Corrosion

[jdmunzell]

I know this has been answered before, but I want to see if there are updates or fresh ideas to this problem.

Because it is taking so long to do these wings. a lot of my pieces of alum. still have the blue covering on it. I am finding out that with time, this stuff gets really hard to get off first of all. Secondly, along the edges of some pieces, I am starting to see very small amounts of corrosion (small funnels, maybe only a quarter to half an inch long develop. These pieces are stored in a nice dry temp. controlled basement, so I thought I would be immune to this sort of thing.

Should I get rid of all the blue wrap left on all the pieces or can I still leave it on so it doesn't get scratched up during the build?

Also, what's the best way to get rid of this type of corrosion? Is scrotchbrite scuffing enough, along with priming, or do I need to chemically treat the area before priming?

[docrick]

so many folks keep that blue stuff on. I guess I do as there are small scratches on the skins from manipulating them in the jigs but these will be gone when painted or buffed.

Vans instructions in the empennage kit explicitly state to get the blue stuff off asap as it gets hard to remove as time goes on and corrosion can happen underneath it.

As soon as I inventoried my parts ALL the blue stuff was removed. End of problem.

[Jalanci]

I'm sure others will pipe in on the plastic wrap, here is my opinions based on performing hundreds of claim investigations for water intrusion in the NE. We have found that there are many poorly ventilated areas in a basement that set up a micro-climate. What happens is that warm and humid air enters the basement and can condense on areas where the air temperatures and surface temperatures are cool. If nothing else, it raises the relative humidity to near 100%. You will also find that even though the basement walls seem dry, water vapor and conditions near the floor are sources of moisture. It is this moisture that is often trapped by objects that creates problems.

If you haven't already, raise the boxes off the floor and keep away from exterior walls. Have a fan blow some air around the stored boxes to keep the conditions from stagnating and assimulating a cooler and damper condition. If you keep the relative humidity to below 50% that should keep the dewpoint temperature low enough to prevent isolated areas from exceeding 70%. You could set up a dehumidifier with the warm dry air blowing over the boxes.

A clue that you have some moisture in your basement walls is efflorescence (white) stains along the bottom of the wall.

I think the plastic may wick some moisture from moisture on the skins. I have some skins that are over a year old, no signs of corrosion, I have the plastic still on and take the precautions I mentioned above.

[rfinch]

I've heard that it is much easier to remove the blue plastic if you expose it to sunlight a while on a hot day.

Don't know about the corrosion.

[jdmunzell]

Originally Posted by rfinch

I've heard that it is much easier to remove the blue plastic if you expose it to sunlight a while on a hot day.....

I wonder if putting a heat lamp to it would do the same thing seeing as how it's winter time.

[airguy]

I'm peeling mine as I go. As I grab each piece out of the box, I'll cleco and match drill, then peel the plastic and deburr. Any piece with blue still on it has not been deburred, simple tracking.

[pierre smith]

Originally Posted by jdmunzell

I wonder if putting a heat lamp to it would do the same thing seeing as how it's winter time.

........we used a hair dryer to soften the blue plastic and it gets easier to remove.

Regards,

[RudiGreyling]

Start on the edge then roll it into a cardboard pipe.

[jdmunzell]

Rudi,

I see from your videos that after the initial drilling, you remove all the blue plastic before final riveting, or so it appears. Are you glad you did it that way or would you do it differently next time?