Powdercoating Wing Ribs and Spars

Folks

This may be a dumb question but has anyone ever tried Powdercoating their Wing Ribs and Spars, etc??

Lots of nooks and crannies and I wonder how successful it would be??

Also, normally the item to be powdercoated is dipped in acid prior to the application of the powdercoat to ensure adhesion. I guess this would cause corrosion problems if the acid was not removed properly. Has Anyone had experience with this before?

Powdercoating is very inexpensive here in the Philippines and could be a viable option if we could make it work.

The Epoxy Powdercoat is very resistant to MEK

Regards

The powder coaters I know use about 400 degrees to cure the powder. Those ribs are mighty thin. Good question.

I powder coat the high impact stuff--control sticks, torque tube, rudder pedals and brake pedals. I also do the engine mount after a very careful inspection because it looks very nice when done.

Some people like to powder coat the fuselage and there are some merits to that. As for myself I prefer epoxy primer.

The most I've seen anyone around here do to the ribs and spars is to epoxy prime (thin coats) them if they are going to see total outdoors use as hard working floatplanes in the Maine woods. Just a little extra insurance, mind you.

There was a recent article in SPA about the work Kenmore does on Cubs that are being rebuilt and will spend time in a coastal climate and working off salt water. If I recall correctly they use a fair amount of zinc chromate on the aluminum in the wings--understandably so.

As our local guru on All Things Cubs astutely observes, yeah you can coat and paint stuff but why add weight to the airplane's wings? Epoxy primer is fairly dense; so isn't powder coating. It all adds up after awhile. My preference is to put a couple of very thinned coats of epoxy primer on all of the stell parts in the wing. That's it. I know a lot of people that don't even do that.

Ultimately, it's a matter of preference.

powder coating

Hi:

I'm a newby to SC but I've talked to a few A&Es who have their own opinions.

According to most of the opinions I've heard so far, it's better to not powder coat but to annually use Dextron Transmission Fluid as a corrosion treatment within the tubes. It has to be "fogged" into the area that should be protected. Some have seen the tubes corrode from within after being powder coated only.

I'm just passing along some of the stuff that I've heard.

Wing Rib Coating

I feel it's best on aluminum wing parts to use the Dupont or Poly Fiber "two part" aluminum prep. process. It is; 1 acid coat (part "A") - water rinse - dry - 1 conversion coat (part "B") - water rinse - dry. After this I spray on a coat of Crown Metro (now call Axxon) epoxy primer. I am told Axxon is the primer that Boeing uses it's jets. I treat all the aluminum parts this way (leading edge skins, spars, false spar, gap seals, ribs, tanks etc.).

All the steel parts (flap and aileron hangers, wing tip bow brackets, flap bell crank mount, tank straps, etc) I powder coat. I use white on any parts that extend outside the wing (flap and aileron hinge brackets) and black on any parts that are inside the wing (just my personal preference).

I prefer to have the wing all apart to do the coating then assemble with all new screws and hardware.

When the wings are done they look almost too nice to cover up with fabric and dope. Crash

Crash

Where are you getting your Crown Metro?

Frank

Crown Metro

Crown Metro was purchase by a company called Axon two years ago. It is the same product but is "Axon EP-3-GRN (green) epoxy primer". It also comes in yellow. It is from Greenville South Carolina of all places (my wife is from there). Hi Tek paint in Anchorage brings it in by the pallet load and Reeve Air Motive in Anchorage also has it and is a couple of bucks less then Hi-Tek Paint. Most of the aircraft shops up here use the stuff. Crash

Does anyone have any experience with the Randolf Epibond 2 part Epoxy?

I believe it is recommended by Stiits. We are considerng using the Stitts Process!

Regards

Stits recommends their own epoxy primer. I have used Epibond and it works real well. Quit using it because I couldn't get it locally anymore so I switched to the Stits epoxy which is locally available. Tired of paying the high price for Haz/Mat shipping.