Community Forums

helopilot880 · 07-22-2019, 05:20 AM

We have a Winnebago 5th wheel. The underbelly is some sort of material that encloses/protects the underside of the trailer. On our last trip we had issues with the black tank value leaking and had to have it "repaired" on two occasions. Both repair persons used some sort of tape to reseal the opening they cut into the underbelly. Looking at the underbelly the other day I noticed both tapes they used are letting go, allowing the repair sites (underbelly material) to sag. Since I will need to reseal the opening they cut into the underbelly I would like to use the best method possible for the repair. If I use tape what is the best tape, or, is there a better method for a repair? Thanks in advance for any assistance.

Lanny1763 · 07-22-2019, 05:27 AM

I have used Gorilla Waterproof Patch & Seal Tape 4" x 10' Black on my underbelly and it does a good job. Good luck.

**Spdracr39** · 07-22-2019, 05:29 AM

Gorilla Tape is a required toolbox item for me.

redhooker · 07-22-2019, 05:33 AM

Lowe’s sell a tape called “Huber Zip SystemTape”. It is used to seal the Zip system plywood used on many job sites nowadays (green or red waterproof plywood).

A little pricy at $30 or so a roll, it is 6” wide commercial grade rubber flashing tape that sticks like nobody’s business. It also comes up to 12” wide for roof valleys and such. It is waterproof and used to flash seams and windows on houses. I use it all the time it is the better bigger brother to Gorilla tape.

IC2 · 07-22-2019, 05:44 AM

While I do like Gorilla Tape for most patches, have found that black 3 or 4 inch wide Eternabond lasts longer on a 5ers belly Coroplast. The Gorilla Tape tended to fray while the Eternabond has stayed intact.

RV Leak Repair Tapes & Sealants | EternaBond

bigchick · 07-22-2019, 06:47 AM

scrim shield tape is designed for this repair.

egwilly · 07-22-2019, 07:15 AM

Any sealing tape regardless of brand will fail if the area is not cleaned well and wiped with alcohol prior to applying it.

I do my repairs that way and never had a failure.

bigchick · 07-22-2019, 08:25 AM

ditto on what egwilly said. used some underbelly repair tape and the instruction emphasized cleaning with alcohol. i did and the tape is still there.

one other trick i used is to use binder clips to help hold up the coroplast. regular binder clips that you get in the stationery dept. i can clip them to the lip of our frame and hold the edge of the coroplast without having to drill for other fasteners. three years and they are still there.

you can also use metal flashing or wooden slats as supports across the cut. put some screws through the coroplast up into the supports to help hold the coroplast up. then seal with the tape.

helopilot880 · 08-02-2019, 10:06 AM

Quote:

Originally Posted by bigchick

ditto on what egwilly said. used some underbelly repair tape and the instruction emphasized cleaning with alcohol. i did and the tape is still there.

one other trick i used is to use binder clips to help hold up the coroplast. regular binder clips that you get in the stationery dept. i can clip them to the lip of our frame and hold the edge of the coroplast without having to drill for other fasteners. three years and they are still there.

you can also use metal flashing or wooden slats as supports across the cut. put some screws through the coroplast up into the supports to help hold the coroplast up. then seal with the tape.

The idea as supports is intriguing as the hole they cut is three sided and tape they used is falling down. The supports will assist the ape and give the repair some strength, and if necessary be removed to access the site again should I need to. If you did a repair in this fashion, what size/type screws did you use? I assume the supports go street side down on the underbelly

bigchick · 08-02-2019, 07:05 PM

i personally have not used screws but my rv repair guy says they have used metal flashing and self tapping screws. put the flashing into the hole on top of the coroplast along the edge. secure with self tapping screws (i would think 1/2" would be sufficient). then fold coroplast up so the edges align and secure the cut piece with the screws. other have said the use some form of wood (perhaps a furring strip or lathe). if you want to practice this technique get an old campaign sign as is it made fro the same coroplast. practice driving the screws with it.

as far as tape goes the rv guy said they use scrimshiled but it looks a bit pricey. there is a tape called under belly tape that i have used the is about $16 for a 25 foot roll. the instructions very clearly say to clean the coroplast with isopropol alcohol. i have at the tape has been there for over 3 years and is holding swell.

i was actually under the trailer today doing some repair on a hole around the rain pipe. i was using expanding foam to seal the gap. works great but do not drop it on you hair! i advance my hair balding by at least a couple of years getting it out!

one other thing the rv guy told me is that they try to cut the coroplast along a frame support member if possible. if they can they drill a couple of new holes in the frame member and use self tapping metal screws with fender washer to hold the coroplast up.

jacknife · 08-02-2019, 09:35 PM

Easiest way to fix is get a one by 2-3-4 depending how much overlap you want . Cut to the length you need . ( I would go a little past the cut. Put it on the inside . Hold it down and screw in self drilling screws on onside then push up the the other side repeat. Put a good tape over it and done. The wood is now supporting the underbelly material not the tape.

road dogs · 08-03-2019, 10:16 PM

Most underbelly material is Coroplast, same stuff they use to make political campaign signs. Just wait until the next election and harvest a couple of big signs and make yourself a new underbelly enclosure....