Here is a summary of my first lot of tank sealing work. This represents 4 ’sessions’ each about 3 hours long. You get about an hour to work with the sealant once mixed, add an hour for setup and and hour for clean up each time.

First I backriveted the stiffeners to the botton of the tank skin. Everything was given a good scrub down with a scotch brite pad then cleaned with MEK and masked to make clean up easier. The sealand is mixed 10:1 by weight and then applied to the skin, rivets inserted from the outside and taped in place. Then the stiffeners are backriveted in place. Last job is to clean away excess sealant making a nice fillet alone the tank to stiffener seams and covering each rivet shop head with sealant to ensure no leaks.

I also got the filler neck and drain valve sealed and riveted into place.

The ribs were done two at a time. That’s all I could manage within the 1 hour working time of the sealant.

Here you can see inside the inboard-most bay of the tank. Once this rib was installed I installed the vent tube, capacitance fuel sender plates ans wiring and another anti-hang-up guide for the flop tube.

Tank attach bracket drilled for flop tube attach point.

The skin is machine countersunk (not dimpled) along the row of rivets that joing the skin to the baffle. this makes inserting the baffle easier during assembly/sealing.

Made anti-hang-up guides to stop the flop tubes catching on the inspection cover nutplates when I'm upsidedown. I deviated from the plans slightly here to make a more robust and failsafe solution.

It actually worked really well. I used plenty of cutting oil and nice slow rpm.

One down one to go.

Next job was to fit the reinforcing rings around the holes i had just cut, and install the nutplates.

Work continued on the left tank today. I matchdrilled the capacitance fuel sender plates to the appropriate ribs and attached 3 nutplates to each sender plate.

I also drilled the tank nose reinforcing plates and attach brackets to the end ribs.

Finally I deburred all the holes in the ribs,  skin and misc parts. I need to cut the big (5″) hole in the root end rib for the inspection cover but I don’t have a circle cutter. Off to borrow one - and failing that I’ll try and pick one up online.

Made these tank attach/alignment brackets from some angle stock. Did the right one at the same time. They still need a little finishing work but mostly there.

Positioned and drilled the fuel cap flange....Â

...and the fuel drain mounting flange.

Here is the left tank trap door riveted to the rib, and the right one ready to go when I get to that point.

Received my flop tubes and delux fuel caps from Vans today.

I’m putting flop tubes in both tanks so I can fly upsidedown from either. Also, these delux fuel caps are a work of art! Much better than the standard Vans caps which I should have deleted from my wing order. They are very nicely finished and easy to operate without needing tools or a stick to open.