I'm looking for suggestion on cleaning a heavily corruded aluminum tank from a K75.
A couple years ago I picked up an $400 '89 K75 with 23K on it. The bike is complete but was sitting outside uncovered and unstarted for 10+ years. I've been going through a thorough restoration--rebuiiling the forks and brakes, cleaning injectors, replacing hoses and seals, etc,--however one of the areas I'm stuck on is cleaning the fuel tank.
The exterior of the tank is in fair condition considering its history, but the inside is a mess. I've pulled the innards including a fuel lever sensor and fuel pump which were coated with corrosion beyond recognition. The fuel pump dampening gasket had turned to gel and had to be scraped out, and the interior of the tank had a light brown coating of corrosion on everything.
The tank also has a very very small less than a drop a day leak.
I've used the POR 15 treatments before to clean and seal gas tanks and they've worked great. That's what I'd like to do with this one, but those tanks had no where near the corrosion this one has. Also, the POR process uses an acid wash to prep the tank for the sealent and I'm uncertain about using acid on an aluminum tank.
Any suggestions for removing the heavy corrosion and cleaning the deposits out of this aluminum tank out? And will the acid wash be safe?
Thanks for your help.
P.S. I usually post under the moniker "Kontoboy" but that account has been mangled--I'm trying to get it fixed.