Dupont 225S and Dupont 226S

[Jeff Moreau]

Has anyone had experience using the Dupont 225S Cleaner and Dupont 226S Conversion Coating?
From my understaning this is Dupont's version of Alodine.

Do I use the cleaner and rinse it off and then coat with the 226 S and rinse it off. If you have used it, how did it perform for you?
Any help will be greatly appreciated!

Jeff

[Jeff Moreau]

After a bit of research I found the answer to my own question, so I thought that I would share the information with everyone on the board.

The 225S and 226S are Dupont's version of Alodine.

This process involves first acid etching the Aluminum with the 225S and then Alodine it with the 226S. The 226S is a conversion coating with is simply a strong oxidizer. This conversion coating is one of the better ways to prep for painting. From my understanding the paint or primer is supposed to bond to the alodined surface better.

I paid about fifteen dollars per quart for the 225S and 226S at a local auto paint supply store. I will report further after I have tried the products.

Thanks!
Jeff

[Jeff Moreau]

I finally was able to use the Dupont products this weeked. I wish to report favorable results. My first attempt at using this was to prepare my Vertical Stab parts. I used the acid etch first then after rinsing with water I soaked the ribs in a shallow pan filled with the conversion coating. After removing them from their bath I rinsed again with water and placed them on the work table to dry.
This process left the parts witha nice golden hue. The products were easy to to use and I would recommend them to anyone that wishs to alodine their parts. The good news is that you can find these at any local Dupont dealer so that you don't have to pay shipping.

[hngrflyr]

I painted a Cessna 120 using these products in 1981. The paint job has performed very well over the years. I still own the plane.
When you're doing this job, it seems like no matter how clean you get it it is never clean enough, but the paint has stayed on and has not peeled anywhere. The top coat is Imron.

[Jeff Moreau]

I painted a Cessna 120 using these products in 1981. The paint job has performed very well over the years. I still own the plane.
When you're doing this job, it seems like no matter how clean you get it it is never clean enough, but the paint has stayed on and has not peeled anywhere. The top coat is Imron.

I really appreciated learning of your experience. I am now at a stage where I have to etch and alodine some of the larger spars and other parts.
Did you use any special technique for applying the etch and conversion coating to larger parts? (Brush? Foam Brush?)
Any tips are greatly appreciated.
Jeff

[hngrflyr]

The acid etch must be rinsed off after being on the surface of the aluminum for a period of time. If I remember correctly, it must not be allowed to dry on the surface. After applying the conversion coating, the plane looked like it had some bad disease. I used DuPont Corlar Primer under the topcoat. I'm not sure it was worth the difference. I think zink chromate is hard to beat as a primer.

I applied the acid etch with a sponge. I rinsed with lots of water and a clean sponge. 1981 was a long time ago, and I'm not really a painter.
I can't remember all the gory details, but I tried diligently to follow the instructions on the container the products came in. Must have been pretty close. It worked out well. Maybe I was just too dumb to know, I didn't know what I was doing.