Underbelly at blacktank 39FK

[John&Tammy]

Hi,
did anybody ever had the underbelly open on a 39FK near the blacktank?
I'm trying to find out if there is room enough between the black tank and the floor. I need lil over 4 inches to run a 4 inch pipe through bathroom floor and then straight down through belly to outside or to the side of the camper. Installing incinerating toilet and through floor would be right behind existing opening to the blacktank and the bedroom wall. Hoping to do so without removing the blacktank!
Going out the side from/in the bathroom would show a bunch of 4" pipe and not so attractive...
Going straight up through the roof is an option too, but...ya know...
Contacting Forest River service didn't help at all......
Any help appreciated!

John

[dblr]

Do you know the panels on the underbelly are 4X8 sections that are just screwed in? Just thinking you can remove maybe the one near the sewer outlet to gain access to see what your looking for, the underbelly is NOT one large piece like most. I believe Cedar Creek and the River Stone are both made this way. Good luck and let us know the outcome.

[John&Tammy]

Hi dblr,
thanks for your quick reply.
And yes, I know the covers are sectional, and it seems that the outlet part of the sewage is back further than the inlet of the blacktank. What concerns me is the fact that there will be a 'blanket' and insulation and a reflective foil obstructing a possible view once the panel(s) are removed. I haven't received the new toilet yet and also not yet decided to vent the heat (warmth) from the toilet possibly straight through the roof.... I'd do that to keep everything else "intact" so it can be easily reverted back to a 'regular' toilet with blacktank use.
Decisions, decisions..
I'll post what I did for sure! Toilet should arrive in 2 weeks or so
Researching sturdy rain cap if going through roof and where.
(still trying to get used to the thought to cut a 4 inch hole in roof though....)

[dblr]

Have you tried to reach out to the factory, they might be able to give you a heads up to what you might find. Here are some contact numbers. Plus on the web page they have a couple of build videos just not sure if they would show much of what your looking for


https://forestriverinc.com/rvs/conta...gionSelected=1

[John&Tammy]

Hi,
checked all possible videos from FR (factory tours and such) and contacted service department, Their answer was that they can't help me because of possible re-routing piping and such......
My impression was that that person, at least, had no interest in even trying to help me out on my question. One would think that, since the 39FK blueprint has not changed all that much over the years, it would be fairly easy to ask the shop foreman how all stuff was/is arranged under that specific bathroom floor.
I must be wrong in thinking so simplified...
In my, possibly ignorant, view a simple phone call from said shop foreman
would probably answer my question in 3 minutes....tops.
Oh well...it wasn't a real 'service' question or warranty claim or anything like that, but I just thought to call the persons who actually build those RiverStones and maybe that just felt like an ambush to the service department...who knows.
I'll figure it out..

[Jim1521]

I have had to open mine up to replace a sticky black tank pull. It's not a difficult job to get under there. Much better than having to drop a whole sheet of coroplast.

As you have mentioned, there is a sheet of mylar on the bottom, with some yellow fiberglass insulation on top of it. The panels are held in place by screws that go into 1"x1" strips of wood that run across the width of the trailer. These strips are not secured to the side rails of the trailer; they are cut to length, and the connection to the underbelly panels hold them in position.

The underbelly panels are held in place along the side rails of the trailer. Remove all the screws, and you'll be able to look in and see the 1"x1" strips. Move them out of the way. The black tank is two panels forward of the spare tire carrier. For what you're needing to do, I don't think you need to remove the panel directly in front of the spare tire, but you'll know when you get under there.

Once the panel is removed, I believe (IIRC) that I just sliced through the mylar sheet on one end and rolled it up and out of the way. The fiberglass insulation was in sections so I was able to move them out of the way as well.

I'm not sure I'm following where you're looking to route the 4" pipe. If it is above the black tank (between the top of the black tank and the bottom of the flooring) it'll be close. If it's below the black tank and between the bottom panels, the answer is no, there won't be enough room.

Re-installation is just the reverse. Put the panel loosely in place, then set the fiberglass insulation on top of the mylar (as best you can) and put the 1"x1" strips back in place. When I reassembled, I opted to put some additional screws into the panels and 1"x1" so as not to rely on the existing holes.

Take your time. You'll have a surprisingly large space to work in under the RV. I wore a set of coveralls - LONG SLEEVES - to protect from getting the fiberglass on your arms. I would also suggest wearing a hat to cover your hair as this crap will get everywhere.

