Van's Aircraft RV-12, Maintenance Manual

Page: 168 / 217

Rev.1
15-2
OVERVIEW
● NOTE: R
EFER TO
KAI – S
ECTION
4
AND
5
FOR ADDITIONAL INFORMATION
.
The aluminum skins used on RV aircraft are all 2024-T3 alloy. They are "alclad"
meaning both sides of the sheet are coated with pure aluminum during manufacture.
The thickness of the alclad layer on aluminum sheet 1/16 inch thick or less is 5% of the
sheet thickness. Alclad on aluminum sheet greater than 1/16 inch thick is 2.5% of the
sheet thickness.
All non-alclad aluminum parts such as 6061-T6 must be primed for corrosion
protection. Aluminum tubing (other than fluid lines) must be primed on both the interior
and exterior surfaces.
Aluminum bar, angle and tube used in the RV-12 are not alclad and must be
primed to ensure corrosion resistance. Zinc Chromate has been the traditional primer
used on aircraft aluminum. With proper surface cleaning this is still a good choice.
There are however many superior primers now available. Most of these are two part,
catalytic curing primers. Generally speaking it's preferable to replace a coated part with
a coated part.
Following is a partial list of suitable primers:
♦
DUPONT VERI-PRIME (PRIMER #615 and CONVERTER #616S)
♦
DITZLER DP-40/50 EPOXY PRIMER
♦
TEMPO brand Chromate in a spray can
♦
PRATT & LAMBERT Vinyl Zinc Chromate, EX-ER-7 and T-ER-4 Reducer
♦
SHERWIN WILLIAMS WASH PRIMER #P60G2 and Catalyst Reducer #R7K44
♦
MARHYDE self-etching primer, available in a spray can as well as quarts
Decorative paint on the structure of the aircraft can be touched-up by the sport
pilot certified owner or a certified repairman with ‘maintenance’ rating. Control surfaces
can only be repainted by an LSA repairman with a ‘maintenance’ rating or an A&P.
Part replacement must be consistent with the original KAI from Van’s Aircraft.
Priming factory alclad replacement parts remains at the repairmans discretion. Non-
alclad parts must be primed per the KAI. Any parts that require replacement due to
corrosion warrant additional corrosion protection on the replacement part. When in
doubt, prime the part.