Remove "Underbelly" Lining? 2023 Micro Minnie 2108TB

[Blue Sky]

I would appreciate you sharing your experience, thoughts, and comments about the complete removal of the Coroplast lining underneath our MM2108TB.

The reason I would like to have it removed, is because it covers items I would like to access for maintenance and repair.

In today's RV thought bank it's considered "essential", but in past decades we had "no such thing" - and we did fine without it.

I'm not worried about road debris, and while I would agree a lining would help in that situation, it's not a cure-all.

The cold weather folks seem to want it on to help protect against freezing. I never had a freezing issue with trailers that didn't have a lining. Now, we are in Florida and cooling is more the issue. Our trailer could easily be kept climate controlled without a lining.

I guess the issue (for me) comes down to: Are there other reasons to have that lining in place other than insulation or road debris?

And if construction of modern trailers is different than the trailers we used without a lining, what are those differences?

[eatSleepWoof]

From what I've seen on my 2022 2108FBS, the floor construction looks roughly like this:

1. Interior, vinyl flooring.
2. 5/8" plywood.
3. Reflectix-type insulation (bubble foil).
4. Big air gap containing plumbing, tanks, water heaters, wiring, etc.
5. Coroplast.

The coroplast does nothing for insulation. Its main goal seems to be keeping dirt/debris away from everything above it. If you use the trailer in warm climates on clean roads, the coroplast can likely be removed without any issue.

Where we live and camp - we get huge amounts of snow, and endless dirt/gravel/dust on non-paved roads. I'd prefer to keep all those elements away from the plumbing and everything else above the coroplast, but that's a personal preference and the presence of that dirt is not likely to affect the trailer in any meaningful way. I suppose the occasional piece of gravel could tear the soft, bubble foil insulation, but even that's a stretch.

A flat belly also helps with aerodynamics (see Teslas and other EVs), but considering that you're already towing a massive brick, the difference will be negligible.

If you do remove the coroplast you may need to tidy up (zap strap, secure, etc.) some of the wiring that gets exposed, but otherwise I don't anticipate any issues.

[Morich]

But what about an alternate thought?
How much do you know about where you need to get to things and how much is that?

If you have some good ideas of where you need, is it little enough to consider just cutting gaps in the layer and then gluing it back? Contact cement is what we used as it is one that works on lots of types of material and also glues almost immediately after the correct wait time.
I find the layer cuts pretty quick and easy, even when I have to figure how to avoid cutting pipes or wires.
I hack saw blade with large teeth, held in hand seems to go pretty quick but let me feel when I meet something to avoid cutting.
Then repair is pretty simple if I lay a strip on top of what it not removed, glue it with a quick setting adhesive and then push the removed part back up on the strip.
Kind of like patching sheet rock?

In our case we definitely wanted the insulation for winter but I find things tend to sell better if folks don't spot any place where we worked on it!

[eatSleepWoof]

You could also install access hatches (through the coroplast) in spots where you need access. I believe a few folks on the forum have already done just that.

RV underbelly tape is also a thing. I've got a roll of that and will be using it to seal the coroplast back up after I inevitably open it up to reinforce the watertank.

[Blue Sky]

... all good comments. Thank you.

For now, I'm going to do some cutting and patching to avoid removal.

Morich, I'll try the drywall knife first - bigger teeth than the hacksaw blade - and these arthritic hands will like the handle.

earSleepWoof, The tank reinforecment is one of the projects I have in mind.

As far as sealing the cut goes, I have heard both of you.

Thanks again.

[eatSleepWoof]

Originally Posted by Blue Sky

Morich, I'll try the drywall knife first - bigger teeth than the hacksaw blade - and these arthritic hands will like the handle.

I'd urge caution on the drywall knife idea. I suspect that won't work at all.

Drywall knives are great at breaking down the "powder" of drywall, but with the corrugated plastic, I suspect the knife will simply grab & pull without actually cutting, and also increase risk of cutting/grabbing something it shouldn't behind the plastic. A sharp utility knife would be my choice.

That said, a powered multitool with a cutting blade would also be easy to use and control. Just use a slow speed to cut and not melt the plastic.

[Marine359]

Try a dremel

[Fred 2106DS]

x2 a utility knife with new blade. I've dropped most of the underbody on our MM for mods and repairs and have found a utility knife with new blade works well. Used underbelly tape for repairing the cuts. Installed access hatches in areas of future access needs.

Here's a link to one of my posts with pictures that shows the use of the underbelly tape and the round access hatches I installed.

[Blue Sky]

Originally Posted by Fred 2106DS

x2 a utility knife with new blade. I've dropped most of the underbody on our MM for mods and repairs and have found a utility knife with new blade works well. Used underbelly tape for repairing the cuts. Installed access hatches in areas of future access needs.

Here's a link to one of my posts with pictures that shows the use of the underbelly tape and the round access hatches I installed.

Thank you, Fred. Nice post! The link, particularly the pictures, is very informative.

[Jay Tea]

When I picked up my brand new 2023 2108FBS from the dealer last month, two underbelly panels had multiple cuts/repairs (duct tape, smooth tape, screws, and mastic). Most of the tape is 'released' from cover, and is hanging down! I insisted that the dealer replace both damaged panels (replacement is scheduled for next week). The dealer does not know why, of what was repaired (???).

I acknowledge that a Winnebago is not an Airstream ($$$), but what would the additional cost be to a Micro by installing a more durable cover (sheet metal) with access ports under tank sensors & valves?

[Jay Tea]

Traveling on an interstate recently in my sports sedan, I ran over an 18-wheeler tire carcass in the middle of my lane (heavy traffic, didn't see it in time to avoid). Thank goodness my sedan has a smooth fiber/resin underbelly cover! The cover was shredded, but the low-slung car mechanicals survived.

