29-06 -> 07: Riveting Engine Mounts / Longerons

I had skipped the riveting of the engine mounts to the longerons on Pages 29-06 and 29-07, as the plans called for you to rivet these to the longerons (meaning the longerons would need to be primed), but then later on on Page 29-09 asked you to countersink the longerons for the dimples in the skins. I didn't want to have to reprime all these countersunk holes, so instead, i just clecod the engine mounts to the longerons and proceeded with steps on Page 29-08 - clecoing on the side skins and drilling the upper drag fittings and cowl attach hinges. 

So now i went back to Pages 29-06 and 29-07 and riveted the engine mounts to the longerons. All went well using the squeezer. I used the pneumatic rivet puller for the Cherry rivet, and there was one Cherry rivet which did not set properly. I removed this by punching out the stem, then drilling out the rivet as usual (the cherry rivet bodies are just aluminium, so it came out easily). 

The 'no hole yoke' worked well here.

The Cherry rivets can be set with the hand squeezer, but it is a lot more satisfying using the pneumatic tool!

The Cherry on the bottom right did not set correctly - no idea why. The stem broke off early leaving the rivet not properly set. 

Here you can see how the stem did not pull into the rivet body, and the stem broke off early. No idea why! 

I punched out the stem using a pin punch..

Then drilled and snapped off the head as usual (i used a #30)...

The rivet punched out easily.

Dimpling the cowl hinges and firewall

Once other small task which was called out on Page 29-08 was to dimple the cowl attach hinge shim. This gets installed between the firewall flanges and the cowl attach hinge (which is countersunk). A small note here is that there is nowhere in the plans which asks you to dimple the flanges of the firewall - since the side skins will go on very soon (and since i had already done all the required drilling of the side skins), i went ahead a dimpled the flanges of the firewall at this time - but only at the locations where the side hinges will be located. I will dimple the areas associated with the upper skin at a later date.