Rebuilding underside of camper checklist

[mtlakejim]

Copying this from another post because I think it deserves a separate thread.
You know one of these days I need to take the entire corplast off and redo everything under there:

• Put angle iron supports on tank bottoms.
• Build access doors to the important areas like dump valves.
• Tie up the wiring and plumbing.
• Maybe add some valves on plumbing with access hatches for same.
• Make sure the underbelly heating is run properly.
• This one might sound crazy and gross too but maybe add a light inside the black tank so I can see inside thru the toilet for inspection? Tell me I'm not the only person that looks down the pipe with a flashlight to make sure the tank is clean?
• Add good tank level gauges (someone mention a different type recently).
• And then button the Corplast or whatever I replace it with using proper self tap screws.
  
  I'm sure there are a half dozen other things that could be added to the list......??
  
  Basically rebuild the underside like it should be been built the first time......

[Daryles]

I started a list like this a while back.
I like the access hatches idea for the valves.
I was also thinking about adding heat tape for the plumbing if necessary.
Certainly plug all the holes and add insulation. 4 season? Have a look at all the gaps and holes in your frame.

[rohrmann]

I’ve done some of that with our tank repair. The only issue with a black tank light is, light only shines in straight lines unless you use mirrors. On a typical travel trailer, the toilet usually drops straight down to the black tank. On these fifth wheels they seem to use elbows in the line from the toilet to the tank. Maybe one of those inspection camera tools would work.

[richfaa]

We have t done any of that with our Montana's over 13 years and have not needed to but it is a good idea.

[RichardD]

I had to open up the belly on my Montana to repair a hydraulic leak, loose fitting at slide cylinder. While I had it opened I ran 2 pair of 12ga wire from the front to the rear just in case I wanted to add something 12volt on the rear of the camper. I have already used one of the pair to add an LED light bar to assist with night time backing. The other thing I did was to secure and protect the hydraulic hoses. There were several hoses that were rubbing on frame components that could have chaffed the hoses and eventually caused another leak. I also used Galvanized self tapping fasteners to resecure the underbelly covering.
Hope this helps.

[Dave W]

Originally Posted by mtlakejim

Copying this from another post because I think it deserves a separate thread.
You know one of these days I need to take the entire corplast off and redo everything under there:

• Put angle iron supports on tank bottoms.
• Build access doors to the important areas like dump valves.
• Tie up the wiring and plumbing.
• Maybe add some valves on plumbing with access hatches for same.
• Make sure the underbelly heating is run properly.
• This one might sound crazy and gross too but maybe add a light inside the black tank so I can see inside thru the toilet for inspection? Tell me I'm not the only person that looks down the pipe with a flashlight to make sure the tank is clean?
• Add good tank level gauges (someone mention a different type recently).
• And then button the Corplast or whatever I replace it with using proper self tap screws.
  
  I'm sure there are a half dozen other things that could be added to the list......??
  
  Basically rebuild the underside like it should be been built the first time......

A couple folks on a SOB site that I used to visit pulled the coroplast, and replaced it with aluminum sheeting. Galvanized 22ga or thereabouts steel would also work for a bunch less dollars.


Same forum - folks replaced those leaky flex heat runs with aluminum rigid piping, i.e., from Home Depot or similar. They reported much better flow and distribution.


Garnet SeeLevel tank sensors work great. Pull down the coroplast, stick the pickups on the side of each tank. run a bit of wiring to the readout and you are set https://www.garnetinstruments.com/. I did it on our last 5er but wont on this one.


Isn't there a 45 degree elbow on the black tank toilet to tank run? There is on our HC. I've used a low buck endoscope to view the inside condition of that tank. The first one didn't have a wide angle lens (oops!) but the 2nd one did. All you need is a laptop. These endoscopes usually have LED lights around the lens. If need be, it can also ser for personal use as well, saving a 2-3 doctor trips.


Adding water piping valves equals another trip to Home Depot for some Shark Bite fittings. Lowe's has a good similar brand.


