This are my latest decisions regarding corrosion prevention:
Thanks to Indestructible Inc. , a GB firm specialized in high quality paint finishing, I received a very generous (one gallon drum) free sample of their two component aviation epoxy primer. This I will use to coat the complete inside if the airframe. Initially I thought of only coating the mating surfaces, but at a closer look to the forward fuselage sidewalls for example there are so many pieces riveted to them that coating the complete sidewall is simpler/easier and looks better at the end (I probably will not install sidewall upholstery).
The primer I will spray using a HVLP (high volume low pressure) spray gun as soon as outside temperature raises to acceptable level. This will reduce overspray and save some of the precious primer. The coating will be very faint (about only 2 to three microns).I'll prime the parts when all rivet holes are drilled to final size and after final deburring. The epoxy primer provides sufficient vapour barrier to the underlaying metal surface so I will omit a cover coating (this is a big advantage of the epoxy primer over the traditional zincromate primer). I expect about 3 lb of additional weight - tolerable in my view.
My first work are some small parts to become familiar with the alumn sheet metal. I currently fabricate some wingrib-gussets (SNX-W15 etc.).
Before this I spent some thoughts about corrosion prevention (I expect this flying machine to outlast myself). I studied the RV mailing lists for some time and anything else to this subject.
So this is my final decision now:
This treatment I'll do after deburring and before riveting.