pcard

I will be starting the installation of the Dynamat product in my car in a couple of weeks and thought I would begin a thread specific to this so others can reference it easily.

The purpose of my application is twofold: first is noise reduction. I know that riding in a convertible is noisy, but anything to reduction the shake, rattle and roll is good. The second purpose is thermal insulation. I do not have AC and riding around on tarmac that is 100F plus in the summer means a lot of heat is hitting the underbody; I aim to reduce the amount hitting my feet as much as possible.

For starters, I would refer anyone interested to the great thread posted on CO by Lady72nRob71 on his interior restoration.
https://classicoldsmobile.com/forums...html#post49251

Other Links which are worthwhile checking out:
http://www.bmwcarclub.org.ph/forum/s...ead.php?t=4377

Also see some great Youtube videos:
http://www.youtube.com/watch?v=2rwhT...eature=related
http://www.youtube.com/watch?feature...&v=1eu5zYREZro

These, and the others that come up in a search of Dynamat, give you an idea of the different techniques used. Some people work from the centre to the edges, using full pieces first and then filling in the gaps, others start at one side and work inwards, cutting pieces to fit as they go along.
Some people use the roller tool, others just use their hands.
Because of this variety, I plan on trying a few different techniques in the beginning to see which works the best for me.

I have purchased the following:
3 “Dynamat 10455 Xtreme Bulk Pack 9 Sheets”
6 “Dynamat Dynaliner TM Sound Absorber 32X54 X 1/4 Sheet
I know this is probably too much but I did not want to be short, and any left over will be used on other projects. I will let you know exactly how much was used when the car is finished.
I plan on going from cowl to the back side of the rear seat support, inside the doors, kick panels and rear seat quarters as well as their interior faces. I may also apply under the trunk mat, but do not want to jeapardize the cars "originality" in any show judging.

I will be setting up with the following tools:
4 x 2 cutting board
small roller tool
box cutting knife
Exacto cutting knife
Goo Gone cleaner
Heavy duty scissors
Regular scissors
lots of cleaning rags
Magic marker
Roll of masking tape
Straight edge
Roll of heavy duty wrapping paper, 24" for templates
Hiking headlight to see under the dash
Heavy duty latex Gloves
Movers protection pad (to lay on while doing under the dash)
Large bottle of Tylenol Extra Strength

If anyone can think of something else please let me know.

I have a few questions directed to our more experienced members:

What is the best way to protect any floor fastening points, like holes for seat belt bolts, or pass-throughs in the firewall? Do you lay the dynamat first and then cut out around the holes, or do you cut the hole out of the dynamat before laying it down?

The interior of my car has been blasted and the plan is to prime and paint the interior. Laying the Dynamat down will invariably create some small voids between the dyanmat and the floor, and I am concerned about condensation in these voids. Is this an issue? Should I put POR down before painting?

Unfortunately, I will be laying the Dynamat before any wiring is installed. Can the wiring be laid down on top of the Dyamat/Dynaliner, or should I leave channels in the Dyanmat and Dynaliner where the wires and loom will go?

Thanks for your interest and input.
Peter

Lady72nRob71

Haha - "fond" memories...

Here is where i did the dynamat stuff ont he floorpan:
https://classicoldsmobile.com/forums...html#post60544
In the door (DOORnamat):
https://classicoldsmobile.com/forums...tml#post160519

I POR15'ed mine first and let dry a few weeks before matting.
I ran the wiring on top of the dynamat extreme and made channels in the thicker foam mat.

Ditch the latex gloves for light cotton ones. The stickiness of the mat will rip the latex right off.
The little roller thingie was useless as the metal is NOT flat. Cotton gloves glide over the mat easily.
Poke bolts in the holes and cut the mat around them. BEST yet - do this BEFORE POR15ing. POR15 in threads must be removed with a tap.
Substitute wimpy tylenol for hydrocodone 10-325 (if your doc prescribes it of course!!)

oldsguybry

That's good advice on the re-tapping thing , I found out the hard way not to get POR15 on threads

pcard

Thanks Rob!

