Repairing the cracks in the now REMOVABLE winglets

[lenb]

So we have the winglets removable, but we need to repair the cracks.



This one first, I was repaired by the previous owner and repainted, but then damaged again. This is very common on these winglet when permanently attached to an outer panel.








With a cut off dust and steady (ish) hand, cut along the leading edge of the winglet.





You can see they're hollow, so spread it open a bit and to expose the damage and allow epoxy to get into the cracks



Ill be using 12k carbon tow as the insert, you could use a piece of thin ply or even G-10. I feel this will make the strongest, stiffest and lightest repair.




Precut some pieces and get ready to repair

[lenb]

Unfortunately I didn't take any photos of the carbon tow being inserted, I didn't want to get epoxy on the camera. But basically wet out the carbon on a piece of plastic or wax paper, make sure its fully wetted out. I spread the LE apart and stuffed the whole bunch in at once.
Be sure the cracks are realigned and smooth.

Lastly, I took a couple pieced of tow and wet them out, twisted them up and ran them down the LE to fill the slot and make a nice strong edge. Leave it a little high so we can sand it off later.



Once cured, I wet sanded off all the old paint right down to the original gelcoat finish.



Here is where you need to make a decision. Many guys would just fill, prime and paint the winglet at this point.

If you do that it may be fine, but if its ever bumped again the chances the original crack will appear is very high.
I prefer to put a think 1/2oz layer of cloth over the cracks and them just fill the whole area to prevent future ugliness.





This is what it looks like after applying the epoxy.





Now to lighten it up and smooth it out. Use toilet paper vs paper towel, toilet paper has a finer weave and gives excellent results.

Roll the paper over the cloth, pushing down firmly as you unroll it. Then backroll back over to remove the paper. This will push down the glass cloth tightly and remove all the excess resin, leaving only what needed to hold the cloth down. Unroll the wet paper and throw away, repeat for the other side.


Big difference.



Dont worry about the edges, that will get cleaned up in the next step.

[mlachow]

Len, you should look at modern carbon choices. Some of the spreadtow fabrics are great for repairs.

First make sure things are glued up. Then sand and fill any remaining indentations. Autobody icing works great but leftover doesn't keep very well on the shelf. West Systems micro light works almost as well with a resin that sands OK. Then I like fabrics like carboweave over the outside and use release film over that to give a really smooth surface. I will blot off the excess laminating resin then put the release film over that, squeegee air bubbles out and tape the edges. The stuff is as thin as the glass you put on.

If I have a repair that needs tow, I use the tow from some spreadtow fabric. Much thinner and easy to stagger layers. If things have to be done in stages, cover the earlier ones with teflon coated glass or peel ply to provide a rough and sandable surface for the following application.

Search for DLG repair kits if you just need enough for a winglet.

[lenb]

excellent info Mike, I'll look into that.