Alodine Question

Just working on my wing spar and would like to apply Alodine to the countersink holes. ACS sells two types; 1001 & 1201. The 1001 appears to require no prep outside of the hole being clean whereas the 1201 suggests using alumiprep first.

Can anyone offer any recommendations?

Thanks Jim

alodine pen?

have you considered using an alodine pen for ease of application? I dont think the pen needs a water rinse after. Stein air has them on the website store under chemicals...

I used primer and a Q-tip. Just spray some rattle can primer into a small puddle on a paper plate and use that as your paint palette and the Q-tip as your brush.

+1 for Bruce's suggestion. I keep a nail polish bottle filled with zinc phosphate primer. Just dab some on whatever needs it, usually where steel meets aluminum, and move on.

I used alodine on the tail section of my first RV-4 back in 1987. Then I read the MSDS and decided that I'd rather die from the wings corroding off, 200 years from now, than to die a slow death from hexavalent chromium poisoning. YMMV.

But seriously, alodining each countersink? How old will you be when (if) you finish the plane.

No offense intended, just the reality that perfection is the enemy of completion, which is something that many builders fail to understand when they start and is why so many kits never get past the tail kit.

Thanks for the replies, I didn't realize the Alodine pen existed (expensive thou). I'll probably follow Bruce's recommendation ... quick, simple and non toxic!

Driving '67 said:

Just working on my wing spar and would like to apply Alodine to the countersink holes. ACS sells two types; 1001 & 1201. The 1001 appears to require no prep outside of the hole being clean whereas the 1201 suggests using alumiprep first.

Can anyone offer any recommendations?

Thanks Jim

Click to expand...

Alodine 1001 used correctly should have the Alumiprep first -

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/A7576B3C5C1FDB23852571ED0055E89B/$File/ALODINE?%201001-EN.pdf

The only real difference between the two alodines is that the 1001 is clear, and the 1201 has a gold conversion coating.

The application steps are similar -

https://tds.us.henkel.com/NA/UT/HNAUTTDS.nsf/web/5966875CA5C37A6E852571ED0055ED8E/$File/ALODINE?%201201-EN.pdf

If your preparation information came from ACS, it's probably not a good source...

It's probably not the best idea to use alodine on the spars, as the Alumiprep etchant might get into spaces where you cannot rinse it out. The presence of trace amounts of acid could initiate the corrosion process. Best to use either the alodine pen (yup - $$) or dab on some primer as suggested.

The intent was always to use a Qtip. Thxs

If you dab 1201 on a fresh-cut countersink it will turn gold. No need to etch with alumiprep since its fresh aluminum with no oxidation.