>>Have some Neubie Painting questions:
> What type of primers can be used over composites?
For a physical bond, any primer will work according to System III
Resins, except they as do others recommend that the primer be formulated
to provide UV protection.
> What type of top coats can be used over composite primer?
The UV stuff can limit choices, as all topcoat mfrs say use their
specified primer. However, there are nontechnical reasons for saying
that, and one mfr says otherwise that a test coat followed by the
fingernail scratch test, after good cure time, is sufficient to test a
different mfr's top coat.
> Heard of an old timer IA who used to store fuse, or wings in a garage
> or hangar with a bit of heat so it was warmer than outside. Would
> bring out the item to be painted and paint outdoors with dew still
> on ground. Pollen and dust would be held in obeyance.
Huh?? You're shooting hundreds of square feet, multiple coats, minimum
specified time between. Won't temps equalize in mere minutes?
> Granted you need to spray when conditions cooperate, but is this a feasable
> technique for an europa?
IME, the right conditions can minimize dust, but not insects. They lead
boring lives, until finding $400/gallon paint to ruin. The death
struggle can damage a large area. How about an outside spray booth from
PVC pipe or lumber and plastic sheet?
> As far as smaller stuff, not composite, thinking pretty hard about self
> etching
> Dupont 615S Variprime (use real good gloves) and Dupont Imron (have real good
fresh
> air source) using a homemade spray booth using furnace filters and 220V fans
in my
> garage.
IMO, a solvent polyurethane is expensive overkill for small parts as is
a spray booth. A big factor for painted metal parts is resistance to
abrasion (installation, maintenance), and the primer alone can do the
job. I have found two-part epoxy chromate primer (e.g., PolyFiber
EP-420) adheres tenaciously. Anything in a spray can, in comparison,
does not; nor does any lacquer.
> Are there any parts on the Europa that self etching primer may effect thier
> structural integrity?
I hope not! The etching is microscopic, and if the parts are that
marginally designed, I suggest refabricating them with thicker stock! :-)
> Is Dupont Imron an acceptable final coat for composites?
All solvent polyurethanes do a great job on aluminum, plastic and steel,
but they cannot be spot repaired without looking like a repair. Shops
will shoot a repair panel-to-panel, but on a composite plane, the entire
fuselage counts as one panel! Solvent polys are also very tricky to
shoot for the amateur, and my 3rd plane (despite half-dozen cars before
that) came out acceptable.
Regards,
Fred F.
N3EU
|