Sound deadening doors and waterproofing after removing plastic sheet (Dizzie?)

[j_s]

Hi guys

To Dizzie etc that have sound deadened their doors.
I will begin shortly on my doorbuild for my 6.5" speakers. I have taken the door card off as I intend to bolt the MDF straight to the inner door skin and then carefully cut the door card around the speaker baffles (square to keep the square lines of the car). Yesterday with all the rain I noticed how much water actually comes in to the door (drips down from window rubbers I guess). First of all I believe their is a waxxy substance on the inside of the door, did you scrape this off before applying the dynamat?
After you finished sound deadening did you get a new plastic sheet and stick it over the gaps in the door to stop any water getting on to the door card?
I'll need to protect the MDF from water so intend to paint it or apply some sort of finish to it so  it doesn't crumble when the water soaks it.

[Dizzie]

I haven't got any membranes in at the mo lol
the door cards don't get wet in mine.
I cleaned the wax and then stuck the Dynamat over it. I removed most of it though with turps before sticking it on.

[Ozz]

Does everyone use dynamat? I looked into that but seemed ridiculously expensive for what it was. I went out and got some bitumin (i think thats what its called!) stuff, cant remember what its meant to be used for but comes in a big roll and doesnt cost much, used it on my last golf and worked a treat! Gonna be doing it to my current golf soon too!

[Dizzie]

Most people yeah.
the cheapest online is www.dynamat.uk.com with free P&P too!

[Ozz]

Still seems a lot to me!! Think I did my whole car for less than a tenner last time and still have some left over!!

[Judderi]

How do you make the bitumen stick? I also found this stuff which im thinking of using. http://www.deadmat.co.uk/

Anyone got any pics?

[Ozz]

The bitumin stuff comes in a big silver roll, and you peel off one side and just stick it on. It can get a bit messy but once I'd got the hang of it I was getting it really neat, and as all mine is behind the door cards it doesnt really matter!!

Tip tho, dont do this in the sun on a really hot day, you can get in a proper mess!!!

[Judderi]

So is it like a roll of sticky tar?

[Ozz]

Kind of yeh, sticky tar in between a silvery sheet and a clear sheet that peels off, rolled up. Does the job fantastically tho, need to do it on my present car too which thankfully is only a 3 door so only half as much work to be done!!

[j_s]

I'll only use Dynamat or Brown bread as I've heard the difference they make.
I wouldn't use bitumen backed stuff due to it melting when it gets really hot, this is what i've heard from guys who used everything under the sun to sound deaden their panels (on talkaudio.co.uk and I value their opinion highly).

Thanks for getting back to me dizzie 
I assume white spirit can be used as well?