Wing Build/Fuel Tank Install

[Maverick]

I am building the wings on a KF5. I had the wings built on my first build but, on this one I am doing the wings myself and I've run into a question that I don't really find the answer for in the manual, either hard copy original or the Kitfox, Inc, web manual. It has to do with sequence of the build. I have the spars, ribs, compression struts & brackets done and ready but, the manuals don't make it clear when to install the wing tanks.

There is a series of instructions for fitting the wings to the fuselage for rigging and placement of the strut brackets on the spars. Do you install the wing tanks before or after this process of fitting the wings to the fuselage? The manual seem to imply that it is after the wing rigging is accomplished but, it also seems that there are things that might need to be done before the wing tanks are installed. Does anyone have any words of wisdom on this question?

[bholland]

I purchased my kit with quick build wings that were pre rigged. I put the fuel tanks in myself which was one of the last things done.

[jiott]

I built my own wings and the tank install was one of the last things to do, after rigging to the fuselage and after installing the #1 rib.

[Maverick]

Just what I needed to know. Thank you.

[Maverick]

New question: I am reading the instructions and I find something a little confusing. I've got a call in to Debra but, I thought maybe others could share their knowledge on this question.

In marking the ribs for location on the front and rear spars (see attached PDF) the instructions are to use a half inch spacer between the end of the rear spar and the jib stop thereby offsetting the rear spar outboard 1/2". (done).

Next the language below the wind diagram showing the distances from wing root outward states: All rib center line locations are referenced from end of rear spar. Locations along the front spar are the same as rear spar plus 1/2".

The way I read this, using the rib location for rib #3 is 37-1/2" from root end of spar. Then the front location would be 38" (37-1/2" + 1/2" = 38). I marked these all using the rear spar dimensions plus 1/2". Then I started trying to fit the drag braces and found that they will not fit. In order to make them fit, if I slide the front of the rib on the front spar toward the root end 1/2" then the drag tubes fit as described in the instructions. What am I misunderstanding?

[Geowitz]

Nevermind, I was thinking of the wrong thing...

[efwd]

Okay, here it goes. Many questions on this in the past. Be aware of the clearance you have for the fuel fittings and the finger strainer at the #1 rib. Some people have trimmed the tank edge at the #3 rib to allow the tank to be pushed out further to get the space for the fuel fittings. I notched the #1 rib capstrip so that the fuel fitting will spin. Im still not certain it is going to work. I question if I have adequate space to get the finger strainer out. Anyhow, whenever you trim from the tank flange you will need to do your leak test again on the tank. However you chose to do it, the next problem is getting the gap filled with structural adhesive. My gap was maybe slightly wider than what is in your pic. I just used painters tape and stuck it under the tank flange to the web of the ribs. I used flox in the Hysol and filled the gap. It won't be smooth and nice so use some Super Fil to allow sanding after its dry. As for the overlap on the spar. I left mine as yours appears to be. I used Super Fil to feather out the transition from fiberglass to underlying structure. I think I used a dremel to remove a little fiberglass at the point it lays over the rivets.

[jiott]

You can either notch or relieve the tank corner so the spar reinforcement doesn't hold the tank up.
I used some aluminum tape on the underside of the rib cap-tank flange to span this gap and then put the Hysol in the gap. I only did it at the #1 rib, and used some spacer blocks at the #3 rib because it leaves room for rib stitching.

[Maverick]

My new tanks arrived and I've cleaned and tested them and am ready to install them. I am doing the left tank first (for no particular reason except it was the one on the saw horses). In reading page 40, step 7, of the online manual where it says apply structural adhesive between the top cap strip and wing tank edge on ribs #1 & #3 ribs. This is a little nebulous. Also, there is a gap between the tank and the #1 rib of up to 3/8" and up to 1/4" at #3 rib.
Can anyone elaborate on this step as to how to accommodate the gap, as in what keeps the structural adhesive in place while it sets up?

Also, the tank sits on top of the spar attach brackets. Does anything need to be done to the tank to accommodate the brackets of just let it sit on top of the brackets? See below:
20190923_093736.jpg
Thanks,
Maverick