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05/06/26 - installing nutplates on plenum cover - 3h

Some days ago, I have epoxy glued the doulbers to the plenum cover with epoxy and sillica to thicken it.
The annoying thing with epoxy is that it glues all of it and closes up the holes again in the epoxy. After removing the cleco's from glueing, I had to redrill the holes through the aluminum side holes. 
I then drilled the nutplate ears and countersunk them so I could start setting the nutplates on the cover..

Nice and flush, firm and strond on the inside. A bit of extra weight yes, but with all that vibration going on, I don't really trust just on some epoxy.

 Continued on the rest of the contour.

 

All done. 

 In order to protext the engine, I had installed 18MM AN4062-1 Dehydrator Plugs  into the spark plug holes of the engines. These are spark plug size glass containers that contain silica gel balls that absorbe moisture that might form inside the cylinders and engine. Everything that prevents corrosion sounds good to me so I installed them in all 8 spark plug holes some while ago. They screw into the spark plug hole. 
As some of mine started to turn pink, I decided it was time to revive them by cooking them into the microwave. They turn blue again and you can reinstall them then in the glass containers.

When you install them, DO NOT OVERTHIGHTEN THEM !

Ask me how I know. I tried to remove some of them to cure the sillica but one of the bases broke off. I immediatly got cold sweat and had a half panic attack. Everything on a 50K engine that goes wrong is reason for big dollar spending.
This is how it looked like when it broke off.

 It's broken under the base so no way to get a grip in there.

Fortunatly I was able to find a flat screwdriver which was wide enough to be just oversize for the hole in the plastic. But tapping it lightly inside the hole, It clamped onto the plastic and I was able to turn it out.
I can't think about what would have happened if the plastic broke or had particles break of and end up in the interior of the cylinder. A disaster solved.
So again: do not screw these all the way until they but up against the cylinder, it will be impossible to remove later. Better safe than sorry on this one.

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6. Firewall Forward
6.12 Bill Lane Plenum
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6. Firewall Forward

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