[Taz Pengra]

There is a very thick rubber building material adhesive that I purchased at Home Depot before, it's like 1/16" inch or thicker. No foil on it. I think it's 8 or 10 inches wide by 20-25' long. I used it on my old Corvair with pretty good success. Some people said it loses adhesion on vertical surfaces when it gets hot, but that never happened to me. The density and weight of it makes for a pretty good sound barrier.

 

[sschefer]

There is a very thick rubber building material adhesive that I purchased at Home Depot before, it's like 1/16" inch or thicker. No foil on it. I think it's 8 or 10 inches wide by 20-25' long. I used it on my old Corvair with pretty good success. Some people said it loses adhesion on vertical surfaces when it gets hot, but that never happened to me. The density and weight of it makes for a pretty good sound barrier.

That's Bituthene. It's basically rubberized asphalt cross laminated with HDPE. It's intended for use on wood, masonry or concrete.

 

[Unchained_Souls]

Check out this video a guy did with bituthene.

Sent from my VS985 4G using Tapatalk

 

[Hein]

That van will smell like asphalt when it gets warm. If he had installed Thinsulate(TM) SM600L first then he would be done with thermal insulation and noise reduction. No need for all that extra effort/cost/weight.

 

[klp]

Yeah but the $200 he saved will buy a lot of air fresheners!

 

[BabyBuffy]

Yeah but the $200 he saved will buy a lot of air fresheners!

Do you mean those air stinkifiers shaped like trees? How will he get the smell of them out?

 

[Emdaughtry]

I started some acoustic treatment on my cargo van that will be used for contracting work. Main reason is to keep road noise down to make talking on the phone easy while traveling between appointments. So far the cargo floor has been covered with 80mil butyl under the rubber mat and the slider door, rear doors and walls have been treated with 80mil butyl and then covered with Bonded Logic UltraLiner (2" cotton insulation).

Did you find large / long sheets of the 80 mil butyl someplace? I can only find 30" x 20" sheets or is that what you put down too?

Eric

 

[DrJean]

I went ahead and covered the skin under the wheel well covers and also over the top of the covers. (with Prodex).

 

[keweenawbee]

Did that too. I know it might look like a work van, but there's nothing like the Sortimo (mind you w/door) to isolate you from your 18 piece orchestra back there.

 

[plumbstar]

3M Sound Deadener

Has anyone tried 3M Sound Deadener (08840)? Seems like a good alternative at a fraction of the Dynamat price.

 

[Hein]

Has anyone tried 3M Sound Deadener (08840)? Seems like a good alternative at a fraction of the Dynamat price.

Thinsulate(TM) SM600L is an acoustic absorber/blocker, thermal insulator and also controls panel resonance. There is no need for Dynamat or 3M Sound Deadener 08840.

 

[surly Bill]

The 08840 varies in price by dealer; from 3M it's $2.20 sqft, from Amazon it's $10 sqft (unless they listed it wrong, says "1 pad").

 

[Travlin]

At this point I don't have a dog in this hunt and am exploring all the possibilities and their use in my intended application. I want to find something that will both reduce thermal transfer and provide a modicum of acoustic damping in the rather tight space I have to work with.

Looking at Prodex on the "insulation4less" website it clearly states that in order to achieve the high R-value listed for the product it requires an air space on both sides of the product.

"FACT #5:Prodex Total insulation 5mm has an R-value of 16. The R-value was measured under the real-world parameters of:
24-inch on center 2" x 6" wood assembly. Roof application. Test Method ASTM 1116. Airspace of 2.64 inch on each side of product. Heat flow direction down."


This business of putting 2.5" of airspace on both sides of Prodex to achieve stated R-values seems like quite a hassle when it comes to van installation. Perhaps it is possible by cutting foam blocks that are glued to the Prodex and then to the skin of the van, then again between the inside of the Prodex and whatever covering will be covering the walls and ceiling. Then using some tape to place the edges at just the right place. It could be rather time consuming if one expects to achieve the full effect. Still, it is unlikely to get the same airspace as used in the test above, and less airspace may likely equate to a lower R.

Reflectix publishes that their product only provides R-1 when applied directly to a surface. On the "Fact vs. Fiction" page of the Prodex vendor's site no mention is made of the R value of Prodex when applied directly to a surface the way most probably would on the skin of a van. It does list a 19dba "contact noise" reduction on that page, which is a significant amount of acoustic damping.

Prodex does seem as if it would be better suited to insulation and sound damping than Reflectix. Mostly because of the Poly filler instead of bubble-wrap. Still, both products require air space on both sides to get maximum thermal insulation benefit. How either fares for damping sound could be quite good, but we're dealing with a limited space where the goal is to do both thermal and acoustic insulation.

I'm leaning toward Thinsulate for the walls and ceiling as I have owned coats and sleeping bags with the stuff and it is quite amazing the way it prevents body heat transfer. The fact that the SM600L is listed in 3M's Acoustic line and not as insulation probably is an indicator of the purpose this product was designed for. I've not known 3M to be anything but good at what they do based on the products I've used. They aren't known for selling purpose-designed products that don't work as advertised, the way some companies often come to be known for.

As for the floor, I'm wanting to avoid adding significant thickness in a MR van so will investigate closed cell foam that is sold for sound damping, in 3/8" or 1/2" thickness, with maybe 3/8" to 1/2" plywood over it, and something attractive and durable on top. This should also meet the light duty needs of Texas camping with the occasional trip to higher elevations in the Summer.

In the mean time I'll keep reading, looking for the magic combination that will fit my purpose best.

