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Can't line up my tank ribs/baffles.

Skybolt Al

Skybolt Al

Well Known Member
My leading edge skins and ribs fit perfectly. Different story with the tank skin and ribs. I don't know if the tank leading edge curve is off in relation to the skin rivet holes or what, but I'm having a heck of a time lining them up. The skin/baffle holes are about 1/2" off. The leading edge curve is about 1/4" out in front of the rib nose and I can't seem to force the rib any further down into the skin.

Thanks for the help.
 
tank skins to ribs

this was a tough one for me too.

Just keep struggling to get those clecos in there. very hard on clecos.

funny thing is, once it was all pinned together it was OK.

each time I clecoed it back together after match drilling, deburring & dimpling, it got easier.

at first though it seemed like the parts would not fit.

no magic here, just perseverance.

Dave
-9A finish kit
N514R reserved
 
Start to cleco from the very leading edge holes and work your way back. I had the same difficulty. This worked however.
 
Oh yeah, don't put it in your fixture until it is all clecoed together. just start to cleco tip to tail and the skin will wrap itself nicely around the ribbies.

Tony
 
Keep after it.

I am at the exact same point on the 7. The ribs will go in but you have to make sure the flanges are 90*, if they are more they will never fit. I thought mine were good but I had to bend all of them before they would go in. I know everyone says go from leading edge to trailing edge with the clecos but I found that I could get the tip one in then move to the tail end and move back to the leading edge. They are still hard to get in but with force and patience they will fit. Hope this helps a little.
 
I feel your guys pain, I hated the fact that the holes just didn't want to line up. I thought it would be so "simple" to cleaco in all the ribbies. Took me hours! All in all, they'll look fine when its all done.
 
I agree with smitty..I did it the same way on my 7 tanks...start with the leading egde holes first, top and bottom and work backwards. see pic..

P1000966.JPG
 
Yep - the skins here seem to be slightly underbent, and take a little "persuading" to get them to settle nicely around the ribs.
 
I got the ribs clecoed into the skin today, but not without a fight. I think the radius on my leading edge is smaller than it should be or the radius is off in relation to the holes. Anyway, check out the pictures.
This is the gap at the leading edge. I pushed, pried, and even came close to buckling the rib from too much force trying to get the rib down into the skin leading edge enough to insert a cleco.
tankbaffle3.jpg


Finally I clamped a former down into the jig just behind each rib to reform the leading edge enough to allow the rib to seat properly.
tankbaffle1.jpg


I really had to crank down on the strap to get the skin to take the proper shape to get the rib in. I inserted the clecos starting at the leading edge and still had some prying to do with my trusty icepick to get the holes aligned.
tankbaffle2.jpg
 
Now you've figured out the trick!

Once you've got them all in place and matchdrilled, you'll find that they go together easier next time.
 
Success With Tank #2

Fortunately, clecoing my 2nd tank was much easier than the first. To save a lot of aggravation for the next tank builder, here is how I clecoed the 2nd tank to its baffles/ribs. The order that I installed the clecos made all the difference. Use an icepick to align the skin/rib holes.
Fuel Tank Cleco Install Order
*Rib holes are numbered from leading edge.
*Ribs are numbered 1-7 from the outboard end.
1. Ribs 1-7, topside, hole #1, out of the cradle.
2. Ribs 1-7, bottomside, hole #6, in the cradle.
3. Ribs 3-5, topside, holes 3,5,7,9, adjust up/down in cradle to line holes up with icepick.
4. Ribs 7,6,2,1, topside, holes, 3,5,7,9, adjust up/down in cradle as needed to line up holes.
5. Ribs 3-5, bottomside, hole #1.
6. Ribs 3-5, bottomside, holes 3,5,7,9,11.
7. Ribs 7,6,2,1, bottomside, holes 3,5,7,9,11.
8. Ribs 4,3,5,2,1,6,7, topside, holes 11,13.

Hope this helps the next builder.
 
You will also find it easier if you blend out the flange slots where the leading edge radius is tight so that you end up with a scallop shape. This also prevents the corner putting a small dent in the leading edge. On the -10, I found this procedure was documented for nose ribs in some places but not others. However, there is plenty of correspondence in the forum.

It also gets easier once it's been match-drilled and dimpled!
 
My first tank was a snap but on the second one, I experienced the same issues. I used the same technique on both tanks. It's clecoed and waiting because it bothers me that it was so hard to put together.
 
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