Rear cockpit bulkhead oilcanning

[tortuga]

So I've tracked down a rattle to the fire extingisher mounted to the back of the cockpit CL on the rear bulkhead, which is appears to me an unreinforced single Matt of fiberglass...it is separate from the front bulkhead in the trunk: the gap is visible from the sie of the car above the rear wheels.

Thinking about simply fabbing up a piece of wood to fit relatively tight in there transversely, slathering with sikaflex, and screwing the extinguisher mount to it from the front, and a temporary screw from the trunk to secure it while setting up?

Any one else tackled this issue?

Thanks

Steve H
1764

[Apex_speed]

I observed the same thing on my car (#2312) which was interesting as the Hillbank guys had told me they thought there was only one layer with no void.

I think your solution would work BUT I would get a spacer in there and then through bolt through BOTH bulkheads from the trunk with machine screws and then use some nice cap nuts on the cockpit side.

There might be some better ideas coming as I haven't actually done that yet but it's on the list to put the extinguisher there or on the tranny tunnel under the dash.

[mikeinatlanta]

I'm not familiar with this particular car, but very familiar with composites. How big is the void in both square inches and gap, how many bolts?

Depending on void size, I'm thinking along the lines of injecting an epoxy solid filler into the bolt holes to make an approximately 1" solid pad to redrill and through bolt. You could also do the same in any areas where flex is an issue. Not talking large areas, just injecting in strategic areas to stop the movement.

[Buzz]

The epoxy is a good idea. I was going to suggest injecting expanding foam depending on depth of the void.

[Blas]

Perhaps a piece of hi density foam pushed between the two surfaces will do the trick?
Blas

[tortuga]

If you remove the rear wheels from a SPF you can look right though a void about 1.5" wide probably a good foot high? I think some stiff foam cut very precisely to the right thickness and very parallel could be slipped in there and bonded some how. Expanding foam would work with the right volume and mold...might be hard to control and possibly make a big mess...

[Apex_speed]

Just an update as I put my car on my lift and looked back there yesterday. When it's up in the air, you can reach two hands up over the differential and get in there to back it up with a metal plate. I'm using a 1/8" aluminum plate through bolted from the inside. In other words, there is a MILE OF ROOM in there but you have to get under the car. I would not want to go in from the side after looking at it carefully. That would still be a pain.