Sorting out lack of floor covering, underlay, NVH and heat insulation (1 Viewer)

[sunrk]

Last week I ordered a set of Tru-Fit vinyl flooring, some resomat, and some premium underlay (not the felt stuff) to commence re-doing the interior floors.

I need to address the lack of NVH + heat insulation on the floor as well as not having any floor covering at all in the front seat area except an old car mat and the original factory-fitted pieces of bitumeous stuff.

I'm going to pull out the front seats, console, etc. to treat surface rusting, etc. on the floor and re-coat with POR-15 white topcoat (maybe over POR 15 itself in any areas that need it) before fitting resomat to the floor with premium underlay over that before new flooring itself.

I'm not having any carpet on the floors - I thought about getting new genuine toyota vinyl flooring but decided to go for Tru-fit's product instead.

I know that in the US the 'fancy' brand is Dynamat, but I'm trying out genuine Aussie product to see how it goes.

This is what the front passenger floor area looks like today with the cheapo car mat I was using removed:

flickr page

I don't know of any practical way to get all that factory-fitted stuff off the floor as it's completely adhered to the metalwork. I'm considering just giving everything (same on the drivers side) a total clean and treat any surface rusting, then apply resomat over the top including the bare metal areas, then use tru-fit's premium non-felt underlay over that, and then vinyl flooring over the underlay.

On the right (drivers) side, I've got the heat from the gearbox/transfer plus the heat from the exhaust coming in through the floor. Don't have working AC (yet) but just reducing heat + NVH noticably would be really nice for the old beast.

Craig.

 

[scottryana]

Getting the old stuff down before you put the sound deadener on top is really your best move. What makes the sound deadened work is the weight and then the metal foil backing that resists distortion/waves.

If you really don't care about weight, just throw the new sound deadener over the top, and then fill in the low spots with a lizard skin type paste, but if you want to do it the most efficiently and without just adding 100+lbs to your truck, use dry ice mixed with isopropyl alcohol to freeze the old factory tarry sound deadener. Listen for it to stop cracking and then hit it with a dead blow hammer and it will come off in big sheets with no mess.

 

[sunrk]

so are you saying that the factory stuff will 'interfere' with NVH damping of the composite resomat/dynamat type material?

Dunno how I'd get dry ice and isopropyl alcohol in suitable quantities here in Oz. One guy I spoke to said he's put resomat down straight over the top of the factory stuff.

My driver's side (RHS) footwell has a damaged floor I need to 'restore' back to proper shape due to a previous owner mistreating it and the floor metal getting bent in. Mostly straight behind the bottom of the brake pedal.

Doesn't affect drivability but for installation of new floor coating/covering it needs to be pushed/hammered back out first. I've had a bit of a go already (but don't have big enough tools yet) and the bitumeous stuff in that area that's all deformed/cracked has been coming off easily.

 

[scottryana]

No you don't have to remove it, but the aftermarket stuff just won't work as well. This stuff has a life and once it dries up and gets all hard it can no longer do it's job well. But if you lay the stock stuff over it you will get some decent dampening, but probably less than if you removed the old stuff and probably at a weight penalty of 35lbs if you leave the old stuff down, so not the end of the world.

 

[Funner]

if you want to do it the most efficiently use dry ice mixed with isopropyl alcohol to freeze the old factory tarry sound deadener. Listen for it to stop cracking and then hit it with a dead blow hammer and it will come off in big sheets with no mess.

 

[sunrk]

I got the front section all done before I relocated for my job about this time last year.

Lots of work involved, but it now has a fully re-painted floor pan under the front seat area and footwells (three layers of hardware store rust-preventive gloss white went in after a tedious cleanup but I left all the bitumenous stuff in place), then applied Resomat, then installed Tru-Fit's premium underlay, then installed new Tru-fit vinyl flooring. That last step was quite fiddly and I didn't get the trimming right in a couple of places but it's worked out to be a good install and the reduction in heat and noise through the front section of the floor is quite noticable.

The rear (under second row seats and footwell area) hasn't been started yet but once our winter is over I'll get stuck into it.

The decision to not fight with the factory-fitted bitumenous sheeting was a smart one and all said and done my 80 is 26 yrs old so it's not like it's an almost-new vehicle with a massive lifespan remaining.

 

[nukegoat]

No you don't have to remove it, but the aftermarket stuff just won't work as well. This stuff has a life and once it dries up and gets all hard it can no longer do it's job well. But if you lay the stock stuff over it you will get some decent dampening, but probably less than if you removed the old stuff and probably at a weight penalty of 35lbs if you leave the old stuff down, so not the end of the world.

