Zinc chromate primer (or Alodine) - where to get?

[Ultranomad]

I have a couple of bare metal spots on my aeroplane, which have to be primed and painted. For the last several weeks, I've been trying to locate a place selling anti-corrosion primers for aluminium in small quantities. Nothing less than 5 litres in the immediate vicinity; some places in Europe have 1-litre tins with outrageous delivery charges (dangerous goods, probably). For my purposes, I need about a spoonful of the stuff, and I imagine there should be quite a few other similar cases to create a demand for small tubes/jars. Has anyone seen anything like this?

[this is my username]

LAS?
LAS - Zinc Chromate Primers (http://www.lasaero.com/site/products/article?id=E029UJIJ9)

Airowrld?
Aviation Paints - Zinc Chromate Primer 300616 (http://shop.airworlduk.com/aviation-paints---zinc-chromate-primer-300616-1040-p.asp)

[McGoonagall]

This any good?

Floquil Enamel F110601 Zinc Chromate Primer 1 oz Paint Bottle (0052244106017) | eBay (http://www.ebay.co.uk/itm/Floquil-Enamel-F110601-Zinc-Chromate-Primer-1-oz-Paint-Bottle-/150797055847?pt=LH_DefaultDomain_0&hash=item231c347767)

[Jan Olieslagers]

A well-known shop in the North of France offers DOXALU yellow at 25,- € for one litre. I might have a solution for transport, pm if interested.

[Ultranomad]

McGoonagall, no one knows whether it's a real primer or merely a colour imitation. Furthermore, I suspect there may be a difference between zinc chromate primer and zinc chromate paint - otherwise I'd just go to the nearest art supplies shop and get a tube of Zinc Yellow.

This is my username, thanks for the Airworld link! A spray can is the ideal solution I was hoping for.

[Zulu Alpha]

LAS - Zinc Chromate Aerosols (http://www.lasaero.com/site/products/article?id=G03H0GVF9)

[peterh337]

I have used the standard aerosol zinc chromate primer on a number of jobs and it is rubbish.

A number of "pro" spray people I have spoken to concur.

It doesn't dry properly and doesn't stick properly. The spray can also doesn't deliver it anywhere near evenly, for some reason.

The best primer is a 2-pack epoxy primer. Zinc Chromate has been around since WW2 and is popular because of that, but is not the best stuff.

One can get 2-pack zinc chromate primer too but I never found anybody selling small packs of it.

[Ultranomad]

Peter, knowing your inquisitive nature, I'll ask - are you sure epoxy primer would be just as good on heavily oxidised surfaces? One of the spots in question is already quite weathered (it was a piece of paint that must have been loose for a while and finally flaked off), so I was thinking of using a deoxidiser and an etching primer on that one.

[peterh337]

My understanding is that in all such aircraft repairs, every trace of the corrosion must be removed (which may involve replacing a piece of skin, etc) and then you prime and paint as usual.

But then I don't repair planes for a living so maybe others will chip in :)

[Ultranomad]

In my case, according to the engineer in whose hangar I'm parked, there's no real corrosion yet, it's merely a dull surface of aluminium that has been exposed to the air for a while. Unfortunately, he only does engines now, and has no airframe repair materials at hand.

[pulse1]

I would suggest that you look at Brush Alocrom 1200. This will remove light corrosion and provide a good chromate key for paint.

Brush Alocrom 1200 Kits (http://shop.trimite.com/brush-alocrom-1200-kits).

Alochrom is the standard chromate finish used throughout the metal finishing world in which I spent far too much of my life.

[stevef]

Deoxidene 624 is a simple and effective treatment, which comes at about £20 per litre. Best to swap a bottle of beer for a eggcup-full from your local friendly engineer. :) A little goes a long way. Cee-Bee B-55 is a good metal brightener too.
I agree about the aerosol zinc chromate. Useless... you can wipe it off with Avgas!

[peterh337]

FWIW I bought the stuff in post #3. It has just arrived.

It does indeed appear to be just a lacquer rather than a primer.

The link to it is here (http://www.testors.com/search?q=F110601&x=29&y=11).

This is an atrocious con, but non unusual for Ebay.

Zinc Chromate Primer is not an actual Primer but the color of primer that was sprayed on the inside of old Military Airplanes.

Floquil Classic Railroad enamels are authentically matched to real color samples provided by some of the best known and historic railroads in North America. Floquil railroad enamels dry to a permanent durable finish on plastic, resin, wood and metal models and can be applied by brush or airbrush.