View attachment 57037Ok it's now done on the main section. The original question was a bit silly because on the non-slide out section the track can only be placed +/- 5cms because of the aerial and vents... which would put the track section on the slide out onto the main body of the slide out anyway. I didn't do the track on the slide out in the end.
I used
10g s/steel metal screws 15mm
Sikaflex 11FC adhesive (white)
Turps to clean up excess and prep surface
Method
Predrill holes 800mm apart on top and bottom on the track. Offset the top and bottom so that every 400 mm there is a hole either on top or bottom. The 2x holes at either end should be 1mm bigger than screw
Pre-flare the track on the end of the track you will be threading from (pliers are fine using a rag to ensure you don't take paint off)
Position the track on the van ... drill and screw both ends loosely to the van. Then put one in the centre making sure there is no bow in the track.
Pull off track and put on glue
Replace track on van (replace end screws lightly) and start drilling/screwing from the centre out. When you have one (after the centre one) in remove the end screw or loosen it as much as possible. Keep drilling/screwing until you reach the end. The end screw may have moved slightly out of alignment when you reach it just touch up the drilling into the van and screw tight. This method of screwing from the centre out pushes any bow to the sides and fits the track absolutely flush to the van.
I was in a rush to beat the heat to keep the van surface temp down and so made one error (I hate rushing a job). I put a screw in every 200mm instead of every 400. So my result looks a bit over engineered. Using s/steel instead of white accentuates it a bit. So here is the result.