Comment

Comment by Russell Johnson on June 4, 2018 at 8:43pm

 I had an empty can of PVC pipe cleaner that had a cotton ball swab attached to the lid. Filled it with thinned ZC and just swabbed the mating surfaces.

Comment by Mark Baenen on June 3, 2018 at 9:50pm

Okay, the idea of using a convenient small roller to put ZC primer on the contact surfaces makes sense. I have bad influences from restoring cars and such - I think I need hose down and encapsulate everything. No so with new aluminum and weight constraints on airplanes. I would just do it differently next time, not completely prime everything.

Comment by John Edwards on June 3, 2018 at 12:15pm

Alodine is my corrosion product of choice. After using Cortec I discovered with a test piece of aluminum left out in the weather for about 7 years now there is nothing harder or bullet proof. It needs to be handled with care just like zinc chromate...

Comment by Perry Delano on June 3, 2018 at 9:29am

I was doing the same process, but Matt Heintz came out to help us start with the RAA Ch 85 750 Cruzer project, which is nearing completion, and what he suggested is: Thin the ZC "a lot" after you deburr the part just paint it on, he even went so far as to say don't even wait until it is fully dry to assemble. I have been following that procedure on my 701 with no apparent draw backs and maybe even better adhesion than I got with the process you are following, and I was.The greatest improvement I have found with working with ZC is I use disposable 3" rollers I cut in two w the bandsaw and reassemble on a modified handle (what appears to be about a 10 or 12 gauge wire), pour the primer into used and cleaned aluminum food tray (Cosco Buttered Chicken works well) and roll away with ZC thinned 25 to 30%. Biggest job is getting ZC out of cooler I keep it in, in 125 mm mason jars. Tip, as you probably are already aware, if you are going to reuse a tray you need to be sure its cleaned well with thinner or you are going to get ZC snot showing up in your paint job. I have some disposable paint brushes permanently set in some thinner for tight spots. To get at some surfaces I missed or left unprimed, not many, I will spray with Krylon Tough Coat 00344, Green Corrosion Inhibiting Primer. It blends in inperceptably with the ZC, adheres well to it and does not seem to affect it. I've only experimented with it on parts where the ZC has been allowed to dry for an extended period of time, but since the ZC will have been on the parts I will respray for a long time it should work out fine. Hope this helps.

Comment by Mark Baenen on June 2, 2018 at 9:27am

Basically because it seems to be a big PITA without a lot of extra benefit.

My routine right now:

Put together assembly - final fit

Disassemble, debur, sand, wipe down with lacquer thinner, paint, reassemble, sand, touch up, wipe down, final paint.

Next time:

Disassemble, debur, coat mating surfaces with Cortec, reassemble, acid wash, DTM polyester urethane final paint.

I be this would save 33% assembly time and be just as corrosion resistant and less toxic - plus save weight!

I will continue to do the regular routine on this go around. I plan on painting the fuselage this next week.

Mark

Comment by Perry Delano on June 2, 2018 at 8:33am

Hi Mark,

I have been using Zinc Chromate as well, with what I thought were good results, low exposure of myself to fumes and a house that did not smell of the stuff. I would be interested to know why you would not use it again.