# Deadening Technique - Vacuum Compressed Foam



## Fus1on (Feb 25, 2011)

The other day I asked for suggestions oh here on how to deaden my q-panels and got back zip, nada, zero feedback ... nothing but crickets chirping. I believe i've come up with original technique on how to do this or at least i've never seen it done before and i'm sharing it. I'm not afraid to use spray foam and could have filled it with multiple applications of it but I just knew there had to be a way to do this and it not be permanent like it would be had I gone with spray foam.

The opening to the q-panel area is like 3" so it's tough to get a big wad of foam in there and placing small pieces in there could be done but time consuming and a pain to do to get it packed in so that it does the job and stays in there .... also it could loosen up over time and move or fall out.









The view of the passenger side q-panel looking forward if you were to look in from the tail lights, notice that it's triangular in shape, wider at the bottom compared to the top ... we will address this problem below.









My idea ... Is the light bulb going on right about now? They sell these bags in a bunch of different sizes, you need to use a bag that is bigger than the foam you stick into it so it can expand, just fold the bag's edges as needed but don't do it in a way that it can't expand. I used foam from WalMart because it was late at night and I wanted to try this out but use whatever you can find locally or on the .net. 









If I was doing this example for my q-panel's triangular shape shown up above, I would cut strips and stack them to fit the q-panels triangular shape, maybe 3 full width layers and 2 more half width layers at the bottom. *Warning: I'm not sure if this could deform your body panels like expandable spray foam will do IF DONE INCORRECTLY so use your best judgement on how much to use, DO NOT over do it. *









Around 10" and it's not even done expanding to full size as you can see from some of the layers.









Vacuum packed ... I did the entire package of foam just to show how effective this technique is. In this example the bag is over filled, I did this just as an example but you don't want to do that, you need to leave space in the bag for the foam to expand.









Sucked down to 2.25" (The angle causes an illusion). I would add a thin (1/8"-1/4") layer of CCF to the top of the bag's vacuum opening, it's cap is hard plastic cap and might vibrate. Once you get the package where you want it, just puncture it with a pencil or similar item and let it expand. Since the foam is enclosed and with only a small puncture, you don't have to worry about water getting into the foam and molding, you could always tape over the hole once the foam has expanded just to be safe. Also make sure you duct tape over any sharp metal edges so you don't puncture the bag and you might need to temporarily pull out any of those plastic wire holders that might hang you up.


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## thewatusi (Feb 1, 2011)

Good idea.


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## Mic10is (Aug 20, 2007)

nice idea

Simpler method--use fiberglass insulation. The yellow or white kind, not PINK.

stuff handfuls at a time in as tightly as possible till you can cram no more. 
You can even shoot some spray glue in the area if you are really paranoid about it moving around--but if you cram it tight enough it isnt going anywhere.

Ive done this in many vehicles with great results. It isnt that time consuming at all.


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## ErinH (Feb 14, 2007)

Mines crammed with polyfill. Cheap and effective.


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## Fus1on (Feb 25, 2011)

The 2 bags were less than $8 (single bag <$5) and the foam around $11, I checked on Polyfill there and it was about the same price as the foam and the foam was going to give me the stiffness I wanted, but could probably shop around and get polyfill cheaper and i'm sure it would work too. This method using the bags affords you the option of un-installing it and no worries about the material getting wet or molding on you. 

I used to do custom home theater and stereo installs and have a huge dislike for fiberglass insulation after crawling around in attics lol


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## Mic10is (Aug 20, 2007)

I dont think polyfill is dense enough and after talking with alot of people over the years, I went with Insulation.
Yellow and white stuff arent itchy like PINK. 

I also did something similar to what youre doing using remnant carpet padding. just folded it over a bunch and crammed it tightly into quarter panels of my wifes civic when it competed.


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## ErinH (Feb 14, 2007)

Meh, the fill works for me. Not moisture and it's been there for two years. To each his own, really. It's just a good way of stiffening the panels using a material that can be stuffed in there. The polyfill, at least to me, works well because it can be stuffed in very tight places.


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## Fus1on (Feb 25, 2011)

I was originally looking to get a memory type pillow/foam pad to put in there, I bet you could flatten one of those damn near flat.


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## Second Skin Rep Jon (Oct 5, 2007)

I think this is a very valid way to fill voids.
A cheaper method that would probably work just as well is to use large ziplock or other similar plastic bags instead. Yes it's not the easiest way to vacuum seal stuff, but it works. 

And chances are when it expands it wont deform body panels considering thin plastic constrains the foam just fine, so 22-20 gauge steel shouldn't be an issue.

This definitely puts the DIY in DIYMA.


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

Some call me "Foamy the Clown" for reason...


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## Aaron'z 2.5RS/WRX (Oct 24, 2007)

(that C/D pillar, wheelwell opening you showed)


















:laugh:


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## The Baron Groog (Mar 15, 2010)

Nice idea, will use it in the future


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## 808Munkyeee (Jun 6, 2011)

good ideal man......


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## MrUntouchab1e (Mar 23, 2011)

GREAT IDEA! I was thinking of stuffing something in that area, but was worried about leaks ( I have a 94 civic lol ) So this should work great!


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## DAT (Oct 8, 2006)

interesting idea. I have used the white and yellow insulation before and polyfill both worked great.


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