26-10 -> 11: Lower Skin Preparation

The lower skin preparation was fairly simple for the taildragger version - most of Page 26-10 relates to cutting holes in the lower skin to take the landing gear which is poking out of the centre fuselage, for the nose-dragger version. As i am building a taildragger, all of this could be skipped. There are a few steps on 26-10 which are marked as being applicable to the taildragger, however these relate to covering up the holes in the skin where the boarding steps poke out (the taildragger has the boarding steps as an option). Since i am installing the boarding steps, i skipped these instruction steps and kept the holes open.

So basically, the entire page of 26-10 was completed by dimpling some holes which would have taken nutplates on the nosewheel version, in order to fill these holes with rivets later on (since they are not used on the taildragger). Simple! I like pages like this. 

Page 26-11 was preparing some skin doublers and some skin stiffners, as well as deburring the bottom skin itself. Once these were done, they were cleaned, etched and primed. The bottom skin was primed on the outside, where the forward lower skins will overlap. 

Deburring the lower skin. I used the front skins to mark where the overlap was located, so i could mask this for etching and priming.

For rinsing the etch off the skin, i hung it on a couple of nails on the fence.

On a properly cleaned and etched surface, the water forms a sheet

A nice sheet of water

I think this is the biggest part i have primed yet.

The skin doublers and stiffners

Dimpling the lower skin

Dimpling was completed using the DRDT2 and my dimple tables, as well as a couple of woodworking roller stands - I managed it solo. There was one rivet right in the middle which would be reached from only one side and then by bending the skin up a little. Otherwise, it was 3 hours of work but fairly simple. There was a mix of #40 and #30 holes. 

This rivet, right in the middle could only be reached from one side of the skin and by bending the skin up into the dimpler frame

This was the middle rivet.

This setup worked very well. Was tedious and i had sore pecks afterward! 

Next up was to rivet the lower skin doublers and the little skin stiffners onto the lower skin. I backriveted these - it was nice to backrivet again. I also installed the little -3 rivets into the nutplate holes which are not used on the taildragger. On Page 26-11, there is a note to ensure the orientation of the skin stiffners. However, there is also a note "do not rivet" 2 of the 4 holes in the skin stiffners. These are holes which are common to the bottom large skin and the lower forward skins. I had installed rivets in all 4 holes and was about to rivet them on when it didn't feel right - lucky i checked the plans! 

Here you can see the groups of 3 rivets which would have had a nutplate if i was building a nose-dragger.

I dusted off the ol backriveting plate