Sealing the corragated plastic liner (coroplast)

TxCowboy

Well-known member
BLUF: I need your recommendation on a heavy, weatherproof sealant that works on plastic.

Story:

Our new Landmark Key West was delivered to our RV park last week. As the trailer came rolling in, I noticed something flapping under the rear. At first, I thought it was just a plastic bag that the trailer had picked up along the way.

Nope.

This is what greeted me when I checked it.

Cut plastic liner.jpg Cut liner and thermal barrier.jpg

I was finally able to get in contact with the dealer's Service Manager late yesterday afternoon to discuss this issue. Apparently, a maintenance technician was troubleshooting an electrical issue with the shore power connection under the power reel. Instead of removing the corrugated plastic, their technician cut through it. Some of the cuts are almost 2 feet long and even cut through the thermal barrier. In the first picture and others that I have, it looks like the techician started to remove the plastic because some of the installation screws are missing.

Per the Service Manager, the shortcoming isn't that the plastic was cut. It was that the technician should have repaired the damage but did not.

The fix for this is that the dealership is mailing me a roll of industrial grade cloth-imbued tape. The Service Manager suggested that I also get a heavy duty spray sealant to apply over the top of the tape as well.

Anyone have a suggestion as to which spray to use? It needs to seal but be flexible enough so that it doesn't pull away from the plastic when traveling.

(Side comment: According to the Service Manager, cutting through the plastic instead of removing it is HL's accepted and published procedure. There are other posts that I've read on this Forum that says HL does NOT endorse cutting the plastic and specifically includes time to remove/reinstall the plastic in their warranty work reimbursements.)
 

2psnapod2

Texas-South Chapter Leaders-Retired
(Side comment: According to the Service Manager, cutting through the plastic instead of removing it is HL's accepted and published procedure. There are other posts that I've read on this Forum that says HL does NOT endorse cutting the plastic and specifically includes time to remove/reinstall the plastic in their warranty work reimbursements.)

This happens at the dealers as they repair under warranty. I also would be very curious as to what HL actually says about this!
 

TxCowboy

Well-known member
Clean the surface with alcohol and use Gorilla tape.

Prepping the surface is, of course, important. I am looking forward to seeing what arrives in the mail from the dealership. Gorilla tape is likely what I'll be using since I have a good history with it.
 

rxbristol

Well-known member
Take note/pictures of what's under there so you know what was repaired and what you have access to at that cut point.
 

justafordguy

Well-known member
I noticed that the screws and washers look very rusty, is that normal on a new unit? I know mine aren't like that.
 

Bohemian

Well-known member
Thew proper procedure for those repairs is to unscrew the corroplast and lower the section where needed. Cutting is not acceptable. You should really have them replace the whole sheet of corroplast.
 

TxCowboy

Well-known member
I noticed that the screws and washers look very rusty, is that normal on a new unit? I know mine aren't like that.

Looks to me like the dealership put those in and used the cheap kind.

Unit was produced in January 2015 so the rust most likely occurred as the result of salty roads when it was moved from Indiana. That's just a guess. But the rest of the undercarriage is virtually rust-free so who knows?
 

danemayer

Well-known member
Thew proper procedure for those repairs is to unscrew the corroplast and lower the section where needed. Cutting is not acceptable. You should really have them replace the whole sheet of corroplast.

When you buy your Bighorn, I think you'll get underneath where the coroplast goes into the rear cap and you may come to a different conclusion about proper procedure. The rear section is also tucked into the drop frame at the other end.
 

TandT

Founding Utah Chapter Leaders-Retired
I cut my own access panel near the sewer valves, as dropping all the coroplast is very time consuming.
I agree that Gorilla Tape is the best option to reseal it. Trace
 

Westwind

Well-known member
We bought our 2012 in August 2011 and in April 2012 I had to cut the Coroplast to get to the Kitchen Hydraulic to reattach it, the bolt had fallen off. I used Gorilla tape to reseal where I cut it, I took my time and cleaned the Coroplast with mineral spirits first and then attached several layers of Gorilla Tape. It has traveled through Ice storms and multiple rain storms and has really held up, I cleaned a couple of area's this summer and reapplied some areas but it has really held up.
 

JanAndBill

Well-known member
Something that SHOULD be on every trailer are bolt access doors in strategic locations. After dealing with valve problems 3 times, I finally cut a large access door in the corroplast. I then cut a sheet of aluminum slightly larger than the hole. Self tapping screws into the cross members and caulk sealed the plate till the next time.
 

rxbristol

Well-known member
Something that SHOULD be on every trailer are bolt access doors in strategic locations. After dealing with valve problems 3 times, I finally cut a large access door in the corroplast. I then cut a sheet of aluminum slightly larger than the hole. Self tapping screws into the cross members and caulk sealed the plate till the next time.

Would love to see some pictures.
 

JohnD

Moved on to the next thing...
I noticed that the screws and washers look very rusty, is that normal on a new unit? I know mine aren't like that.

Our new 2015 Prowler (manufacture date is 1/26/2015) is more rusty underneath than our old 1978 Coachman TT was when we traded it in three years ago for our other Heartland, which was not rusty on the bottom.

Here are a couple of shots of the underside of our Prowler:
 

Attachments

  • ProwlerFreshDrain-P1000181.jpg
    ProwlerFreshDrain-P1000181.jpg
    128.8 KB · Views: 53
  • ProwlerDrains-P1000175.jpg
    ProwlerDrains-P1000175.jpg
    702.2 KB · Views: 50

windviewer

Well-known member
our prowler tt (2015 manufactured 03/2014) exhited similar poor paint coverage underneath. the gas line had never received paint. i had pointed this out during our prepurchase and the dealer did paint it. however, i just spent yesterday with a spray can of tremclad (one entire can) spot spraying all the welds and various pieces jnder the trailer.

i also discovered some access points where the black foam missed sealing. does anyone know what this foam is ? and where do i get some?
 

rxbristol

Well-known member
our prowler tt (2015 manufactured 03/2014) exhited similar poor paint coverage underneath. the gas line had never received paint. i had pointed this out during our prepurchase and the dealer did paint it. however, i just spent yesterday with a spray can of tremclad (one entire can) spot spraying all the welds and various pieces jnder the trailer.

i also discovered some access points where the black foam missed sealing. does anyone know what this foam is ? and where do i get some?

Expanding foam for exterior applications: Link
 
Top