Sound insulation

[mitchelln]

I bought a couple of batches of this stuff:
http://www.carinsulation.co.uk/product/ ... -sheets-20
(I am not affiliated in any way!)

I stuck it under both driver and passenger engine covers under the (rather thin) existing sound proofing panel. Right up to where the seals mate. Also applied it all over the dog house and the front seat panel of the footwell. Also inside the panels under the steps and the panel behind the seats.

Fired up the engine and could not believe the difference. Drove it round grinning like an idiot.

In 4th gear there is a barely a hum now. Loudest sound in the cab now (apart from my manical laughter) is wind noise.

Stiff acceleration or hill climbs that used to make me wince are no worse than my car now. Truly amazingly. Best £30 I've spent so far

The remaining hum under revs seems to be mainly from behind the cab. Maybe from the rest of the exhaust system? I suspect when the vinyl floor was put down no sound proofing was installed.

Next step is the door panels, wheel arches, floor and roof panels (probably not total coverage for weight reasons). Let's see how quiet we can make this thing!

I guess the foil layer will provide some level of thermal insulation as well?

[Bob]

Good info, thanks.

[mikeonb4c]

Very interesting find. Does the adhesive look ok for coping with the engine bay temperatures on all models i wonder (the diesel has less clear space in the engine bay than the 2l)

[mitchelln]

It's a very sticky bitumen based pad. I can't see them coming off. I applied them after a run, so the panels were very warm. Moulded onto the contours a treat. They're definitely on mine for good now.

The foil must deflect heat as well. I've noticed the gearshift housing doesn't get warm now.

I had a look see round earlier after the 30 mile trip home and they seem fine. The ones sited on the engine cover above the exhaust were pliable when prodded, but definitely not going anywhere. You've also got the standard fit insulation between them and the engine of course.

Probably worth ringing the company for advice. They are very helpful. If these particular ones aren't suitable I'm sure they'll have some that are. They sell all sorts of amazing stuff.

[mitchelln]

Okay, the spec says they have ”Typical Temperature Stability” up to 100C. If the panel under my seat got to 100C I'd be very worried!
It looks like the fitted panel between them and the engine is some sort of heat resistant woven glass mat, so I think we'll be okay.

I'll keep an eye on them over the next week or so.

They are flame retardant, so at least they won't catch fire

This stuff has caught my eye as well:
http://www.carinsulation.co.uk/product/ ... -cell-foam

[BigPanzer]

Hi,

I did the door panels & rear panels up to window level in the sticky aluminium faced stuff and found that it did have the effect of reducing the panel resonance. It also made the standard speakers sound better, but the most startling effect was the absence of the horrible tinny "sounds just like a VW" clang when closing the doors. More of an expensive sounding "thud" now! Was tempted to do the engine hatches, but decided against it because of the high temperature.

Peter

[mitchelln]

Hi Peter.

That's great. I was hoping that would be the case. Thanks for confirming!

I'm now thinking of a layer of the tiles covered with the close cell foam in the doors and roof panel. Won't need 100% coverage of the tiles then probably.

[BigPanzer]

Hi,

You will find it almost impossible to access parts of the door interiors, but will be able to get enough in there to do the job. I found a stick and a very small diameter paint roller useful, but don't press too hard - the tinwork is very thin! While you have the trim panels off it might be worthwhile squirting some clear waxoyl around AFTER you have stuck all the bitumen in there. Watch out for the plastic sheet, its stuck on with sealant that is horribly sticky and gets everywhere - your clothing, fingernails etc.

Peter

[mikeonb4c]

I found the black mastic that holds the plastic sheet in place is most easily persuaded to let go by using a sharp steak knife or similar and a sawing action through the stretching mastic as you slowly peel the sheet back so that it parts company and you can then peel the plastic sheet back. When you have finished you just press the plastic sheet back in place and the mastic reseals to itself. There's no need for it to be getting anywhere and the last thing you want to do is to cut away the plastic sheet which is an important damp membrane.

[mitchelln]

Thanks for all the replies.

When I took the rear door membrane off, I prised it with a damp wooden spatula. Latex gloves were definitely a good idea. Key thing is not to stretch the plastic sheet. You can then refit quite easily.

I've got to take it off again now to change a bulb in the tailgate (why, oh why Madza?). So I'll fit some of the PeaceMat strips and cover them with 6mm closed cell foam as far as possible whilst I'm at it.

By the way, I've fitted this under the engine covers now:
http://www.carinsulation.co.uk/product/ ... insulation

It's good for 180 degrees. I've stuck it over the PeaceMat pads. All seems worth the effort so far!

Cheaper to buy from their eBay shop by the way.

[pauldeb]

Nice. I need sound insulation also and I think that is a good solution.

[BongoBongo123]

Good find the only thing I would add is... where is the foil potentially reflecting the heat back to, engine bay ? Bongo cabins are hotter
than the average vehicle, great in winter and not so great in summer when you tend to use them most. The Mrs. especially
finds it hot because the exhaust manifold is on the passenger side (on the diesel variant at least).

[mitchelln]

Yes, the area under the seats and the dog house are definitely cooler to the touch now.

I'm moving onto the roof today starting with the front area (simply because it looks easier to get off!). Large Peacemat XS sheets to kill vibration covered with a layer of 3mm (or possibly 6mm) close cell foam. I'll be chucking the old yellow low density factory fit foam sheet - I doubt it's achieving much!

Pictures to follow

Poking around, it seems the company that converted the van didn't fit any sound proofing at all when it was done in 2014 (before I owned it).

I have to confess I'm a little annoyed by this, as I'll now have to strip the interior to do the floor. It would have been half an hours work to stick some down whilst they were at it. The plywood sheeting has been bolted straight onto the bare metal floor. Most of the remaining engine noise is now emanating from the exhaust system running under the floor vibrating the panel. .

Even removing the rear headlining is going to be a bit of a challenge as the cupboards look like they are clamping it. I noticed it's creased around the cupboards, obviously from a previous attempt to get behind it. Not looking forward to that job! Teach me to buy a tin top

A little baffling as the modern materials are pretty cheap and give great results for little weight penalty.

So a bit of a philosophical question here - why go to all the effort of fitting an expensive conversion and then not bother putting any modern sound proofing in?

[mitchelln]

I had to tension my air con belt this morning, so took the opportunity to finally photograph the sound insulation I fitted under the seat engine covers. Pictures being worth a 1000 words and all that

This thin sheet of factory fit glass fibre type material is all the insulation between you and the engine normally:


I've fitted this layer of 10mm close cell foam heat proof GlassMAT cut to the shape of the factory cover (taking care not to obstruct the rubber seal area). The GlassMAT is stuck over the strips of vibration killing Peacemat XS that are applied to the metal cover - they obviously can't be seen now. The factory sheet then fixed on top: