How to Install an Adhesive Heat Shield

An adhesive heat shield only works as long as it stays stuck. Most failures come down to prep: oily metal, a cold panel, or cut edges left open to dirt and water. This guide shows you how to install heat shield sheets so they stay put.

The method below covers the flexible peel-and-stick sheets in the Kool Wrap heat shield range. It works the same on a firewall, floor pan, transmission tunnel, airbox or fuel tank.

Pick the right thickness

0.5mm Gold Reflecta Shield: thin gold reflective foil on fibreglass, in 60 x 60cm sheets. Suits airboxes, intakes and tight spots.
1.5mm silver Aluma Shield: heavy duty aluminium foil on a fibreglass backing rated to 593°C, in 60 x 30cm, 60 x 60cm and 60cm x 1.2m. Suits firewalls, fuel tanks and panels near hot exhaust pipes.
4mm silver light duty: embossed aluminium on a fibreglass and polyester core, in 60 x 50cm and 106 x 60cm. Can be cut and moulded to curves. Suits tunnels, floor pans and body panels.
5mm silver heavy duty: 0.25mm embossed aluminium on a 5mm core, in 60 x 50cm and 100 x 58cm. Kool Wrap recommends it for under-car jobs where the exhaust heats the floor.

Tools and materials

The heat shield sheet in the right thickness and size
Scissors. Use heavy duty scissors for the 4mm and 5mm sheets
Degreaser, clean rags and isopropyl alcohol for the final wipe
Paper or cardboard for a template, plus a marker
A seam roller, or a clean rag wrapped around a block
Aluminium foil tape for sealing cut edges and joins
Gloves and safety glasses
A heat gun or hairdryer for curves, used gently

Step 1: Prep the surface

Let the vehicle cool completely. Adhesive does not bond to hot metal and you cannot work safely near a hot exhaust.
Strip off any old insulation, underlay or failed factory pad. Scrape off what is left of the old adhesive.
Degrease the panel thoroughly. Oil, wax, polish and underbody spray all stop the adhesive bonding.
Wipe it down with isopropyl alcohol and let it dry fully.
Work in mild conditions. A warm, dry panel bonds best. Cold metal and damp air are the two most common reasons a sheet lifts later.

Step 2: Make a template and cut

Make a paper or cardboard template of the area first. It is much cheaper to get the shape wrong in cardboard than in heat shield.
Mark around wiring grommets, brackets, bolt holes, the steering column and anything else that passes through the panel. Cut around them rather than over them.
Transfer the template to the back of the sheet and cut with scissors. Use heavy duty scissors on the 4mm and 5mm sheets.
Test fit the cut piece before you peel anything.

Step 3: Peel and apply

Peel back about 50mm of the release liner at one edge rather than pulling the whole liner off. The adhesive grabs on contact and you do not get a second attempt.
Line up that edge and press it down.
Work across the panel, peeling the liner back as you go and smoothing the sheet down ahead of it. This pushes the air out instead of trapping it.

Step 4: Press and roll

Press the whole sheet down firmly from the centre outwards.
Roll it with a seam roller, paying particular attention to the edges and corners. Edges are where lifting starts.

Step 5: Seal the edges

Run aluminium foil tape along every cut edge and every join between sheets. This keeps water, oil and road grime from working under the sheet, and it keeps the reflective layer continuous.

Curves and moulding

The 4mm sheet can be cut and moulded to shape. Work slowly, warm the sheet gently with a heat gun or hairdryer if it resists, and press it into the curve in stages rather than stretching it in one go. On a tight radius, cut a relief notch and overlap the edges rather than forcing a single piece around it, then tape the join.

Where adhesive shields must not go

Never stick an adhesive heat shield directly onto an exhaust pipe, manifold or turbo housing. Kool Wrap does not publish a temperature rating for the adhesive, so the sheets belong on the panels and parts near the heat, not on the heat source itself.

For the heat source, use one of these instead:

Exhaust heat wrap on the pipe
A turbo blanket on the turbine housing
An embossed semi-rigid heat shield clamped or bracketed near the pipe

Also leave clear of O2 sensors, flex joints, moving linkages and anything that needs to be inspected or disconnected.

Check clearances

Before you call it done, check the panel still does its job. Close the bonnet and the doors. Move the steering, the pedals and the throttle linkage through full travel. On a floor pan, refit the carpet and check it still sits flat. Adhesive sheets add real thickness, and 5mm is enough to foul something that used to clear.

Aftercare

Check the edges after the first few heat cycles and re-tape anything that has lifted.
Keep oil off the sheet. Fix leaks rather than cleaning up after them.
Re-tape a cut edge as soon as you see it opening up, before water gets under it.

Adhesive heat shield FAQs

How do you install an adhesive heat shield?

Degrease and dry the panel, make a cardboard template, cut the sheet with scissors, then peel about 50mm of the liner and work across the panel smoothing as you go. Press from the centre out, roll the edges, and seal every cut edge with aluminium foil tape.

How do you cut heat shield?

With scissors. The 0.5mm and 1.5mm sheets cut with ordinary sharp scissors, and the 4mm and 5mm sheets need heavy duty scissors. Cut from a template rather than freehand, and always cut around grommets and brackets instead of over them.

Will an adhesive heat shield stick to a dirty panel?

No, and this is the most common reason a sheet lifts. Oil, wax, polish and underbody spray all stop the bond. Degrease properly, finish with isopropyl alcohol, and let the panel dry before you peel anything.

Can you put a heat shield straight on an exhaust pipe?

No. Kool Wrap does not publish a temperature rating for the adhesive, so the sheets stay on the panels near the heat. Use exhaust wrap, a turbo blanket or a clamped semi-rigid shield on the pipe itself.

Can you remove and reposition a heat shield sheet?

Not cleanly. The adhesive grabs on contact and pulling a sheet back up usually tears the foil face and leaves adhesive behind. Test fit every piece before you peel the liner.

Need help choosing?

Not sure which thickness suits your job? Call Kool Wrap on 1300 44 33 34 with the part you are shielding and how much clearance you have. Compare every sheet in the heat shield range, or read the best heat shield material for each engine bay part.