Surface Corrosion Must Go, Now!

[RLCarter]

@RoundTwo like @M20Doc said above….Don use glass beads on your plane, it will stretch the aluminum in very short order. I’ve used my bead blaster to bend 1”x1”x .125” aluminum angle into an arc, took less than 5 minutes to bow a 7” piece a 1/2” and that was at 35psi… scotch brite (not sandpaper) to remove the bulk, aluma-prep to remove what is left, Alaeddine  for the conversion coat, then either epoxy primer or zink-chromate primer…. The other down side of blasting is it work hardens the aluminum and will cause the skin to crack in the future 

[RoundTwo]

6 hours ago, RLCarter said:

@RoundTwo like @M20Doc said above….Don use glass beads on your plane, it will stretch the aluminum in very short order. I’ve used my bead blaster to bend 1”x1”x .125” aluminum angle into an arc, took less than 5 minutes to bow a 7” piece a 1/2” and that was at 35psi… scotch brite (not sandpaper) to remove the bulk, aluma-prep to remove what is left, Alaeddine  for the conversion coat, then either epoxy primer or zink-chromate primer…. The other down side of blasting is it work hardens the aluminum and will cause the skin to crack in the future 

Thank you. I appreciate the input. Is the same true for soda blasting, since it’s a much softer media than glass beads? I’ve got plenty of different scotch Brite Roloc discs in different grits. Is there one grit/color better suited than others? 

[LANCECASPER]

Just my opinion, but I would let someone do this that's done it many times. I know my personality and for years it was "shoot first, ask questions later". My tendency would be to go at that too aggressively since I want it gone and I would end up creating some other problems. I'll do the basics and I enjoy learning, but I've also found that if I let the experts do what they do best, I can go make what they charge doing what I do best and it gets done right. 

Also with this much surface corrosion you're not going to be satisfied until the airplane looks like you want it to look. If circumstances allow I'd at least get on the waiting list at a paint shop with a good reputation. You have a great platform to work with there and since you plan on turning it into your forever plane it will be worth it.

[RoundTwo]

21 hours ago, LANCECASPER said:

Just my opinion, but I would let someone do this that's done it many times. I know my personality and for years it was "shoot first, ask questions later". My tendency would be to go at that too aggressively since I want it gone and I would end up creating some other problems. I'll do the basics and I enjoy learning, but I've also found that if I let the experts do what they do best, I can go make what they charge doing what I do best and it gets done right. 

Also with this much surface corrosion you're not going to be satisfied until the airplane looks like you want it to look. If circumstances allow I'd at least get on the waiting list at a paint shop with a good reputation. You have a great platform to work with there and since you plan on turning it into your forever plane it will be worth it.

That was exactly my plan until I was told by a paint shop, very well respected on MS, that they use brass coated wire wheels for this. I agree that it is an effective means of getting rid of it, but steel on aluminum is a non starter for me. I’ll quickly realize if this is the wrong path and will then reevaluate my options.

As they say, this isn’t my first rodeo as I did a total strip and repaint of my ‘65 Cherokee back in 1990. My take away from that endeavor was never spray Imron in a row hangar unless all other aircraft have been moved. 

When I get into this, I’ll gladly offer up my results, good or bad. Maybe that will be helpful for others that may find themselves in a similar situation.

 

 

 

 

[RoundTwo]

32 minutes ago, bluehighwayflyer said:

I agree.  That is a lot of corrosion.  Once filiform is that well established it is very hard to get rid of.  

I did my best to get pictures of the worst places which of course makes things look worse than they really are. Most of the paint is nice and shiny, punctuated by spots of corrosion.

[LANCECASPER]

2 hours ago, RoundTwo said:

I did my best to get pictures of the worst places which of course makes things look worse than they really are. Most of the paint is nice and shiny, punctuated by spots of corrosion.

Beautiful airplane - well worth whatever it takes.

[Guest]

4 hours ago, RoundTwo said:

Thank you. I appreciate the input. Is the same true for soda blasting, since it’s a much softer media than glass beads? I’ve got plenty of different scotch Brite Roloc discs in different grits. Is there one grit/color better suited than others? 

