Alfa Romeo SZ Technical Page

Underbonnet Foam Replacement (August 2012)

SZs are now 20+ years old and foam doesn't usually last that long, losing it's springiness and crumbling to dust; particularly when it's in the harsh environment of an engine bay.

Mine had done well at keeping itself together but had begun to look very tired and starting to show the early signs of it's complete demise. The usual indications are chunks of foam on the lovely V6 engine or perhaps a burning smell as deposited foam is melted on the exhaust manifolds.

However, the last time I opened up the engine bay there was a large chunk missing from the underside of the bonnet on top of the engine...time to do something about a replacement!


A large chunk of foam missing, the smaller area at the top had gradually been eroding, but the large piece prompted action.
Cleaning up and preparing the surface will be fun, lots of very old and sticky glue remains.
Time to order some replacement foam; it's 25mm to the peaks and appears to be standard sound insulating foam (make sure it's fire retardent!).
This is supposed to show the length of the foam, it reads 800mm.

...and this one shows the width required, at roughly 1100mm.

Removal of the foam...first cover your engine, this is going to get messy!
Start ripping it off.
All gone!
I started to remove the nasty old glue using white spirit and soft scraper, but it took a huge amount of time.
So I changed to cellulose thinners, still took a long time and is incredibly messy and sticky, but you just have to presevere!
I used a plastic spreader to help with removal, the type used for body filler.
I also found using a spray bottle helped to ensure everything was covered in thinners. After a few hours it had all been removed.
Another wipe over with clean thinners and it's all gone!
More to follow soon...

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