J

jwilbur

Well Known Member
Is there any reason you shouldn't put a coat of primer on an assembly after it's been riveted together? This would potentially coat rivet heads and spots of primer worn away during the assembly process.
 
Thats what I do. I spray a little primer on the shop and mfg heads. It also recovers any primed spots that were scraped off during riveting.
 
jwilbur said:
Is there any reason you shouldn't put a coat of primer on an assembly after it's been riveted together? This would potentially coat rivet heads and spots of primer worn away during the assembly process.
Click to expand...

It won't cause your aircraft to fall out of the sky. It may require an extra inch of runway due to the extra weight. :D

I personally don't worry about it unless I really managed to scratch the previous primer coat. Most parts are going to get hit again with interior and/or exterior paint. I'm not overly concerned about the rivet heads not getting primed.
 
I'm with Bob on this. For the most part, I didn't go back and prime the rivets. Nothing wrong with doing it, just takes time.
 
I don't care to actually prime the rivet heads. I've got a few spots where the primer got really scratched up and I just want to make sure that if I DO prime over the rivet heads as I recoat the ugly spots, that this isn't going to bite me in some way in the future. I should have been clearer in my question.
 
Nope, touch up as required. If you happen to prime some rivets in the process so be it--won't hurt a thing.
 
Joe,

Not that I'm an expert. Actually the more non-expert you are the more this applies I think. Anyway I started adding some tape on my bucking bar to reduce the scratching. The blue painters tape leaves blue marks so thats not too good either. Clear strapping tape seems to last OK and doesn't leave marks. Once I started adding the tape the primer damage was less. The veterans may have a better solution, but this seemed to help.
 
rapid_ascent said:
Joe,

... I started adding some tape on my bucking bar to reduce the scratching. ... Once I started adding the tape the primer damage was less.
Click to expand...

Ray,

I appreciate the tip. I've actually been putting masking tape around the bucking bar AND along the flange behind/around lines of rivets and STILL I manage to scratch up the primer. Maybe I have unrealistic expectations about how pristine it should look, but when I see some of the pictures out there from the experienced builders, I'm amazed at what I see. I want my stuff looking that good, too.

Anybody out there have other tips beyond using tape and waiting for years of experience in order to avoid scratching up the primer while bucking rivets?
 
Bucking "Shield"

I tape the bar with a piece of gorilla tape.

Depending on the bar, I've also used a slice (think big rubber band) from an old bicycle inner tube around the bar.

I've also used a thin piece of cardboard (old spiral notebook cover) as a "shield" to protect other parts if I'd working in an awkward spot.

Good luck,
Mike
 
jwilbur said:
.......tips beyond using tape and waiting for years of experience in order to avoid scratching up the primer while bucking rivets?
Click to expand...
You do not say what type of primer you are applying but based upon my experience, it is only natural to suppose you are not using epoxy primer. Using epoxy primer, I rarely feel the need to wrap protective masking tape around a bucking bar.

If while bucking rivets you find the primer mars or scratches easily, it is not much of a leap to suppose you might be applying common rattle can, as opposed to far tougher epoxy primer. See post #13 here for my first hand observations using Akzo. The post also happens to directly address your first question about priming the shop heads of the rivets.

Note fully cured Akzo's superior touch-up qualities using an artist brush dipped in fresh primer:

http://www.vansairforce.com/community/showthread.php?t=66672
 
Last edited:
Rick,

You have a point on the primer. I'm using white EkoPrime so far. The color might be part of it, and the primer selection the other part. I don't know if this is my final primer selection, but it is pretty easy to use. I might try the EkoPoxy too. That's probably half way to Akzo since it is still water based or waterbourne. I like the white primer color, but I might just be making it harder on myself trying to keep it pristine. I read here the Akzo is pretty bullet proof, but some people (me) have to prove everything to themselves.
 
Rick6a said:
If while bucking rivets you find the primer mars or scratches easily, it is not much of a leap to suppose you might be applying common rattle can, as opposed to far tougher epoxy primer.
Click to expand...

Correct. I'm using Moeller's Zinc Chromate rattle cans. I've heard and read good things about the product and it does look good in general (until I start rivetting). As with Ray, I'm also considering weather I should switch to something else. My biggest issue is that I simply hate painting in all its forms and want to go with the easiest application method possible. Going beyond self-etch rattle cans implies to me lots of extra prep work, extra products and tools to buy, more chemicals, top-coats, ruined clothing, streaks of color all over the children (and therefore everywhere in the house), primer on my hands and face and in my hair that won't come off for days, and a massive cleanup effort after every use. .... But at the same time, if what I'm using scratches off too easily, what's the point of using it? ... Just not sure what route I'm going to take moving on.

Rick, your post from last year was helpful. Thank you for pointing it out.
 
For the minor little scratches or areas where the primer needs a touch-up, I've used a Q-tip dipped in the can of primer (or soak a Q-tip from a spray can) and then touch it or roll it on. I've fixed quite a few little areas with this technique. The prep work is nothing, and the cleanup is a snap (just throw the Q-tip away!).
 
that zinc chromate stuff I used on my tail, then I got some of the napa 7720 and i've had no issues with scratching like I did with the zinc chromate product

just sharing my experience
 
You must log in or register to reply here.