Not entirely true. The mass damping stuff works by lowering the resonant frequency and harmonic signatures of vibrating sheet metal but isnt really going to behave much different over time.

For what its worth, everyone installs dynamat or equivalent and claims some placebo effect for noise reduction. Thick jute, lead lined foam, actual sound absorbing material will be more along the lines of what people think they want.

 

[scottryana]

It is absolutely true, what dampens resonance more, something soft and pliable or something hard and crusty?

I also used barium infused foam in the rear half of my truck.

Sound deadening is in, covered from tailgate to firewall with Dynamat Extreme, then from the raised floor of the second seats back to the tailgate I used Second Skin Audio's Mass Loaded Vinyl Barrier (Luxury Liner Pro), its a vinyl pad with a dense foam attached to it. I can tell you that the dog certainly approves! He thinks it is like a dog tempurpedic.

The rest of the day will be spent changing the pre-filter sock on the in tank pump and then pulling off the factory roof rack and all of the plastic cladding. Next week the rest of the stereo install and then off to get the roof and the trim lines line-x'd
View attachment 587282

Not entirely true. The mass damping stuff works by lowering the resonant frequency and harmonic signatures of vibrating sheet metal but isnt really going to behave much different over time.

For what its worth, everyone installs dynamat or equivalent and claims some placebo effect for noise reduction. Thick jute, lead lined foam, actual sound absorbing material will be more along the lines of what people think they want.

 

[nukegoat]

It is absolutely true, what dampens resonance more, something soft and pliable or something hard and crusty?

I also used barium infused foam in the rear half of my truck.

The damping comes from adding mass to reduce resonant frequency. It doesnt matter if it was steel, concrete, or asphalt, so long as its mechanically coupled.

edit: what i'm saying is that the ability for the material to turn vibration into heat is negligible - some elastomers insulate by absorbing noise, but the dynamat / bitumen / tar based deadening is more about reducing resonant frequencies

source: spent way too many years in SPL and SQ competition circles for car audio.

 

[sunrk]

Remember that (at least for our Oz 80's) under the factory-fitted flooring (at least on those that got factory vinyl not carpet like mine) there was a 1/2" layer of underlay padding made from recycling fabric (basically a layer of cotton waste) and everywhere I've pulled it out it's been horrible. Early on I was removing it from anywhere that would get wet because it was just holding water all the time, going mouldy and that's going to make rust happen.

Only area of that stuff not out yet is under the middle section of original flooring still remaining under the second row seats. I have no idea if higher-spec 80's (or your US LX450's) ever got that stuff under the factory carpetting.

But that stuff is probably quite good at low-cost bang-for-buck insulation so from a factory perspective very cheap to use.

 

[Golgo13]

I feel like this debate can go on forever. In production there are several different products used for improving the NV characteristics of the sheet-metal. Typically sound-damping sprayed on the inside floor is heavy and gets baked to a hard, crusty condition. Inside the door panels there are pads added to increase mass/stiffness of the panel to change the resonant frequencies of those panels to frequencies that are not common in the vehicle. These can be hard/still panels OR just heavy. The hard panels are made to be baked(similar to the floor damping) and have a fiberglass face to help improve stiffness. The heavy panels are just big sheets of butyl slapped in after the paint process.
There is also a layer of undercoating on many vehicles now which not only helps with corrosion protection, but also adds mass and softens the blow of small stones and reduces that noise.
Typically, coatings outside the car are soft and heavy, coatings inside are hard and heavy.
There are many other things to be done to reduce the noise, but it costs in terms of added mass and actual dollars to include it. This is why even though they are all basically the same car, an Avalon is quieter than a Camry, and a Lexus ES is quieter than the Avalon. These things are all painstakingly tuned and confirmed to make sure the best bang for the buck is achieved in each class of vehicle.

 

[nukegoat]

I feel like this debate can go on forever. In production there are several different products used for improving the NV characteristics of the sheet-metal. Typically sound-damping sprayed on the inside floor is heavy and gets baked to a hard, crusty condition. Inside the door panels there are pads added to increase mass/stiffness of the panel to change the resonant frequencies of those panels to frequencies that are not common in the vehicle. These can be hard/still panels OR just heavy. The hard panels are made to be baked(similar to the floor damping) and have a fiberglass face to help improve stiffness. The heavy panels are just big sheets of butyl slapped in after the paint process.
There is also a layer of undercoating on many vehicles now which not only helps with corrosion protection, but also adds mass and softens the blow of small stones and reduces that noise.
Typically, coatings outside the car are soft and heavy, coatings inside are hard and heavy.
There are many other things to be done to reduce the noise, but it costs in terms of added mass and actual dollars to include it. This is why even though they are all basically the same car, an Avalon is quieter than a Camry, and a Lexus ES is quieter than the Avalon. These things are all painstakingly tuned and confirmed to make sure the best bang for the buck is achieved in each class of vehicle.

