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Anti corrosion

D

Duncan

I'm New Here
Hi,

I'm expecting my empennage for the RV8A to be delivered soon. I have looked over the subject over and over on this forum (and the internet) but failed to find the way to go. Can someone recomend me an environmental friendly (as possible) anti corrosion treatment for the internal parts of the plane?
"Friendly" as in: don't kill the guy spraying/putting it on (me :)).

Please included some suggestions about using the same stuff on the outside of the skinns as well. As a base for the color paint to go on.

When finished, the plane will be hangared close to the North See, so some protection against the salt is needed in my opinion.
I'm planning on treating the whole of the internal parts of the emppenage (not only the contact parts).

Thank you,
Duncan
 
Corrosion

Hello Duncan,

CorrosionX works really well. We use it at the Airlines. http://www.corrosionx.com/
As far as being "friendly to the user", it's probably not. If you are in a well ventilated area, you'll probably be ok. However, I ALWAYS use a respirator. They aren't very expensive and well worth the investment.
Of course, once this product dries, it's no longer a hazardous materal...
Once started corrosion is difficult to eliminate!
I hope this helps...

Good Luck with your project!
 
Duncan

Try Bullseye 123 Made by Zinsser Paints - that's what I'm using. It's a water based acrylic resin. Fast drying (recoat 1 hour) adheres glossy surfaces. Safe to use and cleans up with soapy water. Being latex it is more tolerant of flexing than some of the more traditional primers. It is also available in Europe at about £35.00 for 3.75 litres, so it's also cheap. I'm sort of relying on a combination of that and the Alclad keeping my RV from rotting to pieces. I live in Cumbria, (NW England) which is very wet. Can be rolled rather than sprayed, but I wouldn't recommend brushing, except for touching up.

The only problem I've had is thinning it enough to spray - advisory max dilution 10 fl oz water per gallon of paint, does not make it very thin, so you'll have to use a biggish nozzle .

Technical data bulletin is available online from Zinsser. If you can lay your hands on the November? Issue of 'Popular Flying' (the UK PFA magazine), I think you can get back issues at www.pfa.org.uk, there is a very good article about using Bullseye 123 by J T B Ellis, who has done lots of trials on fuel immersion, flexing etc. and certainly sold it to me. I'm never happy playing with toxic chemicals so this is a really interesting alternative. I think this is probably a very similar material to the Stewart Systems water based primer that is marketed as aircraft primer in the USA, but is not available in Europe.

Hope this helps and keep my fingers crossed that I don't get shot down in flames for suggesting it.
 
Last edited:
Hi Richard,

I did a search and found an article on Bob's site:
www.rv8a.co.uk/PDF_Docs/PF_Nov_2007.pdf

That sure looks the way to go for me.

Do you also use that on the outside of the skins, or do you leave these in the blue wrap until painting the exterior?
Now to find a supplier overhere in Holland...

Thank you all for the suggestions.
Duncan
 
Duncan,

Some good information here: www.glosterairparts.co.uk/corrosion_prevention.htm
applicable to European conditions. I would suggest not using corrosion X or ACF-50 until after you have finally painted your airplane, otherwise the outside paint won't stick. PPG products for commercial trucks have a good reputation - see their primers and etch primers. Also suggest that you wait to prime the exterior until you have decided on the finish paint supplier, often a good idea to use primer and top coat from the same company.

Pete
 
Duncan said:
Hi,

I'm expecting my empennage for the RV8A to be delivered soon. I have looked over the subject over and over on this forum (and the internet) but failed to find the way to go. Can someone recomend me an environmental friendly (as possible) anti corrosion treatment for the internal parts of the plane?
"Friendly" as in: don't kill the guy spraying/putting it on (me :)).

Please included some suggestions about using the same stuff on the outside of the skinns as well. As a base for the color paint to go on.

When finished, the plane will be hangared close to the North See, so some protection against the salt is needed in my opinion.
I'm planning on treating the whole of the internal parts of the emppenage (not only the contact parts).

Thank you,
Duncan
Click to expand...
I have used lots of time investigating this (maybe way too much :) ). The thing is - you need a primer with anti-corrosive agents. Automotive primers usually work well on steel, but do not have the right ingredients to give aluminium proper protection. In the aero-industry, at least in Europe, one key element is epoxy primer with strontium chromate.

Just up untill some few years ago, Zinch Chromate in rattle cans was readably available, but is now illegal and very hard to get. I got hold of one can that I use as touch-up.

Zinc Oxid and phosphates, the ingredients in "real" non-chromate wash/etch primers, are excellent on steel, and will also prevent filliform corrosion in aluminum, but is a coating that need more coats on top. On internal parts of alclad I wonder if it is just as good leaving the polished alclad alone instead of using a wash primer that is specifically designed as an undercoat for topcoats. Filliform corrosion is probably one of the most common corrosion on aircrafts in salt/humid environments, but is something that occurs under the topcoat, so when you have no topcoad, you have no chance of filliform corrosion either.

The standard for corrosion protection is:
* Cleaning the aluminium (derinoxalu for instance)
* Wash primer, with zinc oxid and phosphates

OR

* Alodine

Then

* Strontium chromate epoxy primer
* Top coat(s) of polyurethane/epoxy

On internal parts, strontium chromate epoxy is enough.

The Strontium Chromate epoxy primer protects the aluminium electrochemically against corrosion, and is tough and hard so it also protect against physical damage and chemicals (oil, fuel etc) and is waterproof (a wash primer usually isn't).

I use primer/paint from Monopol in France. Except from a little local "primer war" with the importer here in Norway, I am very satisfied. They don't sell this stuff in local house and garden kind of shops, but I guess you, living in Holland, can just drive to them an get the stuff? You can also contact the sales agent Gerard Florsch ([email protected]).

The strontium chromate epoxy will give you the best possible protection on internal parts. It is probably the only thing that will give you full protection. Given the choice though, I would use zinc chromate rattle cans on all internal parts, because it is much easier to use, even though i is not nearly as good as the Strontium chromate epoxy.
 
Regarding health issues, I have come to the conclusion (right or wrong :) ) that you need a mask and proper clothing anyway, whatever primer you chose because they are all unhealthy. Then it is more a matter of how much mess you make. Rattle cans are less messier than two-component spray gun, and you can also just spray a dash in case you have to drill an extra hole. But rattle cans are inherently single component, and what they lack in physical and chemical protection, they have to make up for in corrosion inhibitive agents, making them more toxic (zinc chromate).
 
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