Sunday, May 5, 2019

Cutting to the Chase

Well, the next logical sequence of this long drawn out process would have been to go through the steps to rivet the top side of the LE ribs together after finishing up the ones on the bottom. However, right now I think its just best to cut to the chase and remind any readers following this blog that deviating from the plans always involves risk.

To cut to the chase, I did unclamp everything and flip over the cradle and reclamp everything back together and begin the process of riveting the top side rivets to the LE skin, subskin, and ribs. In fact, I thought that this had gone just as well as I had thought that the bottom side had gone - perhaps even a bit better, now that I knew what to expect. I felt that way -  right up to the point that I shined the flashlight on the bottom most forward rivets attaching the subskin, outer skin, and ribs. If you have read the last 2 posts or so you will note that at one point I commented that I did have some difficulty with one of those most forward rivets, but at the time I did not know why, and I thought that I had overcome the problem eventually without doing any damage to anything in the process.

Well, when I viewed the shop heads of the forward rivets in that area, it become very apparent what had happened, and it was exactly what I had said all along that I absolutely could NOT do if  were to successfully complete the mod. In short, I discovered a crease on the subskin where the edge of my bucking bar had been digging into the subskin just beyond one of the most forward rivets on one side, so all the energy from the rivet gun was being passed through the bucking bar and into the subskin, which is why that one rivet would not set properly. My continued pounding with the gun only served to tighten the skin and stretch it a bit, which caused the outer skin to stretch a bit as well.

You can almost see it in the very last pic from my previous post by double clicking on it to make it larger and clearer, and look at the forward area next to the cut out in the outerskin along the one side. You can just see that the outer skin des not sit the same way against the subskin that the rest of area is, and that means that the outer skin has been stressed.

Here is a pic that I took, that, without even realizing it, captured the issue.
Look at the left side, just past the most forward nut plate on the bottom, and you will see what appears to be a whitish line. This is the crease that was hammered into the subskin. Remember to double click on the pic to make it larger. If the sides of my bucking bar had not been covered by duct tape I most certainly would have plowed the obviously incorrectly placed bucking bar right through the subskin and continued to pound into the outer skin. 

Finding this just about made me sick to my stomach, because this was precisely the thing that I feared the most that I knew I absolutely could not do. I now fear that the only way to correct this issue would be to completely remove all rivets, and remove and refabricate a new custom subskin. This is something that I absolutely will NOT do. I hate the fricking forward rivets just about more than anything I have ever hated in my whole life, and I will absolutely NOT start over to remanufacture a new custom subskin.

Right now I am waiting for a tech counselor visit to thoroughly inspect this damage and determine what to do next. Even if I am told to remove the subskin to effect a repair I don't think I will even do this. Instead, I am now prepared to order a new LE skin and perhaps new ribs to go with it, and rebuild the stock LE and completely abandon this idea so that I can hopefully have a flying airplane sometime before I leave this earth.

For anyone out there following - and I have said this before - if you are thinking about building then I strongly urge you to get the quick build wings and then you can decide if you want to do the quickbuild or slow build fuselage. The quickbuild wings will already have the LEs and fuel tanks completed by the factory - so you wont have to mess with ANY of those fricking forward-facing rivets. 

So I am pretty disgusted right now - but I still have fuel tanks to finish, so until I get a chance to talk with the TC about my latest blunder I will shift my focus to the fuel tanks once again. I  have discovered through this process of building a metal airplane that I absolutely hate riveting - so this will most definitely be the first and last time that I endeavor to build one. There is just too much aggravation involved for me. YMMV.

1 comment:

  1. Bryan,
    I know you hate to have that ding in the sub-skin, but I think it's okay to keep going. If you're super worried, I'd suggest making a patch over that area, out of a small piece of 0.025 material and pro-seal it in place. That should help to transfer some of the stresses through that area. Don't get discouraged. That's my job! :)

    Mike

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