I’ve never used soda blasting for this type of thing.  Anything blasted at the aluminum skin has the potential of work hardening the skin and driving powder between layers and lap joints.

With Scotch brite, I’d start with a finer grade and see how it goes, you can alway back up in coarseness if you need to.

[Andy95W]

@RoundTwo- Ihad similar corrosion on my first Mooney and also on my Aztec.  I removed it the same way on both airplanes: Time, red ScotchBrite, and a little lacquer thinner.

Removing filiform corrosion actually goes very quickly using just finger pressure and red ScotchBrite pads.  The lacquer thinner helps soften and remove the paint in the vicinity.  Some of the ScotchBrite discs are really aggressive and can damage the aluminum almost as fast as glass beads.

I spread the project out over a few weeks.  Work for a few hours, take care of 5 or 6 spots, and take a break and go fly.  Repeat once a week and before you know it, it’s done.

Since you have experience painting an old airplane, I don’t doubt you already know this.  Good luck, let us know how it goes!

[RoundTwo]

1 hour ago, Andy95W said:

@RoundTwo- Ihad similar corrosion on my first Mooney and also on my Aztec.  I removed it the same way on both airplanes: Time, red ScotchBrite, and a little lacquer thinner.

Removing filiform corrosion actually goes very quickly using just finger pressure and red ScotchBrite pads.  The lacquer thinner helps soften and remove the paint in the vicinity.  Some of the ScotchBrite discs are really aggressive and can damage the aluminum almost as fast as glass beads.

I spread the project out over a few weeks.  Work for a few hours, take care of 5 or 6 spots, and take a break and go fly.  Repeat once a week and before you know it, it’s done.

Since you have experience painting an old airplane, I don’t doubt you already know this.  Good luck, let us know how it goes!

Back to good old elbow grease, eh? That’s definitely the easiest method when not in a nicely equipped hangar. Once I get possession of it, I’ll take a whack at it and see how it goes. Hopefully it won’t be that bad.

[Fly Boomer]

6 hours ago, RoundTwo said:

Back to good old elbow grease, eh? That’s definitely the easiest method when not in a nicely equipped hangar. Once I get possession of it, I’ll take a whack at it and see how it goes. Hopefully it won’t be that bad.

I hope to learn from your experience.  I too have a bunch of spots.  Not much corrosion but places where paint is chipped, and some spots painted with a color that didn't quite match.  Looks bad to me, but other people say "what's the problem?".

[RLCarter]

19 hours ago, RoundTwo said:

Thank you. I appreciate the input. Is the same true for soda blasting, since it’s a much softer media than glass beads? I’ve got plenty of different scotch Brite Roloc discs in different grits. Is there one grit/color better suited than others? 

Soda is great for removing paint, no so good for corrosion. Be careful using the RoLocs, the heat from the friction will deform the aluminum skin also. I’ll get slammed for this but I use toothbrush size wooden Stainless Steel brushes on aluminum to remove corrosion. I use these ss brushes to clean aluminum before welding (TIG) as the bristles become worn the brush gets used on corrosion (once they get used for anything else they never get used on aluminum again). The Aluma-Prep is an acid (diluted) that eats the corrosion, on vertical surfaces you can use modeling clay to help control drips and runs of the aluma-prep which is applied with wooden cotton swabs (Q-tips). Use light pressure when scrubbing the aluma-prep withe SS brush, the solution will turn dark until all the corrosion is gone so keep cleaning and re-applying until it’s corrosion free. It’s not hard work but it is tedious….. as a side note aluminum starts oxidizing once it is cleaned so work only a few spots close together at a time, once a spot is cleaned get at least the conversion coat (alodine) applied, primer can be applied latter on (with in a few days)…. Read the instructions on the Aluma-Prep and Alodine, if your a little worried about damaging the surrounding paint with the alums-prep you can dilute it with water, but the weaker the solution the longer it takes to work

[jetdriven]

That looks like great advice