The wing skins are too big to dunk. So I took a Hudson sprayer and sprayed the acid etch over the skins draining it into a big tub. Worked very well.
Then I took a new paint brush and brushed undiluted alodine on the left wing skin. It worked okay but didn't go a great job of covering evenly. So for the right skin, I used the sprayer to keep the part coated in alodine for 3 minutes and then rinsed. It worked a little bit better but the covering is still pretty uneven.