pcard

Well, I am finally getting around to writing up the notes of the DynaMat installation. I went out to Denver for the last week in March to put this stuff in the car. All the materials had arrived and after reading Rob’s posts on the subject, and watching numerous Tube instructions I estimated that it would take between 12 and 16 hours for the DynaMat and DynaLiner install.
I had ordered 3 packs of DynaMat (9x 32”x18”) and 6 packs of DynaLiner (5x 32”x54”). I bought them via Amazon and got really good deals. I had thought I bought more than enough, but I ended up using every inch of the DynaMat, and all but a little DynaLiner.
Here is a picture of the tools I used, as outlined in my earlier post. Everything was very useful, and the only thing I did not get, but really wished I had, was a rolling tool. However, rather than a small flat one like DynaMat sells, I wanted one that had a small (1 to 1.5 inch diameter) roller ball on it, that would fit in all the indentations on the floor pan. After I was finished pressing that DynaMat down with my thumbs I ended up losing one of my thumb nails, and both thumbs were swollen and very painful. Definitely try to find a roller ball tool.
Here are some photos of my virgin canvas. I started with the wire harness in place, but quickly took that out. I started with the driver front floor and worked back on the floor pan, then went to the passenger side. I found that pressing the pad down in place with the backing still on and then drawing the cutouts with the marker worked pretty well. I would then take the pad out, cut one cutout, fit again, and repeat. My Dad always said “measure twice, cut once” and this is the philosophy I used. But it is time consuming. The first piece took me about 45 minutes to lay down. When you start taking that backing paper off be careful not to get too far ahead of yourself, or you can tear it and leave bits behind, which is a real PITA to try and recover. I learned quickly that once you put this stuff down, even with minimal pressure; do not bother trying to get it back up.
This stuff is pretty thin, but I tried to cutout those places where attachments were made to the floor so that the gooey tar would not get in the threaded bits.

pcard

I then went up the firewall and to the area under the dash and all the flat areas behind the dash support frame itself. I kept track of where the attachment holes on the firewall were and poked them through with the tip of a pen, or sharpened wooden stick, depending on the size. I found later when installing the firewall insulation pad, that the DynaMat did not impeded the insertion of the plastic pad attachment pegs. I also found later when gluing the under-dash insulation pad with 3M spray glue, that the DynaMat formed a good foundation for the glue.

pcard

More Pics under Dash

pcard

I then went on to the doors. I did the inside of the passenger door first. After looking at various videos I did not see any technique that was going to work well with that large internal brace running along the door. So I came up with the plan of cutting the DynaMat into 6 inch wide strips about 22 inches long and inserted them vertically down through the window opening and behind that internal brace. I then would remove the backing starting at the bottom and working my way up to the top. It worked ok, the only problem I had was that I had to be careful not to leave a void behind the brace, since applying tension to the strip from the top tended to bend the strip over the brace and pull the DynaMat away from the door surface. This was aggravated by the fact that it is very hard to get your fingers behind that brace and apply any kind of pressure there. After the first try resulted in lots of cursing, I realized the trick is to not apply too much tension, not try to press the stuff down too much initially. Get it in place first, then go back once the whole inner surface is done with a body working tool called a “spoon” (used to push out sheet metal dents from the inside) and use that to smooth out the mat; this tool fits behind the brace and you have to be careful not to apply too much pressure. I overlapped these strips by about ˝ inch. Leave a good space (1-2 inches) at the bottom and extend up as far as possible to the first curve of the door skin. That way water coming in from the window cannot sit at the top, not is trapped anywhere at the bottom.
The worst thing about working on the inside of the door skin is having to put your arm through those little cutouts on the interior, plus mine had some extra cutouts for a speaker, which had some really nasty jagged edges. I ended up wrapping duct tape from my elbow to my wrist like a gauntlet to protect my arm.
Next came the interior of the door, and played cut and paste. A must learn trick here is not to be too precise in making the cutouts. I was trying to leave a margin around each hole. Waste of time that. A better way is to cover the holes, then cut out with your box cutter leaving an inch or so extra, then bending this extra bit onto the back side of the surface. This is much less time consuming and has the added benefit of making those edges nice and smooth. I did this on the second door and my arms had hardly any cuts. I left many parts of the interior door naked, thinking to go back with little leftover bits at the end.

pcard

Now to the quarters, and rear seat support and then to the floor under the rear seat. I came up with the idea of putting small pieces around those areas where a cutout was needed since it was easy to do, and then on the larger pieces I did not have to be so precise in measuring where the cutouts should go. This speeded things up a bit.
I went up the rear wheel wells, using vertical strips about 2 inches wide to accommodate all the curves, reaching back until I thought the visual limit would be when viewed from the trunk. I do not want any of this visible since I do hope to show the car. I then proceeded into the trunk, doing the area that would be covered by the floor mat.
Throughout, but especially on floor areas, with special attention in the trunk, I made sure that the DynaMat was pressed down firmly (hence losing my thumb nail) so that there were no voids that might retain moisture.

