Repairing warped wing tip

Has anyone tackled a warped fiberglass wingtip? My RV-3 tip is riveted in place, but has a pronounced 'upsweep' that is probably responsible for the significant bend in the fixed tab on the aileron. It's been this way for nearly 500 hours (I presume), but while apart for painting I'd like to get it right. Any and all advice welcome.

Bob Knauff
RV-3 N65ZM

If its been that way for 500 hours, probably your only option is to cut the seam/ mirror line and reposition the tip, then redo the seam joggle. If it is a very significant amount (can you estimate how many inches it sweeps out of symmetry?) you will have to cut a significant portion of the midline, probably at least half

Danny7 said:

If its been that way for 500 hours, probably your only option is to cut the seam/ mirror line and reposition the tip, then redo the seam joggle. If it is a very significant amount (can you estimate how many inches it sweeps out of symmetry?) you will have to cut a significant portion of the midline, probably at least half

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The wingtip is upswept approximately one inch at the tip of the trailing edge. The leading edge seems correct; when you compare the opposite wingtip the upper surface from the rib line to the bow edge is practically flat, whereas the warped tip top surface is concave, dished out about 1/2" in the middle. I'm away from the shop right now, or I'd take a picture to try and make this clearer.

Thanks for the thoughts.

Bob

New One

Hey Bob,

The BS factor in fixing that one is pretty great if it can be done at all. If only 1/4" or so, I'd say fix it. Order new tips and be done with it. You'll have a truer flying plane and it will look better.

Replace them.

I agree with Darwin. I spent too many hours trying to fix warped wingtips. Bite the bullet, use the credit card.

rvbob said:

Has anyone tackled a warped fiberglass wingtip? My RV-3 tip is riveted in place, but has a pronounced 'upsweep' that is probably responsible for the significant bend in the fixed tab on the aileron. It's been this way for nearly 500 hours (I presume), but while apart for painting I'd like to get it right. Any and all advice welcome.

Bob Knauff
RV-3 N65ZM

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This isn't too bad imho if you can stomach fiberglass work. I had this problem on my RV-8, and just split the trailing edge of the warped wingtip with a cutoff wheel, and carried the cut forward on the chordline about halfway to the leading edge. I could then move the trailing edge up or down to match the other side. For example, if I moved it down, the lower skin would stick farther aft than the upper skin.

When I had it where I wanted it, I drilled a few #30 holes and clecoed the top and bottom together so I could walk around and make sure I liked it. Then I glued the top and bottom together with flox, and later filled with micro.

It really wasn't too bad, and I did it all on the wing before paint.

Thanks for the thoughts guys. I'm inclined to go ahead and try to repair the tip with the thought it mind that if it doesn't work I'm no worse off (except for time spent) than if I had just replaced the tips in the first place.

Epoxy or polyester for the repair?

Regards,

Bob
RV-3 N65ZM

Epoxy

Clean as thoroughly as you can and scuff the area. If you can, split the trailing edge with Dremel and cutting disk. And, the outer edge.

Use some wood blocks and clamp to get conformity. You may need to heat it with a heat gun.

Do the internal epoxy and glass work from the inside first while clamped in place.

Good luck.

Take a long, 4 to six feet long piece of straight angle and clamp under the trailing edge of the aileron and flap and extend it out to the end of the wing tip. Cut the trailing edge of the tip, and forward only as far as needed ,to get the wing tip to rest on the piece of angle; clamp to angle. Using some flox and glass cloth do a band aid fix to the outside of the tip along the cut line. When it has cured remove the tip and do a flox and cloth lay up inside the tip. After that has set up grind off the exterior bandaid cloth and finish using flox and micro as required.
This will amount to, three, one hour sessions and be guaranteed to line up with your aileron. There is no way to know if a brand new part will be perfect.

Any other thoughts on techniques? Your suggestions so far are helpful, but the difficulty in getting a good bond and a strong, durable repair without removing the tip has me concerned. Any elaboration would be appreciated.

Thanks.

Bob
RV-3 N65ZM

The best method would involve removing the tip by drilling out the rivets. You could remove the aileron and rill out the aft tip rib and work through that hole but that would be more work then removing the tip. If you are trying to save painted rivets then that might be your best method but you will still need to repaint the tip rib rivets and trailing edge.
The whole process, and soundness, will be much better and likely faster if you just remove the tip after the alignment procedure I mentioned in an earlier post.

The only thing that I could add is to sand all the gel coat off in the repair area. Machine sanding is best. Personally I use a 36 grit disk on a die grinder.

fiber glass tip problem

I have RV8A in process, wing tips (W715, bat wings) are warped badly (actually the left one) from apparently being stored flat in a garage for several years.
I can lay tongue depressers across an area 4" from the inboard (so the sticks are pointing wing tip to fuselage for about 20" in length.
A marble could be rolled under the sticks without them.
We have tried heat gun, heating up glass putting a piece of 1/2 wood and clamping to inside let it cool to no avail.
We had someone suggest heating, clamping and putting ice on it to supercool, again no help.
We are thinking of adding foam ribs, or wooden dowels or ?????
Maybe easier to buy new set if anyone has extra they might want to sell.
I have lights installed and also nutplates for mounting which took a lot of work. Any suggestions would be helpful and appreciated.
Please email me @ [email protected]
L45 Bakersfield, CA Thx

Socal,

I had the exact same problem, and I stored my tips vertically!. I bought another used set on this site, and they had the problem as well. I mentioned it to some other fellow builders to check their tips, and they had the issue as well. I was going to buy a new tip, but I'm not convinced a new one will be any better.

With a heat gun I was able to push out most of the divet. I am now adding ribs, then I will fill what's left. I'm open to other great ideas if others have them.

Thanks,
Scott

Same problem

When I got my kit it had been sitting for several years and the wing tips were very wavy. I tried several things but ended up using the credit card to solve the problem.

Me too

The right tip for my RV7A was of absolutely abysmal fabrication. I have reasonable fibreglassing skills but it didn't take long for me to realise that the supplied tip was beyond repair. I couldn't believe that they had sent me such junk. In the end I had to cough up for a new tip plus freight to Australia. The freight was more than the cost of the tip. That hurt but I had no option.

I asked Vans to ensure that the replacement tip was of good quality...and it was. In fact there was no comparison between the two. I don't believe that they were made by the same company.

Even a small deformity of the tips can have a big influence on the aircraft being out of balance because they are located so far outboard.

I recommend you buy a new tip and specify to vans in no uncertain terms that you want a decent one this time. It worked for me.

PS. If you try to repair the tip you'll have to remove it from the wing first. There's no way you can repair it with it still attached. You've got to get inside.