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Flap Anti-Abrasion Tape Problem

M

mdevans9

Well Known Member
I just removed the UHMW tape and installed clear 3M 8674 tape on the top forward 3"s of each flap on my RV-7. Nothing on the bottom of the wing skin. Looks nice, but the flaps now bind, both extending and especially on retraction - to the point that I will not fly the airplane until the problem is resolved. The binding (sorta stick-and-release) is mostly when the flaps are in the 30 - 40 degree range, which is where the clearance between the flap and wing skins is the tightest. Shouldn't the tape allow the surfaces to just slide? There were no noticeable operational problems with the old tape.

What do you think?

Thanks,

Merrill
 
Thanks for the thought, Larry. No, the edge is not catching as the forward edge of the tape wraps under the flap and the aft edge is about 1/8" aft of the wing skin when the flap is up. When it sticks/binds is about mid-tape.

Merrill
 
Thanks Bob. Nope, airplane painted about 4 weeks ago and all is pristine Imron under the wing skin. I'm thinking that the coefficient of friction of the new tape is not good enough, unless one spaces the skins sufficiently apart through the entire flap travel range. Thinking that I'll have to go back to the UHMW tape.

Merrill
 
mdevans9 said:
Thanks Bob. Nope, airplane painted about 4 weeks ago and all is pristine Imron under the wing skin. I'm thinking that the coefficient of friction of the new tape is not good enough, unless one spaces the skins sufficiently apart through the entire flap travel range. Thinking that I'll have to go back to the UHMW tape.

Merrill
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I hope this is different stuff from what I just bought from a VAF advertiser for the same purpose. My flaps fit tightly with the trailing edge of the wing skin and this could be a problem for me too.
 
3M says the tape is only 8 mills thick. Isn't the UHMW tape 12 mills thick?

Could you simply have a build up of heavy paint on the two opposing surfaces?
 
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Disconnect the flaps and maneuver them by hand till you find the problem....... It might not be what you think.

Swing them down and place a piece of paper or folder under the wing skin and bring the flap back into position. If it is the skin, you will see where it is binding....... if the skin is really binding??
 
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gasman said:
Disconnect the flaps and maneuver them by hand till you find the problem....... It might not be what you think.
Click to expand...

That's what I was thinking. the 3M tape is not as slippery as the UHMV, however I don't see how that can cause noticeable sticking. I and many others use it without issue.
 
They are not the same!

Hello

Those tapes are not the same!

UHMWgets low friction, so that you can move things on it easyly around for decades.

The oter is a protection film, that is somewhat "rubbery" on the surface, it protects the paint underneath, but has a much higer gliding resistant.

I' also have the paint protection film applyed, but i bent my flaps in a way where it barley touch the upper wingskin.

Put some tube powder (talk?) onto a tissiue and wipe down the paint protection film. do this again and again. with time it will also dry somewhat ant the problem will go away.

Dominik
 
Gasman, I had done as you suggested regarding disconnecting the flaps, but had not tried to diagnose with some paper in between. So, I tried that and that showed no binding with the paper as the rubbing surface. Swisseagle has it right, I believe. Thanks, Dominik. Will try some talc and see, but I think I'll just go back to UHMW tape. Will report back.

Merrill
 
mdevans9 said:
Gasman, I had done as you suggested regarding disconnecting the flaps, but had not tried to diagnose with some paper in between. So, I tried that and that showed no binding with the paper as the rubbing surface. Swisseagle has it right, I believe. Thanks, Dominik. Will try some talc and see, but I think I'll just go back to UHMW tape. Will report back.

Merrill
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Before you remove it, try some slippery tape on the lower surface of the wing skin.

If the paper doesn't make it jam a thin tape should be OK - perhaps Teflon tape.
 
Like Gill said ...

Hello Merryl

The UHMW does yellowing ... the paint protection film not.

So one solution could be, that you just place a small strip uf UHMW underneath the upper wing skin, so you bring one "gliding" partner into this pairship ... and hopefully it does not bend anymore.

Dominik
 
Mark Dickens said:
I hope this is different stuff from what I just bought from a VAF advertiser for the same purpose. My flaps fit tightly with the trailing edge of the wing skin and this could be a problem for me too.
Click to expand...

Indeed, this part number is a different tape than our Paint Protection Film, and this is the first we have heard of anyone having this issue.
 
Maybe the problem isn't where you think it is. If the flaps are binding, check the push rods and that they're not what's binding in all phases of travel. Do they "twist" freely at all points? Are they hitting the hole in the bottom of the fuse at any point?
 
same problem with 3M protection tape on the lower side of my RV9 flap. when deploying flaps there is some force that is required from the flap motor to break them free. I used some white dry bolube on tape and it helped. It should dry and get easier over time.
 
swisseagle said:
Hello Merryl

The UHMW does yellowing ... the paint protection film not.

So one solution could be, that you just place a small strip uf UHMW underneath the upper wing skin, so you bring one "gliding" partner into this pairship ... and hopefully it does not bend anymore.

Dominik
Click to expand...

