Quick and Easy Sound Deadener Removal - A Pictorial Guide

[mic*]

Stu,

You are the metallurgy wiz here and im not even gonna suggest im in the same freakin plannet of knowledge as you are, but i was trying to be a bit of a simpleton tho.

I know 0deg K is theoretical, and i said that.

I didnt say protons move at low temps. I said as they move more as they approach melting point.

Twould have been better to say; the nuclei (proton & neutrons) of each atom start to move more freely of each other within the lattice as a metal melts, untill actual boiling point where the bonds are broken altogether. Which i guess suggests that boiling point is more indicative of the bond strength in a particular metal than melting point is.

When i said MORE electrons, i meant metallic elements with greater numbers of valance shell electrons. When i said moving FASTER, i meant that the faster the electrons move the more protons that an individual electron "effectively" neutralises the postive charge of as it moves. To my knowledge these things increase ductile strength - being the opposite of brittle.

If thats wrong point me out coz id like to know. If its right, its a simplistic view that im sure you can elaborate on to explain it properly coz you know better.

[tricky]

0deg K

Wrong... Look in your text book and figure out why this is incorrect. Damn, I even have lecturers at uni who talk about 'degrees kelvin'. Makes me wince. It's just 'kelvin'!

Nice tip on removing the stuff, Takai. I think leaving the deadening for 30 years makes it easier too... The stuff in my celica floor pan came off in huge chunks with nothing but a rubber faced hammer and a screwdriver.

[tricky]

And vaporisation isn't the breaking of a bond (generally). A liquid is essentially a more dense gas. To vaporise a liquid at constant pressure, you need to add more energy (heat), which translates to vibrational energy. The equilibrium distance between atoms increases, thus the material becomes less dense.

The more electrons statement is also incorrect. Have a look at a periodic table and have a think about the specific strength of certain metals. You can't draw a correlation there.

I don't mean to burn you, so if I offend, my apologies.

[bathurst-91]

BACK to the topic>

Good stuff Takai. Id heard the rumor that dry ice WAS the go. But never got around to actually trying it. All that said.

I think a combination of ALL methods is best::

Me and Ae86slut found that for the large flat sections such as the centre/rear gbox tunnel and rearseat floorpans and mostly under the driver/passenger seats it comes off in large chunks on its own and it appears dryice definately helps this process even further. (20min?? thats crazy good)

That said.. there are sections (foot pedal area and leading up to the firewall) where using dry ice would be a bitch (just generally using a hammer/chisel is an anoyance). This is where we found the heatgun and paint scraper come in. You virtually heat it for 5sec and then your able to push it off with the scraper. The downside being that it leaves a residue (which is easily cleaned with terps/metho).

And from memory, we put all the sound-deadener from an AE86 in a bag.. and Id say it weighed ATLEAST 5-7kg. Possibly upwards of 10kg.. which doesnt seem like a big deal but grouped with other weight saving measures it all adds up and becomes a definate factor. every 100th/sec counts on a track. Or when rushing home to catch that episode of top-gear

NOTE: An AE86 is an fairly small car, on a sedan type vehicle the weight of sound-deadenning would be increased. Ive heard that in R33's Its in the vascinity of 20kg.

[EldarO]

Ive removed all of the deadening in the back of my van, i did it on a hot day, with a heat gun and a plastic scraper.

it came off in big sections, and the adhesive that was left i got rid of with kerosene and a rag, when all done, i hosed out the back (kinda hard in a normal car) and the result was spotless metal, really easy, and took about an hour and a half.

this is on a 1991 model car, so id expect people with older rides might not have the same results :/

Eldar.O.

[takai]

Yeah, when i weighed my deadening up it came to about 14-15kg, but that was with some aftermarket stuff added. So figure at about 12kg.

[mic*]

And vaporisation isn't the breaking of a bond (generally). A liquid is essentially a more dense gas. To vaporise a liquid at constant pressure, you need to add more energy (heat), which translates to vibrational energy. The equilibrium distance between atoms increases, thus the material becomes less dense.

The more electrons statement is also incorrect. Have a look at a periodic table and have a think about the specific strength of certain metals. You can't draw a correlation there.

I don't mean to burn you, so if I offend, my apologies.