 

[SecondSkinUSA]

At Second Skin we offer many different products for many different applications and van styles. We out fit about 10 transit van customers a week. Give us a call or email and we will be glad to help you get the best American made sound deadening for your project. 17 years of high quality American made sound and heat insulation manufacturing with customer reviews all over the net. Website is in signature. Have a great day.

Team Second Skin

 

[SecondSkinUSA]

Check out this video a guy did with bituthene.


Sent from my VS985 4G using Tapatalk

You should never use roofing material inside of a closed off and sealed vehicle, especially if you plan on living inside of this thing as an RV. It is not good for your health to be breathing in those asphalt and tar toxic out gassing vapors. Not to mention, that stuff will melt in hot conditions. Insist on high quality American made butyl rubber for all your sound deadening needs.

 

[Salire]

If you look at the 3M sound curve for Thinsulate sm600l, the effectiveness falls off rapidly below about 600hz. I suspect well placed vibration dampening stick-ons can help a lot with low frequencies. I don't think low frequency treatment in addition to Thinsulate would be an unnecessary addition.

 

[Eiko]

If you look at the 3M sound curve for Thinsulate sm600l, the effectiveness falls off rapidly below about 600hz. I suspect well placed vibration dampening stick-ons can help a lot with low frequencies. I don't think low frequency treatment in addition to Thinsulate would be an unnecessary addition.

From what I believe I understand after reading on this, the butyl mats (Dynamat, Noico, Fatmat) stop the panel resonance. For radiated sound waves, Thinsulate handles the mid/higher frequencies and MLV (mass loaded vinyl) is needed to block the lower frequences. You need all three for maximum noise reduction. MLV is a pain because kinda like the Prodex, it has to hang freely, not applied to a surface, so can't be used on ceilings. I think Hein's point is probably the best from a practical aspect. You can't get perfection in the van and there is a significant dropoff in return on investment so just throwing in the Thinsulate is probably the best solution for practical results and value.

People like me who are not engineers and don't fully understand a topic tend to throw in everything under the "more must be better" theory. I definitely have that tendency, afraid that just thinsulate isn't good enough.

 

[BabyBuffy]

I used MLV for the floor. My understanding is that it works best if isolated from the surface intended to be dampened. Somewhere I read that could be accomplished (or at least the situation improved) by interposing a layer of foam. I used 1/8" polyethylene as a top and bottom layer over/under the MLV before laying the plywood.

 

[Eka]

From what I believe I understand after reading on this, the butyl mats (Dynamat, Noico, Fatmat) stop the panel resonance.

Actually all they do is lower the frequency the panel likes to vibrate at.

System ate my long post.

For walls I'm looking at doing: Order listed is outside to inside.

• CLD strips
• CLD strips
• CLD strips
• VHB Tape
• Foil faced MLV, 1lbs/sq ft, foil face to sheet metal skin
• HH-66 PVC Vinyl Cement
• EDPM elastomeric closed cell foam, 2", R4.1 per inch.
• HH-66 PVC Vinyl Cement
• Foil faced MLV, 1lbs/sq ft, foil face to inside
• fill rest of wall cavity with thinsulate

Multiple runs of the three layer strips of CLD will be crossing the middle of panels, as well as going around the borders. Between them and the VHB tape, they hold the reflective layer and MLV away from the sheet metal skin. Also every pound of MLV and EDPM needs so many square inches of VHB tape to hold it in place. Plus I should use more square inches because of the vehicle vibration.

Both the MLV and EDPM are water vapor barriers.

Trying for absolute sound deadening is impossible. The windows will let in lots of sound. I'm not sure I'd have bothered with the inner layer of MLV if it wasn't for the foil face reflecting in.

Audioseal Sound Barrier MLV, 1/8" or 1/4" thick, 1 lbs/sq ft or 2 lbs/sq ft. 1 lbs/sq ft can also be purchased with foil facing, or fabric support. Comes in rolls up to 60' long in 48" and 54" widths.

Aerocel EPDM Elastomeric Sheet Insulation. Is a flexible closed cell and lightweight elastomeric material with a smooth and durable surface, designed for insulating large pipes, tanks, vessels, air ducts, inside air handling panels and more. It is available in 3' x 4' flat sheets and rolls in thicknesses of 1/8", 1/4", 3/8", 1/2", 5/8", 3/4", 1", 1-1/4", 1-1⁄2" and 2".

I don't have the VHB tape selected yet, but I know 3M has ones that will handle the very high skin temps of vehicles in the hot sum.

I'm thinking of filling the hard to get to voids with low expansion foam that remains flexible. I need to find ones that may work. Great Stuff hardens stiff, so it won't work.

 

[orton]

Aerocel EPDM Elastomeric Sheet Insulation. Is a flexible closed cell and lightweight elastomeric material with a smooth and durable surface, designed for insulating large pipes, tanks, vessels, air ducts, inside air handling panels and more. It is available in 3' x 4' flat sheets and rolls in thicknesses of 1/8", 1/4", 3/8", 1/2", 5/8", 3/4", 1", 1-1/4", 1-1⁄2" and 2".

The Aerocel insulation was easy to use. My installation in deep pockets above and below window indents was simpler:

Two coats of insulation paint. Value?
Two layers of 1" Aerocel
layer of Reflectix
about 2" of air gap
layer of 1/8" closed cell foam (glued to plywood)
7/32" plywood wall covering

Pleased with the results.

Also used Aerocel above the headliner and to insulate the sloped van forehead.

Another use for 1" thick Aerocel is to plug the Maxxair roof vent opening for insulation and/or block the street lights at night.