bend in HS skin

DRitz · #1 10-27-2019, 08:08 AM

While I was riveting the nose ribs in the horizontal stabilizer, my skins got a bend (or crease) in them that I could not get out once they were clecoed onto the rest of the HS skeleton. Of course it has to be on the top of the HS so I'm forever doomed to always be able to see it. My question is what can I do about them? Do I need new skins? Can it be covered down the road with filler during the painting phase? Is it OK to leave? The thought of having to redo the HS makes me sick at this point. I've went through more HS-0003 doublers and HS-702 spars than I can count trying to get edge distances to where I thought it was satisfactory. A link to a google photo album picture is below. This is the left side. It is the worst with the right side being slightly better. Thanks in advance for your words of wisdom.

https://photos.google.com/share/AF1Q...5HT3RxbmpDa3Zn

Robin8er · #2 10-27-2019, 08:20 AM

Was this a pre punched skin?

DRitz · #3 10-28-2019, 07:50 AM

Yes, it was a prepunched skin.

chaskuss · #4 10-28-2019, 08:51 AM

More to the point is your horizontal stabilizer the older pre-punched kit or the newer matched hole kit? Too bad you actually kept going to the point of riveting. There's obviously a defect either in the skin or the underlying structure. I had multiple quality control issues on my older pre-punched horizontal stabilizer. On the older pre-punched kits only the skins and the rear Spar have pre punched holes. As I started, I placed the right skin on and Cleced it to the rear spar. I installed Clecos top and bottom and everything went fine. However as I went to Cleco the left skin onto the left side of the rear spar, starting inboard and working my way out I also got a wave in the skin. I stopped and started removing clecos until the wave disappeared. Then looking very carefully with a magnifying glass I could see that at a point about 80% of the way outboard the holes between The Spar and the skin no longer matched. They were offset by about one-third of the diameter of the hole. At this point I realized I had a defect. The question was, which was defective, the spar or the skin? I determined that issue by swapping the left side skin with the right side skin. Doing that verified that the issue was with the skin and not the spar.
I then contacted vans. Rather than have me send the entire skin back they said to simply cut the defective area off and mail it back to them. They then sent me a replacement skin at no charge.

Charlie

chaskuss · #5 10-28-2019, 09:04 AM

Later I had more issues as the pre punched holes on both horizontal skins ran off the flange of the forward Spar at the inboard edges. Studying the problem I realized the issue was that both the inboard ribs on my horizontal stabilizer were to long. I contacted my RV building guru, Jody Edwards. He said not to lose time and spend money mailing these parts back to Vans. He told me that there was a simple fix for the problem. I simply cut off the rear flange of each of the offending ribs and created what are called scab flanges. This basically allowed me to make the bad ribs the correct length so that everything would line up. I did this. Everything turned out perfect and it was super easy to do. Jodi coined a term for when things are defective or incorrect on your RV build. He calls it being VANdalized. When I got my wing kit, I had to make scab flanges for multiple main ribs on the wings as well. You really should have stopped at the point where you discovered the wave while you were clecoing everything together. Definitely need to fix that. Are your ribs and your forward Spar also match hole?

Charlie

Ralph Inkster · #6 10-28-2019, 12:34 PM

Wildly speculating here, check the hole spacing on both top & bottom sides of the spars, is there any difference in the hole spacings? Is the mid ribs mounted with flanges facing in right direction (inward vs outward) per the plans? If you still have part#s on the ribs & skins, ask Vans Tech if there is a way to verify they weren't somehow mixed not mis-labeled.
The picture may be exaggerating the ripples, but from the impression, they look like they would be cosmetically unusable even if you got everything else to align.
I'd push the extreme to identify the cause of the problem before resorting to cutting up parts. That tends to snowball later.