Need some advice from all the builders. I noticed the upper trailing edge of the aileron bay has started lifting off of some of the ribs. Is there a way to repair this without recovering the wing.

Monte

I made Gussets for mine clamped it down and glued them, if the edge is curling up.  You must make sure that your aileron is not affected by anything you do in there.
I think there's a method for repair of it on Team's website.

Can you post a picture to help us understand the problem?

thanks Puff. i will try to upload some picts this weekend but have had problems with the website not accepting them. did you use T-88. i tried the clamp method useing epoxy but the eventually lifted.

monte

Monte,  What finish do you have on your fabric?  The reason  I ask is if you have Stits with polytac glue, you could: 1) use MEK to loosen the glue, 2)lift the fabric around the T/E, 3) install the wood triangle overlays on each rib T/E attach point, 4) reattach the Dacron with polytac, 5) use a warm iron to smooth out the repair.
I have done this type of repair with success.  May require touch-up of paint after repair.
BobN

Please post pictures of what you do! I suspect that because my kit is old, I'll be having to do these very same repairs..

Bob i have no idea what finishing technique was used. i bought the A/B used and the documents show it was built in the 90's. i have used "c" clamps in the past along with epoxy to pull the strip down but after 3-4 weeks it lifts again. do you have any pict. of your repair.

monte

Monte,  I have looked thur several hundred photo's and have found not one.   Dacron was used during the 90's and I suspect you may have it on your AB. It would appear white with a course weave as compared to cotton or linen.  Assume it is dacron and being you are in the aileron well, put a little MEK on a clean white wrag and rubb a small area of fabric in the well.  The adhesive should come lose with soaking.  Read and follow directions/WARNINGS on MEK before using.  Then do the aforementioned repair.  
BobN

You may have already seen this one. Sounds like another take on a similar repair.

https://www.youtube.com/watch?v=1K1Slc8ISH0

Quoted from LSaupe

You may have already seen this one. Sounds like another take on a similar repair.

https://www.youtube.com/watch?v=1K1Slc8ISH0

Thanks i just watched the video. i got some t-88 ordered and decided to add some small gusset blocks the each side of the ribs to increase the bonding area. should be an easy fix and since cold weather is coming it will be a good time to start the repair.

monte

Monte,  Very good youtube video.  Very good repair.  However, I don't think it addresses the root cause of the problem.  I believe the the fabric was heated to high of a temp on installation. Over the years gets a little tighter, due UV on the lazy sunny days at the airpark and eventually pulls hard enough to cause separation in the wood fiber not the T-88 at the glue joint.  He does mention a concern of fabric lifting inflight, at the fabric glue joints, and rightly so.  In his case and maybe yours, he suggests he would release/undo the fabric at the trailing edge and reinstall it over the wood repair.  You may want to release the fabric along the entire trailing edge and over lap a 2" fabric tape on re-installation.  This would remove the tension of the fabric pulling on the trailing edge and cleanup the overall repair, adding better security.  More winter work but safer in the long run.
BobN

I will be removing the ailerons tomorrow to get a closer look. It’s strange the lower trailing edges are all secure. I hope the t88 along with the gusset blocks will do the trick.

Monte

Is the fabric rib stitched?

Imaging if that whole trailing edge separated in flight with no reinforcement tape and rib stitching to securely hold the fabric onto the ribs.

It happened to another aircraft with similar trailing edge design:
https://youtu.be/n1Cnlv7Ggo4

Yes the ribs at the trailing edge are all rib stitched. i will be doubling the bonding area at the ribs with some spruce 1/4 in sq useing t-88 epoxy. in fact i will be doing this to all the ribs top and bottom. this will give me a 3/4 bonding surface.

monte  

Thats how I built my wings. Added a 1/4" square by about 1" long block on each side of the rib at the trailing edge.

That’s great to hear, I thing I’m on the right track now. Thanks!

Monte

Is it safe to put screws through the dacron or should I avoid piercing them at all costs?

In theory any hole through Dacron (polyester) cloth should be heat sealed at the edges.  Normally using an adjustable heat soldering iron.  However whether this is really needed in any particular hole is problematic.  If there is the slightest chance of the hole having stress across it, probably it should have the edges heat sealed.

The right needles for stitching should be probably be triangular in section rather than round so they can tease the fibers apart rather than cutting through them.  At least that's what I was taught.  So you should only have to worry about anything that screws or bolts through fabric.


Tom

I was thinking of solving this problem by melting little holes in the dacron and then drilling and putting small through the rear strip and into the ribs.  It doesn't seem like it because much to hold it together and it would be a lot easier then glueing a bunch of new wider blocks.

Rather than screws into the rib cap, I suggest drilling two holes, one on each side of the rib, through the trailing edge and using several loops of sewing thread. Then use some CA glue to secure and toughen the thread and seal the holes.  This would be easiest before a failure has occurred.

Quoted from ITman496

I was thinking of solving this problem by melting little holes in the dacron and then drilling and putting small through the rear strip and into the ribs.  It doesn't seem like it because much to hold it together and it would be a lot easier then glueing a bunch of new wider blocks.

That sounds like a good idea. Thank you!

https://youtu.be/k7riI8Z4zkE Here is a video showing the repair I am doing on my wings. I have finished one panel and so far it is working. For those who are building wings they might want to use this repair.

Monte

texasbuzzard,

I take it your video is of an airbike wing? I wondered if it was as there's no sign of any anti-drag braces. These are fitted diagonally in the Minimax wing to help prevent the wing from distorting backwards during flight, but there's no sign of them on your wing. They look like the attached picture, which someone else posted up on here of their Minimax wing build.

Hello again,

Upon rewatching the video I think you may have a couple of anti-drag braces after all, but they don't go all the way out to the end panels like the Minimax ones. Which means the wing is very similar to the 'light' wing design of the early 'maxes.

Bob the video is not my wing being repaired. I used it to reference the same failure of the trailing edge and how he repaired it. Not sure if it is a A/B wing or not.

Monte

My minimax is apparently something like 20 years old.. I wonder if it has the braces.. I better go look tomorrow..