Expandable Foam Vs Dynaspray

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=77689
Printed Date: April 26, 2024 at 7:59 PM

Topic: Expandable Foam Vs Dynaspray

Posted By: italian_virus
Subject: Expandable Foam Vs Dynaspray
Date Posted: May 12, 2006 at 4:15 PM

Hello everyone,

I had a question regarding the Expandable Foam (its the stuff that the plumbers, carpenters use) Vs Dynaspray. I was reading some of the previous posts by members, and they were saying that the Expandable Foam is just as good as the Dynaspray. I know the expandable foams do not have the proper "characteristics" as the Dynaspray, (sound dampening capabilities). Because i am Dynamatting my entire car, i was just curious to know which one would be better to use? and should i spray the trunk lid before applying the Dynamat. Cause previous posts have stated to spray before to decrease the chance of trunk vibration. I just do not want to apply Dynamat and later on find out that i should have sprayed. If any one can help me out it would be greatly apprecaited

Thanks.

Replies:

Posted By: prophesybh
Date Posted: May 13, 2006 at 10:07 PM

the expanding foam is only good if your trying to fill in empty space. I used it in my trunk lid, inside of the bracing, that was just an extra step that i took thats you don't have to. the dynaspray or dynamat is what you use to acually help "limit" rattling.

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Don't Ask Questions When You Already Know The Answer!!!

Posted By: kirktcashalini
Date Posted: May 13, 2006 at 11:38 PM

Mannn I tell you that spray doodie, well the commercial stuff is SERIOUS.. its going to be a mess unless youve done it a ton before... Ive sprayed some of this stuff in walls and cielings for construction, and I will say i would never want anyone spraying this in my car... a half inch of it will expand more than you would imagine, and your going to just be butchering it all off and probly be a bigger project than you think. I can see where it would be good for filling space. But you wouldnt want to do it on big flat areas. I dont think anyway.

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99 Blazer LT. Yellow Top. Big 3. Infinity Kappa Speakers All Around. Jensen CD/DVD flip out. 2 Infinity Kappa Perfect 12DVQs powered by a Alpine PDX600.1 (in one custom box, building a FG box)

Posted By: mustangfoo
Date Posted: May 14, 2006 at 3:12 AM

I have seen this done before, they sprayed the expandable foam in the crevices of a trunk lid in a Honda Accord. But like Kirkcashalini says, be very very VERY I cant express it enough, with the spray. Try some tests first on a piece of cardboard to see the difference in how much you spray and how much it expands. It will help from vibration quite a bit as the foam will absord vibration, and with the added dynamat will increase the productivity of the foam.

Posted By: kfr01
Date Posted: May 14, 2006 at 8:48 AM

Just a note here.

Dynaspray - one of its primary functions is to hug panels and add mass to hard to reach places. Mass adding is the single best way to reduce resonance frequencies.

Expandable Foam - on the other hand, is very light. There probably isn't much mass adding going on. Will it help ringing, rattles, and road noise? Sure. Will it deaden a panel like Dynamat or Dynaspray? No.

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New Project: 2003 Pathfinder

Posted By: italian_virus
Date Posted: May 14, 2006 at 10:23 AM

Yah i figured,

cause i was going to use the expandable foam first let that dry then Dynamat on top so im guessin it would almost be the same as Dynaspray, cause ur going to get the added weight from the dynamat? so relatively speaking that should do the job?

Posted By: stevdart
Date Posted: May 14, 2006 at 10:49 AM

Apply the Dynamat or Dynaspray directly to the sheet metal.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: italian_virus
Date Posted: May 14, 2006 at 11:06 AM

thanks stevdart i knew that posted_image

i was just curious to know if the expandable foam & dynamat will have the same added weight as the dynaspray and dynamat