pcard

One thing I learned is that I should have worked from top to bottom. In other words, do the floor last. This is because sitting on the laid DynaMat invites that sticky tar to ooze between the edges and cover your pants. I did put down the cardboard sheets that come in the DynaMat boxes and laid the moving blanket on top of that during the whole process (made a nice comfortable “bed” to sit on and lay on while working under the dash), but I always managed to find some little area of tar to play with. All in all, it was not that dirty of a job, and I never got it on my shoes. I wore latex gloves with cotton gloves on top and that worked very well.
I ended up using every square inch of the DynaMat and while laying it down was supposed to take me about 10 hours (Rob says he did it in a day and a half), it took me a total of 26, not including the setup and organizing tools. I was not rushing, and I may have done areas where you would not normally go, but it takes time.

pcard

I put in the under dash insulation and the firewall pad next. The dash insulation went like a charm. The firewall pad was a real PITA. I do not care how “just like OEM” it is, those bloody little holes you put the plastic pegs through do not line up with the holes in the firewall. Also, I believe the factory must have had a special tool for aligning the pegs and keeping them straight while hammering them home. I kept on putting them in crooked and breaking them while hitting them with the mallet. I used a 2 foot log piece of 2x2 as a drift, allowing me to get a good swing at the suckers. I ended up breaking 5 of them.

pcard

Then it was time to put down the DynaLiner started with the floor under the rear seat and moved forward to the bottom of the firewall pad. I did not do the interior of the doors for fear that the liner material would retain moisture coming from the windows. . This stuff is a lot easier to work with than the mat. It is more flexible and is more forgiving if you need to lift it when making adjustments. I left a channel for the wiring harness and it took me 10 hours to lay the liner down, including covering the convertible board divider and underside of the rear seat support. I also doubled up on the liner under the rear seat and in a strip 14 inches wide down the passenger side of the floor up to firewall pad, and have intentions to do the same on the driver’s side once the wire harness in laid down.

pcard

I have hopes that this will provide a nice quiet ride, and also give me some heat protection from hot summer tarmac. I already notice a big difference when tapping the outside of the doors and the quarters, which now sound like a solid ripe melon rather than an empty tin can.
I hope you enjoy reading this, and for those whom it inspires to try this stuff, I hope it provides some guidance on what to expect.

jslabotsky

Clean install. Way, way, way more Dynamat than you actually need to accomplish what Dynamat was designed to do, but it looks nice.

Lady72nRob71

EXCELLENT job Peter!
But wait - why is the dynamat logo upside down on the trunk divider??


In all, you laid it down much neater and securely than I did. I was short on patience...
I think you had something there about fitting it with the paper on it, then removing it and sticking it.
That is why yours took longer. I bet the results will be better, though maybe not detectable.

Looks easy in writeups. In reality, that stuff is a PITA!

pcard

Rob - you noticed that about the logo on the trunk divider eh? After I put that bit on I said "oh **** - it is the wrong way", but then I thought "no one is going to notice but Rob"
You are right - after a while the incremental benefit will probably be small.
This feeds into the comment by Telecom Guru: I did more than was neccessary, but "in for a penny, in for a pound".
Cheers, Peter

MrRocket

Nice job! I wish I had a "smooth" floor surface to work with on my car...the 73-77 cars had the floor braces above instead of below the floor pans. NOT an easy task to be sure! I found a ballbearing roller at a yard sale the week before I layed down my Fatmat. Worked great! Again, nice work!

Rocketbrian

Excellent documentation. I'll stick it in my "favorites" for when I reach that stage.

OLDSRI

Hi Peter,

Unreal thread here.. Great detail and thank you.

I have a 72 vert with a rather loud, grumbling exhaust that at times produces a dull drone sound that can get to be a little much.. I was thinking of doing dynamat this winter.

How did the dynamat perform for you?

Thanks for any feedback. Buddy

501Paratrooper

Nice work, didn't do my floor yet how many boxes of the Dynaliner did it take?

pcard

501 - I used every bit I bought - see first post.

jag1886

You don't need to go to such extremes, I wire brushed, vacuumed my interior, washed it good let it dry and installed the stuff with my wives pizza roller, it worked perfect. I'd also do the trunk that really helped in my car.

pcard

If you wire brush the floor I would advise putting some sort of sealer on it before the dynamat in order to prevent rust. There will inevitably be some pockets of air under the dynamat and these will be perfect breeding grounds for corrosion.