Priming inside W-716 aileron push tubes

[John Courte]

Hi all,

I'm about to prime the inside of the W-716 aileron push tubes on my QB 7. Question is, is it legit to use a cylindrical brush attached to a long dowel to apply the primer instead of spraying a load of paint in and rolling the tube around? I'm using SEM self-etching primer and it tends to flake if it's laid on too thick, which is what I'd expect from a flood-and-roll operation.

If I thin the paint out a bit, will that help?

thanks,
-John

[cjensen]

I can't offer any advise on using a brush/dowel, but it sounds like a good idea.

I flooded mine with NAPA 7220, and it seemed to work fine...one will never know what it will look like in the middle of the tube regardless of how you go about priming it since we simply can't see it, and will never see it once the ends are riveted on.

[tmbg]

hm, I may consider building a trough just big enough for the longest tube and dip priming them.


Of course, that might just be a colossal waste of primer

[Lycosaurus]

When talking to Bruce at Van's a while back, he suggested to just use compressed air and nozzle to help distibute the paint on the inside of the tube. Makes for less paint usage. (of course, this advice was a little too late for my use)

[John Courte]

Originally I had this idea of pumping it out of a micro-head irrigation sprayer on the end of a length of 1/4" tubing and pulling it down the length of the tube. But further investigation looked like more of an engineering problem and time spent wandering around Home Depot than I wanted to deal with. It sounds like the key to making this work is to have the tube clean before paint goes in it.

[captain_john]

To prep the tube, I used a chunk of scotchbrite pad wrapped around an electrical snake. I chucked the setup into my drill and spun it while pulling it through!

I wouldn't do it any other way after seeing how well it worked!

I then taped up the other end and dumped a few ounces of paint in the end. I was REALLY shocked at how little came out after rolling it around a bit!

I then poured it into the remaining tubes that I had to do and the whole affair was set to dry.

It worked VERY smoothly!

I strongly recommend it!

CJ

[Lorin Dueck]

CJ -
What primer did you use?
Thx, Lorin

[captain_john]

When I did that I was using DuPont VariPrime. Now I am using either DuPont Nason Self Etch or DuPont Nason Epoxy.

I like all three. When I want super durability, I use the epoxy. It is pure magic in a can!

CJ