Underbelly panel insulation removal

[romeotrd]

Hi i have a 2019 Alpha Wolf with the cold weather package and wondering if anyone has removed the underbelly panel that protects the grey black and fresh water tanks? It seems to be one panel wedged between the frame. I would rather not cut it since I don't know how i would correctly repair it.

[romeotrd]

Pictures of panel and sanitary pipe i need to repair.

[Toby]

I researched this recently myself. If it helps that stuff is called coroplast. I got a few tips on how to create a patch. Just like you I’m a little hesitant on this project in fear of getting it all back together.

[romeotrd]

Thanks for the tip. So I watched some YouTube videos and people cut the coroplast and then used a very strong duct tape to patch it. I would like to find a better approach. Because I wanted to start the repair to the sewer pipe, i cut an access panel/square into the coroplast. I will deal with the repair to the panel later and fill the holes with expanding foam which is how it appears forest river filled the gaps.

[dward51]

The foam is a UV resistant expanding foam. You can get it on Amazon. Search for Great Stuff Multi-purpose foam. Pretty much the can is a one shot thing as once you start to use it, the foam will set up in the dispenser part. So if you have anything else that needs foaming, line it all up to be done at once. They also use it as a glue to help adhere the coroplast to the frame at the sides.

The Lippert repair guy told me a lot of people use some pressure treated wood as a backer to a cut section/splice in the coroplast. It's better than tape. I would use some stainless #12 or #14 screws with a large washer to hold the coroplast on either side of the cut with a 3" section of 1" pressure treated wood (I would cut and rip a PT 5/4 deckboard). Weight is next to nothing and you could still tape over that with something like Gorilla Duct Tape as a backup seal against insects or heat escaping in cooler weather (usually if you have coroplast underbelly, you have a heat duct into the belly).

[Toby]

Originally Posted by dward51

The foam is a UV resistant expanding foam. You can get it on Amazon. Search for Great Stuff Multi-purpose foam. Pretty much the can is a one shot thing as once you start to use it, the foam will set up in the dispenser part. So if you have anything else that needs foaming, line it all up to be done at once. They also use it as a glue to help adhere the coroplast to the frame at the sides.

The Lippert repair guy told me a lot of people use some pressure treated wood as a backer to a cut section/splice in the coroplast. It's better than tape. I would use some stainless #12 or #14 screws with a large washer to hold the coroplast on either side of the cut with a 3" section of 1" pressure treated wood (I would cut and rip a PT 5/4 deckboard). Weight is next to nothing and you could still tape over that with something like Gorilla Duct Tape as a backup seal against insects or heat escaping in cooler weather (usually if you have coroplast underbelly, you have a heat duct into the belly).

Great stuff is great stuff! I used it to seal up some of the gaping holes they left and kept the mice out last winter. I also discovered that when I had water pouring through a concrete wall, if I stuck my gun into the hole and squeezed the trigger, I got an instant plug. Get the great stuff pro gun and you can use it whenever you want. Don’t need to use up the whole can at once.

I want to modify my plumbing as well so will be doing some surgery too. I’m just not sure yet how big and exactly where I need to go as far as the cut goes. On my camper the pump doesn’t draw water from the bottom of the tank so I can never get that last 15 to 20 gallons of water out. I’m going to splice into the drain line.

[romeotrd]

Originally Posted by dward51

The foam is a UV resistant expanding foam. You can get it on Amazon. Search for Great Stuff Multi-purpose foam. Pretty much the can is a one shot thing as once you start to use it, the foam will set up in the dispenser part. So if you have anything else that needs foaming, line it all up to be done at once. They also use it as a glue to help adhere the coroplast to the frame at the sides.

The Lippert repair guy told me a lot of people use some pressure treated wood as a backer to a cut section/splice in the coroplast. It's better than tape. I would use some stainless #12 or #14 screws with a large washer to hold the coroplast on either side of the cut with a 3" section of 1" pressure treated wood (I would cut and rip a PT 5/4 deckboard). Weight is next to nothing and you could still tape over that with something like Gorilla Duct Tape as a backup seal against insects or heat escaping in cooler weather (usually if you have coroplast underbelly, you have a heat duct into the belly).

Thank you for the suggestion, I will give it a shot with the pressure treated deckboard.

[tbarb]

I dropped mine to get access to the tanks. To remove the pop rivets that hold it up at the edges I used a air chisel. Removed them all and replaced with the largest washer I could find and self tapping metal screws. Now I can access the under belly when I need to. Just two weeks ago my black tank valve pull came undone and I had to open a section for access. The original job took about 1.5 hours and was not a fun job but I am glad I did it because I have easy access now. The above threads reference the foam and I had to redo that also but I was able to do a much better job than the factory. As a side note I put a lot more fasteners in than the factory and my washers are twice as big so The seal along the frame is better now. Good Luck!

[SailorSam20500]

Mine partially ripped off while on a trip, front half folded back under the axles. I found a pair of angle cutter to partially bend up the washer and then a framing hammer effective in pulling out the fastener.

[dward51]

Those "pop rivets" are actually power nails driven through the coroplast and into the steel frame. They are a real pain to pull out. Some of them will twist back out via the hex head, others can be twisted out with vice grips, and others just take brute force and a cat's paw nail puller. Why they use those on a trailer for something like the underbelly is beyond me. It's not like the coroplast is structural. Although it's probably quick for them to blast them in vs use self tapping screws.

[831 BHDS Flagstaff 2015]

When done with Great Stuff unscrew top and blow it out with air before it sets up. Then you can reuse. Have done it more than once.

[Toby]

I finally got the surgery done. I found this stuff which works good for sealing things up. It’s a little pricey but works great.

Surface Shields 4 Inch x 180 Foot AP Products 022-BP4180 Scrim Shield Repair Tape-4" x 180' https://www.amazon.com/dp/B002SSGAZG..._MFyoDb0329CM8