The order of operations for protection of hidden cavities from corrosion:
1. Place the vehicle on a lift, remove any parts or trim that obstruct access to hidden cavities.
2. Wash with water at a temperature of 40-50°C through technological and drainage holes hidden cavities (Table 8-2), the bottom of the body, wheel arches until clean water flows out. In this case, the rotary windows should be closed, the drop-down windows - raised.
3. Remove any moisture that has entered the interior and trunk, blow out all hidden cavities and areas where anti-corrosion compounds have been applied with compressed air.
4. Drive the car to the anti-corrosion chamber and place it on a lift. Spray the anti-corrosion compound to the areas shown in Figures 8-6, 8-7 and 8-8. Perform the treatment at a temperature of at least plus 15°C.
The article is taken from an online resource: VazBook.ru
5. Lower the car from the lift, clean the front surfaces of the body from dirt with a rag soaked in white spirit.
Table 8-2. Hidden cavities treated with anti-corrosion compounds
Fig. 8-6. Hidden cavities (front view of the body): 1 - upper front cross member; 2 - headlight housings; 3 - lower front cross member; 4 - under the front wing; 5 - external threshold; 6 - internal threshold; 7 - Tailgate pockets
Fig. 8-7. Hidden cavities (rear view of the body): 1 - rear side members; 2 - upper rear crossbar (in the gap with the rear lights removed); 3 - between the rear wheel arches and the sidewalls; 4 - rear side members; 5 - rear floor crossbars; 6 - rear door pillars; 7 - front door pillars; 8 - door pockets
Fig. 8-8. Hidden cavities (view of the body from below): 1 - front side members, 2 - front side members connectors; 3 - middle spars; 4 - middle side member connectors; 5 - rear floor crossbars; 6 - rear side members; 7 - lower rear cross member