Fact or fiction installing dynamat

[IH2LOSE]

So dynamat it seems is being used in alot of our classic cars to cut down on noise and heat,

I plan on using it on my 62,I had planned to spray 3m heavey duty spray trim adhesive and the glue the mat to it. let me back up.in a C1 behind the sail panels/kick panels is the inside of the front fender.I had planned on installing it on the inside of the fender just spraying the glue on.My local auto parts store(yes I still use one because the counter help and freindley talk is still there) the counter guy explained NOT to use glue on the back side of fiberglass because it would wick into the glass and stain it from the back that would eventually show it self on the outside under the paint,Steel is no problem but glass is pourus and will soak the glue in and stain the glass under the paint,

Fact or fiction has any one heard of this? I did see in person this happen with a thin granite counter top and construction adhisive

 

[JohnZ]

Larry, you don't need any glue - Dynamat comes with adhesive already on one side; you just cut the piece to fit, peel off the plastic liner, press it in place, use a small wallpaper seam roller all over it for good conformity to the surface, and then go over it with a heat gun to activate/cure the adhesive for good.

I lined the entire inside of all my Cobras and Grand Sport with it to deaden any panel "drumming"; here's a pic from one of the magazine articles on one of my Cobras that shows the interior lined with Dynamat.

 

[vette]

Larry, as Jonh Z said you do not need any glue. I used dynamat in my first grand sport coupe. I even did the roof before the headliner went in. With the windows up you almost could not here the sidepipes. As for glue staining the glass. It is possible. With a light color paint I would not take the chance. Back in the late 70's bondo would stain a light colored car. The peroxcide in the red hardner would stain thru after it sat in the sun for awhile. I don't think a light coat of glue would do this but why find out the hard way. I plan on using it again in the 60. Keep up the good work. Brian G.

 

[IH2LOSE]

Thank guys No glue it is.

I thought I was doing this dyna matt thing last (to avoid damaging it) But I need to start getting it installed so I can start lacing my wires,

 

[critchie]

I used 3M spray adhesive when I installed my dash pad. Just had the body painted in lacquer. Dash pad, then the windshield, then the interior. Didn't mask, because I figured I'd just wipe off any overspray. Figured I could get to the overspray glue quick and wipe it off before it dried. Worst case, I figured that if the glue dried that some solvent would allow me to wipe it off. I was careful, but still got a few blobs on the cowl.

Didn't realize that this glue will lift lacquer. Still have the scarred spots on the cowl where the glue blobs fell.
I don't know if the glue would migrate through the fiberglass panel to the out side and lift the paint. But I do know it's not friendly to paint.

 

[vette]

Larry. Your right you should put all the dynamat in first. Then drill any holes or whatever after. All you need is a good heat gun and some gloves so you don't burn your hands. A small roller works well in some areas. I'v got all the body work done on one side of my 60. and I'm starting the other side on Sun. The money pit is getting off to a good start.Brian G.

 

[IH2LOSE]

I used 3M spray adhesive when I installed my dash pad. Just had the body painted in lacquer. Dash pad, then the windshield, then the interior. Didn't mask, because I figured I'd just wipe off any overspray. Figured I could get to the overspray glue quick and wipe it off before it dried. Worst case, I figured that if the glue dried that some solvent would allow me to wipe it off. I was careful, but still got a few blobs on the cowl.

Didn't realize that this glue will lift lacquer. Still have the scarred spots on the cowl where the glue blobs fell.
I don't know if the glue would migrate through the fiberglass panel to the out side and lift the paint. But I do know it's not friendly to paint.

A couple of fellow here are going to be installing there dash pads very soon on C1 cars do you care to give us a quick over veiw of what you did and what you would not do again

 

[IH2LOSE]

Larry. Your right you should put all the dynamat in first. Then drill any holes or whatever after. All you need is a good heat gun and some gloves so you don't burn your hands. A small roller works well in some areas. I'v got all the body work done on one side of my 60. and I'm starting the other side on Sun. The money pit is getting off to a good start.Brian G.

Thanks Brian

Email me your phone number again I want to ask you about some parts I have before I list them on ebay on sunday night.

