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Discussion Starter · #1 ·
I'm looking for a safe place to put a gray water drain through the floor of my Metris. I want to replace my internal holding tank with something like this that I can hookup outside the van when I camping. The point is to save space so I can put in a larger fresh water tank and make it more convient to dump my grey water.

Based on the position of my sink, the passenger side tie-down located just behind the slider near the back wheel well is just about perfect for routing a drain on the inside. The location also looks like it will just line up with a void on the underside, just in front of the read wheel well. I removed the tie-down d-ring and bolt - by the way it is pretty beefy:

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I probed around in the threaded hole and the were no obvious obstructions. I could feel solid metal 2" down from the top of the hole. My plan would be to carefully drill out the threaded part of the hole so I could get a better look at what its below (i.e. make the hole bigger). That part seems safe enough.

I'm not sure what to do next. Does anyone know what the thickness of the floor should be? Does 2" sound right?

What is safer, drilling down through the void I made inside, or drilling up from underneath the van where I want the drain to come out?

Both options seem risky. Especially if what I'm feeling when I probe down 2 inches in not the outer shell of the underside of the van. I'm leaning toward drilling a tiny hole up from the underside of the van, with a drill stop in place - just enough to get through the anticipated thickness of the metal. Then I can look though the hole on the inside and try to detect some light coming though from my new hole in the underside.

If that works, and the two hole lineup close enough, I can enlarge each hole to the desired size for my drain. If it does not work then I just have a small hole to seal up?

Does anyone want to share any opinions, experiences, warnings, or snark?
 

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What kind gray water are you anticipating? What diameter do you want?

Any chance we could trick you into just keeping the internal tank? BTW: I like those Scepter brand jerry cans. You can pressurize them :)

Do you have the tracks out of your passenger van? When I did mine I feel like I saw daylight through some of the holes.

BTW: really like what you did with that low profile drawer project Custom Camper Van Console
 

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Discussion Starter · #3 ·
Thanks... the diameter of the hole will need to be 3/4 in. Our grey water in pretty clean... biodegradable soap, a little food - we wipe dishes thoroughly before washing, toothpaste and whatnot so in place where is is allowed and won't make a mess, I won't even hookup the external tank.

I have not replaced the tracks or explored much under the floor beside what I described above. I don't want to have to pull out my cabinet, fridge slider, battery locker, and seats if i don't have to.
 

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That's a good sized hole. Have you looked at the BEG?

There are some areas where you should not drill. I think that tie down is one of them. There is a section called areas of non drilling you can look at.
 

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Discussion Starter · #5 ·
Super helpful thanks @pounce! I had no idea we could get at the BEG by just surrendering an e-mail address.
That covers a lot of what I was looking for.

It looks to me like the tie-down I'm looking at is just outside of the longitudinal member (non-drilling zone). I'n any case I want a point that is outside of the longitudinal member since that is a big obstacle under the van. I think the passenger tie-down I want to drill out is the same on that I marked with a red arrow of the photo @RansomRidge uploaded:
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Looking at he BEG, here is where I think the hole would be relative to the structural members
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And the fuel, wiring duct, and exhaust non-drilling areas:
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Super helpful thanks @pounce! I had no idea we could get at the BEG by just surrendering an e-mail address.
I had attached it to my post so you didn't even have to leave the thread. But you should also know that the site doesn't validate email addresses so you can put anything in that looks like an email.

To me this suggests that the tie down is a bracket or more than just a hole in the floor. Who knows if the illustration is factual.


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Also, there is this note:
 

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You can maybe consider running the hose out the back panel where the wiring for the trailer hitch runs under the bumper.
 

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Discussion Starter · #8 ·
Thanks again. I have my external solar panel connector running out the back panel and I will take a look at that option again. And yes, I was just curious about the source of the attachment and what else might be there. It looked like everything else was sprinter-specific. I didn't see any model-year-specific BEGs for Metris.
 

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Yea, they only have the one guide for Metris, but they have updated it. Not much if anything has changed on the van.

Let us know where you finally tunnel out. I'm curious.

Maybe there is an easy way to go through the step area ahead of that no drill area. At least you could always cover it up with another plastic replacement part later.

I saw these totes. Would fit under the van.

 

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Discussion Starter · #10 · (Edited)
I will update this thread as I go. Based on a review of the BEG, I will definitely avoid the tie-down bracket. There is no need to drill it out.

