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What are you using for sound deadener in SV Hartops?

Discussion in '"Stock" Alpine' started by sunalp, Oct 1, 2019.

  1. sunalp

    sunalp Gold Level Sponsor

    I have my hard top finally painted, and ready to assemble. I've been looking at
    Dynamat and Eastwoods version of that but want to make sure it will stay on
    the hard top once the headliner has been installed. Looking to see what you guys have used
    when restoring yours.

    Cheers!
    Steve
     
  2. Tim R

    Tim R Silver Level Sponsor

    Hi Steve,

    While it is bare it is a good idea to use some of Eastwood's internal frame coating paint to spray down the rear arms and across the lower rear section of the hardtop. This stuff sprays out of a long extension tube, creeps everywhere and then sets rock hard. The hard top won't go rusty again any time soon!

    Some of the generic sound proofing on E Bay works extremely well for a fraction of the price of the big names. I usually use a solid self adhesive 12" square bitumen sheet in the centre of the hardtop roof and then a self adhesive sound and heat reflecting foam over the top, covering the entire roof area. This combination seems to work really well, catching a wide range of frequencies. Also we always put identification information on a small laminated card inside the hard top above the headlining so that it is possible to prove what the true identity of the vehicle is in case it ever gets stolen.

    Tim R
     

    Attached Files:

    puff4 likes this.
  3. DanR

    DanR Diamond Level Sponsor

    POR 15 is made and used on pilings in salt water.

    Highly recommend it!

    But beware of the Eastwood stuff they sell as a substitute for Dynamat.

    I used Dynamat in my 1st Alpine and thought to go with the Eastwood for My 2nd Alpine (theGreen1).... Used up a box of it and went to some other work then a month or so later discovered the Eastwood was melting through some seams and running at room temperatures. It is a mess to deal with IMO. Never again! Dynamat has never done that for me, so Dynamat is for me!!
     
  4. DanR

    DanR Diamond Level Sponsor

    Steve, Just a bit more on the POR15 and Dynamat. The hardtop on my Blue Boy was restored back in '08. It is a very solid sound proof top for any Alpine. There is not indication of a speck of rust anywhere nor is there any sign of the dynamat coming loose from where it was placed near 11 years ago. I drive it in all kinds of weather and here in sunny South Carolina it does get rather hot at times.

    I also glued in some felt (1/4" thick used for underlay for hardwood floors) that is still in place without any sags.

    All of that makes for a great sound proofing too:)
     
    puff4 likes this.
  5. Gordon Holsinger

    Gordon Holsinger Platinum Level Sponsor

    Good ideas all our hardtops are serial numbered. If you remove the aluminum retainer that holds in the window and weatherstrip on the r/h side there is a number stamped there
     
    puff4 likes this.
  6. sunalp

    sunalp Gold Level Sponsor

    Thanks for your recommendations! I really appreciate it!

    I was looking at Eastwood products and may go with the inner frame coating
    as that sounds really good.

    I was thinking a "dynamat" type of product, just want to make sure that it stays
    in place, as this is upside down from the floors were it usually goes.
    Gordon, didn't know the hard tops were numbered. I'll have to look at mine to see
    where it is.

    Cheers!
    Steve
     
  7. Gordon Holsinger

    Gordon Holsinger Platinum Level Sponsor

    Wally Swift showed me that many years ago RIP uncle Wally
     
  8. Billm

    Billm Platinum Level Sponsor

    I stripped the headliner and the tar like patch off of the inside of my hard top. I plan on using a one foot square piece of Boom mat and 3M automotive Thinsulate insulation. I used the Thinsulate in my Ford Transit van to insulate the roof and walls. 3M 90 spray adhesive is used for the glue. The Thinsulate allows for moisture to pass thru it. Purchased it off of eBay. I have not had much luck with Por 15. I have used Master Series Silver, a bridge coating product or SPI epoxy for coating metal. I also used Eastwood’s Internal frame coating. Tape over all holes before using. I did my x member and the stuff ran out all over the place! Nice work on the headliner Tim!
     
  9. birdfan56

    birdfan56 Platinum Level Sponsor

    I've used dynamat on both my hardtops have have ZERO problems with it.
     
  10. DanR

    DanR Diamond Level Sponsor

    What's the purpose of a "one foot square piece" ?
     
