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powder coating
Posted: Sun Aug 15, 2004 1:25 am
by kimble
Powder coating is a tough, excellent finishing process. Can powder coating be legally used to coat aircraft parts?
Kimble
Posted: Sun Aug 15, 2004 1:56 am
by GAHorn
Powder coating has been used for many aircraft items including yokes and other non-structural items. There is disagreement on whether or not it can mask cracking in important structures though.
powder coating
Posted: Tue Aug 17, 2004 2:37 am
by kimble
I had a customer who needed his control wheel recoated. The cost of plastic coating is $100 and powder coating is $30.
That being the case, why plastic coat? I asked the FTW FSDO about powder coating a control wheel, the answer: "powder coating is not an approved material".
The reasoning probably comes form what George said, it could conceal a flaw or crack.
Be careful in what you powder coat. If in doubt, ask your Friendly FAA Maintenance Inspector.
KImble
Posted: Tue Aug 17, 2004 4:07 pm
by Roesbery
Most Piper cubs that are rebuilt around here have the entire airframe powder coated.
Posted: Tue Aug 17, 2004 4:12 pm
by GAHorn
As a follow-up to my previous comment, it should be noted that mfr's specify the coatings to be used on their products. Paint is the most common (for anti-corrosion purposes) but plastic coatings can be specified where the high heat of powder-coating (400F) mightn't damage the base material, alter it's strength, or hide cracks. Powder coating is not easily removed (for inspection) chemically and mechanical means can be harsh.
The yokes of the 170 are generally aluminum castings with so many pits and blemishes that any powder coating process merely highlights the faults. Therefore, the most attractive yoke refinishing I've seen were bead blasted, filled, and painted with Imron and clear coated. (I've seen Beech Baron/Bonanza yokes that were powder coated and they were very nice indeed.)
If powder coating has got a basis of approval for a particular application it can be very attractive and darn near permanent. (part of the problem, again.)
Those who've already done it swear by it. Those who sell it swear by it. Those who find it during inspections where it's not approved swear at it.
Posted: Wed Aug 18, 2004 3:26 am
by blueldr
If you're going ask your friendly inspector from the local FSDO about anything other than the weather (VFR not recommended)
be prepared for a negative answer. They can never go wrong if they say "No!" Then if you do it, anyway, you're in violation.
Remember, it's always easier to beg forgiveness than to get permission.