Do-it yourself bedliner goop

[mws]

Reading all the mentions of Herculiner and stuff in JJ's painting thread made me realize some of you may be able to help answer a question that's been rattling around in my head:

 

You've probably heard me mention Frankenvan. It's our monster tow van project - an '87 Chevy Van body with all my crazy ideas released on it. It will be used for the next 20 years or so to haul our dirt bikes and travel trailer around. It already has a 450 lb-ft small block chevy, built TH700R4, 1 ton drivetrain, and convenience features galore - power freakin' everything. It's going to have a very high end stereo because, well, I like music. Not loud (although that will be quite easy to achieve with the power on tap!), but very clean and accurate. One of the keys to good sounds is low road noise. So it is being soundproofed to the hilt. 30 some pounds of damping material on has been added to the sheet metal, and lots of insulation, wood, foam, and dense fabric is being added to the walls and roof. Basically, dampen the metal 'til it's dead, then use energy absorbing materials wherever feasible to absorb what gets in.

 

The floor of a van pretty much amounts to an immense steel drumhead - perfect for amplifying road noise!. And there is about 60 square feet of it, so enough acoustic damping mat is $$$. So far, I am planning to lay down 1/2" of plywood, 1/2" of high density carpet padding, and dense carpet.

 

But I was wondering if coating the floor with brush on liner under the plywood would be worth the $150 it would cost? Anybody do the interior of a vehicle? Did it make a noticeable difference by damping the metal resonance? As much as Dynamat type damping mat?

 

TIA!

[Pezzy]

I have a friend who did the inside of his pick up.. I'll ask him if he noticed any difference...

[mws]

About time I got a response... I was getting impatient!

 

Thanks, Pezzy!

[Pezzy]

I know, an entire 4 mins - what is wrong with me!

[Simon]

On, but off topic.....

 

What if you laid the plywood, then drilled a couple of holes, and used some of that mono expanding foam insulation? Should work and only cost you about $10.

 

Just a thought.

[mws]

That's a damm good thought..... hmmm..... acoustically couple the metal to the plywood! That would deaden it something fierce!

 

Would be a whole lot of holes (I'd guess about one every 6 or 12" and would have to do a row between each "rib") but last time I checked, they were cheap!

[deej]

This Stuff is pretty cheap up here in Canada ($30-40), it might be an option for you that is significantly cheaper than $150.00

[jj big shoe]

How about laying some foam rubber under the plywood? I'm not sure if it would be more effective, but definately much easier than squirting insulating foam in two dozen holes, plus easier to remove if you want. You can buy an 1.25" thick foam mattress pad for a California king size bed for $35 or so. I would think a couple of those might keep things quiet.

[GrimGreg]

I removed the carpet and bedlined my 88, I don't think the bedliner does anything for sound deadening in it, though my exhaust leak drowns out any other noises.