[Adrian Gordon]

Originally Posted by John&Tammy

... One would think that, since the 39FK blueprint has not changed all that much over the years, it would be fairly easy to ask the shop foreman how all stuff was/is arranged under that specific bathroom floor.
I must be wrong in thinking so simplified...
In my, possibly ignorant, view a simple phone call from said shop foreman
would probably answer my question in 3 minutes....tops.

Blueprints? The have blueprints for manufacturing these things? My own impression is that for any given model there probably aren't two units that are identically constructed.

[John&Tammy]

Originally Posted by Jim1521

I'm not sure I'm following where you're looking to route the 4" pipe. If it is above the black tank (between the top of the black tank and the bottom of the flooring) it'll be close. If it's below the black tank and between the bottom panels, the answer is no, there won't be enough room.

Hi Jim,
as for routing the pipe I'm looking to go straight down (as possible) thus probably removing the black tank all together. The idea of this vent pipe is to go out as un-restricted as possible. (2 elbows max and/or 10 feet max. The air coming out is warm, not hot and the pipe is barely getting warm. It takes 1 elbow to go down to the floor, so if I wanted to go out to the side (driver side) it would take another elbow to go sideways, then straight to out. You mentioned "it'll be close" and I absolutely take your word for that. This is the kind of info I was looking for! Thank you!
Going through the floor behind the toilet is for cosmetic reasons only. At this point I'm leaning strongly going straight up through the roof and perhaps build a box around the pipe or so, if that pipe would bug me...
DW is already very happy with the idea we/she would never have to deal with black tanks anymore.... Sooooo...I could use that fact against her, potential, argument that the pipe bothers her...
I know, I know...brave here now....

(ps: Incinolet toilet)

[Jim1521]

Originally Posted by John&Tammy

Hi Jim,
as for routing the pipe I'm looking to go straight down (as possible) thus probably removing the black tank all together. The idea of this vent pipe is to go out as un-restricted as possible. (2 elbows max and/or 10 feet max. The air coming out is warm, not hot and the pipe is barely getting warm. It takes 1 elbow to go down to the floor, so if I wanted to go out to the side (driver side) it would take another elbow to go sideways, then straight to out. You mentioned "it'll be close" and I absolutely take your word for that. This is the kind of info I was looking for! Thank you!
Going through the floor behind the toilet is for cosmetic reasons only. At this point I'm leaning strongly going straight up through the roof and perhaps build a box around the pipe or so, if that pipe would bug me...
DW is already very happy with the idea we/she would never have to deal with black tanks anymore.... Sooooo...I could use that fact against her, potential, argument that the pipe bothers her...
I know, I know...brave here now....

(ps: Incinolet toilet)

Hmmm... just looked that up. Never heard of it before.

But, if I'm reading this correctly, this completely does away with the concept of a black tank, correct?

Not trying to talk you into our out of this solution, but here are my thoughts:

1. This will mean replacing the traditional bowl toilet with this. These things are pretty expensive from what I'm reading (~$2,000). It requires a dedicated 20A circuit to run, which means you're going to have to have a generator running every time you want to use it while traveling.

2. Running a pipe up from the bathroom through the roof is not something I would want to do on a $100,000+ RV. That's a whole lot of work that you're looking to bite off. I couldn't even get anyone to drill a hole in the roof so that I could get 12vdc up there for my AT&T Togo Roadlink. I can't imagine someone taking on this job on a new RV. You could run it down, and go 90º to the side, then put a vent cover on it to keep critters out. Since it doesn't get really hot, it's really just a matter of getting to the cover to remove it.

3. Installing this systems will mean uninstalling the traditional toilet. What are your plans when it comes time to trade in/sell?

3a. I personally would not even consider buying a used RV with this setup. You're going to get killed on resale. it could be the greatest invention to the RV industry, but not a lot of people are going to buy into a technology that - for the most part - nobody's ever heard of. Dumping a black tank 2x per week is something everybody knows and understands.

