Progress Report and Question about FW Overflow/vent

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Progress Report and Question about FW Overflow/vent

May 30, 2013, 11:25:33 pm

The goal of getting the coach back on the road is getting closer! There is still a fair amount to do, I know... but looking back, the project has come along way and changed in scope several times. I'm starting the process of putting utility bay back together. Today I caulked the rear bulkhead insulated fiberglass skin. Seeing that sheet metal bulkhead covered up for the first time in a very long time sent shivers down my spine! It feels like another significant milestone's been reached, because whatever else I might've thought to do or redo back there is now put to bed because that area will never see the light of day again. Gluing that 2.5' x 8' fiberglass and insulation wall in place was a bit of a challenge and took a bit of clamping ingenuity. I use polyurethane construction adhesive in place of the original contact cement. Even though the glue is high-tach, clamping was mandatory because the wall was bowed a bit. There are three layers of caulking protecting the bulkhead joint. First layer is underneath the bottom fiberglass skin, second layer is the between the bulkhead wall and the top of the fiberglass skin (I used black polyurethane roof flashing for these first two layers), and finally the white polyurethane caulking between the fiberglass bulkhead covering and the bottom skin.

Now I have to figure out how to reconstruct the plumbing. I need to drill holes through my aluminum plates for the drain lines and figure out how to vent the freshwater tank as well as provide the overflow, which brings me to my current question. I don't want to route the overflow vent pipe out over the bulkhead as it was originally done at the factory. I know many have run that pipe down through the floor behind the maniblock in the waste tank compartment. Since my freshwater bay is in a virgin state, and there is no water heater to obstruct my access, I plan to run the overflow down through freshwater bay floor alongside the other drains. My question is, how can I provide the vent for the freshwater tank and still prevent the sloshing during left turns when the tank is full? My current thought is to run the vent/overflow tube up and tee into the washer dryer vent stack which is in the bottom of the closet right above the freshwater tank. It seems to me that as long as the tee is a bit above the top of the freshwater tank, it should not slosh and yet will still vent through the plumbing stack in the coach. When filling the freshwater tank with the city water inlet, it should still overflow out the bottom once it reaches the height of the tee. Now it may slosh a little bit but that would only last as long as there was water in the tube above the level of the tank.

Now, it's not like I have my heart set on this particular implementation, and I am certainly willing to be instructed from those of you who know this game so much better than I. what do you think? Is my idea as described above a viable solution? Other ideas? Since I basically have a clean slate here with no holes in the floor of the utility compartment whatsoever, I want to try and get this right the first time! Of course, one of my main goals is to keep water from accumulating in the floor of the utility bay or it might eventually enter into the basement framing down below (perish the thought!). I'm sure that those of you who have been following my never ending project will understand why I feel strongly about this...

A little side note here... You can see in two of the pictures two 12"X12" pieces of plywood that are inserted in place of insulation behind the fiberglass. One is in the top street side corner and the other is 8" from the curbside edge about 4.5" up from the deck. I took pictures of these two pieces of plywood with the measurements written on them so that I would be able to refresh my memory in the future as to their location just in case I want to use the plywood for mounting something, which is presumably why they were put there in the first place. My guess is that the location is similar for coaches of this vintage. Many of the pictures that I have seen of the fresh water pump shows it being mounted on the wall in location of the curbside plywood square. Our water pump was mounted on the deck between the water heater and freshwater tank which is where I plan to put the new one that I will be installing.
Don

Re: Progress Report and Question about FW Overflow/vent

Reply #1 – May 30, 2013, 11:59:52 pm

Do not connect freshwater tank vent to gray-water vent. Do not want to allow any contamination of fresh water.

We just spill a little if fresh water tank is very full. We try not to fill fresh water tank to very top, to reduce tank stress. We allow a few inches from top, enough to be below overflow.

Our overflow has only one hose and it goes through floor far from bulkhead. It sticks down a couple of inches below floor and is covered with a screen to keep critters out.

Re: Progress Report and Question about FW Overflow/vent

Reply #2 – May 31, 2013, 08:44:39 am

Water will inevitably get into the bay's floors...trust me. All you have to do is drain the hot water tank once without placing some sort of catch to get the water as it exits the water heater.

James Stallings suggested pre-drilling a few small holes in strategic places to allow water & moisture to find a way out once inside the bay.

Re: Progress Report and Question about FW Overflow/vent

Reply #3 – May 31, 2013, 10:56:55 am

I second Peter's comment about water inside the bay...it will happen, and probably the first time you turn on the water too!!!

I would run the overflow up through the floor (as high as you can go, maybe to the top of the washer/dryer) and turn it around (two 90 degree fittings) and then straight down through the basement floor. After filling the tank until it overflows, it should take very little water usage to drain out the riser section and then you should not have any overflow on the road unless you make a very high G left turn (depending on how high you put the two 90 deg fittings). I also don't know if you need to use a large of hose as the original. I would think a 1" would be more than adequate, maybe even 3/4".
This is what I was planning on doing on my coach but, as yet, is still untested.

Re: Progress Report and Question about FW Overflow/vent

Reply #4 – May 31, 2013, 12:31:00 pm

Thanks Barry, that makes sense to me. In fact, it seems obvious now that you mention it... As you can tell I'm still a newbie when it comes actually using these coaches! I didn't think that the gray tank could contaminate the freshwater tank just by having them share the vent connected, but I certainly wouldn't want to take a chance that fumes from the gray tank would contaminate the FW tank.
Don

Quote from: Barry & Cindy – May 30, 2013, 11:59:52 pm

Do not connect freshwater tank vent to gray-water vent. Do not want to allow any contamination of fresh water.