Imagine the potential damage to an RV's water/gas plumbing & electrical & holding tanks without a cover to deflect typical road hazards? I doubt the inexpensive corrugated plastic Winnebago uses would do much, but thin sheet metal shields would not cost nor weigh much. Food for thought?

[Marine359]

Probably 80% or more of all towables have coroplast underbelly, or worse, nothing at all. I’d stay awake at night chewing on that food for thought if insurance did not cover road hazard losses.

[Morich]

All things get down to being a compromise when we deal with ideas of what works best!
So metal starts out sounding good but if we think further and what thin metal does, we may get a different idea?
All thin metal has one common problem that folks who do sheet metal work like ductwork will tell you about! It is SHARP and cuts like a knife!!!!

So when you look at one of the first pictures above and see things like electrical lines and maybe four propane lines running down through the covering, do we really want those running down through thin metal? How about the rubber brakes lines?

I know this post is about the problems we may have with the current materials but I'm not wanting metal under there!

[wahoonc]

Originally Posted by Morich

All things get down to being a compromise when we deal with ideas of what works best!
So metal starts out sounding good but if we think further and what thin metal does, we may get a different idea?
All thin metal has one common problem that folks who do sheet metal work like ductwork will tell you about! It is SHARP and cuts like a knife!!!!

So when you look at one of the first pictures above and see things like electrical lines and maybe four propane lines running down through the covering, do we really want those running down through thin metal? How about the rubber brakes lines?

I know this post is about the problems we may have with the current materials but I'm not wanting metal under there!

Airstreams still have metal bellies...

Just for the record LP gas.lines are supposed to be outside the belly pans for safety reasons, also somewhere along the way they got away from using hard pipe in the LP systems.

I have owned a few Airstreams, they weren't that hard to work on underneath, you either cut access points or removed sections. I actually like the concept of the coroplast, IF it is installed correctly.

Aaron

[Morich]

Agreed, it is a compromise and there are options. It likely could be done right but after seeing some of the damage done on trailers when tires blow out, I'm not interested in metal.
Some I've seen, the tire wraps around the axle and removes much of anything in the area, so that I want the underside to tear up, rather than wrap with the tire to tear so much more of the other things it snags!
One of the bad things about trailers is the number of tire failures I see. Agreed that first step should be to avoid that problem but it still happens more than I want around me!

[wahoonc]

Originally Posted by Morich

Agreed, it is a compromise and there are options. It likely could be done right but after seeing some of the damage done on trailers when tires blow out, I'm not interested in metal.
Some I've seen, the tire wraps around the axle and removes much of anything in the area, so that I want the underside to tear up, rather than wrap with the tire to tear so much more of the other things it snags!
One of the bad things about trailers is the number of tire failures I see. Agreed that first step should be to avoid that problem but it still happens more than I want around me!

I find it quite ironic that we have to deal with trailer tire blowouts these days. I towed a wide variety of trailers over the past 45 years and can only recall one blowout. It was caused by a scrap of steel in the road that I could not swerve far enough to miss. I have NEVER had a blowout on an RV trailer tire. I recall that they started to really ramp up in the mid-90s when the tires started coming from somewhere else and the manufacturers started adding all the extra items to the units. I had a 1975 Airstream 31', it had a GVW of 7100# and weighed a bit over 5000# from the factory. What was even more interesting is that the owner's manual was 90 pages long and actually had useful information in it, like how much various options weighed! Along with a diagram of how to get a proper tongue weight using a bathroom scale! And what is really mind-boggling... no warnings to not do stupid things, like drink battery acid, or use of a lighter to find an LP leak... my how times have changed.

Aaron

[Jay Tea]

Great responses, especially regarding modern Owner's Manuals

[JoshBap]

Hi, so funny this topic came up today! I JUST finished working under my trailer and removing its underbelly. We had a plumbing leak I needed to fix and I wanted to make sure everything else was in good shape. Removing it wasn’t a problem…..putting it back up, by myself…..PAIN IN THE CABOOSE!! Got it all done tho. I’m pretty sure you don’t “need” it, but it’s a nice thing to have in my opinion. If you seal it properly it allows for protection from critters as well. My trailer has vents that pump hot air u see there to keep the tanks from freezing in cold weather. It also (I would think) give u some form of cold weather insulation from wind and such. Air is a good insulator and there’s like 6” at least of space between the floor and that plastic. If u did have to repair something, maybe just do what I did and wait till then to cut it open. I made access points today by just cutting 3 sides and creating a “flap” and then taping back up. If that fails I’ll just get a larger piece and glue it over like a lid. Just throwing in my experience. Hope it helps!
Josh

[rattlesnake]

Just dropped the underbelly on my '21 2100bh to access the fresh tank and wanted to add that I needed a #2 size SQUARE bit driver to remove the screws from the two aluminum strips that hold the coroplast in place at the front. After removing the screwed in "patch job" around the gas line manifold and the bowed angle iron under the fresh tank (only had 3 self-tapping screws to remove because one was snapped off), it was easy to drop the coroplast back to the first axle. I was then able to see where it was safe to cut a flap above the axles without hitting any wires to access the rear of the fresh tank. A folding utility knife worked well for me. Thank you all for all of the info above!!!!

[JoshBap]

Just a quick on “what I did”

-Used drill to remove any strip with screws holding underbelly up
- cut with lutility knife at any seems that screws were already in, making sure I wasn’t cutting into any pipes/wires/whatever. Peaked in to see if there were any wires or pipes prior to cutting.
-cut what I wanted with box cutters