 

[critchie]

A couple of fellow here are going to be installing there dash pads very soon on C1 cars do you care to give us a quick over veiw of what you did and what you would not do again

1. Check the archives over at the NCRS Technical Board and Corvette Forum. There's been a fair amount of discussion on this over there.

2. Put the glue on with a brush and sparingly at that. Watched an old timer do this at a Corvette resto shop. He used very little glue. Don't forget the speaker grille surround, the defroster outlets, and other stuff hold the pad in place. He used the glue mostly on the underside and at the leading edge by the windshield.

3. Get the pad out of the box and undold it. Drape the pad over the the dash and let it "relax." Gets the folds and the bends out.

4. Don't cut anything and don't glue anything until you dry fit the pad. Then dry fit again to be sure. Finally, dry fit one more time.

5. You used to have to cut padding out from behind the speedometer and the cove insert. Don't know if you have to still do that. Even if you do, you want to keep it to a minimum. It will take 2 people to get the cove insert in.

6. Try to get the leading edge as far under the windshield as possible. Glue it pretty good there too. The pad, over time, will want to retreat back from that edge.

 

[Stan's Customs]

Hey John Z..


Where do you get the foil faced fiber underlayment the article mentioned.

Where do you get dynamat for that matter?

....and last to anyone who has used the dynamat..what do you think about it? Worth the effort on a C1?

Regarding the glue issue for other applications...Spray grade contact adhesive...or standard grade contact adhesive thinned with laquer thinner....either one used sparingly will not leach thru. I've used gallons of it on boats and other fiberglass projects. It might if you gobbed it on...but why would you? A very sparing even coat of contact adhesive sprayed on both surfaces with a $20 cup gun will handle 90 percent of the glue jobs in car and boat projects....and work good. Just wait till both surfaces are dry to the touch, before letting them make contact...hence the name "contact cement". The cup life is amazing too...the gun will still spray after several days and even weeks. We keep a cheap gun with adhesive in it around the shop all the time.....even if it does finally gum up , a cup of laquer thinner will usually get it going again. Needs to be thinned some with laquer thinner when filling the gun......that makes it spray better, xtends cup life, and drys a lot faster to boot. Rule of thumb...if it drys fast...it probably won't leach...thru fabric, foam rubber or vinyl...and especially something as thick as fiberglass..

3M is good stuff but too expensive and no better than contact for upholstery type chores in my opinion.

Just my 2 cents...Stan M.

 

[JohnZ]

Hey John Z..


Where do you get the foil faced fiber underlayment the article mentioned.

Stan M.

Stan, I use Thermo-Tec #14001, foil-faced woven ceramic cloth as a heat barrier; incredible stuff - I also used it on the entire engine side of the firewall, footboxes and trans tunnel of my Cobras, before covering those areas entirely with fabricated .062" aluminum panels. Engine and header heat POURS through those areas into the cockpit in a Cobra, but not in any that I built. I also used it to cover the lower half of the engine side of the firewall and the entire trans tunnel in my tube-frame Grand Sport; super-effective reflective heat barrier. Here's a pic of the Cobra application; Thermo-Tec application on the left, after aluminum panel installation on the right.

 

[Stan's Customs]

Thanks John...


I imagine these vettes have heat issues too. That looks real good on the Cobra. Is Thermo Tec similar to Dynamat....I'm not familar with either one ...at least by that name. I'm assuming it is an insulator too...?? Who is a supplier...

Texas is hot..so I have wondering what should be done to combat that situation on my project.

Thanks...Stan

 

[JohnZ]

The original Dynamat was developed as a panel-deadener, and was used by high-end stereo installation shops to deaden panel drumming in cars; it's very dense (and heavy) for its thickness. I think they have newer products now that also have foil backing to double as heat barriers. Thermo-Tec was originally developed by NASA, and is a ceramic wool fabric with a heavy foil layer on one side (the foil side goes toward the heat source); incredibly effective reflective heat barrier, and not cheap. Summit sells it, and if you Google "Thermo-Tec" you'll find other sources as well.

 

[Stan's Customs]

Roger that.. JohnZ and thanks...

 

[Gasman]

Here is another one i was looking at.

http://www.b-quiet.com/brownbread.html

 

[fatboy34]

And yet another
http://www.koolmat.com/main.htm