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Best option to spray cavity wax in the floor sills

Started by Gpapaniko, 24 May 2023, 07:39 PM


Hi All, any advice or insight on how best to access the sills in order to respray both floor sills with a new batch of cavity wax. While there is a little bit of rust evident at the end of the sills (in the rear wheel arch), a good coat of cavity wax in the sills should halt any further deterioration.  There appears to be sill plugs at the end of the sills and the underside and was hoping if any in the forums had undertaken this protection method in the past and the best way to access the sills to provide this treatment.  Cheers
Never stop loving
1980 280SEL


There is a plug at the front and rear of each rocker panel accessable from the wheel arch. If you remove the plastic door sill plates you will find about a dozen plug holes there under the carpet and padding. Use a lot of compressed air to blow any loose dirt out. New plugs are available if needed.

Prior to wax you shppould also spray a rust convertor in there. A boroscope would be handy to look around. There are some decent inexpensive ones available the hook up to your phone. I  recently saw photos from a better handheld unit that had amazing pictures, it was @$300 I think.
'68 250S
'77 6.9 Euro
'91 300SE,
'98 SL500
'14 CLS550,
'21 E450 Cabrio


Thanks Rumb. The cavity wax I'm using is a two in one wax and rust converter that comes with a long spray tube and multi directional nozzle purpose built for this type of application. I will lift the door sills to look for the holes you suggested  as the plugs at the end won't give me access to the entire length of the sill
Never stop loving
1980 280SEL