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Flap Chafing

jeffkersey

Well Known Member
I did not build my RV7a. I purchased it flying. There were 2 layers of wide clear tape between the trailing edge of the wing and the leading edge of the leading, pivoting, bevel of the flap. Sunlight and use has flaked off and worn through most of the first layer and is starting to work on the second layer. I want to prepare for my next condition inspection due in March.

What is the process to remove the flap. Big Hassle? What is the best replacement type/brand/size? I have seen some "metal" tape on other RVs that look more robust that clear tape? Who is the best supplier for the tape?

Thanks for your help...
 
Remove flap?

CAREFUL use of a hot air gun will help get the old tape off. Don’t get carried away as the hot air gun can damage your paint. Use your favorite “goo gone” product if you have any leftover tape residue.

Do not use the old SS tape Van’s used to sell for this. You will immediately loose your religion. Use the Van’s UHMW tape: https://shop.vansaircraft.com/cgi-bin/shop.cgi?ident=1610901861-230-591&browse=misc&product=uhmwtape

Carl

Carl, Thanks for the response. It seems like I would have to remove the flap to work on it and get the new tape where it needs to be? How do I remove the flap from the airframe?
 
Carl, Thanks for the response. It seems like I would have to remove the flap to work on it and get the new tape where it needs to be? How do I remove the flap from the airframe?

I depends on how the builder has the flap pin inserted. So:
- Lower the flaps.
- Disconnect the flap push rod from the flap and/or the flap actuator bar.
- Let the flap extend all the way down after it is disconnected.
- At this point I suspect you will find you don’t need to remove the flap to replace the tape. If you really want to remove the flap anyway, continue as listed below.
- Look at the hinge pin. If it is in two pieces, remove each half from the middle of the flap hinge. If one piece, the pin is removed by passing it outboard via a hole in the aileron hinge. For this you may or may not need to let the aileron drop down to remove the pin. On reassembly a little light oil on the pin goes a long way to making your life easier.

On reassembly you will need to adjust the flap push rod assembly so that you get full flap retraction. You might want to verify you already have this before disassembly.

Doing one flap at a time might be a good way to go for your first time doing this work.

Carl
 
Thanks

I depends on how the builder has the flap pin inserted. So:
- Lower the flaps.
- Disconnect the flap push rod from the flap and/or the flap actuator bar.
- Let the flap extend all the way down after it is disconnected.
- At this point I suspect you will find you don’t need to remove the flap to replace the tape. If you really want to remove the flap anyway, continue as listed below.
- Look at the hinge pin. If it is in two pieces, remove each half from the middle of the flap hinge. If one piece, the pin is removed by passing it outboard via a hole in the aileron hinge. For this you may or may not need to let the aileron drop down to remove the pin. On reassembly a little light oil on the pin goes a long way to making your life easier.

On reassembly you will need to adjust the flap push rod assembly so that you get full flap retraction. You might want to verify you already have this before disassembly.

Doing one flap at a time might be a good way to go for your first time doing this work.

Carl

Thanks Carl. Hopefully it will rotate enough just detaching the push rod and I won't have to remove the hinge pins :)
 
I have replaced all of the UHMW tape on al our RV’s with stainless steel tape from McMaster - Louise had this on her RV-6 when she got it, and I think the builder (Seager) put it on when he painted the airplane in 1991. The RV-3 has had it since painting in 2012, and now I have it on the RV-8. I don’t think I’ll ever have to touch it again. Wear gloves (the SS tape is like a razor blade), be deliberate, have an extra set of hands, and it goes on great.

And yes - if you remove the actuator connection, the flap will swing down so you don;t have to remove the hinge pins.
 
Thanks

I have replaced all of the UHMW tape on al our RV’s with stainless steel tape from McMaster - Louise had this on her RV-6 when she got it, and I think the builder (Seager) put it on when he painted the airplane in 1991. The RV-3 has had it since painting in 2012, and now I have it on the RV-8. I don’t think I’ll ever have to touch it again. Wear gloves (the SS tape is like a razor blade), be deliberate, have an extra set of hands, and it goes on great.

And yes - if you remove the actuator connection, the flap will swing down so you don;t have to remove the hinge pins.

