Holding tanks

[andyg]

I was reading about Kenn's build in the "Frame Welding" has reminded me of an issue with my coach. For some reason NRC used equal sized tanks for the black and gray water. Most people produce much more gray water then black. The RVs I have been around always had a larger gray water tank. When using my toter last summer I did have trouble with the gray tanks filling up while the black was nearly empty. Changing tanks would not be practical. I'm thinking about rigging an overflow from the gray into the black tank. Has anyone else done this?

[bushpilot]

my haul mark is basically the same - 60 gallons each if i recall
strange cause ive got 210g capacity of fresh water

ive heard suggested that some folks "leak" their GRAY water down (after dark)...
ive done it (w/ permission) when ive camped in my brother in laws drive way...he was happy to have the water for his lawn.

I also do it when i "camp" on the curb at my parents and in-laws
*I* know my gray water is CLEAN...nothing but soapy water - so its really not a big deal.

I'd be concerned that an overflow could allow odors (and waste) to escape into the gray tank

[hot rod]

I seem to remember or misremember from blizzardnd's build that his gray water tank has a pump to transfer gray water over to the black water tank to dump. Just wire in a demand pump on a switch to transfer. I don't think I'd want just an overflow pipe as I would think you would get odor and possibly backwash from the black tank.

I'm not a fan of dumping gray water on the ground, but I know a lot of guys do. Our trailer only gets gray water from the bathroom sink, just soapy water like you said and we do put the appropriate treatment in it, but it can smell amazingly bad for soapy water at times.

[bushpilot]

Originally Posted by hot rod

I'm not a fan of dumping gray water on the ground, but I know a lot of guys do. Our trailer only gets gray water from the bathroom sink, just soapy water like you said and we do put the appropriate treatment in it, but it can smell amazingly bad for soapy water at times.

Texas & Florida were so dry last year my brother in law was practically BEGGING me to "water his lawn" w/ our gray water.

interesting - ive leaked my gray water SEVERAL times (and never had any odor)...even when its sat w/ gray water in it for several weeks....and my treatment of gray water is on the LIGHT to NON-EXISTENT

now that BLACK tank PHEW - even w/ light <urine only> use...and we are heavy on the WATER/DILUTION ratio use...doesnt take much for that water to STINK.

[andyg]

Sometimes I can't let the gray water out on the ground. The shower and sinks have traps to prevent odor from the tank. I would connect between the tank and the traps so stink should not be a problem. I'm also pretty sure that the holding tanks are vented through the roof. I could just open both dump valves with the cap still on the outlet but you can imagine how messy that would be. I think I can pipe an overflow from the gray into the but I would have to be careful not to let the black get full also. I do have tank monitors and would have to keep an eye on them.

[SHORTS]

IIRC Haulmark is using 3 identical waste tanks, black plastic, 1 black and 2 for grey, they looked to be about 2 ft wide and fit all the way across the coach with a large sump that used most of the basement space on the right side of the coach

[bushpilot]

Originally Posted by SHORTS

IIRC Haulmark is using 3 identical waste tanks, black plastic, 1 black and 2 for grey, they looked to be about 2 ft wide and fit all the way across the coach with a large sump that used most of the basement space on the right side of the coach

our haulmark does NOT use 3 waste tanks...and ive never seen one that used 3 OR any conversion trucks that had tanks that went across the width of the coach...not sure how they'd do that w/ the drive line in the way.

our 65 gallon "gray & black" holding tanks are only on the road side - accessed by a SINGLE basement/bay door.

[andyg]

I had a chance to look today. I have (2) 24 gallon tanks. I'm not sure why they used such small holding tanks when there is room in the compartment for more capacity.

[SHORTS]

I went thru the haulmark factory in early october and the new units that I saw had tanks that were mounted ahead of the rear axle, above the truck frame and below the floor structure, about 24 '' wide,4 to 8'' deep with a 24'' deep sump on the road side, IIRC they are 65 or 70 gal each, with a spiffy manifold and drain system all mounted in in the cabinet. potable water was either 150 or 200 gal under the master bed depending on center or side mount.

[bushpilot]

Shorts - i DONT believe thats their "conventional" build and certainly youll find far fewer units built like that....how do they manage getting WASTE water in a holding tank thats higher than the FRAME the floor is built on ?

I've seen pictures of ONE unit that had a raised REAR sleeping quarters...which permitted a 2nd level of basement storage (above frame)...which allowed for pass thur storage - it had FRESH water tanks in the pass thru, but again fresh water is PUMPED to the faucets / showers etc.

im wondering how they could get gray/black water to drain into tanks that are above the floor/frame.