While under the dirty side of your RV, consider adding a MorRyde X-Factor cross member to that long and floppy MorRYDE CRE3 or 4000 system. Installed on all spring hangers are best but be sure there is nothing in the way first. I have one that's impossible to install without moving galley drain piping and another that needs a 1" shim to pass the gas line.

[DQDick]

Put outside the tank sensors on the old rig. They worked great, but by then I knew when I empted the tanks so I never looked at them after the first month. Didn't waste the money on this rig.

[mtlakejim]

A couple folks on a SOB site that I used to visit pulled the coroplast, and replaced it with aluminum sheeting. Galvanized 22ga or thereabouts steel would also work for a bunch less dollars.



Oddly enough I suggested that on here some time back on a different thread.


I also got to thinking that working on that stuff would be a LOT easier if I waited till after we have IS installed. Then the axles would not be in the way.......

[jeffba]

Just remember if you replace the coroplast with aluminum you will loose the insulation value of the coroplast.

[Dave W]

Originally Posted by jeffba

Just remember if you replace the coroplast with aluminum you will loose the insulation value of the coroplast.

I doubt that the coroplast itself has very mch if any insulating R-Factor value but a single layer of Reflectix, found in any big box store will more then replace it and will match, at least what our HC has in the front on the step down's coroplast

[Texan]

I've installed the Valtera valves with rods, installed bracing under tanks and added See Level gauges and tied up the wires so I hope there is not a reason to have to take the coroplast off anymore . I would think the coroplast would be just about as easy to handle as the aluminum or galvanized sheets and I can let down the coroplast by just peeling back what I need and no more. I have the self tapping screws on the coroplast so it's much easier to remove than the nails. Coroplast is not nearly as hard to remove and install as many make it out to be.

[mtlakejim]

Does the underside of the floor have ANY insulation? If not, would it make any sense to add Styrofoam to the floor?


I'm not saying that the Corplast is hard to work with. What I want to do is have the underbelly in sections with hatches where ya need access. In fact, if I used thick and stiff aluminum I could potentially insulate the backside of it I think? Guess just depends on how much work and $$ to put in that sort of project. The longer I keep the unit the more I lean towards do it on the next one. I do suspect we have one more RV in us.

[Daryles]

Yes they do have insulation under the floor
Factory tour video
https://youtu.be/cV0OZv0bCgc
Tanks at 3:55 and 9 minutes
Bottom insulation 7:20 and 8:35 and 12:38 minutes.
Water line routing/insulation 12:38 minutes.
Racetrack AC ducts 32:42min.

When I take the bottom off mine I do want to add more insulation and plug all the air gaps. I would like to install Prodex insulation but their shipping costs as much as the Prodex. I'll probably go with something similar off Amazon.
I am currently insulating the forward battery compartment and plugging all the air gaps there. I'm preparing it to install lithium batteries (they dont like freezing temperatures). We are planning our spring trip and will be doing some boondocking.
If all goes well and we decide we are ok with boondocking I'll install solar panels etc.

[Daryles]

I am about to pull down the back end of my coroplast to chech/reinforce the freshwater tank.
To those who have done this before, what did you use to pull out the nails they drove through the steel beams to get the coroplast off?

[jeffba]

Originally Posted by Daryles

I am about to pull down the back end of my coroplast to chech/reinforce the freshwater tank.
To those who have done this before, what did you use to pull out the nails they drove through the steel beams to get the coroplast off?

cordless drill to spin them and small prybar to remove while spinning

[Daryles]

They look like masonry nails. Not sure they would spin.

[jeffba]

Originally Posted by Daryles

They look like masonry nails. Not sure they would spin.

they do. I did it

[jeffba]

thread showing tools I used

https://www.montanaowners.com/forums...ad.php?t=73217

[mtlakejim]

Originally Posted by jeffba

thread showing tools I used

https://www.montanaowners.com/forums...ad.php?t=73217

Jeff,
What kind of bit was that on your drill?

[mtlakejim]

Remember to use large fender washers when you go back up with Corplast. It does tend to tear when installing screwed in fasteners in the same hole as the original nails.