Can I Grind and Paint?

[fathom]

Hey all,

I threw this up on the Facebook group but figured I’d shoot it up here as well. We are starting to really jump into our IV build and I noticed the small area of rust shown in the picture attached. Can I sand/grind and paint this or what is the best option to get control? It doesn’t appear to be significant but considering this is where the wing strut attaches to the fuselage I would like a second opinion.

Also, any thoughts why someone would put hysol on the weld unions? I’m guessing to prevent mositure from sitting in the corners and causing corrosion?

[efwd]

I'd wire wheel it, prime and then paint.

[Dave S]

3M has a wheel at most hardware stores that works really well for stripping rust and paint from irregular surfaces and small areas.


picture here:



http://www.tcpglobal.com/MMM-3171.html?sc=114&category=3728313

[Dorsal]

I need to do a bit of this myself, thanks for the tip on the 3M wheel. Is epoxy primer the preferred method or is there something netter?

[Dave S]

Dorsal,


Since a spot repair is not going to involve re-powdercoating, I believe the epoxy primer is the best option. Epoxy primer is far superior to the old school paint used for airframe repair and painting.



All other general painting "rules" apply in a spot repair also. Feathering the repair so the paint can overlap on the existing coating (epoxy sticks real well to powder coating if the powder coating is roughened and cleaned), degreasing with an effective solvent, acid etching the exposed metal (if a person doesn't have traditional etching acid, a little diluted pool acid will do) Detergent wash (dish soap is excellent) to clean off any stuff not soluble in organic solvent is a good idea, good rinsing and a final solvent wipe before shooting the primer.


Maybe a bit putzy - but surface prep and cleaning is what makes a spot repair last.

[Dorsal]

Very helpful, thanks Dave.