Plus the shape of the vehicle and aero are hugely important. Thick glass, panel dimpling, etc. Hard to engineer solutions that the oems didnt implement from the factory.

 

[MrMikeyG]

So, not to hijack the thread, but in my preliminary explorations in my 94, I found a random cut wire (small 18-22ga brown) and started to peel back carpet to trace.
When I started to disturb the old Jute or whatever the factory carpet pad stuff is it unleashed a smell like a hundred rotten feet.
I happen to have some “memory foam” type residential carpet pad that I salvaged in the garage are there any potential pit falls using a non automotive product in a vehicle?
I don’t remember exactly which product it is, and its up in the rafters but it’s right near 1/2” thick and a light green in color. Its a “solid” product, not the typical many chunks of foam glued together type stuff.
Or, anyone have experience with a good automotive carpet pad?
Thanks.

 

[nukegoat]

So, not to hijack the thread, but in my preliminary explorations in my 94, I found a random cut wire (small 18-22ga brown) and started to peel back carpet to trace.
When I started to disturb the old Jute or whatever the factory carpet pad stuff is it unleashed a smell like a hundred rotten feet.
I happen to have some “memory foam” type residential carpet pad that I salvaged in the garage are there any potential pit falls using a non automotive product in a vehicle?
I don’t remember exactly which product it is, and its up in the rafters but it’s right near 1/2” thick and a light green in color. Its a “solid” product, not the typical many chunks of foam glued together type stuff.
Or, anyone have experience with a good automotive carpet pad?
Thanks.

One might think flammability but the carpet jute toyota used is about as flammable as acetone

 

[MrMikeyG]

My 2 initial worries were water/condensation (my non standard stuff not allowing evaporation), and flammability
Perhaps I’ll get the propane torch going on a scrap. Intentional fire is always fun

 

[MrMikeyG]

What I have is very similar to this:
Shop STAINMASTER 12.7 Millimeters Foam Carpet Padding at Lowes.com

 

[mudgudgeon]

Plus the shape of the vehicle and aero are hugely important. Thick glass, panel dimpling, etc. Hard to engineer solutions that the oems didnt implement from the factory.

I don't know, there's more than a few mud members with dimpled panels

 

[mudgudgeon]

What I have is very similar to this:
Shop STAINMASTER 12.7 Millimeters Foam Carpet Padding at Lowes.com

That looks interesting.
Padding that thick can be just enough to make carpet fit a little off, and fitting up consoles, seats etc a bit of a pain.
Been down a similar road a couple of times now.
Best result for me was with dynamat in rear quarters, underside of roof, in doors to dampen vibrations. And 1/4" foil lined EVA foam roof insulation as an underlay under carpet and above hood lining, and over rear wheel arches, and in quarter panels door skins to block heat and absorb noise.
Tape all joints with foil HVAC tape and insulate as high up the firewall as possible, plus neat fit around gear shifter penetrations in the floor pan.

Doing wheel arches and quarters made a huge difference, roof lining and around gear stick also made a surprising difference. Doors, not so sure.

 

[sunrk]

My 80 doesn't have a sunroof, so the whole roof panel is one big flexible vibrating piece of sheetmetal that at some point may get some attention. But most of the NVH comes through the floor and side, not the roof.

 

[Golgo13]

My 80 doesn't have a sunroof, so the whole roof panel is one big flexible vibrating piece of sheetmetal that at some point may get some attention. But most of the NVH comes through the floor and side, not the roof.

You would actually be surprised how much noise comes through the roof. The ridges in the roof panel help eliminate most of it, but you hit the nail on the head with the fact that you have a steel drum above your head.
Keep in mind the difference in customer expectations between now and 30 years ago. People don't expect to hear the outside world in the comfort of their luxury SUV these days, so there is a lot less in the way of insulation on our trucks.

As far as negative effects of non-automotive stuff in your vehicle, @MrMikeyG I'd hazard to guess it is fine. Newer vehicles have chemicals to self-extinguish in a closed vehicle. But all bets are off if the windows are open. I have actually considered just buying carpet and padding from Prosource and installing it. If I really didn't care about time, I'd tile the floor with a nice, small, hexagonal porcelain tile like an old bathroom or swimming pool. Who cares about weight, right? Just get heavier springs... Fuel economy is already crap. And with tile, you really could just hose that sucker out!