
techsupport@composite-arf.com
(above) One of our 2.6m Extra's, in
the popular 'Fantasy red/yellow' paint
scheme ... all painted in the moulds.
(below) A customer with a 3m Extra
330S practising his tail-in hovering !