Preparation of Wing Spars for Fabric

[Tomfox]

In the Poly Fiber Manual, it says to wipe the aluminum with MEK, Scotch Brite it and then wash with E-2300 Conversion Coating. What else can I use other that E-2300 (none came in my kit)?

Thanks
tom

[TJay]

i've heard 1201 alodine solution works too

[Tomfox]

Thanks for the response. Indeed I looked up the E-2300 and it is not made any more. This is what Polyfiber says:

This product has been discontinued and is no longer manufactured by PolyFiber. You may substitute ALODINE 1201 for this product. PolyFiber makes no guarantees as to how suitable this replacement is for your application. It is your responsibility to verify that this replacement product will work for your application

Frankly - not what I would consider an adequate position from a manufacturer of this covering system.

Thanks

Tom

[jiott]

I used the epoxy primer sold by Polyfiber and Kitfox to coat the inside and outside of my spars. I believe it is a better product than Alodine, however Alodine has been used for many years by many people.

[ken nougaret]

I did the same as jim. Love that primer.

[Dave S]

I probably went a bit overboard on corrosion protection.......spar tubes, inserts, drag tubes, elevator push pull tubes......solvent then detergent then acid prep, much rinsing much scrubbing .........alodined inside and out on the aluminum parts........epoxy primered all of these inside and out (spray outside - slosh inside). On the wings, did an overlap between the primer and the epoxy wood varnish on the recommendation of the local polyfiber rep to get the best sealing. I think the last step I did was to epoxy slosh the spars after the wings were covered.

One of the things that drove me to excess was previous experience recovering 40 year old piper short wings and finding way too much corrosion on unprotected contact surfaces between aluminum and covering material....absolute worst was the crappy old fiberglass cloth covering called "razorback" ...no offense intended to anyone who liked razorback - just my limited observation - the stuff held a lot of moisture.

Regarding "PolyFiber makes no guarantees as to how suitable this replacement is ..." IMHO.....that has legal man wrtitten all over it and I bet legal man is not a mechanic nor a chemist.

So much of the prep stuff you see out there is "branded".....a name unique to the company with little or no information about the composition or ratios of ingredients..sometimes a person can get a hint from checking the MSDS sheets which are required to be made available - although MSDS are for safety reasons, they often have to tip their hand on the composition to meet the safety requirements....I bought one jug of the E-2300 and all after that went to the auto paint store to get a materially equivalent product. Same same with the cleaner..... differently branded products likely vary little in composition or ratios but will serve the same purpose. We're not all chemists, but my opinion is there is more similarity among products like this than the plethora of brands would indicate - figuring it out can be another matter.

Now...when it comes to paint & covering systems.....that's a different deal - a little more care is needed. I don't mix brands here.

At least the Epoxy primer is excellent as a coating between the spars and covering but probably not necessary in all cases, particularily if you alodine, due to the fact we baby our kitfoxes a lot by storing them inside.

Sincerely,

Dave S

[Geowitz]

That statement maybe sounds more like they are trying to say that they won't comment on compatibility of Alodine with your airframe, not necessarily with the PolyFiber products. It's also obviously not their product, so no guarantees anyways.

Thanks for the response. Indeed I looked up the E-2300 and it is not made any more. This is what Polyfiber says:

This product has been discontinued and is no longer manufactured by PolyFiber. You may substitute ALODINE 1201 for this product. PolyFiber makes no guarantees as to how suitable this replacement is for your application. It is your responsibility to verify that this replacement product will work for your application

Frankly - not what I would consider an adequate position from a manufacturer of this covering system.

Thanks

Tom

[n85ae]

The truth is the spars are 6061, and even if you did nothing to them
at all they will still be there long after the rest of the plane is gone ...
Epoxy primer is more than enough protection quite honestly ... Not that
it hurts to corrosion protect them, it's just that it's not really something
that will become a problem.

Actually the only place you might see corrosion is where the bolt/clevis pins
go through, since there's some dissimilar metals there. Maybe the rivets, but
likely there's not going to be any problems.

Jeff

[jiott]

I protected my spars inside and out with the epoxy primer mainly because I have a dream that someday I may want to put floats on my Kitfox. If a person is even thinking about flying around (or in with floats) salt water, the corrosion protection for the aluminum is a must. Salt water will eat up 6061 aluminum in a heart beat.

[Northof49]

Tom
I am doing my wing spars now . I preped them with Aldine 1132 Touch-N-Prep coating ,from aircraft spruce . It comes in its own applicator , when it warms up enough ,will spray them with epoxy primer.
Mike