Mar 042013

The final task to complete the heat insulation was to install the Koolmat in the cabin area. My main concern had been the ability to be able to bond the underfelt to the silicone side of the Koolmat. A number of adhesives were tested using off cuts of Koolmat and underfelt. Normal silicone sealant was found to be the best product by a considerable margin, which alleviated my fears.

However I’m now leaning towards replacing the underfelt with some 1/4″ Dynaliner when the final trim goes in. The combined thickness of the Dynaliner and Koolmat would be closer to the original bitumen sound insulation with underfelt and so there shouldn’t be clearance issues with the central console. Also the underfelt was destroyed when it was removed during the adhesive tests and so would probably cause more headaches if (when!) the trim needed lifting in future.

The Koolmat instructions suggest starting the installation with the toe box and then work backwards. I decided to do the two panels under the seats first, rather than dive straight in, as I’d not used the ALPHABOND AF178 high temperature contact adhesive before. This would provide a few easy panels to become familiar working with the adhesive before having to assume contortionist positions to install the toe box area.

Holes were cut in the Koolmat for the seat belt mounting and seat runner fittings, the latter would be screwed in place during the gluing to ensure good alignment. However, when the Kootmat panels were trial fitted, they would not lie flat on the floor as the ends of the Huck bolts for the radius arm mounting protruded above the floor pan. To overcome this an off cut of brake piping was used as a punch to cut out suitably size holes in the Koolmat, just about visible in the photo above.

The AF178 contact adhesive needs to be applied to both surfaces and then allowed to become touch dry, when it no longer lifts away when touched. The Koolmat can then be pressed in place. I chose to apply the adhesive using a brush and purchased a small wallpaper roller to apply pressure once in place, which was a good buy.

The contact adhesive certainly lives up to its name as there’s almost no opportunity to reposition the Koolmat once the two surfaces have made contact. As a result, the alignment of the first few panels was acceptable rather than perfect. I was glad I had started with the easier under-seat panels first. I then started adding alignment markers on the Koolmat and bodyshell during the trial fitting which help enormously during the final fitting, when you needed to get it right first time.

Martin Robey replacement floorpans had been fitted during the bodyshell rebuild. These are manufactured to cater for both the non-flat floor Series 1 and 2 cars and therefore have two separate sets of seat runner mounting points. The unused mounting points and floorpan holes were blanked off with short bolts and blanking grommets (9mm & 19mm) respectively to ensure the floor was watertight. I’m assuming the various floorpan holes are to provide drainage should it ever be required.

The instructions on the AF178 tin are conspicuous by their absence. I wanted to take my time and planned to install the Koolmat over several days, and therefore needed to clean the brush. The manufacturer’s ‘technical’ department wasn’t particularly helpful with their suggestion to use ‘a solvent’. I would never have thought of that! When pressed on the type of solvent, they didn’t know, and it took trial and error to determine it needed to be cellulose thinners.

I wasn’t too impressed with the accuracy of pre-cut kit supplied by Koolmat and if I were to do it again would probably purchase a roll of Koolmat and cut it from templates I made myself.

I think the person cutting the kits must have been working from memory and from a car they’d only seen once. I very much doubt they had ever fitted one of their kits!!

The issues that needed to be worked around were:

  • They suggest making incisions at each corner for the piece covering the lowered floorpan area. A much more effective way to mould it to the floorpan and avoid crumpling was to cut out narrow wedges perpendicular to the length of the floorpan as shown in the photo above.
  • They provide a piece to cover the area between the lowered floorpan and the toe box. This piece bears no resemblance to the area it is intended to cover. In the end I cut this into two small pieces for the floor, in front of and behind the lowered floorpan, and two very narrow strips to run along the outer edge.
  • From their installation photos, Koolmat simply cover over the gearbox cover. Therefore the two lower side pieces for the transmission tunnel around the gearbox were far too high and required trimming. They now finish just below the transmission/gearbox cover so the cover could be removed for maintenance.
  • The same transmission pieces overlapped the rear transmission tunnel piece by such an extent, that it was almost pointless fitting the latter.

To be fair to Koolmat, at least they provided a reasonable amount of off cuts to be able to complete the job where gaps existed.

The gluing of the Koolmat to the gearbox cover will wait until the trial fitting of the interior trim, including carpets, just in case there are issues with clearance. Finally a bead of silicone sealant was run along all the joints in the Koolmat.

Jan 202013

Several people had mentioned issues with heat soak due in the footwells due to the proximity of the exhaust. I was interested in avoiding this because I’ve had the same issue in my Elise while on long continental drives. I also remembered an article in one of the Jaguar magazine years back recommending lining the transmission tunnel with a reflective heat covering to reduce the heat coming into the cabin.

My main concern was to rebuild the car and then regret not fitting a reflective heat shield as it would be far harder to change my mind later on. Therefore, as a precautionary measure, I decided it was best to line the transmission tunnel now rather than later – probably overkill but hey ho.

After a little research into reducing exhaust heat, I went for a product from Zircotec which seemed to fit the bill. Their heat shield material comes in sheets and in three different thicknesses. The thinnest sheet should be sufficient as additional heat insulation was also being installed within the cabin. I’m glad I didn’t go for the next thickness up as I subsequently used the middle thickness Zircotec sheet to make a replacement exhaust heat shield. It would have been a little too rigid to mould to the curves of the transmission tunnel.

Paper templates were made to determine the smallest size of sheet needed (it's quite expensive!) Four pieces were required: two for the front footwell area, two for the transmission tunnel around the gearbox

Paper templates were made up to cover the transmission tunnel from the front of the footwells back to where the transmission tunnel becomes enclosed, near the handbrake. The templates could then used to determine the size of Zircotec sheet required and then to cut out once it arrived.

The installation was really helped by making accurate templates to cut out the Zircotec sheets rather than try to re-shape in-situ. I ditched the original paper ones as they were too flimsy. In the end I used the clear sticky-backed plastic sheet that was often used to cover my school books of old.

Next is the installation of the Koolmat cabin insulation ….