Installing Under Bonnet Insulation

Date Posted:8 September 2015 

There a few different approaches to apply our under bonnet insulation pad, depending on your bonnet design will determine your approach.



Do I cut the foam to size then stick it down? This works for flat bonnets with minimal corrugated reinforcement panel. For later model cars we suggest leaving the material over-sized and cutting it on completion. The reason for this is, as the material conforms over all the lumps and bumps it typically becomes shorter in length and what was neatly cut to size ends up short. 


We suggest the following method as a general guide to achieving an expert finish

Step 1. If able remove the bonnet from the vehicle, it will make it much easier to install. If it’s not possible suck it up and do it over a cold engine bay, stretch those hamstrings first!

Step 2. Clean down the underside of you bonnet with a white based sprit such as wax and grease remover. Make sure there is no traces of contaminates such as oil, this will guarantee our self-adhesive backing to stick and last the life time of you vehicle.

Step 3. Start in the middle of the bonnet by removing minimal paper backing, exposing the adhesive.  Do this by simply tearing the paper backing  to expose centre area. Apply liner to the middle of the bonnet and start working towards the outside perimeter.

IMPORTANT:  This is where most people come unstuck! Feed the liner into all concave shapes ensuring you do not stretch the material in length. “ But what the hell do you mean?”  Think of it as vinyl wrapping the surface, if you bridge the material across the valleys and then attempt to force it down by stretching it will shrink back. It’s important that you feed the liner into the valleys not stretching it in length, this way the liner will stay stuck and not shrink back or bridge.

Step 4. As you work your way around the bonnet surface, release more paper backing to expose the adhesive. Apply pressure to the foam by means of an application roller to ensure the pressure sensitive adhesive is effective stuck. You can be creative here and we have seen people use inflatable balls to roll the material down.

Step 5. Once you have effectively stuck the liner to your bonnet now you can trim it to size. Our install kit contains a utility knife with 5 x spare blades,  don’t be shy use them all. It is surprising how blunt they become whilst cutting the foam!


Use a steel rule in the straight areas to achieve a neat edge, be sensitive with your blade pressure not to score down and cut through the paint on your bonnet. A skilled hand should be able to apply just the right amount of pressure and cut through the foam and adhesive layer.

Remove the excess material whilst cutting to see the results and monitor contact with the painted surface.

Step 6. Use xmas tree clips supplied in kit as a secondary fastener if desired. Be mindful not to push them in all the way and crush the liner, unless you like the look of an old Chesterfield couch!

Step 7. If you think you’ve nailed it send us a picture so we can share it’s and boast how good you are!


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