# Has anyone used plain old butyl tape?



## nubz69 (Aug 27, 2005)

I'm just curious if anyone has tried using plain butyl tape for sound deadening? If so did you go back and attach aluminum foil to it or EPDM yourself?

If no one has done this I am curious why not. Depending on the thickness of the tape it should behave just like butyl based automotive products (ie dynamat extreme, second skin). The thin rolls you can get butyl in would make it easy to get into hard to reach places.

I don't want any talk about asphalt based products, they do not belong in cars!!!!!


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## Fiercetimbo17 (May 17, 2007)

I searched and cannot find anything thicker than 2" in width. Thats a deal killer for me, no way will i ever lay down 100+ sq feet of material with a 2" width


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## Jtejedor (Dec 19, 2008)

Never felt the need to. If I need smaller pieces of deadener I just cut them to fit.


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## nubz69 (Aug 27, 2005)

I have found 4-6" before. The reason I ask is because I used to roof way back when, and we had this stuff laying around all the time. I just didn't realize what it was or that I could have used it for sound deadening.


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## drufuss (Mar 13, 2009)

what is about asphalt that doesnt belong in cars? not trying to object, i just wanna know why you feel this way.


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## Rudeboy (Oct 16, 2005)

You'd definitely want foil on top of it. It won't work without it. Non constrained dampers have a completely different consistency than constrained layer dampers. Without foil you end up with something like the eDead ² series - very poor vibration dampers.

You'd also want it to be at least 60 mils thick. Most of the tapes I've seen are much thinner than that. I guess you could pile up 6 layers, but only if it doesn't have a plastic or aluminum facing. Once you get to the first aluminum interface, additional layers are just damping the previous layer.

The biggest issue would be the butyl itself. Butyl isn't just one thing. There are a few different butyl bases that are mixed with other materials to make them suitable for their intended use. Butyl compounds can be anywhere from very viscous to very elastic in a wide range of densities. It's possible, with experience, to get some idea of how well a particular mixture will work, but more in a relative than an absolute sense. In general terms, more elastic than viscous is what you want. Higher density seems to work better and for whatever reason, high heat tolerance seems to correlate with vibration damping effectiveness. Unfortunately, cheap butyl mixes don't seem to perform very well.

Doesn't mean you might not be on to a good thing, but the only product I've ever found that worked fairly well was designed to protect oil pipelines and actually cost more than what we're paying for sound deadener.


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## talibmohamid (Dec 5, 2008)

never felt like I should or need to


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## sqshoestring (Jun 19, 2007)

I used it all the time. When I started in install they also had a glass shop. But I did not deaden panels with it really, I used window tape for sticking door panels down and quieting dash panels, sealing speakers and baffles to the car, sticking things together....it was magic for sure. Realize before you dis it, that if it melts then all older cars had the front windshields fall out too...that were right in the sun. Window tape is around 3/8 round or so, but now they use urethane on newer cars. I used peel and stick in my current car, but I only did a few areas and it helped but needs some other stuff done yet depending on what I change.

Asphalt can melt in enough heat, very messy.


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## nubz69 (Aug 27, 2005)

You can find butyl tape from 10-50 mills pretty easily and it can be doubled up. Good butyl tape can handle -30 to 160o F unlike asphalt based products. If you don't mind ordering from China you can get this in 50 mil, 20 meter long lengths, and it looks like 2-12" widths for what looks like $2-3 a roll. Granted you have to email them to get a true price and if you are making a small order you will have to pay an extra charge but even then it may end up being pretty cheap. You can always see if they will send you a few samples (look on instructables for great tips for ordering from china)
Butyl Tape
I am sure someone in the US is importing this as well, find them and see if you can buy it from them. You would have to add a foil layer but you could also do something like add a 1/8" EPDM rubber layer instead.

Just food for thought.


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## TREETOP (Feb 11, 2009)

nubz69 said:


> You can find butyl tape from 10-50 mills pretty easily and it can be doubled up. Good butyl tape can handle -30 to 160o F unlike asphalt based products. If you don't mind ordering from China you can get this in 50 mil, 20 meter long lengths, and it looks like 2-12" widths for what looks like $2-3 a roll. Granted you have to email them to get a true price and if you are making a small order you will have to pay an extra charge but even then it may end up being pretty cheap. You can always see if they will send you a few samples (look on instructables for great tips for ordering from china)
> Butyl Tape
> I am sure someone in the US is importing this as well, find them and see if you can buy it from them. You would have to add a foil layer but you could also do something like add a 1/8" EPDM rubber layer instead.
> 
> Just food for thought.





