OUMF PRACTICAL PROJECT: Application of Zircoflex, Zircotec, and Epoxy Mastic to the Underside and the exhaust system of the 1968 Riley Kestrel 1300
The problem that we had with the 1968 Riley Kestrel project arose only after painting the interior of the shell and then comprehensively lining the floor, doors, and other panels with a sound-deadening product called Kilmat. This is a butyl rubber backed foil, similar to other products like Dynamat, and is a dense, malleable sheet - very like the bitumen panels found on older cars - that absorbs drumming, and drivetrain and road noise very effectively. Once the lengthy process of cutting it to shape, sticking it down, and thoroughly rolling it into place is completed, it is extremely difficult and very messy to remove. The Kestrel came to us following extensive renovation of the floor, including replacement of the sills and much of the floorpan. We stripped the floor inside back to bare metal and it was very sound prior to painting with Rustbuster epoxy mastic , and top coat in body colour. The underside had been finished with a coating of black ‘schutz’ type underseal which was lavishly applied and did not appear to need further attention - all of which gave us the confidence to apply the Kilmat.
It was at this point that two issues arose in quick succession. The first was that we were kindly donated an LCB manifold and pipework by John Ashley Exhausts, and Joe Ellis at BTB Exhausts generously offered to help by undertaking various modifications in the course of making it fit as snugly along the underside of the car as he could. His artistry resulted in there being very little clearance between the stainless steel silencer boxes and the walls of the tunnel - which looked fantastic, but spelled big trouble for the very meltable Kilmat now glued just above it. The second problem was the chance discovery that the schutz underseal had been applied to bare steel – without any signs of it being primed or painted first. Water had already made its way underneath the schutz in places and surface rust was starting to take
hold. As you can imagine, this disappointing find meant a very serious rethink of how we were to take the project forward.
Inspiration was followed by a call to our great sponsors at Zircotec, as we knew through their support for all previous OUMF practical projects that their ceramic plasma process is the most effective heat management available for exhaust systems. Furthermore, their self-adhesive ceramic Zircoflex sheet reflects heat and shields vulnerable areas in close proximity to the heat source from damage. We felt a combination of these two protective barriers would be a severe test of their performance, but represented the best way to try and solve the problem. On hearing of our predicament, they generously agreed to support us again, and the exhaust system was duly Zircotec coated, and sheets of Zircoflex provided too. At the same time, we were faced with stripping all the underseal from the underside of the Kestrel back to bare metal, but again, this would be extremely difficult without using heat, because of the Kilmat. By chance, we learned that our sponsors at Rustbuster have recently become agents for a novel hand tool called the MBX Bristle Blaster. Similar in looks to an angle grinder, it has a patented revolving belt with long steel bristles which pick off paints, underseals, mastics, etc., Without generating heat or smearing, it quickly strips the coating, removes rust, and leaves a clean bare metal surface which has the appearance of having been grit blasted – and is
therefore a perfect key for protective coatings.
This promised to be exactly the tool we needed, but there was no way this unfunded club could afford one. However, to our delight, Chris at Rustbuster explained our problem and our situation to Cactus Industrial, the
European distributor, and they generously donated one of these MBX machines for us to use.
What a revelation! What would have taken many students days and days with scrapers was
done in just two practical evenings – leaving an ideally prepared surface for sealant and paint,
and no sign of any further welding that we feared might be required! It also convinced
everyone who used it that it should be considered as an essential tool for any restoration,
whether hobby or business.
Chris had sponsored the project with Rustbuster’s unbeatable Epoxy Mastic two pack paint and after all the exposed welds and seams were sealed with Tiger Seal, three coats of grey Epoxy mastic were applied, leaving a smooth, bullet-proof surface for the application of the Zircoflex heat protective sheets. These were cut and tailored to even the tricky parts of the Kestrel, such as the fuel and brake pipe hangers, fuel tank, gear shifter hole, seat mounts, and hand brake cable holes. All were covered accurately to ensure that these parts were fully protected, following every curve of the floor and tunnel, and the Zircoflex was gently heated before application to warm the glue and give it the very best ‘stick’
possible in what will be a very hostile environment. The material was carefully positioned on the surface and pressed down firmly to ensure good contact and adhesion. Rollers were used to smooth out the material and get rid of any wrinkles or air bubbles. We paid extra attention to the exposed edges, making sure that they were flat so that no dirt or water could get behind it. We were impressed at how easily it could be cut and shaped, and we even wrapped the rubber hydrolastic pipes that run from front to back alongside the exhaust in it too.
Finally the exhaust, attractively and professionally coated by Zircotec was fitted which will also
contain and manage the heat generated in the steel system. So all in all, The application of the Zircoflex to the underside of the Kestrel was successful,and the Kestrel is now best protected on every front, and looks superb underneath. The Zircoflex will provide maximum thermal protection to the Kestrel when it finally runs again.
The use of the MBX Bristle Blaster, and the application of Rustbusters Epoxy Mastic and
Zircoflex to the underside of the Kestrel was a careful and precise process that required
attention to detail and accuracy. The use of Zircoflex provides an effective means of thermal
protection for the Kestrel, and the careful application of Epoxy Mastic will ensures that the
Kestrel is fully protected for years to come. The results demonstrate the importance of the
right tools for the job, proper surface preparation, accurate measurement and cutting, and
careful application to ensure that both the paints and the Zircoflex adhere properly and
provides maximum rust and thermal protection.
-Joseph Farley, 1 st year computer science student at Oxford Brookes University