Tank Repair and Oxidation?

I decided to go ahead and prime the outside of the tanks just to make sure to keep the oxidation to a minimum on the plane but it looks like it beat me to it. I’m going to guess something in that soapy water mixture was corrosive to the aluminum as I noticed that both of the tanks had these spots over them where I had sprayed the soapy water.

I tried using acetone and NAPHTA on it but neither of them really helped with removing them. I was really hoping it was just residue of the soap dried on. So I’m going to have to see how to buff this off before I paint the outside of the tanks. I might just use the scotch brite pad to scuff the surface since I will be putting the primer on which is what they will be doing to the outside of the plane when I do the paint job down the road. Either way it all looks very superficial so I’m going to see how to buff it off and then prime.

But most of my time today was just removing the tank from the wing I installed it on. I also need to file down the outside edge of the skins just a slight amount as when I had it installed on the wing it overlapped just a tiny bit in certain areas. So I removed all of the bolts around the edge and on the rear Z brackets and put it back in its cradle. I might do one more test on this tank just to make sure it is sealed since I didn’t have good success with the second one.

Speaking of which, I cut open the two bays I had leaks in, cleaned it up and then inspected to see what went wrong. The cutting tool actually came in really handy! We had an EAA meeting that talked about it and demonstrated it so I decided to buy one since they were fairly inexpensive. It can be used free hand, with a stylus that allows you to follow a straight edge or that same stylus can be used to put inside of a hole drilled in the middle to allow for circular cuts.

Either way, in the third bay I can see where it might have an issue with the bead of sealant looking a little bubbled and messed up.

But the second one looked perfect! I have no idea where the leak is coming from here. I’ll just have to add more sealant over this section and since I’m in here I’m going to do it all across the rear baffle just so I don’t have to reopen this area again.

All in all, I’ll get started first thing tomorrow with putting the rear panel on temporarily to drill the rivet holes and then get the sealant put on and riveting the rear panels. Then I will scuff up the outside of the tanks (at least the non-exterior skin portions) and get them cleaned and prepped for priming. Then I will prime all of the parts for the left flap as well as the tanks at the same time. And if I have enough time left in the day I want to start assembling the flap. The garage is a mess right now with so many parts laying all over the place in various stages of build LOL.