> Minimum Order Quantity: 10000 Square Meter 10,000sqm


Ouch.


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## nubz69 (Aug 27, 2005)

Treetop many Chinese companys will sell you a smaller amount then their minimum order but will end up charging you a fee.

How to Buy from China

Is a great way to learn how to order some amazing products from china. Soon you will be skipping the middle man and buying your Chinese junk (maybe even a Chinese junk) from China.


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## FoxPro5 (Feb 14, 2006)

The butyl tape I've used is hard as a rock at freezing temps. It's not very visco and it's elasticity when cold is nothing like what it is when it's warm (think chewing gum). The challenge, it seems, in making adhesive layers for CLD mat out of butylene compound is to get it to damp over a greater temp range. Plus, like Don just said, it's not pure butyl these guys are using. 

Instead of foil, I'd use a liquid extensional damper. If fact, that's what I've started to do with this similar idea.


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## Rudeboy (Oct 16, 2005)

It's really important to understand the theory behind constrained layer damping before building one. I've tested several butyl formulations alone and they do almost nothing without constraint. The magic happens at the interface between the viscoelastic adhesive and the constraining layer. The ideal constraining layer would be the same as the substrate - if you are trying to damp 22 gauge steel, the theoretical ideal would be a 22 gauge steel constraining layer. Since that isn't practical, foil is used as a reasonable compromise. EDPM rubber wouldn't make a good constraining layer because it is too elastic - it would just return all of the energy it receives. 

Whatever you use, you want it to resist the strain force it receives from the viscoelastic material. This is why applying a liquid applied material on top of a thin foil CLD improves its performance - it reinforces the constraining layer. It really isn't an extensional damper at this point. Anything that increases the foil's rigidity would do the same thing. 

I realize this is sort of obscure stuff, but it's important if you want to make your own vibration damper. Constrained and non-constrained damping work in completely different ways. In a constrained layer system vibrations travel from the substrate into the viscoelastic medium. The ve medium is deformed and the vibrations are converted to heat by strain forces between the ve medium and the constraining layer and the substrate itself. Extensional or non-constrained systems work by resisting deflection of the substrate. These approaches require very different material properties. In practice a CLD uses a much more easily deformable material. Adding a constraining layer to an extensional damper won't do anything and using a CLD adhesive without a constraining layer is just as pointless.

EDPM might make a pretty good barrier based on mass. At .5lb/ft² at 1/8" thick, you'd have to accommodate twice the thickness of MLV to achieve the same mass/area (and many times the thickness of lead). There's a theoretical disadvantage to an elastic barrier but I doubt it would be a problem in reality. This seems like the best potential use for rubber sheeting to me.

When I mentioned the apparent correlation between a butyl compound's heat tolerance and its damping performance, I should have been more specific. I was talking about temperatures in the 400°F+ range. Any product with a butyl base should be able to handle 180°F - although I've seen several that just barely made it.

I guess the most important points are that as useful as butyl is as a chemical compound, it isn't necessarily a good vibration damper and it isn't one at all without a constraining layer. It is inherently more stable than asphalt so it is much less likely to melt or fall off when used in a vehicle. Not melting or falling off is the lowest possible standard and has nothing to do with vibration damping except that nothing will damp vibrations if it doesn't maintain its contact with the substrate. Unfortunately, melting and falling off has been a problem in this market because some sellers haven't cared enough to meet this absurdly low requirement.

A manufacturer sent me a few dozen butyl samples a while ago - different formulas and different thicknesses. All of these materials easily met the 180°F test. All of them had reasonable adhesive bond strengths. Only two had good vibration damping characteristics when a constraining layer was added. That's something like a 5% shot at getting a good ve damping medium if you just specify butyl. 

I'm not suggesting that everything being sold as a butyl vibration damper has been optimized for that purpose. In too many cases "looks like Dynamat Xtreme" is all that matters. Even so, something is going to be at least marginally better than nothing. Many products get great testimonial support because the users mistake isolating adjacent panels with vibration damping - it stopped my rattles - not realizing that a single strip of duct tape would do exactly the same thing.

