Stamped Aluminum Rib Prep

ilpilot

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ilpilot
Greetings POA,

I am in the process of rebuilding my wings off of a '46 Taylorcraft BC-12D. Doing a variation of the swick and cole conversion.

This is my first build, and I'm looking for advice regarding the wing ribs.

They are in pretty good shape. In many similar builds that I've seen, the ribs were primed with some form of primer/paint.

Wondering what you guys think. Should I acetone the ribs, and reprime them? Acetone/scotchbrite/reprime? Just acetone clean and call it a day?

Appreaciate any and all advice. Thank you!
 
Not a building, but I vote for primer. Another layer of insurance against corrosion.
 
I would not use scotchbrite,, It scratches.
I would fabricate a tray to soak them in epoxy remover, then use a brush to any dirt/grime. then wash and rinse, after the ribs are dry use a Stainless steel platers brush to any corrosion, and leave bare.
 
I would not use scotchbrite,, It scratches.
I would fabricate a tray to soak them in epoxy remover, then use a brush to any dirt/grime. then wash and rinse, after the ribs are dry use a Stainless steel platers brush to any corrosion, and leave bare.

Thank you all. Tom, I happen to have lots of Xylene and Acetone on hand. Would that be an appropriate substitute for cleaning the ribs?

And just to I know I understand, after cleaning, you suggest not using a primer at all?

Thank you very, everyone, for helping a beginner like me!
 
Ribs, and primers, be careful, many the fabric systems you can't paint and get good adhesives.

It really depends upon which fabric you use, which coating can be used.
 
Thank you all. Tom, I happen to have lots of Xylene and Acetone on hand. Would that be an appropriate substitute for cleaning the ribs?
Anything that will leave the surface clean and dry.
most stripers are a super soap soluble with water .
I use a stripper because it removes all old glues.
 
never use metal brush to remove anything except S/S to remove corrosion
 
They are in pretty good shape. In many similar builds that I've seen, the ribs were primed with some form of primer/paint.
Are all the ribs bare aluminum now? Original? Whether to prime will depend on operating environment, personal preference, and as mentioned above, what fabric covering method will be used. In general, I use a good 2 part epoxy primer on metal wings and use the fabric system recommended primer on fabric wings. Regardless, aluminum needs a specific prep to ensure proper paint adhesion which consists of a cleaner/conditioner (e.g., Alumiprep/Bonderite 33) and a conversion coating (e.g., Alodine 1201/Bonderite 1201). You can use your Xylene/Acetone stock to pre-clean the ribs prior to the Bonderite prep. If water still beads on the rib surface after the Alumiprep stage you can use some red scotchbrite to help clean but usually the Alumiprep works on its own, unless there is some existing corrosion areas. Also, if you're not the one who be signing off the work, you should keep whoever is updated to the methods you will use. Good luck.
 
Are all the ribs bare aluminum now? Original? Whether to prime will depend on operating environment, personal preference, and as mentioned above, what fabric covering method will be used. In general, I use a good 2 part epoxy primer on metal wings and use the fabric system recommended primer on fabric wings. Regardless, aluminum needs a specific prep to ensure proper paint adhesion which consists of a cleaner/conditioner (e.g., Alumiprep/Bonderite 33) and a conversion coating (e.g., Alodine 1201/Bonderite 1201). You can use your Xylene/Acetone stock to pre-clean the ribs prior to the Bonderite prep. If water still beads on the rib surface after the Alumiprep stage you can use some red scotchbrite to help clean but usually the Alumiprep works on its own, unless there is some existing corrosion areas. Also, if you're not the one who be signing off the work, you should keep whoever is updated to the methods you will use. Good luck.
Post #1 says they are working on a 46 T-crate. That is a certificate aircraft, There are several STCed fabric systems which must adhered to.
Or you can still do dope and cotton, that is the glue. (no paint)this gives an ability to see thru the wing for inspections
 
I am in the process of rebuilding my wings off of a '46 Taylorcraft BC-12D. Doing a variation of the swick and cole conversion.
Correct me if I am wrong but isn't that a CLIP WING version?
 
Or you can still do dope and cotton,
Perhaps you might want to start another thread on fabric stuff so as not to skew this one? But to answer your question, yes, you can still do dope and cotton via a 337, but it's usually more expensive than using Stewarts or Stits. As to "see-through" cotton wings never saw one. All the cotton wings I saw had aluminum dust/dope coatings. But then again I'm not that old....;)
 
Perhaps you might want to start another thread on fabric stuff so as not to skew this one? But to answer your question, yes, you can still do dope and cotton via a 337, but it's usually more expensive than using Stewarts or Stits. As to "see-through" cotton wings never saw one. All the cotton wings I saw had aluminum dust/dope coatings. But then again I'm not that old....;)
Dope/Cotton is the Original fabric. the 337 is for the major repair. any other system does require STC.

