[mlwynn]

Hi folks
I am busy building the tank attach brackets. Dan Checkaways approach makes great sense and that is the approach I am using. The question I have is when to prime. Both Van's and Dan's say to drill and then attach the platenuts. Neither say anything about priming between those steps. It seems to me that if you attach the platenuts before priming the brackets that you will not prime the area under the platenuts. Am I being (my usual) over compulsive? Suppose it actually matters?
Thanks
Michael Wynn
RV 8 Wings (tanks)

 

[Dave Cole]

Alodine first

I used an Alumiprep/Alodine conversion coating process on the Z-brackets before riveting the platenuts on. This is a good process for any extruded parts, which do not have an alclad surface.

I am going to install them on the tanks without priming to make sure I get good proseal adhesion around the rivets, then I'll prime only the surface that mates with the spar.

Dave Cole
RV-7 wings

 

[osxuser]

I used an Alumiprep/Alodine conversion coating process on the Z-brackets before riveting the platenuts on. This is a good process for any extruded parts, which do not have an alclad surface.

I am going to install them on the tanks without priming to make sure I get good proseal adhesion around the rivets, then I'll prime only the surface that mates with the spar.

Dave Cole
RV-7 wings

I think that sounds like a good order, I don't think you want to prime before you proseal all that stuff, proseal will stick better to bare aluminum.

 

[dan]

Am I being (my usual) over compulsive?

Yes. Nutplates (at least the ones we commonly use and buy from Van's, Spruce, etc.) are treated. Nutplates and aluminum get along without the usual galvanic issues of mating steel w/alum.

If you're really, really concerned, spray some primer over that side of the Z-bracket flange before riveting the nutplates in place.