  11. Billm

    Billm Platinum Level Sponsor

    Dan the Boom Mat I bought comes in one foot square pieces. It is about the same size as the original piece of sound deadening I scraped off. While researching insulation for my van, I read some where along the line that one only needs to put sound deadening material on 25% of the surface of the section of sheet metal to keep it from making noise. I put a piece of boom mat in side my doors and they don’t sound tinny when closing them. I scrapped some ashphalt material from the inside of my doors and replaced with the Boom Mat. Bill
     
  12. Warren

    Warren Silver Level Sponsor

    "I read some where along the line that one only needs to put sound deadening material on 25% of the surface of the section of sheet metal to keep it from making noise."

    Hmmmm, maybe that was written by the fellow who decided to put the 25% piece of sound deadening tap paper like stuff under the hard top headliner;)
     
    Billm likes this.
  13. Bill Blue

    Bill Blue Diamond Level Sponsor

    At least read by the guy that decided that 25% was enough. I think that 25% is enough to prevent panel drumming, but not sound transmission. Two totally different issues.

    Bill
     
  14. Paul A

    Paul A Alpine Registry Curator Platinum Level Sponsor

    I have used B Quiet on four different Sunbeams. I used it through the car, including the hardtop. I am well pleased with results. It is similar to Dynamat but not as pricey. I have a leftover roll in my shop that I will sell very reasonably. PM me if interested and I can give you dimensions and price. You can research the product at www.be-quiet.com. P
     
  15. DanR

    DanR Diamond Level Sponsor


    Mr Bill, I believe you provided me an answer to why the foot square piece, Thanks!

    I have 3 late series Hardtops, all of which I found a square piece of tar paper in the center of the roof. Could not figure its purpose until now!

    Sure am glad I finished my Hard Top on Blue Boy with the POR15, Dynamat, LizardSkin and the felt.... it is a cool, quite Alpine.
     
  16. Bill Blue

    Bill Blue Diamond Level Sponsor

    Also keep in mind that in order to have a quiet car, you need to stop sound reverberation inside the car. While the cloth top allows sound to enter the cabin, it also deadens the sound once it penetrates the canvas or otherwise enter the car. Not so with the hardtop. It is acoustically hard and traps any sound that finds its way into the cabin. My top is thick fiberglass, and was very noisy. I lined it with two layers of sound absorbing 3/8" high density foam rubber. Proved to be very effective.

    Bill
     
  17. Tim R

    Tim R Silver Level Sponsor

    When my right hand drive Alpine was in bare metal I welded closed all of the left hand drive holes in the bulkhead that are normally covered with thin rubber grommets. I seam sealed all of the joins in the car body with flexible Tiger sealant and took a long time ensuring that everywhere where wires or cables passed through a panel it was sealed, initially with a grommet then with some butyl rubber to provide a TOTAL seal. I tightly sealed around things like the steering column, speedo cable, oil pressure pipe etc etc. Then I sound/heat proofed all along the gearbox tunnel underneath the car on the outside. Then I sound proofed the entire inside of the car. This included all of the floor, inside the rear wings, boot (trunk) floor, boot lid, inside the bonnet (hood), the inside bulkhead under the front scuttle and inside the doors.
    Inside the hard top I used a square of hard rubber matting then covered that with a sheet of soft rubber faced with aluminium foil that covered the whole inside roof area.
    I used a variety of different densities of sound proof material all over the car to ensure that I caught as many different frequencies as possible. In the footwell I used self adhesive rubber butyl sheets that you melt to the floor with a hair dryer. These are fantastic, they mould to the exact shape of the floor and set hard like a super thick coating of rubber paint. After the soundproofing was in place I sprayed creeping wax over it inside the doors, wings etc. The wax helps to dampen unwanted sounds as well as protecting from rust.
    The end result is a VERY quiet Alpine. There are zero rattles or unwanted noises or smells. The engine bay is totally separated from the cabin as is the boot area.
    I spent a lot of time doing this as we use the car regularly and want it to be a pleasurable experience.

    Tim R
     

    Attached Files:

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  18. Bill Blue

    Bill Blue Diamond Level Sponsor

    How did you isolate the boot area?
    Bill
     
  19. Tim R

    Tim R Silver Level Sponsor

    Hi Bill,
    I did not make a solid barrier between the boot and the cabin if that is what you mean by isolate but I am aware that a number of people had done this. I find that with the soft top folded down, the vinyl cover underneath it and the thick vinyl flaps over the top it is pretty well isolated as it is.. I soundproofed the floor and lid. I also have a wooden under carpet tool box that is lined with felt that absorbs a lot of noise.
     

    Attached Files:

    puff4 likes this.
  20. DanR

    DanR Diamond Level Sponsor

    Just realized my response here is not related to the Hard top, should be in another POST...

    Deleted and will move likewise.
     
    Last edited: Oct 13, 2019 at 6:22 PM

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