Dynamat

[MrBrad]

Hi,

has anyone used dynamat before? I want to use it in my doors, has anyone done this before? I'm think it needs to be enought to cover the door skin and replace the plastic and black goop on the trim side of the doors.

Brad

[hks_kansei]

Plenty have used dynamat before, and other brands of the same stuff.

It's used in doors quite often, and should do a good job at reducing any door rattles, and help speakers sound nicer.

Usually you would just cover the inside of the door skin, and then if you want would trim sheets of the matting to fit the front skeleton of the door, then put the clear plastic moisture barrier back over the top of it all.


Google how it's done on other cars, it doesnt matter if it's an MX5 or a semi truck, the principal is the same.

[davekmoore]

Not a fun job. The black gloop is horrible to get off and difficult to find proper replacement for. As your car is at least 11 years old there's a chance the plastic will rip. If so, builders viscueen vapour barrier works well, albeit it's a bugger to cut to exactly the right shape and will never be as perfect as the original moulded-to-shape plastic. When you've done the job you'll have slightly less rattles and better sound from your speakers. It'll still have the acoustics of a convertible though, and shutting the doors still won't feel and sound like a Golf. If you must do it, see if you can also get hold of replacement plastic window guides to stop the glass rattling quite so much, and consider getting new door stoppers (delrin(?) to replace the OEM rubber), to stop the door moving about so much.

[Mr Morlock]

Dynamat etc is for sound proofing- the MX5 probably needs a lot of it to be a quieter car! There is no such product as goop. Its Butyl and its actually quite easy to buy. The idea of the plastic membrane on this and just about any other (at least older cars) is that its a moisture and dust barrier between the door trim and the glass and inside door. It therefore is a very useful and cheap solution to waterproofing. What you do find on older cars is the door trims suffering water damage i.e. water marks and warping of the trims.Consider that water runs down the window into a door apart from what is diverted by the trims. There are drains in doors because they are not water tight I replaced plastic membrane on an older car recently and it was an easy job. The membrane on older cars is in my opinion simply a plastic sheet of X thickness which is almost surely die cut- i.e. on a knife die on a platten and run thru a printer type machine. This allows quick repetition cutting and repeatability for the car maker . For the DIY you can buy clear plastic sheet say at a garden supplies- in clear - available cut off a roll. All you do is mark out the holes and shape from the old membrane- easy job.

[KevGoat]

I've used Dynamat on a few cars and it's very effective at absorbing and deadening vibration and sound. Added to my old NA6's doors, it made them feel a lot more solid with a nice "thunk" when closing them, and by putting some on the outer skin behind the speakers they sounded a lot better. If not worried by the extra weight, some added to the rear deck and inside the boot makes a big difference to noise as well.

If using this stuff, just remember that the aluminium foil cover gets very sharp on the edges. Be careful!

[Jeo]

Yep, did the doors, parcel shelf, and parts of the boot. Have used both Dynamat and other brands on different cars over the years - all much of a muchness I found.

Don't stress about the black goop holding the water shield on your door trim. Degreaser to get all the goop off, then make sure you seal up the holes good with the sound deadener. Provided you get some overlap it will act as better water shield than the little piece of plastic ever did.

Where really just depends how far you want to go. You'll notice a difference in doing just the inner door skin, but the sky is the limit really.

[NitroDann]

Dynamat etc is for sound proofing- the MX5 probably needs a lot of it to be a quieter car! There is no such product as goop. Its Butyl and its actually quite easy to buy. The idea of the plastic membrane on this and just about any other (at least older cars) is that its a moisture and dust barrier between the door trim and the glass and inside door. It therefore is a very useful and cheap solution to waterproofing. What you do find on older cars is the door trims suffering water damage i.e. water marks and warping of the trims.Consider that water runs down the window into a door apart from what is diverted by the trims. There are drains in doors because they are not water tight I replaced plastic membrane on an older car recently and it was an easy job. The membrane on older cars is in my opinion simply a plastic sheet of X thickness which is almost surely die cut- i.e. on a knife die on a platten and run thru a printer type machine. This allows quick repetition cutting and repeatability for the car maker . For the DIY you can buy clear plastic sheet say at a garden supplies- in clear - available cut off a roll. All you do is mark out the holes and shape from the old membrane- easy job.

I love reading about manufacturing processes, thanks Morlock.

[Apu]

Morlockopedia

Morkipedia

[BlackLeaf]

MM - thanks for the post. I have to do some work on my doors and had been wondering about the "goop". As a DIY gumby I appreciate posts with a bit of detail.