RV10Rob

RV10Rob

Well Known Member
Hi, all.... I've sanded out some scratches in a skin with the maroon scotchbrite pads. For the interior sides, I'm using a self-etching primer, so I figure there's no issue since I'm planning on priming soon.

What about the exterior? I've exposed the aluminum underneath the alclad--should I be worried about corrosion? I'm going to paint it eventually, but not for a couple years at least. I don't want to use the primer on the outside now, since I hear it makes paint adhesion more difficult later. Any suggestions? Unless I hear a better idea, I'm just going to leave any new scratches as-is on the exterior, then sand them down when I get closer to painting.

Thanks...

-Rob
 
Are you really sure that you're through the alclad? You'd have to scrub a loooong time by hand with scotchbrite to get through it. I actually tried it once while checking with a micrometer every so often. It took a whole lot o' scrubbing.
 
When I re-primed my first empennage ribs, I had to scratch a lot - even with sandpaper - to take all old prime off. And you can easily see the slightly different colour (this was my idea...) detween the pure aluminium and the the alloy.

Anyway, you can now prime and de-prime (and re-prime) with acetone before painting or I think you can apply oil, as Van's does with QBs.

Only my humble opinion...
 
Go buy some alodine and rub into the areas that you have sanded. This will protect it for many years.
 
Thanks, all... on second thought, I may not have sanded through the alclad. I'll check it out again, but it sounds like I might be okay as-is.
 
I've got some alodine that I keep on hand. If I believe I've gone through, I go ahead and spray some on. It makes the part ugly to look at, but once the primer goes on it doesn't matter.

Phil
 
alclad

is only .002 thick and is buttery soft..comes off redily esp with a RED pad.
just alodine it for now.or sem or any other self etch. good luck.
 
Touch n Prep

Regarding touchups with alodine, these are nice to have...

Look around, you can find them cheaper (I think I gave a little over $50 for ours from a local supplier).
 
cytoxin said:
is only .002 thick and is buttery soft..comes off redily esp with a RED pad.
just alodine it for now.or sem or any other self etch. good luck.
Click to expand...

Ok, not that it matters, but have you ever actually checked on this? I had seen this statement made over and over on here and other sites until I finally tested it myself. I found that red scotchbrite (by hand) takes a real long time of continuous, vigorous scrubbing. I think a lot of folks are under the false impression that the alclad is gone when the shine is gone.
 
well

szicree said:
Ok, not that it matters, but have you ever actually checked on this? I had seen this statement made over and over on here and other sites until I finally tested it myself. I found that red scotchbrite (by hand) takes a real long time of continuous, vigorous scrubbing. I think a lot of folks are under the false impression that the alclad is gone when the shine is gone.
Click to expand...
that depends on the operator i suppose. its very easy to see when it happens. the resistance in effort is quite obvious and you can see it open up. the metal is clearly a different shade and much harder. this has been my experience as i have had to polish out several scratches. then if you actually try to shine it it takes much more effort than polishing clad. it is only .002 thick....your statement says "a looooong time" my experience is just the opposite. ymmv i guess we agree to disagree. :)

added
you know if you laid a pad on the wing and went to scrub it i would tend to think it would take along time. but to finger sand a scratch it would come of quickly
 
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