danielhv

danielhv

Well Known Member
working on the tail section... im planning on using alodine on all aluminum parts, skins included, interior and exterior of the skins, etc...

Will this provide good corrosion protection? where is the best place to buy the material? im in dallas so somebody should have it locally...
 
That should be more than enough for the skins and bulkheads but I wonder about the aluminum angle. I only say that because the AA is not alclad. I would check with Van's and go with what they say.

FWIW, After I alumipreped and alodined each part I primed them. (I'm not trying to start a "should he or shouldn't he" or "use this method or that method". Just stating what one guy did.)
 
Last edited:
I'll look into the AA... where is a good place to get the alodine? Doesn't it come in a powder or pill form? I was told to get 2 large tubs... and 3 spray bottles. Clean all oil off etc, spray with hydrochloic acid/water mix to etch, then rinse with water, spray alodine, wait 3 minutes, rinse with water, dry with towel, rivet in place. The tubs will catch all the drips, and can reuse the captured solutions... Sound right?

I was also told that as a further precaution, I could spray rattle can auto primer through the inspection holes where able.
 
Etch with phosphoric acid (alumiprep), not hydrochloric acid.
I would not towel dry. The alodine (chromic acid conversion) surface is soft when wet. Allow to air dry.
Powdered chromic acid (alodine) is available. I believe someplace in Florida has it. Search the archives.
There's lots of info out there on this process. Remember that the hexavalent chromium used in these products is a carcinogen and is hazardous waste.
 
Last edited:
didnt know it was haz... guess i should have known that since i work for an environmental company! :eek:
 
Even thought the angle aluminum is not al-clad, it is also not 2024. It is 6061 which is very corrosion resistant anyway.
Many of the aircraft kits that come from Canada such as Murphy and Zenair are built totally with 6061 alloy. Many are built unprimed and unpainted and last a very long time.
 
Mel said:
Even thought the angle aluminum is not al-clad, it is also not 2024. It is 6061 which is very corrosion resistant anyway.
Many of the aircraft kits that come from Canada such as Murphy and Zenair are built totally with 6061 alloy. Many are built unprimed and unpainted and last a very long time.
Click to expand...

Mel, would it be beneficial to go ahead an alodine the AA's anyway?
 
It wouldn't hurt anything. Personally I don't think it's worth the extra trouble. Just my opinion.
I'm sure there will be others that say "It MUST be done!"
 
FlyerJumper said:
Check post #3 of this thread...

http://www.vansairforce.com/community/showthread.php?t=10808
Click to expand...

Just got off the phone with those guys... aparently you cant call up and ask for a bottle of alumiprep and a bottle of alodine... seems there's about 100 different types of each! So, I ask my fellow builders... what type am I looking for? He also gave me the # for Henkel Service Products who he said makes the alodine, and said they have a Tech Help department that will tell me exactly what I need... but I wanted to ask here first.

Oh, and how much do I need for my very slow build?
 
Last edited:
I've got no opinion about aluma prep and alodine other than to say it's a big pain in the butt. I noticed you mentioned tubs though and wonder if you've ever considered using large plastic (large for the big parts) bags instead. I've seen people use the bags from those seal a meal vacuum things and it looks almost painless. A big plus to using bags would be being able to easily pour the stuff back into a container and then there's also not having to have so much of the stuff on hand in the first place. I quit using alodine before I'd used even a gallon. Most of the parts I alodined were fairly small, your results may be different. If you're going to the trouble of alodining your parts you should know that zinc chromate is awesome in combination with it. Another thought is NOT to use a self etching primer after the parts have been alodined.
 
Last edited:
Mel said:
Even thought the angle aluminum is not al-clad, it is also not 2024. It is 6061 which is very corrosion resistant anyway.
Many of the aircraft kits that come from Canada such as Murphy and Zenair are built totally with 6061 alloy. Many are built unprimed and unpainted and last a very long time.
Click to expand...

Do we know why Van's uses 2024 instead of the inherently corrosion resistant 6061 used by some of the others? Better structural characteristics, economics, or something entirely different?
 
2024 is stronger than 6061 and somewhat of an industry standard. However 6061 is fine so long as the aircraft is designed around it. And because 6061 is usually not al-clad, it's much cheaper.
 
Last edited:
Prep

danielhv said:
Just got off the phone with those guys... aparently you cant call up and ask for a bottle of alumiprep and a bottle of alodine... seems there's about 100 different types of each! So, I ask my fellow builders... what type am I looking for? He also gave me the # for Henkel Service Products who he said makes the alodine, and said they have a Tech Help department that will tell me exactly what I need... but I wanted to ask here first.

Oh, and how much do I need for my very slow build?
Click to expand...
Dan,
Gotta ask you-are you surrounded by salt water in TX? Man you are talking about alot of extra work and money. What I did was got some Alumiprep from ACS and gallon kits of Akzo epoxy primer. Get some big clear plastic storage boxes from Big Lott's 48x18x8 with lids were $8 each-one to dip, one to rinse the Alumiprep. Air dry, spray with Akzo. This was a ton of work and no doubt total overkill. Only the bare Al/steel stock really needs to be primed, per Van's. Unprimed a/c fly for 50+yrs. Just my thoughts on it. My 8A will not get the same treatment. Too time consuming and expensive.
Mike H 9A/8A
 
mike109g6 said:
Dan,
Gotta ask you-are you surrounded by salt water in TX? Man you are talking about alot of extra work and money. What I did was got some Alumiprep from ACS and gallon kits of Akzo epoxy primer. Get some big clear plastic storage boxes from Big Lott's 48x18x8 with lids were $8 each-one to dip, one to rinse the Alumiprep. Air dry, spray with Akzo. This was a ton of work and no doubt total overkill. Only the bare Al/steel stock really needs to be primed, per Van's. Unprimed a/c fly for 50+yrs. Just my thoughts on it. My 8A will not get the same treatment. Too time consuming and expensive.
Mike H 9A/8A
Click to expand...

No, its not... but I dont only plan on flying in TX. In addition, Im only building ONE airplane... its gotta be in tip top shape until I decide to sell it (if ever). Im 26 years old now, so it better last a long time!!!! Better safe than sorry.

As far as cost, compared to the cost of building the plane a few gallons here and there, and an hour spent dipping parts is minuscule. Just IMHO, YMMV
 
You must log in or register to reply here.