When I change the subject I'll let you know.

Appreaciate any and all advice. Thank you!
 
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Poly Fiber has a nice manual. It specifically states what to use on aluminum, steel, etc. I am only familiar with the Poly Fiber process (and that was many years ago!), but I am sure the other systems have similar guidance.
 
Poly Fiber has a nice manual. It specifically states what to use on aluminum, steel, etc. I am only familiar with the Poly Fiber process (and that was many years ago!), but I am sure the other systems have similar guidance.
That is a great product, it is labor intensive, it was called the Stiz (sp) ceconite system, Ray Stiz(SP) then A&SS bought it product.

Google " aircraft fabric systems" to get a whole list
 
Correct me if I am wrong but isn't that a CLIP WING version?

Correct. Wings are cut down to about a 27' span total. Wingtips squared off. Lycoming O-320 up front. Should be fun :)
 
Is this aircraft going to be hangared? If so, I'd clean and alodyne the ribs and be done with it. Epoxy primer = weight, time, and money.
 
Correct. Wings are cut down to about a 27' span total. Wingtips squared off. Lycoming O-320 up front. Should be fun :)
Has this aircraft been done prior ? or are you still doing the major modification?
 
Has this aircraft been done prior ? or are you still doing the major modification?

Doing all modifications here in the shop. Started with the '46 BC-12D. New spars on the way.

Yes, it will be hangared.

Thanks all for the advice!! Happy to talk about the project.
 
Yep leave them bare. Just clean them up and apply a conversion coat. Tom mentioned Alodine, I prefer PPGs EAP 12, it's more environmentally friendly than alodine.
 
Yep leave them bare. Just clean them up and apply a conversion coat. Tom mentioned Alodine, I prefer PPGs EAP 12, it's more environmentally friendly than alodine.
I wonder if it is as good, there is a hazard when the Alodine is not removed.
 
It's actually better IMO. Having used both, I prefer EAP 12, or EAP 9.
 
Yes, -12 is the purple stuff, -9 is clear.
 
I wonder if it is as good, there is a hazard when the Alodine is not removed.
I believe it to be as good as, if not better than alodine. And don't wash it off after application. Put it on, let it dry, and you're good to go.
 
I believe it to be as good as, if not better than alodine. And don't wash it off after application. Put it on, let it dry, and you're good to go.
Tell be again, why the new stuff needs to better, we had have Alidine (chromic acid)since WW2 and before and there has never a problem.
 
why the new stuff needs to better,
FYI: Alodine/Bonderite is considered hazardous material and is regulated. The EAP-12 is not. Big difference on shipping/disposing of between the two. Down side is the shelf life of the EAP-12 once activated is short.
 
FYI: Alodine/Bonderite is considered hazardous material and is regulated. The EAP-12 is not. Big difference on shipping/disposing of between the two. Down side is the shelf life of the EAP-12 once activated is short.
Oh Hell yes,, Thank You California

You may believe Alodine/Bonderite are the Same, they are not.. the product we used to get does not act the same of the stuff we now get, is way different.
 
You may believe Alodine/Bonderite are the Same
I don't believe that. But for the newer users here, I try to tie things in. Nothing today is the same as it was even in the 80s. It is what it is.;)
 
Tell be again, why the new stuff needs to better, we had have Alidine (chromic acid)since WW2 and before and there has never a problem.
Not saying there has been a problem. But when a better less dangerous product comes out, why not use it? Alodine is not the same stuff today as it was years ago.
 
I use Variprime on the assembled wings. No adhesion problems with Ceconite or Stits products, and the only place that matters is leading and trailing edges. Rib caps get rib stitched. My leading edges are extended back and the rib stitching goes through that metal. There’s no separation between ribs. I like Variprime on aluminum. Used it on an engine and top coated with gray Imron. That worked great, too.


A28AB19F-7DFB-493B-A67A-B2A931AEE383.jpeg
 
Rib caps get rib stitched. My leading edges are extended back and the rib stitching goes through that metal.

How do you chafe protect the stitches where they go through the sheet aluminum?
 
anti-chafe tape, just like with ribs. The stitch holes are located so that the stitching doesn't touch the drilled holes.

B74DF564-AB89-4750-B678-7942CF24EFE8.jpeg
 
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