I think the winning location will be through the slider step and out and existing hole. Under the van, just behind and below the step (right behind the bottom slider door track), there are a few holes with plastic plugs. One of them is a convenient location for my drain. Here is a shot with the plug removed:
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Under the plastic step trim there is a relatively thin metal plate that holds the tabs that keep the step trim in place. Under that is the void you see through the hole. I drilled tiny exploratory hole through the plastic and metal and could see the drill bit poking through. Here is where I would drill the final hole:

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The picture shows the corner of my galley cabinet frame and the back of my fridge slide.
Not quite as clean looking as it would have been in a different location, but it is more easy reversed with some new trim parts or just a plastic plug. And no drilling through the van floor. I'll put a rubber grommet back in the hole under the van and put my hose through the grommet.
 

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Hi @brow, you might be on to something. I happened to see your post earlier today and this evening was in that area guiding some wire.

You may already have knowledge of this but I snapped a few photos that might assist you. I shined my little flash light from the above and below and there appears to be an already existing hole by the last screw holding the metal step bracket (below the plastic). In my case it seems that hole has some type of membrane (maybe a roadside underbelly protectant) that is semi translucent with light. My photos are from the driver side and I circled the bolt that has that existing hole below (at least on my passenger van).

Below plastic step there is a metal shelf support bracket:
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Right below that, this is how the surface looks like:
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Shining light from bottom with camera on top:
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Same angle but closer look into the hole.
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Photo from bottom with light on top. The membrane seen in the next/last photo is semi translucent and feels very thin/flexible:
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Underside of my van approx. where the light was shining through:
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Discussion Starter · #12 ·
Wow @thefinnisher, that is BEYOND helpful. You have definitely solved a few mysteries for me. In the hole pictured below, I could see one of the black plastic clips protruding into the void, but only one.
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I expected to be able to see or feel a few more clips, but from this photo you provided (I added the blue circle):
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It is clear that only three of the seven clip protrude into the channel. The clip that I could see looking into the void from below is the one I circled with blue above. It seems to poke through the foil membrane you noted, but some of the membrane is visible surrounding the clip. You can actually see a reflection from the foil in my photo of the hole (@10 o'clock against the edge of the hole). From the side view I could see the sandwich of metal that sits under the plastic step, but I believed that only the shelf support was present where I wanted to drill since I could see the clips. But clearly three of the clips go through the shelf support and the painted metal surface just below. Not a big deal, I drilled through both easily with my tiny exploratory hole.

The most significant piece of information I was missing is THERE IS A WIRE that runs in a channel between the two metal surfaces against the back wall of the step. I will need to avoid that! It should be no problem, but I will choose the location for my hole to provider a wide margin for error. Thanks again for posting these pictures.
 

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I feel like I'm watching a game of Operation! Be careful, there's 'lectricity in there!!!!!
 
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@brow glad that helped. I think you are on the right path. Keep the drill straight and avoid those 'lectricals as focus called them. Would enjoy to see how it all comes together.
 

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Discussion Starter · #15 · (Edited)
Did the deed. Through the plastic and metal tray below the plastic.
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Then all the way.
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I'll probably use this 7/8" OD hose - that is what I used for the hole diameter.
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And out:
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I'll use some grommets around the hose to clean up the final installation. I'm not sure If I will use a fitting on the drain end of the hose or just slip it inside a "friction" fitting I put on the tank.

The inside location is not as tidy as I would have liked, but is it is usually covered up with my stored lagun table top:

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Normally my fridge is on the slide and when I extend the side I can get my clean and gray water bottles out though the open frame in back. Now that I don't need internal gray water storage, I'm upgrading from a 4 to 7 gallon fresh water tank.

On another topic... pricey but love these window bags for passenger vans:

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I've seen those bags and wondered about them. Mostly seen them on the VW vans. I worried what would happen if the airbags deployed since it blows out above them. Great concept though and they really got my attention.
 

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Discussion Starter · #17 · (Edited)
I wondered about the airbags as well. they fit pretty nicely into the recess around the window. Even so, I decided that we would just use them for clothing and not use them in place with rear passengers on board and stow them on long legs of a road trip.

I have no idea if that mitigates a problem with air bag deployment or not, but makes me feel better.
 

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Discussion Starter · #18 · (Edited)
Finishing up here...

I have my new 7-gallon water tank installed where my fresh and gray water tanks were. I added a fill tube with a breather valve so I can fill the tank in place. The sink drain now exits through the hole in the step.

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Behind the filler cap
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With fridge slid back in
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Discussion Starter · #20 · (Edited)
Looks good. What are you using to catch under the van?
I have a two-gallon accordion water container, but it is clear poly. This size is good, and it is easy to store, but I don't like how dirty it looks. I'll probably get something like this:


And modify the cap.
 
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