Booming belly pan fix

[wecoyote]

After two years of a "booming" belly pan on our 2014 Flying Cloud 30, I finally got off my butt and did something about it.

So you know, I work in the automotive industry and know a fair amount about what goes on behind the scenes in fixing noise on cars when they are designed and developed. One of the things that is used to address automotive body and structure noise are "constrained layer damping" material. It is in essence an elastic damping material that holds a thick metal "foil". This combination is good at damping out noise on long flat sheet metal.

I got to thinking and realized there was something similar at my local home improvement store. "Instant Waterproof Repair Tape" is pretty much a layer of sticky rubber with an aluminum outer layer. (picture). Since it isn't very expensive I figured it wouldn't hurt to give it a try. I bought a 6" wide 25' roll and got to work.

I placed a long strip from just behind the spare tire carrier, all the way back to just before the gas line runs across the underside. Then I put strips in the area between the rows of rivets from the center to the outside edges. Then, not pictured, I put the remaining pieces behind the gas line between the rows of rivets. As you can see in the picture, I wasn't all that precise.

It works! No booms, no sounds, nothing! In fact, when you close the entry door, it sounds more solid.

Money and time well spent!

Tape:
https://drive.google.com/open?id=0B-...WRGR2xUMFJzNzQ

Installed forward of gas line:
https://drive.google.com/open?id=0B-...0JfOHpmdDY1d2s

[J-Dog]

I am going to have to give this a go... ours doesn't boom, but the oil canning as we walk back and forth in the trailer is certainly an annoyance.

[wecoyote]

Originally Posted by J-Dog

I am going to have to give this a go... ours doesn't boom, but the oil canning as we walk back and forth in the trailer is certainly an annoyance.

Booming = oil canning. If you lay under the belly pan while someone walks above, you can actually see it move in and out.

[Monza]

Off topic, but I wonder how a tape like that would work on the seams and rivet lines on the shell taped to the inside of the skins? ( on a gutted inside)

I've always thought some sort of tape would make a lot of sense for such a seam sealing application.

Glad it fixed your booming.

[wecoyote]

Originally Posted by Monza

Off topic, but I wonder how a tape like that would work on the seams and rivet lines on the shell taped to the inside of the skins? ( on a gutted inside)

I've always thought some sort of tape would make a lot of sense for such a seam sealing application.

I wonder the same thing. It appears that this material is designed to provide sealing from the outside (aluminum). For "reverse" use, I would think you'd have to make sure that it is pressed in place firmly. The glue they use is very sticky. I don't see a reason why it wouldn't work.

[AnnArborBob]

What a great idea. Did you have to wash the belly pan first of is this stuff able to adhere to a "normally dirty" surface?

[David F]

Maybe a word of caution if you use this type of material on the interior of the skin....

There two basic compositions depending on quality and brand. The cheaper products are mostly asphalt emulsion based and will mostly likely produce a oil like smell when heated to the temperatures that would exist on the back side of the aluminum skin exposed to sunlight. This smell would definitely be noticeable inside the trailer. The better products are butyl rubber based and do not produce an odor. Further the asphalt based products can actually melt at high temperatures, whereas the butyl products have a much higher temperature tolerance. And finally, the butyl products (such as Dynamat) are way more expensive. Now, if sound deadening is not part of the equation, you can find butyl rubber based flashing tapes. But, if you are going to install on interior side of exterior skin, look for melting temperature information and make an informed decision.

Most of the above is from my years old memory from the research I did when I restored my '52 Chevy pickup. I found a Butyl rubber sound deadener with almost exact specs ad Dynamat for way cheaper...wish I could remember the name.

[wecoyote]

Originally Posted by AnnArborBob

What a great idea. Did you have to wash the belly pan first of is this stuff able to adhere to a "normally dirty" surface?

I didn't do any sort of surface prep. The "dirty" surface wasn't too bad since our camper is a 2014 and we don't drive on dirt roads any more than we have to. The adhesive on the rubber portion is VERY sticky. In fact, one of the side pieces wasn't were I wanted it to be when I first stuck 1/2" of the end. I couldn't get it loose without damaging the piece. I just had to turn it as I was pressing it in place. Since you can't see it without going underneath, I'm not to worried.

[Tinbox]

I plan to try this right away. Have the same problem on a 14 International.
Thanks

[Sovereign85]

Would EternaBond Tape work as well?

[Harrysheets]

I found some Butyl rubber tape with aluminum layer from Nashua. Was it something like this?

Thanks for the tread as I was looking at an asphalt based tape called DeckWise. I think the comment about smells from the interior were something I had not thought of.

Scott


https://www.amazon.com/Nashua-360-17.../dp/B003ZCXNZO

[silvereagle2]

I tried to order the U-Seal Instant Waterproof Repair Tape but Amazon no longer supplies this. Does anyone know where to get this tape? I looked at Lowe's and Home Depot and they have flashing material type tape, or "Peel and Seal Aluminum flashing tape 6 inches by 25 feet. Would this tape work? I am not sure if it has enough rubber to dampen the noise...

[wecoyote]

Originally Posted by silvereagle2

I tried to order the U-Seal Instant Waterproof Repair Tape but Amazon no longer supplies this. Does anyone know where to get this tape? I looked at Lowe's and Home Depot and they have flashing material type tape, or "Peel and Seal Aluminum flashing tape 6 inches by 25 feet. Would this tape work? I am not sure if it has enough rubber to dampen the noise...

The "Peel and Seal" is pretty much what I had used. I'd say that would work. The best part is, it isn't too expensive and is easier than all the other methods people have tried.

[wecoyote]

Originally Posted by Harrysheets

I found some Butyl rubber tape with aluminum layer from Nashua. Was it something like this?

Thanks for the tread as I was looking at an asphalt based tape called DeckWise. I think the comment about smells from the interior were something I had not thought of.

Scott


https://www.amazon.com/Nashua-360-17.../dp/B003ZCXNZO

The Butyl rubber tape is very similar to what I used. On mine, the rubber was black but did not appear to be asphalt. Definitely worth a try in my opinion.

[wecoyote]

For anyone who is interested, I'm happy to report that we did a nine trip from the Detroit Area up to Northern Michigan then down to Mammoth Cave, KY with absolutely no "boom". The flashing tape is still adhereed just as when I put it on.

We went through a temperature range from 40-90+F with no noticeable difference in performance or adherence. We drove through high heat and very strong rainstorms.

So far so good. Maybe in a month or so, I'll do another update.

[J-Dog]

Bought and installed some GTmat Automative Sound Insulation. I ordered 25 sq ft of 80 mil material. I received it in a roll which was 3'x8.5' in size. This is used primarily for automobile audio guys. I found it hard to work with in large sections, so I cut it into more manageable sizes and am hoping it will work out.

The kit came with a small wooden roller and a small package of orange colored powered degreaser.

Mixed the power and water into a spray bottle climbed under the rig with a roll of paper towels and cleaned the areas which were noticeably bubbled and wavy.

We will be taking off for a trip in the next week or so, and I will let you know how it performs in a few weeks. By the way, this roll was a bit pricey ($66.99).