Washers replacement - part 2

(3.0 hrs)

With the teardown part completed, it was time to put everything back in its rightful place. 

I saved the relative position of the hand-carved, one-off washers, using a marked cardboard. This way I would not wonder why they didn’t fit later, after putting them in the wrong hole.

Every washer was individually fitted to its location, and this is how I kept track of them

I decided to make sure no gap would go unfilled, so I took care of floxing anywhere I though there might be an issue. 

Flox under big washer that will end up on the outside of the sidewall

Flox in proximity of the sidewall holes / gear bracket holes

Most of this flox was squeezed out during tightening of the bolts

A lot of flox was expelled during the tightening of the bolts, but cleanup was pretty easy.

Landing gear bracket back in place

As far as the tightening itself is concerned, I went for 60 in/lbs which is the middle of the 50 to 70 range specified for this size bolts (see my other post). I also used blue Locktite thread locker on the bolts to prevent vibration from loosening them up in the future.

The outside came out pretty decent, and also cleaned up easily. 

Outer sidewall before clean up

Rear lower bracket washers

Top rear bracket washers

After cleaning

I later cut up some leftover pieces of foam to fit, ...

Scraps of foam in place on the left side...

... and on the right side.

... I microed over the bolts, ...

Since I had run out of West System epoxy, I used Easy-Poxy to make this Micro.

... then filled the holes with foam and micro, and used pins to hold it all together while it cured...

These pins were difficult to remove, the plastic heads came right off.

I wouldn't use these pins again, I needed wire cutters and pliers to get them out!

Lots of pins holding the foam scraps in place while the Micro cured

After cure, it was an easy matter of sanding the foam back down to match the rest of the fuselage.

Sanding the Easy-Poxy Micro was not as hard as I had imagined

All ready for final skinning

While I wish I had known about this mod before I put the fuselage sides together, I am glad I found out about it before I glassed the outer fuselage skin. I am happy I did the retrofit now, and I feel confident that I will never see the heads of those bolts again.

I hope this post has helped someone else in deciding whether the amount of work involved in changing the washers is worth it or not. The value of this mod might not be the same in all cases, since many planes have been flying all along without issues, while a few others have encountered some.

As in all homebuilt airplane projects, you, the builder, are the ultimate judge of what you are willing to live with, or sacrifice.