[John&Tammy]

Jim,
yes, it totally does away with the black tank ....stuff. Stand alone system so to speak.
When we're 'out' I'm usually at work and Tammy takes care of the rig. We've been doing this for about 10 yrs now and we both are sick and tired of dealing with black tanks and believe me...we tried all chemicals, non chemicals, flush systems etc etc. Ask anybody what happens when you have a Fantastic fan or Maxx Air running and somebody flushes the toilet and forgot to open a window....
And yes those toilets are pricy but also last you a lifetime and over time we've replaced a few cheap rv toilets, but that's not our decisive factor. Smell is the first thing, second flushing such a tank is second. I could go on and on but we just do not like the black...'system' anymore....been there, done that.

I was/am hoping to get a pipe routing out the side, but that may be hard to impossible as you pointed out as far as the space available for 4" pipe. Straight down would be ideal, I think myself, but that, most likely, would mean taking the black tank out. This would not be a problem either though.
Resale? If I'd suggest that to Tammy I would have to learn to sleep with one eye open!
All would be geared towards reverting back to 'original' and no matter which side it exits the rig....holes and the like can be fixed fairly easy.
I'll even keep the original toilet in the garage at home...
As for a dedicated circuit...there's already one close....the bedroom fireplace, which we never going to use anyway. I could install a separate sub panel since there are no more available spots in the panel now but there's no real need for that.
As for 'under way' to another place we have 2 options: the generator or the porta potty I have in the Volvo.
We do not travel around for fun, unfortunately. Locations are months at a time.

Preference is still going out through the floor straight down. 2nd: to the side. 3rd through the roof.
Either way...no more black tank for us! YAY. We just burn it, including my tampons....

[Jim1521]

Yeah, TMI on the tampons...

How much ash is sent out the pipe when "flushed"? If it's not a lot (and it doesn't sound like it is), then why couldn't you use 4" coming out of the unit, but then reduce the pipe size down to a smaller diameter (i.e. 2" or even smaller) for routing the piping?

[John&Tammy]

no ash out to the pipe. System doesn't allow that.
I asked Incinolet and they told me I can if absolutely needed but not advised.
The whole idea is to not restrict the 'squirrel' cage fan. I'm guessing longevity?
Unobstructed airflow is also better for the build in catalytic converter.
You can't smell anything from this unit.
Btw...it's not a new technology....they've been making these units since 1958 I believe...Mostly used in places where no water or sewage is close or present.
Just a vent to outside...('just' in a RV is quite relative...)
Appreciate your tips and help..

[BMullins46]

Since you are making a major modification the FR folks are probably concerned about liability issues should something go wrong. WHY are you putting in an incinerating toilet? only way I would even remotely think of that would be if you were turning the trailer into a permanatly stationary residence.

[John&Tammy]

Originally Posted by BMullins46

Since you are making a major modification the FR folks are probably concerned about liability issues should something go wrong. WHY are you putting in an incinerating toilet? only way I would even remotely think of that would be if you were turning the trailer into a permanatly stationary residence.

Well Bill,
every time I park my trailer in any RV park it turns into permanently stationary residence. The fact that I leave after a few months only repeats that process.
I briefly explained WHY we are going with an incinerating toilet.
I also don't see it so much as a MAJOR modification building wise. A major improvement, yes.
Try see it like this....existing toilet out, other toilet in.
Happens all the time. Lots of people go to 'composting' toilets and all they do is 1 out, new in.
Granted that it's out of the blueprint of the factory but it's not that far outside of the box.
In my case it's not a dangerous exhaust, but it has to go outside nonetheless and I'm trying to do that as least 'destructive' modification as possible and easiest to revert back to original. Briefly discussed that with Jim as you may have read above.
People have to open their camper belly all the time for various repairs/tank issues.....I only hope to do it once for installation.
To put things in perspective....drilling one 4 "hole (anywhere) in a camper... well...personally I do not consider that MAJOR surgery.

[BMullins46]

John&Tammy, it may seem to be minor to you, but in today's litigous society a manufacturer is very reluctant to say yes to any modification of their product. If something was to go wrong there are enough lawyers who would jump at a chance to sue because they assume the manufacturer has insurance and thus deep pockets. All you have to do is watch tv for an evening and you'll see their ads.


So far as your trailer goes, it's yours so you can do what you want to it, but I certainly wouldn't expect the builder to help because of the liability.


Good luck with your project.

[John&Tammy]

Well Bill,
you are probably right, but telling me how much room between a floor and a tank is, I would not think in liability terms, but again you may be right.
I come from a country where 'common sense' still prevails and sue-ing isn't possible. Still have to get used to that here, I guess...
Thank you for the success wishes though! I may need it.

John