I see this on the metal surface of cars - what is it? It seems to be a "putty", applied to the car body in specific spots. What is its purpose? Why is it there? I was working on my Prius mod, and stepping on the surface I broke a few pieces. That is under the rear bench but I've seen in it in several sports (for eg under the spare tire if I remember correctly). It's pretty brittle and porous. It's almost like a cookie made of tarmac. Please enlighten me; that's the most ridiculous thing I've seen in a car's construction.
I would guess that it's shot out of a gun by a robot in parallel lines that form a sheet. And that's probably faster than using an actual sheet of material. iPhone ?
I cannot talk to a passenger next to me at a speed over 75-85mph because of noise. So yeah I think prius factory noise insulation is a joke.
Those super-quiet and smooth-riding 70s Cadillacs and Lincolns about got about 200lbs of asphalt squirted into the floor pans. So a Prius should get by with 4oz of blown polyurethane, right?
Ah, I remember my Caddy. Best ride ever. I guess I got use to my car noise, but yea, they are pretty loud. I suppose if one spent some time applying a sound dampener in the car doors, fire wall, underside, and trunk, they could probably quiet it down a bit. I am just too lazy to do it.
Toyota’s term for the material is “laminate coat,” and as @Usle kindly notes, it’s there for dampening. If the laminate coat is damaged or must be removed for body repairs, the Collision Repair Manual (more info) for 2010–2015 Prius cars (BM1290U) shows, in a diagram on page PC-15, the locations and thicknesses of silencer sheet that is to be applied as a substitute. Collision Repair Information Bulletin #43 (PDF) gives Toyota part numbers 58651-22H91 and 58651-22H90 for 1100 × 800 mm sheets in 3 mm and 1.5 mm thicknesses, respectively, and suggests using 3M 051135–08080 trim adhesive. If thicker sections are needed, the replacement material is to be built up in layers.
Has anybody seen a 58651-22H91 in person? What does the stuff actually look like? I'm finding only line drawings.
It's actually there to stiffen the sheet metal and to prevent a phenomenon called "oil canning." Antique oil cans had a flexible sheet metal bottom that made a heavy clicking sound like the old "cricket" noisemaker so famously issued to troops during the D-Day invasion, so that troops could recognize each other to prevent "friendly fire."
I could maybe use that on our central heating furnace's return-air ducts. A few years back I paid a bunch of attention to the woeful state of all the ductwork; one by-product was occasional oil-canning, which I periodically chase down.
I'm assuming... That car manufacturers are going on the reality that 90-95% or more of their eventual owners will never see that putty. It's only those modifiers or few that for whatever reason are stripping down their vehicle to do projects that may see it. For a vast majority? They could own the vehicle for it's lifetime with themselves and maybe never see that material or if they do? Not really care. So I'm assuming in it's application the priority is cheap and fast and easy. (insert inappropriate joke here)
Dynamat extreme did wonders for my tin can 04 Prius. Inner and outer doors, floor and trunk area. Even some on the roof ceiling. Doors close with a solid sound. Course it also helped the audio system too. Posted via the PriusChat mobile app.
