What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Dimpling the firewall

msmst25

Well Known Member
I tried searching for the answer to this, but can't seem to find it. The instructions on page 27-2 indicate to dimple all of the rivet holes in the firewall, but I'm not sure if the upper forward fuse rib attach holes and the oil cooler box holes are also supposed to be dimpled. It seems like they should be, but I can't find instructions or a rivet pattern for those parts later in the instructions.
Seems like it would be much more difficult to dimple them later if they need it and I don't do it now.
 
The oil cooler installation is in FF1 section of the plans.
It calls out AN426AD4-4 rivets for the VA-186 to the firewall holes.

I'm pretty sure the ones to the upper forward fuse are dimpled too to make the forward face of the firewall smooth. Not sure where the callouts for those are off the top of my head (other than the 27-2 reference) I can double check when I get home if no one else knows for sure.
 
Dimpling

I found the call out for the upper foreward fuse rivets, and they are also dimpled. Thanks for the help.
 
Did you end up dimpling the oil cooler holes and fwd fuse attach holes at the same time as the rest of the firewall? I was thinking they may want us to wait so we can mock them up without dimples.

What about the holes at the very bottom of the firewall where we haven't final drilled yet? Those wait or maybe arent dimpled? Seems we could get them with squeezer easy enough.
 
I dimpled the oil cooler holes and the fwd fuse attach holes. I final drilled the bottom holes after the dimpling. For some reason, the instructions don't have you dimple the forward flanges of the ribs until very late in the process. I don't know why they advised against dimpling it earlier, and it seems like it would have been fine to do it when dimpling the rest of the holes. If there was an instruction about dimpling the lower holes in the firewall and the FWD fuselage ribs where the skin attaches, I missed it and didn't realize until after I prosealed the skin to firewall attachment and had to separate them and dimple it with some proseal sticking to things it shouldn't.
 
Back
Top