How wide are the ribs in a classic motorhome

[guy99]

I need to attach a stub wall to the side of my motorhome. Unfortunately, the first attempt (not by me) missed the rib and the screw pulled out of the interior aluminum. The rear edge of the wall runs right through the rivets which hold the inside shell to the ribs. My question is if I go slightly (1/4 inch) aft of this line of rivets will I hit the rib? (I couldn't find a fingers cross emoticon)

[swebster]

Guy,
Do you mean a new bulkhead?

I've drilled out and replace most the the interior skin rivets in the forward section of my motorhome as part of my interior redo. The ribs are not very wide but a 1/4" left or right should be OK.

Just be careful that you don't drill into the rib's vertical section as you will weaken the rib itself.

On thing you might consider is to drill out a row of rivets where you want to place the wall and then install new rivets along that same line.

[guy99]

Yes a new bulkhead. I had the interior of my 310 Limited remodeled to turn the rear twins into a east-west king. To do this we removed the street side closet, put the head of the bed curbside over the generator compartment. There is a narrow walk way at the foot of the bed. We also changed the bathroom which required a new bulkhead between the bathroom and the bedroom. When he installed this bulkhead he drove a screw into the inner skin but it has since pulled out. I determined that this was because he didn't hit the rib. The way he placed the bulkhead, the rear edge bi-sects the rivet heads.