Powdercoat Removal

[rcbif]

Well it seems that 2 steps forward, 1 step back is the theme of my 2nd hand model 5 kit build.

I was doing some powdercoat touchup work on some fuselage tabs and such the other night. Lots of the tabs have sharp edges, and that was where a little line of rust showed thru the powdercoat. (the sharp edge makes the powdercoat in those areas thing to non-existent).

I removed the powdercoat on a few of these areas till I could no longer see surface rust. Well, a few of these, the surface rust kept going along a tube to the firewall mounts.

This powdercoat was so adhered from the surface rust, I would peel it off in one long sliver with a knife.

Not everywhere is like this. I did a sample gouge with my knife elsewhere and the powder-coat is stuck good.

However, this is enough to ruin my confidence in the powdercoat on my fuselage, and I am going to strip and paint.

The good news is the rust I have found comes off with some scrubs of a scotchnrite pad. No pitting.

Can anyone share their experience doing this? Did you use chemicals, or blast it all off? If you blasted, did you blast twice - once for the initial, and a secondary pre-epoxy primer?

It seems blasting only once is ideal since it is metal removal, but tricky since you want minimal time between blasting and primer, especially to keep everything super clean.

Any input appreciated.