R

rv8gibbo

Well Known Member
Recently Ive Alumipreped & Alodined my rudder parts and have not got to alodine the parts straight away and have allowed the washed off alumiprep to dry on the surface of the parts (Obviously not washed completely), I have done the alumiprep again and alodined the parts straight away and have noticed after the alodine bath and rince off that there are a few places on the parts (small clear patches)have shown up. I'm assuming as a result of the initial alumiprep drying (or at least i think) on the surface. My question is will these small minimal sections cause any problems later? or should i rub them back with scotch brite and re-alodine the rubbed section?
 
Me too.....

I had a similar issue. I have never allowed my parts to dry before I put my parts in the Alodine. I always gave them a very good Alumiprep but still ended up with small circle clear spots. It drove me nuts for a long time! Then I figured out it was small bubbles of air trapped under the parts that kept the Alodine away from the part. Rotating each part and shifting them around every 15 seconds or so, my problem went away. :)
 
Welcome to VAF!!!!

Nathan, welcome aboard the good ship VAF.

I also had some issues with spotty coverage-----and also solved it with agitation of the container.

Carry on, and good to have you aboard:D
 
Alumiprep

How I do it on smaller parts like rudder pedals is to submerse them in premixed alumiprep for about 3 min. Take them out and thoroughly flush them with water and let them dry, I set them in the sun and make sure there is no moisture in the crevices. Then I submerse them in alodine for around 1.5 min, (I time them with a second hand) depending on the part, if it is raw and not alclad it is a shorter amount of time. Again remove them and thoroughly flush the parts with water and let dry. Water keeps the alodine from touching the aluminum and will leave spots and blotches. You can also do the same thing by putting the alumiprep and alodine in spray bottles, you just can't use the product again. A nice light gold color is what you want, just a tint is all it takes. I just did some ribs for an Aeronca, made a frame out of 2X4 and lined it with plastic to make a shallow tray to be able to submerse them, it keeps the process even. Got this process from an aircraft engineer and I did sheet metal on warbirds for several years. Parts look great and corrosion protection with no paint.
 
Hi Guys, thanks for the reply's and friendly welcome, I`m going to prep some more parts this week and I will certainly put them into practice.

Cheers
Nathan Gibson
 
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