The way to save money on vibration damping, whether you are making your own or buying it pre-assembled, isn't to compare price/ft². The least expensive product is almost certainly going to be the the one that will do the job with as little material as possible. You're much better off with 25-50% coverage at the center of a panel using an effective product than you are with multiple layers covering everything in sight. Less cost, less work, less weight added and less chance of making future maintenance difficult or impossible. The difference between a poor and a good product can easily be 6-10/1, meaning you would need 6-10 times as much of an inferior material to equal the effectiveness of one that works well. This makes price/ft² a completely meaningless metric. 

Part of the problem when comparing CLDs is the severely diminishing return you get with additional layers. You'll often hear people say that because of the price differential it's cheaper to add multiple layers of an inexpensive material. Here's what the "Bible" on vibration damping says:


Vibration Damping - Ahid D. Nashif said:


> Multiple constrained-layer treatments are often used to increase damping of structural applications. Usually, by increasing the number of layers, more damping can be introduced for a given mode of vibration. However, as a result of many tests on the performance of multiple constrained layers, it has been found that most of the shear deformation occurs in the first damping layer, closest to the structure. In other words, all subsequent layers work mainly to increase the stiffness of the constraining layer to which the first damping layer is subjected.


I'm not trying to discourage the experiment and I'm obviously suggesting a higher standard than is used by all but a few sellers of these materials, but if you are going to do it, you may as well do it right


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## FoxPro5 (Feb 14, 2006)

Rudeboy said:


> The difference between a poor and a good product can easily be 6-10/1, meaning you would need 6-10 times as much of an inferior material to equal the effectiveness of one that works well. This makes price/ft² a completely meaningless metric.


Sort of OT at this point, but I don't care. 

Anyway, please define "poor" and "good" as that can cause a whole host of problems.

Also, is that 6-10 from your own findings or where are you getting that?

Thanks and great insight as always. I can tell all that petrol-based product use over the use hasn't degraded your mental capabilities. Now if we can just get some of these manufacturers to stop eating their products, we'd be sitting a lot better off. I mean they _have _to be eating it.....:surprised:


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## Rudeboy (Oct 16, 2005)

FoxPro5 said:


> Sort of OT at this point, but I don't care.
> 
> Anyway, please define "poor" and "good" as that can cause a whole host of problems.
> 
> ...


Good and poor in terms of vibration damping. I've used a few different testing methods to get to those general ranges. Where I've been able to compare the results to reliable Oberst bar results, they've matched up very well.

By 6-10 times I mean it takes that much material to achieve the same result. The numbers are relative to each other - if it takes a single 6"X6" square of material to attenuate resonance at the RF of 12"x12" steel panel, it took 6-10 6"x6" squares to get to the same place. When you start adding that much stuff to the test panel it starts messing with the resonant frequency so it becomes increasingly difficult to compare apples to apples, but even 10 times as much material doesn't shift the RF out of the audible range.

Asphalt products tend to be more in the 10X as much needed range. Improperly constrained butyl, for example butyl with Mylar, are closer to needing 6X as much material to accomplish similar results.

I have no problem admitting that these numbers are pretty lose. I'd love to see equivalent standards based results - but I'm not going to hold my breath. I'm 100% convinced that asphalt is even less effective than we thought it was and that careful combination of butyl and foil characteristics make the difference between a good flashing tape and a good vibration damper.


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## ibanzil (Jun 29, 2008)

We go through boxes upon boxes of 1" wide butyl each month. I do custom sheet metal...we use it under metal we are going to put a screw through. I used some on my recent build. Works good for spots where 2 things make contact like metal to wood, plastic to plastic. Didn't work to good on just sticking to the door so I used it on the creases inside the door right behind the midbass to round out all the corners.

It's more of a slightly tacky gum...wouldn't reccomend it as straight up deadener but you can use it for a zillion other things. If u want good deadener for a good price (I'm sure you've heard) go second skin. Ide like send in some butyl we use if another showdown happens just to see how it would compare though. Given some better adhesion.


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## ibanzil (Jun 29, 2008)

We go through boxes upon boxes of 1" wide butyl each month. I do custom sheet metal...we use it under metal we are going to put a screw through. I used some on my recent build. Works good for spots where 2 things make contact like metal to wood, plastic to plastic. Didn't work to good on just sticking to the door so I used it on the creases inside the door right behind the midbass to round out all the corners.

It's more of a slightly tacky gum...wouldn't reccomend it as straight up deadener but you can use it for a zillion other things. If u want good deadener for a good price (I'm sure you've heard) go second skin. Ide like send in some butyl we use if another showdown happens just to see how it would compare though. Given some better adhesion.


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