Metal Magic: Should You Bother Priming?

Paul Dye wraps up the KITPLANES Metal Magic series with a discussion of whether or not to primer-protect aluminum structures. There's a lot of debate on the subject, but Paul offers a few points of view to help you decide.
This series is sponsored by Aircraft Spruce & Specialty - www.aircraftspruce.com Visit the KITPLANES website for more tips: www.kitplanes.com/metal-magic...
#homebuiltaircraft #kitplanes #experimentalaircraft #eaa #tools #metalworking #primer

[@NosajDEroom]

Paul, in addition (as you know) the type of aluminium has a factor in your decision too. Say 2024-T3 (Van's, Cessna, most Al RPT aircraft etc etc) versus 6061-T6 (Rans, Sonex, Al boats).

[@3dogman311]

Very diplomatic presentation on what is known as a touchy subject. Your example regarding quick builds makes me think that perhaps the company that sells these pre-primed kits may not necessarily be endorsing the priming processing, but find it a necessity for protecting their product from salt water contamination during shipment from the Philippines.

[@marlondelgadillo7444]

Good information, thank you. Resale value may be an important factor too.

[@Vansaircraftbuilders]

Great Video Series! We're sharing all of them as they come out.

[@peteporpora1630]

Heading to an EAA Sport Air workshop on sheet metal tomorrow. I've loved the series and learned a lot but nothing beats hands on.

[@tedstriker754]

I've been using that self-etching primer that comes in the rattle cans for metal. It works great, and is suspiciously similar to what I remember zinc chromate was like. For Poly Fiber, it says to use an epoxy primer. To avoid that, I got a can of appliance epoxy in the rattle can, which dries slow and stays tacky. Then sprayed poly fiber paint over it and it came out great.

[@wareairaviationservicesllc4933]

Great series, please continue !

[@JMAv8Tor]

So helpful! Thank again for all the knowledge!

[@Pilotpaulie]

Great information! Love your program.

[@flyboy98]

Very well presented.

[@n206ja]

To expand on Jason's comment, 6061-T6 is much more corrosion-resistant than other alloys. Another alternative primer you didn't mention is using Cortec primer on mating surfaces of parts - dilutes with water, brushable, and relatively non-toxic.

[@BrilliantDesignOnline]

What? The series is ending??? Noooooooo! How about round 2? These are great, and Paul is GREAT.

[@treetopflight7624]

Another big area of priming is when attaching two dis-similar metals (Aluminum to stainless steel). Rather than moisture corrosion, you are protecting against electrolysis. I use a rattle can Zinc Phosphate which is still available. The theory is that the Zinc in the primer draws away the electrolysis from the metal. If I lightly sand and then clean with acetone, the primer adheres extremely well.

[@glenwhatley7366]

Just a note. You could also mix your own epoxy primer and shoot with prevails and have less cleanup.

[@Nord3202]

When ever riveting new parts together your should aleast etch prime both surfaces in lap joints & seams or where ever moisture or water can get in to start corrosion. This is very easy when working with new metal just clean with solvent & spray. Old metal wire brush, scotch brite or etch first.

[@johnpace7174]

I have worked on commercial aircraft for over 50 + years and never once seen unprotected structures and any replacement parts ordered from the aircraft manufacturer arrived pre primed. Furthermore, any repair work called for priming the effected surface areas.

[@JoshSinclair]

Wait… so what did they prime the Space Shuttle with?!

[@Ethan-mv2un]

I thought self etching primer is porous? It doesn't seal the substrate.

[@knowitalllllllllllll]

You are showing inside priming that only runs along seams and rivet lines. Why are you not coating all the metal? Corrosion does not happen in the bare areas?

[@David1970a]

Some people only prime where moisture can be trapped.

[@marktravis]

And no-one mentions acf-50 or corrosion-x why not? If you prime incorrectly, that might accelerate trapped corrosion. If you use acf-50 or corrosion-x, you just apply it periodically over the years and it eventually dissipates, but it is very simple to apply. Certainly much less work than priming.

[@duanefinley7927]

I was Shocked to see a T-Handle left in the Lathe's Chuck in the background. Bad Practice. The possibility of trauma to a new kid in the shop is likely.

[@BEAMChannel]

24 is in fact not prime :)

[@sirnewton6874]

You believe wrong You missed on this video. sorry. There are two types of primers. There are sealing & non sealing primers. Sealing primer doesn't not require a top coat to protect against corrosion. Non sealing like that "Raddle Can self etching" is a primer that requires a top coat to protect against corrosion. YES I am right correct & Yes I ahve contacted RustOlem directly about their product. That exact product specifically. No need to say thankx

[@sirnewton6874]

I use EPC-2 primer from Endura. It is a true sealing primer. However it is not user friendly. Not even a tiny bit user friendly. I love Aircraft Spruce

[@pamagee2011]

I attended a talk by a couple of Vans engineers and they poo-pooed priming as silly