Thanks Paul. How wide is the tape on your RV8? Are those flaps the same as my 7a?
 
SS Tape On RV-7 Flaps

Much thanks to Ironflight and others for their much earlier posts on using SS tape from McMaster for this as an alternative for this purpose, which were helpful to me at that stage of my project.

Attached are some RV-7 flap pix as a reference for the OP.

I also used 3" tape and would repeat the caution about using gloves or other protection against the razor sharp edges during application, which is not a factor after the tape is applied. In my experience it also went down easily, and if you are into cosmetics, it can be easily polished to a high sheen with common metal polish.
 

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Thanks everyone!

I really appreciate all the responses. I think I have a clear idea as to what I need to do now :)
 
Thanks

Much thanks to Ironflight and others for their much earlier posts on using SS tape from McMaster for this as an alternative for this purpose, which were helpful to me at that stage of my project.

Attached are some RV-7 flap pix as a reference for the OP.

I also used 3" tape and would repeat the caution about using gloves or other protection against the razor sharp edges during application, which is not a factor after the tape is applied. In my experience it also went down easily, and if you are into cosmetics, it can be easily polished to a high sheen with common metal polish.

I think I will go with the SS tape. Thanks for the pictures. :)
 
Why not put the anti chafe tape on the underside of the skin instead of the flap? This would eliminate fading and associated concerns.
 
I stuck the fuzzy side of velcro on the bottom of the wing skin, invisible, easy to apply and does not leave any marks on the flap.
 
Why not put the anti chafe tape on the underside of the skin instead of the flap? This would eliminate fading and associated concerns.

The soft anti-chafe tape gets contaminated with grit, thereby acting as sandpaper on the paint job of the flap. Protecting the paint on the flap is sort of the reason most folks use the anti-chafe tape in the first place....

Paul
 
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This has held up well. Does not yellow or get brittle.
https://www.flyboyaccessories.com/product-p/2301-0004.htm

Paint protection film is an excellent alternative to the recommended UHMW flap tape. This product will never yellow; it stays clear for 10+ years and removes cleanly. I used this stuff all over my Rocket and it never failed to protect the paint, and it never cuts your finger like the SS tape can. You'll find 100 places where it works miracles.

Not for props though.
 
flap chafing

I used teflon coated fiberglass tape 3/4" on the wing skin underside ( hidden), 6 years 500 hours polished flaps no scratch.

Lots of suppliers, i bought mine locally at an industrial supplier but Amazon has it:

1" x 33 feet PTFE Adhesive Tape Teflon Tape High Temperature Teflon Tape PTFE Coated Fabric Teflon Tape - $7.99


Keith Rhea
RV7
 
Put in my vote for the stainless steel as well. Mine has been in place since I finished my build in 1997 and has over 1200 hours on it and I have never touched it. It shows no signs of peeling, lifting, wearing or other problems. Much more durable than plastic. It wears like.....well, steel! And this can be applied without removing the flap but might be easier removing the flap (not too difficult) as you also have to remove the previous plastic junk...........

Someone mentioned putting it under the wing above the flap. The purpose of the steel tape is to protect the flap from scraping against the under side of the wing. Putting it under the wing would not accomplish much as that area would still be scraping against the flap.
 
I've tried the SS tape and the clear anti-chafe tape with mixed success. The fuzzy Velcro has worked well for 375 hrs. with no chafing whatsoever, I also operate frequently from unimproved strips.

First photo is my hangar buddy's -8 with 40 hrs. since replacing the clear chafe seal.

20210118-140626.jpg

https://i.postimg.cc/DyLLPTNd/20210118-140626.jpg

Next photo is my -7 with 375 hrs.
20210118-140614-1.jpg

https://i.postimg.cc/WpDHjdDN/20210118-140614-1.jpg

What width of velcro did you use? Do you have it full aft to the trailing edge? Did you use any other adhesive to attach it? Sounds like a great idea. Have you had any dirt issues as others have suggested?
 
1" good quality adhesive backed Velcro is plenty wide as the actual contact surface is maybe 1/8". As you can see in the picture the Velcro is nearly flush with the trailing edge. I have not had any issues with dirt interference, and the Velcro has never been replaced. Someone posted the idea a few years ago so I thought I would give it a try.
 
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