We just spill a little if fresh water tank is very full. We try not to fill fresh water tank to very top, to reduce tank stress. We allow a few inches from top, enough to be below overflow.

Our overflow has only one hose and it goes through floor far from bulkhead. It sticks down a couple of inches below floor and is covered with a screen to keep critters out.

Re: Progress Report and Question about FW Overflow/vent

Reply #5 – May 31, 2013, 12:39:35 pm

Good point Peter. I have been thinking along similar lines to putting in drain holes, but I have been able to come to any conclusion as to how to execute the idea. Did James Stallings mention as to where he thought the strategic locations for drain holes should be in the floor? The corners are out because of the framing, so as close as you could get to the corners would be about 4 inches in. I'm not too worried about the odd spillage water on the floor the bay, as I'm going to be very sure that all the holes and penetrations through the floor are well caulked. Of course, standing water down there cannot be tolerated! So I plan to add some sort of water alarm in strategic places down there... Like under the waste take plumbing valves, behind the maniblock, and near water pump and water heater.
Don

Quote from: Peter & Beth – May 31, 2013, 08:44:39 am

Water will inevitably get into the bay's floors...trust me. All you have to do is drain the hot water tank once without placing some sort of catch to get the water as it exits the water heater.

James Stallings suggested pre-drilling a few small holes in strategic places to allow water & moisture to find a way out once inside the bay.

Re: Progress Report and Question about FW Overflow/vent

Reply #6 – May 31, 2013, 12:41:09 pm

Thanks John, that sounds like a workable idea... I'll put it in the hopper along with all the other things floating around in my head. It's getting rather crowded in there...

Don

Quote from: JohnFitz – May 31, 2013, 10:56:55 am

I second Peter's comment about water inside the bay...it will happen, and probably the first time you turn on the water too!!!

I would run the overflow up through the floor (as high as you can go, maybe to the top of the washer/dryer) and turn it around (two 90 degree fittings) and then straight down through the basement floor. After filling the tank until it overflows, it should take very little water usage to drain out the riser section and then you should not have any overflow on the road unless you make a very high G left turn (depending on how high you put the two 90 deg fittings). I also don't know if you need to use a large of hose as the original. I would think a 1" would be more than adequate, maybe even 3/4".
This is what I was planning on doing on my coach but, as yet, is still untested.

Re: Progress Report and Question about FW Overflow/vent

Reply #7 – May 31, 2013, 04:45:03 pm

Don, The drainage holes should be as close to the corners as practicable. Should you have an accidental spill, then you can just lower one side or the other so as to bring most of the water to the nearest hole. When you get to this point of the job ensure you caulk well abounf the utility bay faucet area where there is plenty of opportunity to have water spills.

Re: Progress Report and Question about FW Overflow/vent

Reply #8 – May 31, 2013, 08:32:58 pm

@Don,

I keep a large soft sponge in my wet bay to quickly start bailing after I've controlled the inevitable leakage. Like others have said...It will happen! Usually due to operator error.

see ya
ken

Re: Progress Report and Question about FW Overflow/vent

Reply #9 – June 01, 2013, 10:13:48 am

I think it is important to use the same size drain hose on the overflow of the tank. I think they used the large size to prevent the possibility of back pressure on the tank when the tank is full and your dumping water on the ground. With 30 or more PSI of water going in and to small a drain you would be able to build up a back pressure inside the tank .Even a few PSI and the tank will try and go round. 80 gallon tank has 8500 square inch of surface area. Even 2 PSI of back pressure and that's 17,000 pounds of pressure on the tank walls.Gam

Re: Progress Report and Question about FW Overflow/vent

Reply #10 – June 01, 2013, 09:57:14 pm

Thanks Gam. I bought a longer hose that is just slightly smaller than the original one. I feel confident that it will certainly let enough air in to avoid building up too much of a vacuum in the tank. I plan to run it up into the bottom back of the closet and then back down through the floor. That should avoid most of the sloshing issues.
Don

Quote from: gam – June 01, 2013, 10:13:48 am

I think it is important to use the same size drain hose on the overflow of the tank. I think they used the large size to prevent the possibility of back pressure on the tank when the tank is full and your dumping water on the ground. With 30 or more PSI of water going in and to small a drain you would be able to build up a back pressure inside the tank .Even a few PSI and the tank will try and go round. 80 gallon tank has 8500 square inch of surface area. Even 2 PSI of back pressure and that's 17,000 pounds of pressure on the tank walls.Gam

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Progress Report and Question about FW Overflow/vent

May 30, 2013, 11:25:33 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #1 – May 30, 2013, 11:59:52 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #2 – May 31, 2013, 08:44:39 am

Re: Progress Report and Question about FW Overflow/vent

Reply #3 – May 31, 2013, 10:56:55 am

Re: Progress Report and Question about FW Overflow/vent

Reply #4 – May 31, 2013, 12:31:00 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #5 – May 31, 2013, 12:39:35 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #6 – May 31, 2013, 12:41:09 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #7 – May 31, 2013, 04:45:03 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #8 – May 31, 2013, 08:32:58 pm

Re: Progress Report and Question about FW Overflow/vent

Reply #9 – June 01, 2013, 10:13:48 am

Re: Progress Report and Question about FW Overflow/vent

Reply #10 – June 01, 2013, 09:57:14 pm

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