3M™ Thinsulate™ Acoustic Insulation SM600L

3M Thinsulate SM600L is a lightweight acoustic and thermal insulation for vehicle interiors. It absorbs airborne sound and slows heat transfer. At a nominal 1.5" thick, it is the thicker of our two Thinsulate weights. The other is SM400L. It is used in vans, van conversions, RVs, skoolies, semi trucks, sleeper cabs, cars, and trucks. It goes on door panels, headliners, pillars, wall panels, instrument panels, floors, and behind plastic panels. Do not use it in engine compartments. It contains no fiberglass.

3M Thinsulate SM600L has an R-value of 5.2 at a nominal 1.5" thick. That works out to about 3.5 per inch. 3M states that Thinsulate gives up to 2x the warmth of traditional insulation at the same thickness.

Either one works for most vehicle insulation jobs. We recommend SM600L where you have room for it, because the extra thickness gives a higher R-value and more sound absorption. SM400L is the thinner choice for tight spots like door panels, pillars, headliners, and behind plastic panels.

Yes, 3M Thinsulate SM600L is hydrophobic, so it resists water absorption. It won't trap condensation or grow mold or mildew.

Yes, we are an official retailer of genuine 3M™ Thinsulate™ Acoustic Insulation. As an approved 3M™ Preferred Converter, we source our SM600L and SM400L directly from 3M. Buying from us guarantees you are getting the real deal, fully backed by 3M's premium thermal and acoustic technology.

We sell SM600L Thinsulate by the linear foot on a roll that is 60" wide, so you order only the length you need. The minimum order quantity is 2 linear feet. If you want a full 300 linear foot roll, call us at 1-800-679-8511 for pricing.

We recommend either P329 Spray Adhesive or 3M 90 to install 3M Thinsulate. Spray the white web side of the Thinsulate and the surface it will bond to. Wait 2-4 minutes for the adhesive to get tacky, then press the Thinsulate in place for several minutes. The full steps are in our Thinsulate install guide.

Spray the adhesive on the white web side of 3M Thinsulate SM600L, and on the surface it will bond to. The black scrim side faces out, toward the vehicle interior.

You can cut SM600L Thinsulate with heavy duty tailor fabric scissors or an electric fabric cutter. An electric fabric cutter is the easiest way to cut large quantities, and it is how we cut it in our warehouses. For straight cuts, use a T-square.

3M Thinsulate SM600L has an NRC of 0.85 when tested to ASTM C423. It absorbs best between 500 and 4000 Hz.

3M Thinsulate SM600L absorbs airborne sound and insulates against heat and cold. It is great for soundproofing wall panels, pillars, door panels, and headliners by absorbing sound inside those cavities. For the best results, install it over a constrained layer damper like Damplifier Pro.

The white web of SM600L is 65% polypropylene and 35% polyester. The black scrim facing is 100% polypropylene.