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Poorly stored RV6 kit

RoyV.

I'm New Here
I have RV6 emp and wing kits that have been rotting away in an damp old barn for the past 4 or 5 years (after moving). I am finally building a new shop and hope to be able to move the parts this spring. I know I will have to toss out all the steel parts. How can I examine the aluminum parts to see if they are salvageable? If there is any visible corrosion at all will it be a total loss? The wing spars are stored in the hay loft of a horse barn and are caked with dust but have stayed nice and dry. Those are the parts that concern me the most. Will I need professional help with this? (the airplane parts I mean).

Thanks,
RoyV.
 
Corrosion

Roy, You can do most of the looking yourself. If you find areas that you are wondering about then get an "expert" to look. If you are a member of AOPA they have an excellent article on the subject. http://www.aopa.org/members/files/topics/corrosion_overview.html

Here is some information on the subject:

Corrosion on aircraft is nothing more than rust of the metal parts, although aluminum corrosion doesn't produce the reddish color most people think of as rust. Rather, it usually first shows as a whitish or gray "dulling" of the aluminum surface, then progresses to more and more severe pitting and eventual destruction of the metal. Left untreated, corrosion can make an aircraft unairworthy in just a few years.

Types of corrosion normally found on aircraft include:

Uniform surface attack. This is the most common type and is caused simply by exposing the metal to oxygen in the air, such as when paint is worn off wing skin or fuselage. Poor pre-paint preparation at the factory, fumes, acid, pollutants, or high humidity accelerate the decay.
Intergranular corrosion. Normally worst on 7000-series alloys (those with an appreciable amount of zinc, like wing spars, stringers and other high-strength aircraft parts), this is not frequently found but is a particularly nasty type of corrosion. It can be difficult to detect, and once you see it, it's too late: that piece of metal is toast.
Stress corrosion. In highly stressed parts like landing gear or engine crankshafts, this type may develop from a scratch or surface corrosion. Crankshaft failures are often due to undetected corrosion of this type.
Crevice or deposit corrosion. This can occur anywhere there is an area where moisture or other pollutants are trapped. Lapped skin joints or rivets on an oil-stained belly are examples of prime corrosion spots.
Filiform corrosion. Particularly on aluminum surfaces poorly prepared for polyurethane paints, this type of corrosion will show up as fine, worm-like lines of corrosion under the paint that will eventually lead to bubbling and flaking.
 
storage corrosion

Hi Roy,
I also purchased a long term storage RV-6 wing kit. The skins showed signs of surface corrosion, but this was simply the alclad turning into the white/gray powder (alum oxide). A couple rear spar parts (1/8" thick) had deeper grooves that looked like filoform corrosion. The A&P types said that it would need alumiprep with scotchbrite, then a good zinc chromate primer, but not to worry about the slight grooves.

The wing skins were the prepunched type and moisture had crept under the plastic at the holes. This caused local surface corrosion at the holes. The plastic was also a BIATCH to remove! No parts required replacing, but all needed prep and prime. This will not be a good looking skin to polish, but will be fine with paint. When in doubt get a second opinion from a restorer or A&P. They see this every day.

Kelly
 
corrsion

Just wondering, along with the aluminum did you have any rust on the 4130 steel parts? I ran into that problem while building my 6. I used glass bead blast cleaning(sand blasting) to see if any of the parts were damaged. Also, I was very fortunate to have the FAA inspector in our EAA chapter and he saved me many a dollar I would have spent replacing material that I thought was bad.
Follow the advice of the RoyV and Gugoff99 and you'll be fine.
Rich
RV-6 721ET
200 hr.
 
Corrosion on 4130

I have some rust on my aileron brackets. Did you bead blast clean the part yourself or did someone do it for you? I don't have a bead blaster so I would need to take mine to someone or order new parts.


houndsfour said:
Just wondering, along with the aluminum did you have any rust on the 4130 steel parts? I ran into that problem while building my 6. I used glass bead blast cleaning(sand blasting) to see if any of the parts were damaged. Also, I was very fortunate to have the FAA inspector in our EAA chapter and he saved me many a dollar I would have spent replacing material that I thought was bad.
Follow the advice of the RoyV and Gugoff99 and you'll be fine.
Rich
RV-6 721ET
200 hr.
 
bead blast

I have a "sand blast" gun from Sears ($49.00). Power from my air compresser.
Bought a 5 pound bag of number 5 glass beads from a auto body paint supply store. Did the bead blasting outside because of the over spray. The steel parts cleaned up very nicely. Wear heave gloves. No damage to the metal. Used a very good primer to protect the parts.
Rich
 
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