Wing corrosion protection

[Ak Paul]

I have an EX-3 kit coming in August, woohoo! As we live in a beautiful seaside community i desire to corrosion protect the aluminum wing parts in some manner. Zinc Chromate is the standard, not sure if I want to use that in my workshop. So we are looking at potentially less hazardous coatings. Has any builder coated their wing pieces prior to assembly? Any recommendations? Thanks.

[TroyBranch]

I used a self etching primer on the inside wing skins. It is easy to apply, clean, scotch brite, clean and spray.

[Ak Paul]

I used a self etching primer on the inside wing skins. It is easy to apply, clean, scotch brite, clean and spray.

Thank you Troy

[aeroaddict]

I understand your concern, possibly some food for thought.

All of the sheet metal will be Alclad or clad aluminum (the best corrosion protection). Extrusions and machined hog outs are obviously not corrosion protected as you know.

When I was building an RV-7, there was considerable forum discussions on if to prime or not. For my project, I decided not to scotch brite off the best corrosion protection there is (Alclad) and just prime the extrusions as Troy described (interior only, obviously there would be paint on the exterior).

For your build you could leave the sheet metal (ribs and other formed parts) unprotected and just alodine the machined parts (easily done by dipping in a bucket). That would just leave the spars, which could be brushed alodined. You can still buy 'Type II chromated' Alodine.

What ever you choose there are always pros and cons. Weight being one of them (not much with alodine). The other is possible chemical attach of the aluminum if processes are not followed.

For the EX-2 build, I just left it naked as I live in Idaho which is high desert and super low humidity.

[Ak Paul]

I understand your concern, possibly some food for thought.

All of the sheet metal will be Alclad or clad aluminum (the best corrosion protection). Extrusions and machined hog outs are obviously not corrosion protected as you know.

When I was building an RV-7, there was considerable forum discussions on if to prime or not. For my project, I decided not to scotch brite off the best corrosion protection there is (Alclad) and just prime the extrusions as Troy described (interior only, obviously there would be paint on the exterior).

For your build you could leave the sheet metal (ribs and other formed parts) unprotected and just alodine the machined parts (easily done by dipping in a bucket). That would just leave the spars, which could be brushed alodined. You can still buy 'Type II chromated' Alodine.

What ever you choose there are always pros and cons. Weight being one of them (not much with alodine). The other is possible chemical attach of the aluminum if processes are not followed.











For the EX-2 build, I just left it naked as I live in Idaho which is high desert and super low humidity.

Thanks Dan. I'll continue my research, certainly want to do no harm with whichever process I use. We are in a salty environment, I feel I do need to address this.