Mast paint bubble repair

[CarlF]

I'm starting to develop a few bubbles in the 8 year old mast paint where water has gotten under the paint (all at fittings). I suspect that most of these were not galvanically isolated with Tefgel when the mast was built. There are only about six so far but I'd like to fix them.

I really don't want to turn this into a huge project. Any suggestions for an easy treatment?

I read that Duralac can be painted after it has fully hardened. I was thinking of using a Dremel to sand out the bubbles, give it a coat of Duralac, and then paint after it has fully hardened (which takes weeks but that's OK)

My first idea was to spot prime with an etching primer but will that seal the paint at the edges of the repair or will the water just have a new place to start?

[FastTrout]

Originally Posted by CarlF

I'm starting to develop a few bubbles in the 8 year old mast paint where water has gotten under the paint (all at fittings). I suspect that most of these were not galvanically isolated with Tefgel when the mast was built. There are only about six so far but I'd like to fix them.

I really don't want to turn this into a huge project. Any suggestions for an easy treatment?

I read that Duralac can be painted after it has fully hardened. I was thinking of using a Dremel to sand out the bubbles, give it a coat of Duralac, and then paint after it has fully hardened (which takes weeks but that's OK)

My first idea was to spot prime with an etching primer but will that seal the paint at the edges of the repair or will the water just have a new place to start?

Why is it bubbling?

If you luck out and it is JUST a paint systems failure, your idea will work.

But.

I’d make sure you inspect the why first



https://www.aircraftsystemstech.com/2019/04/forms-of-corrosion-aircraft-corrosion.html

[tkeithlu]

So, you'll sand down to good aluminum and feather. You'll leave the surface rough to maximize gripping. Do check on whether your goo needs a primer. Sounds good. But then, do follow FastTrout's caution to find out why this happened in the first place. If it's not already done, ground the mast to the bonding system.

Pretty straight-forward project. Move on to the next one.

Good luck with it.