I initially planned to keep the KK's roof bolts in place to help secure the Rhino tracks in place. There are 3 issues that became apparent which I felt made this idea unsuitable, firstly under some soft foamy seals there was significant surface and some deeper corrosion where the bolts fix to the roof sheet.
Secondly, the roof gutters are a joining point for various sections of sheet metal (more on this later) so I found that when holding the rear bolts firmly and applying sideways pressure the top layer of sheet metal would flex and lift. In fact at these rear bolts there were fine cracks in the paintwork where the sheet was moving. I recorded a video of this and hope to put a link up. These cracks are an invitation for moisture and corrosion, in fact I've noticed the slightest amount of moisture entering the back of the vehicle so this area needs to be sealed up permanently.
Thirdly, the bolts and whatever nut I would use to try and fix it would have obstructed the track and prevented insertion of the mounting blocks for the actual platform rack feet. I considered my options but they had to go, but the base of the bolts were the ideal height to act as spacers for the adhesive so only the threads needed to be removed.
The corrosion cleaned up quite well with a small wire brush prior to prepping for the thread removal so I did this to all the bolts.
Taped up around the bolts to help control the filings and protect the paintwork, would have preferred to use some duct tape but my roll was in hiding. Hint, make sure you double or even triple layer the tape just in case the cut off wheel gets away from you.
I have a cheap Dremel tool copy but use the Dremel brand assorted cut off kit for all this sort of detailed work, came in handy when trimming the guards for the Uneek bar install too.
I just cut off the thread and ground back what was left of it to ensure there were no raised bumps above the bolt base surface. After removing the tape, vacuuming what was left and cleaning the area with some spirits, I then painted the exposed metal with zinc paint. In hindsight I should have used an enamel type zinc paint as its a bit tougher and stickier than the plain old grey zinc paint (cold gal).
Now for the 18 holes, no I don't play golf. The Rhino tracks have 9 fixing holes each and as I explained previously there's also 3 pairs grouped in each. I assessed that it was best to set the rails so the off centre pair were more to the front as that would be closer to the forward platform feet, also it helped to line up all the holes so to avoid interfering with the cut off bolt bases. Ultimately this resulted in the tracks being positioned 30mm from the rear gutter drop off with the first pair of fixing holes being either side of the first cut off bolt base.
Of course before I started drilling I double checked underneath just so I knew what I was drilling into. Had to take off all the upper plastic interiors trims and pry the boot mouldings aside to get a good look. The roof lining is quite firm but had enough give to allow me to inspect visually or by touch the opposite side of each drilling point.
As you can see the KK roof is multilayered and has a double skin with the lower one having many inspection or weight reduction cut outs. The great thing about this is unless I was drilling recklessly with a very long bit there was no chance of drilling a hole in the roof lining or a curtain airbag.
I proceeded to mark with tape alongside each proposed drilling point so I could inspect inside the roof in that area and could see nothing of concern. What I did notice is that the number of layers of sheet metal that combine at the gutters increased towards the front of the vehicle, so there was no way the Rhino supplied rivets were going to be suitable just on length alone.
Triple measured and marked the first hole at the rear end of the gutter with a self punching centre punch, then drilled this with a 3mm rivet drill bit. (I always use these bits to start holes because they're cheap, double ended, very hard to snap, come in packs of 5 or more and lastly when they're worn out I don't feel bad tossing them.) Then on to the 5mm regular steel drill bit for the 4.8mm rivet.
As soon as this was drilled I cleaned up the gutter and riveted the track down using one of the short Rhino supplied rivets. This gave me a solid reference to mark the remaining 8 holes without fear of poor accuracy. The track had to be held down firmly as there's roughly a 40mm curve across the roof from back to front.
Once all the holes were marked I carefully drilled out the rivet at the end and then drilled the other 8 holes. Access to the underside of the rear most rivet is quite good so I was able to catch the back of the rivet with a magnet I placed behind earlier. The last think I need is to hear a rivet rattling around in the bodywork of my KK.
I like to use a strong magnet near where I'm drilling too as it helps control the metal swarf and helps with the clean up. Wrap it in a rag so you can lift it away and easily discard the shavings from the magnet.
The rearward holes won't take long to drill as there's only about 2 laters of sheet, but this grows to 3, then 4, 5 and finally 6 layers of sheet metal at the forward most hole. It's kinda crazy how much is going on in this roof.
Repeated this whole deal for both sides and cleaned up with some spirits. Out comes the cold gal again to treat all the newly exposed metal. The instructions from Rhino suggest using a cotton tip and I found this worked very well. Make sure to get plenty of zinc paint onto the layers of metal and any exposed metal on the underside of the roof.
This is the left underside rear after drilling and paint.
I let this dry overnight and the next day before prepping the gutters for the adhesive. Essentially the Sikaflex 252 instructions strongly recommend surface preparation to produce the results required, this involves keying the surface and cleaning/priming it with Sika Aktivator 205. This solution is mostly made up of Isopropanol 60% and some other nasties to prime the surface. To key the painted surface Sika recommend using a Scotch-Brite pad to scour the glossy finish. I found this ineffective, honestly I'd be better off using a stick as the sides of my Jeep will testify! So I gently rubbed the bottom of the gutters with a pad of regular steel wool which worked perfectly, just had to clean the dry soap off afterwards.
Vacuum and cleaned again with spirits before using the Sika Aktivator. The 252 adhesive needs to be in place after 10 mins and up to 2 hours after applying the primer so no need to rush this part, I instead prepared the tracks first and primed the surfaces just before pumping the adhesive.
Next part is final prep and fixing down the tracks.