Cab Insulation

A bit of discussion on cab insulation on Rockwiz little Trader project. Probably worth its own thread.

I agree with Cobbadog that the best insulation is the flashing from Bunnings. It is very similar to Dynamat, the industry standard, but about 1/3 the cost. It comes in various widths from 2 inches to 2 feet.

Made of aluminium foil with a sound/heat deadening rubber toffee backing. It moulds beautifully to odd shapes and you can go over humps and bumps with no creases.

It sticks like nothing else on earth so you have to be right the first time before you press it on.Cut out your shape before removing the backing sheet.

I have used it for years on many vehicles both on the floor and cab sides and roof. A big bit inside the doors makes a surprising difference to noise as well.

This 10 metre roll would be enough to do a whole cab.

 

    Dyna Mat or this is fine, cuts the resonance from panels. I coated the floor pan and firewall and where thickness was not a problem laid the Clark Rubber insulation over it. Guess the secondary benefit is rust may fine a hard time getting started under matting is it sticks real well.

Thanks for the info. I have the Louie's cab to do as well.

I have tried many different ways of insulating a cab against heat and noise
Dyna mat works good but is it any better than the Bunnings stuff ? I doubt it it is any better

I have tried 5 layers of carpet and that works surprisingly well for both heat and noise, I would say as good as dyna mat and and dyna liner stuff

By far the most important and beneficial thing that I always seem to miss is sealing the cab up for holes and really good gear stick boots

I have noticed on freezing cold days when in one of my Isuzus that the amount of air that comes thru the door handles when zooming along is enough to give my leg a chill and on a longer trip I find myself searching for rags to put over my legs

If I know I'm gunna be in a cold area like this I chuck my old ugg boots in, very stylish look for sure

But definitely sealing up all the holes is the most important thing for heat and noise

When Victorian railways was building the train "Spirit of Progress" they put a car horn in a box, sounded the horn and walked away until they couldn't hear the horn
They then measured the distance and that was their base line
They then tried different types and different configurations of insulation and each time walked away until they couldn't hear the horn
They did to work out which insulation combination worked best

The gear noise of the Mack when the oil is hot and Im coasting along is of a frequency that has profound effect on my ears, I must seal that gear stick boot up one day

Paul

Paul

You are right about holes.

Many years ago when I was building the marina on Hamilton Island Keith Williams was ripping the almost new Rolls Royce diesels out of his "Ulysses" and replacing them with GM's. He got a sound engineer from some big company in Sydney up to design the noise proofing.

I did not realise how scientific this subject is. There are all sorts of considerations that we would not bother about in a truck cab but he got Keith to put floating engine mounts (almost unheard of in boats) on the GM's to stop hull transfer. Various types of boxing, air gaps, absorbing and reflecting layers resulted in the miracle of silent V-12's. Of course the exhausts went past numerous sound-deadening devices without spoiling the flow.He actually sealed the whole engine room not individual engine covers.The engineer needed ear muffs but outside the door it was no louder than a split-system air conditioner in your loungeroom.

All this means little to us except the fact the engineer told me "All this carry-on is completely useless if there are any holes in the system such as bad gap seals on beautifully insulated engine covers"  The Onan/Cummins generators which would run when the boat was stopped had their own boxes and were so good you had to put your hand on them to check they were running.

We are operating an open system and the best we can do is keep the heat and noise from directly entering the cab from engine, transmission and road noise. So like Paul says, fill every gap and crack and ensure gearstick, steering column, door seals, engine covers, floor access plates and pedal boots are sealed.

In a previous life time I fixed lifts in high rise buildings

The vibration of noise traveling down lift ropes was a issue on heavy gear driven goods lifts with lots of sheaves

If a piece of steel screwed to the beams the hoist motor was on vibrated at all it would be heard in the lift car

Unscrewing the plate and putting silicon on between the mating surfaces stopped this

I'm not sure whether our sense of sound and feel get mixed up a bit but doing this was more the enough to keep the customer from complaining

It really is amazing how easy it is to trick the human mind

A fella on the Mack truck forum reckons a product called "Lizard Skin" is all the go sprayed on

I have never tried this product so can't comment

Can dyna mat be stuck on the underside of the cab if there's not enough clearance inside ?

I'm sure it will stick but wonder if the heat will cause it to sag over time while insulating this house I learnt that dense insulation doesn't work as well as I thought

Shoving more layers in a tight hole doesn't work better, it actually works worse as the air gaps in foam or pink bats etc are essential to slow the travel of noise and heat

As Lang suggested, this a lot more to this than we think there is



Paul

When they changed from V8 Chev petrol engines to 3208 Cats in the timber NSW Polce boats, they had to lay lead backed carpet on the cabin deck so you could hear yourself think. Trouble was the vibration went through the entire hull so sought of defeated the effort.
Must admit they were reliable and a whole lot mor economical.

Another source of noise is that which reflects off the head board and onto the rear window.