Is this paint wrinkling cause for concern?

[Veloo]

Cleaning a 2010 Argon 18 Radon. The main triangle is aluminum and noticed the paint wrinkling around the bottle bosses. There is only a cage on the red down tube. Not sure if there was ever one on the seat tube as space is pretty tight on this XXS frame but the top (white) boss looks to be the worse of the bunch.

I haven't given it a super hard tightening but the screws go in and out okay.

Is this any cause for concern?
Should I do any preventative work beyond a good cleaning?

[David Kirk]

My guess is that you have a galvanic corrosion going on between a steel rivnut and the alloy tubes. Not good. Sorry.

dave

[FriarQuade]

Dave is probably right. But that doesn't' mean game over. You could remove the rivnut and buff the corrosion off and then repaint the whole thing. Or just go ride it.

[fmradio516]

i know nothing of this subject, but if the rivnut comes out cleanly, and he sands it down a little, puts some touch up paint on it, isnt it possible to install a new rivnut??

[Veloo]

Thanks for the replies.
That would explain why the down tube bottle screws had (dried) rust on them.
My concern of course would be structural integrity of the frame if there is corrosion of any sort going on.
I'll do as thorough of a cleaning as I can and try to take a closer look. Will probably have to remove some paint in the area to really get an idea of the extent of the corrosion. Hopefully the aluminum is intact and it's just steel rivnuts that need to be replaced.

Never done a rivnut replacement. DO they only come in steel?

[David Kirk]

Originally Posted by Veloo

Thanks for the replies.
That would explain why the down tube bottle screws had (dried) rust on them.
My concern of course would be structural integrity of the frame if there is corrosion of any sort going on.
I'll do as thorough of a cleaning as I can and try to take a closer look. Will probably have to remove some paint in the area to really get an idea of the extent of the corrosion. Hopefully the aluminum is intact and it's just steel rivnuts that need to be replaced.

Never done a rivnut replacement. DO they only come in steel?

You can get aluminum rivnuts...I have a ton of them on my race car.

The tube is compromised around the holes for sure. If you remove the old rivnuts and sand lightly you'll get a white powder that used to be part of the tube. Will the tubes fail? I seriously doubt it. that said stopping the corrosion would be a good thing.

Have you tried sticking a magnet to the rivnut to see if it's steel?

dave

[Veloo]

Yup, they're definitely steel rivnuts.
Magnet went right for it.
I'm assuming it was chosen for less chance of threads getting stripped vs aluminum rivnuts. And probably cost.
Also assuming there wasn't proper application of some medium to prevent contact between the two?

Damn you dissimilar metals!
Can't you just get along.