No problem... Its been a number of years since my last chemistry scrub up so i am asking to be corrected where needed. I think the biggest mistake i have made is misleading myself and others somewhat to the effect that there is a consistent correlation between bond strength and other properties of metals.

I did a bit of scrubbing tho coz i didnt think i was that bad. Would you care to respond to the following passages taken from my "Genral Chemisrty" text which is a 1st & 2nd year tertiary study tool.

Metallic bonding in transition elements

Transition metals tend to have particularly high melting points and boiling points. The reason is that they can involve the 3d electrons in the delocalisation as well as the 4s. The more electrons you can involve, the stronger the attractions tend to be.

and...

The metallic bond in molten metals

In a molten metal, the metallic bond is still present, although the ordered structure has been broken down. The metallic bond isn't fully broken until the metal boils. That means that boiling point is actually a better guide to the strength of the metallic bond than melting point is. On melting, the bond is loosened, not broken.

Picking on the SI units was a bit pedantic tho - if you wana be that way its X kelvinS, not X kelvin.

[tricky]

Sorry bro

It's been a while since transition metal chemistry for me too... My major is in organic chemistry, so obviously I've been sniffing to much di-ethyl ether!

Anyways, end OT!

[NME308]

Thread DIG!

I assume this method is being used on the hard factory sound deadening only?

Why I ask is some 15 years ago I enthusiastically plastered 4 litres of bitumenous sound deadener/rust preventative around the floorpan of my HQ. I put down a layer of carpet underlay after that and finally the carpet. All this back in the day when the old girl was still a cruiser.

Now I pulled all the crap back out a couple of years back when the car became a dedicated racer but the underlay has embeded itself into the bitumen layer and only partially came off. The bitumen crap is still 'partially' soft like you can dig into it with a screwdriver or scraper. Hitting it with a rotating wire brush covered me and everything else within several metres in a fine layer of black muck and was apart from painfully slow just about useless as it simply transfers the crap to another part of the car...

Has anyone got any advice on getting this stuff out? I spent an hour this evening with a sharpened paint scraper and have cleaned a patch of about a square foot...

Cheers,
Jason

[thechuckster]

5-10kg of crumbled dry ice, do in sections, cover with layers of paper & cloth when chilling the goop, move dry ice to next section and then take hammer to frozen bit. Repeat until out of ice or all removed. Don't just let it gas/boil off when laying it on a section, always cover it. To do tunnels or surfaces not flat, gaffa-tape sheets of paper to the lowest point, add ice to the pocket you've just formed, tape down upper edges, wait to chill then smash off the frozen stuff as per other sections. Do not start breaking stuff up until you have removed the ice from the area in question.

If rust is an issue in your climate, don't forget that you might have also loosened the underbody protection at the same time.

Always leave a few chunks aside for obligatory 1.25 litre (co2+100ml water) bombs.

[NME308]

Thanks heaps Chuckster!

I was unsure if the method of dry ice would work on the crap I applied myself as opposed to whatever the factory uses...

I shall get into it some time.

Cheers,
Jason

***Frick*** You must spread the reputation around before giving it to thecuckster again...

[Youngy]

I use a heat gun and a plastic scrapper so as not to scar the underlying metal. Comes off like peanut butter.

Then I use a little citrus clean to get rid of the slightly tacky left overs. Works a treat I think.

[thechuckster]

Jason - the underlay fibre will probably help with cleanup as you won't get as many small chunks of solid bitumen. Just make sure you do this on a cool day and give the ice plenty of time to freeze the bitumen crud. When I did the original Soarer's floor, I gave each section ~10 minutes of freezing (a smoke, a coffee and some general milling about doing nothing useful). Is pretty obvious when you've got it right as the stuff just fractures off the metal when you belt it with a mallet/soft-hammer. If it leaves lots of bits stuck to the floor, allow more time and come back to that section later.

I realised I'm probably just repeating Takai's advice in the thread's starting post so kudos should go to him.

Youngy: I wanted to avoid using solvent cleaners as the ice process seems to leave the etch-prime on the metal. I guessed (and this could be way off) that heat might also remove any protective paints (or weaken their bond) and if you missed a bit of goop, the heat allows it to go back into paste form and then re-bond. However, a lot of folks have had success with heat so my concerns may not be valid.