Design Engineering Floor & Tunnel Shield II 21" x 24" Adhesive Heat and Sound Insulation (3.5 sq. ft.)

It's great at doing its job: it's a good insulator and heat reflector. The adhesive is very aggressive, which is great.

This is a very high quality product but there are things you need to know. First, it is not like working with that rubberized sound deadening material that goes under your carpet. This uses a much thicker aluminum foil over a fiberglass material with a very aggressive adhesive. To give the adhesive its best chance, I started by cleaning my 140k mile floor pan multiple times with mineral spirits, prepped it with scotch bright pads and sand paper, then and gave it a fresh rattle can paint job. I let the paint cure for a week before installing the tunnel shield. It took a 42x48 and 21x48 sheet to do the entire tunnel area from frame rail to frame rail of my '04 Miata. Once the adhesive makes anything more than the lightest contact, its difficult to remove without separating the fiberglass layer so get it right the first time. I created a template with paper bags and masking tape. then cut the template in such a way that it would lay flat. I then layed out the template pieces on the tunnel shield material to plan my cuts. I bought an inexpensive pair of scissors (ASIN B00LSWLAA8) and they made it through the job... I needed to stop periodically to clean the adhesive and fiberglass off them. The cut edges are sharp so wear some gloves! I roughly contoured the tunnel shield to my project BEFORE removing the paper backing. I then carefully positioned my work and gradually removed the paper backing while rolling it in. Work slowly and deliberately. The foil is flexible enough to roll into and around contours but it does have its limits. The roller I used: (ASIN B07X5SV5FD), its a good quality product that should last through many projects. You'll need to seal the edges since water could get into the fiberglass layer. DEI recommends their tape for this purpose but several people had negative things to say about the tape. On the recommendation of another enthusiast, I sealed the edges with RTV. I used loctite grey #5699 ASIN B0794BYCZ2. The pressurized container works in any orientation and made it easy to apply a consistent bead. Mask along your seams so you get straight, tidy edges. Again if you work slowly and deliberately, you can get good results. I worked in the silicone with a finger and wore heavy Venom Steel nitrile gloves to keep the chemicals off/out of my body (ASIN B00Y2OFGMW). Good Luck!

I will re-edit this when I've put some heat to it and seen the miles it holds up to.As far as the product itself though, initial impressions are very good. I had the engine and transmission out of my miata so I could hopefully do this job the right way. There is a video out there of a gentleman putting one of these in with it installed and I can't imagine it would hold up as well. Reasons are numerous but I think the most important being there's no way you could get the tunnel clean enough for proper adhesion. Yes this product is extremely sticky, but like anything adhesive once you clog that surface up with contaminants it's going to lift off the surface and not provide the kind of bond intended.If you've come here, your car is too hot due to tunnel heat most likely. Though I suppose this product would work for lots of places. The aluminum side of this shield resembles the sort of thing I've seen on lots of new oem shields. It's got a cratered surface, it's somewhat reflective in nature. It is fairly stiff as a result, though it bends fairly easily.My application is for a race car (miata) and I've always found the tunnel gets just too hot from exhaust especially during the summer months (I usually don't have carpet either). So hopefully this helps this season. I've attached an image that shows how mine went in. I made sure to thoroughly clean the surface before-hand and started with the driver's side. Working it down and peeling back the adhesive protection layer of the product I was able to get it to finally adhere the way I wanted. Note, I cut my product with tin snips at the folds of the body to help ensure I didn't have any bubbles in where it applied. I don't believe there is any real way to not do this at least on a miata's tunnel. We'll see how well it works but I'm real hopeful it solves or at least helps to mitigate the heat issue. Hoping cutting it the way I did doesn't somehow ruin it's overall effectiveness or make it less long-lived. Will update with how it holds up.[...]

Excellent product! Works well!

Used this as a heat shield and splash guard for a cold air intake on a 2004 Jeep Wrangler. Works amazing! Bent a thin sheet of aluminum then stuck this to it. Solid stick, amazing how well it dissipates heat

I am using this product to protect nylon motorcycle bags sitting in contact with an exposed motorcycle exhaust, so I needed something that could handle direct contact, not just reflected heat. This shield is meeting my needs.The adhesive backing of the shield seems to be adhering well to the neoprene pad on the bag. In testing, the exhaust becomes far too hot to touch, while the neoprene pad and the bag itself become only slightly warm, so I'm confident there will be no meltdown during my upcoming road trip.The sturdy shield material can be cut to size with a heavy-duty pair of scissors, and is flexible enough to shape without distorting at freeway speeds.I would recommend taping the cut edges of the heat shield with aluminum exhaust tape for a little more finished look and keep water from getting into the insulation.

Used on underside of fiberglass Buick GN hood to deflect twin turbo header heat. The adhesive on this material is the stickiest adhesive I have ever worked with, it adherers excellent and works very well.

Put this under my golf cart seat and does reduce heat and some noise.