I also had a similar problem as others with the paint protection film sticking a bit. In my case I also had a bit of sticky tape residue from a a felt strip I installed. I think after I installed the paint protection film, the felt strip slid forward and left the residue. The felt was ineffective as it had gotten pushed too far forward.

In any case, I think I have a winning combination now. I removed the felt strip and cleaned the residue off real well. I installed this underneath the upper wing skin as Swisseagle suggested:

http://www.aircraftspruce.com/catalog/cspages/teflonantichafetape.php?clickkey=12835

It glides soooo smooth and easily now! I left the edge of the Teflon strip hanging off the trailing edge of the upper wing skin about 1/16".

I had the Teflon strip on before I had the felt, but that was before I did the paint protection film. Somehow the unprotected paint on my flap had gotten scratched up even though it was riding on the old Teflon strip. Now the flap is protected and it rides up against the Teflon strip. It seems like this is the way to go.
 
RV8Squaz said:
I also had a similar problem as others with the paint protection film sticking a bit. In my case I also had a bit of sticky tape residue from a a felt strip I installed. I think after I installed the paint protection film, the felt strip slid forward and left the residue. The felt was ineffective as it had gotten pushed too far forward.

In any case, I think I have a winning combination now. I removed the felt strip and cleaned the residue off real well. I installed this underneath the upper wing skin as Swisseagle suggested:

http://www.aircraftspruce.com/catalog/cspages/teflonantichafetape.php?clickkey=12835

It glides soooo smooth and easily now! I left the edge of the Teflon strip hanging off the trailing edge of the upper wing skin about 1/16".

I had the Teflon strip on before I had the felt, but that was before I did the paint protection film. Somehow the unprotected paint on my flap had gotten scratched up even though it was riding on the old Teflon strip. Now the flap is protected and it rides up against the Teflon strip. It seems like this is the way to go.
Click to expand...

thx, I am going to try that. I don't like the pop I get from the flap breaking free of the 3M tape.
 
What I did

Thanks to everyone for the suggestions. In the end, as Steve said, "I don't like the pop I get from the flap breaking free of the 3M tape", and decided not to try talc or Boelube to condition the tape.

So, I went back to the UHMW tape from Van's. Not as pretty as the clear tape, but the flaps slide very easily, as they should, and as they did before I started this exercise.

Best regards,

Merrill
 
Repainting now need the correct tape

Does anyone know the exact film tape that should be used on the flap? Mine is worn but removed to allow new paint.
 
Stainless steel tape from amazon..

Looks great and doesn't bind, but be careful when installing, the edge is razor sharp!
 
Flap tape

Steve Melton said:
I tried the Teflon tape on the underside. I like it. It measures .022 thick.
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Steve
If I put teflon tape under the wing skin will the flap paint stay nice without covering it with paint protection film? Or did you do both?
 
Do both so that the Teflon tape rides on the paint protection film. I had previously tried the Teflon tape riding directly on the paint and the paint got scratched.
 
Personally, I hate UHMW tape. It turns yellow after a few years and is impossible to remove without leaving a nasty residue.

I use 3/4 inch wide felt tape on the underside of the wing skin that the flaps ride on. Silky smooth with no tendency to scratch the flaps.
 
After using mild heat to pull off the tape . . .

ronschreck said:
Personally, I hate UHMW tape. It turns yellow after a few years and is impossible to remove without leaving a nasty residue.

I use 3/4 inch wide felt tape on the underside of the wing skin that the flaps ride on. Silky smooth with no tendency to scratch the flaps.
Click to expand...

The residue can be easily removed by laying down two strips of paper towel soaked in mineral spirits with a touch of naphtha, and covering with aluminum foil for 2+ hours. Then uncover and remove 12-18 " at a time. It is a physically easy process, but the paint must be a 2K variety. 20 min to apply, 20 to remove, but waiting is a pain. YMMV on the paint part, so be careful (experiment).

The "eraser" seems abusive.
 
BillL said:
The residue can be easily removed by laying down two strips of paper towel soaked in mineral spirits with a touch of naphtha, and covering with aluminum foil for 2+ hours. Then uncover and remove 12-18 " at a time. It is a physically easy process, but the paint must be a 2K variety. 20 min to apply, 20 to remove, but waiting is a pain. YMMV on the paint part, so be careful (experiment).
Click to expand...
Sounds easy enough. :rolleyes:

The "eraser" seems abusive.
Click to expand...
It is. I tried it. Once. Never again.

I just spent $$$$$ to get my plane re-painted. UHMV tape will NEVER come near my plane again!
 
ronschreck said:
Sounds easy enough. :rolleyes:
Click to expand...

I love those posts that say it's easy, like making your own plenum . . .( 9 months later) :D

But in this case it really is, I am a lazy guy and getting weary of tedious tasks. I was surprised, leaving one side for 4 hours was a bit easier. The plastic razor blades or a slice from a milk carton to remove the jelly helps immediately after the patch is lifted. Then wipe with the top layer of soaker pad. The bottom pad sticks a little to the goo. This is the reason for two layers. I used flat towels not embossed or with color. VIVA.

Ron, No use changing what you have found to work, but a neighbor may get into this, give it a try with little risk.
 
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