1975 Tradewind - grey tank removal?

[Chuck]

Originally Posted by SmokelessJoe

You interpreted AT the axles as ABOVE the axles, I think.

yep. I did.

Originally Posted by SmokelessJoe

I mean in the area of the axles, up close to the front or rear axle.

yep, that's my plan. as close as possible to the rear axle. It would look very much like the picture...except I don't much care for the position of the dump outlet. very precariously perched behind the tire. I know, that's the way "everybody" does it, but I've heard many stories of tire blow-outs completely taking out that whole assembly, emptying the tanks all over the roadway, and pretty much ruining people's vacations, because from that point on...no more water use.
anyway..in the pic, is that the axle mounting plate I see there behind the valve handle? or is it a shadow? if its the plate, then I think my imagined plan would look very much like that.

But you had said before that you didn't think it would be a good idea to put the same thing in the rear of the trailer. why? clearance? or just too much weight, with the additional moment-arm created by being so far away from the axle?

on my trailer, from the location of the axle to the rear of the trailer, there are three 2-foot wide cavities created by the frame and x members. I would put the grey tank in the one closest to the axles. (the existing galley drain pipe already comes through the floor in that location, so it could easily be attached to the top of the tank to vent it). the middle bay would be skipped over, as its space is consumed by the shower p-trap and drain pipe. The aft bay could house a black tank in the same manner as the grey tank pictured.
which is pretty much what you're doing, right?


oh, and that round thing: I don't know, but I wonder if it is in fact a door stop? if that piece of banana wrap is actually a compartment door that folds down, it could be there to keep it from "banging" into those plumbing fixtures. the painted surface would get scratched up otherwise. just a guess.

[SmokelessJoe]

Chuck:

I wish I knew how to make those neat “quotation” outlines you use.

(Can anyone tell me how it’s done?)

I took the photo at Can-Am’s lot. I think it was one of those combined 70 gallon black/grey tanks Airstream built for only one year.

It’s generally agreed that combined tanks is not so good. You lose flexibility.

Their plumbing does look very fragile and exposed. Ours is being enclosed in a compartment. The sheet aluminum used is much heavier than that used in the Argosy body.

I think a tire blow out would wreck the body and the flimsy plastic wheel well covers before the compartment.

We are putting on new wheels and new tires so that should lessen the chance too.

You do see the axle mounting plate in the photo of the International or Safari, or whatever it was.

Having a deep tank at the rear is probably not good for all the reasons you suggest: clearance, weight, moment-arm.

I think you should go as shallow there as you can.

We are using the space much as you imagine, except that the grey tank was 32” wide so we had to move a cross member. That is usually possible.

Maybe that is a compartment door above the main drain in the photo. I didn’t notice. That would explain why the “stop” is there, so the drain doesn’t scratch the body panel.

Our compartment door will open DOWN so as to be less in the way.

Sergei

[Chuck]

Originally Posted by SmokelessJoe

Chuck:

I wish I knew how to make those neat “quotation” outlines you use.

(Can anyone tell me how it’s done?)

Easy! what you do is start off your reply to a given post with the "quote" button, instead of the "reply" button. that will copy the quoted post in its entirety into your composition window, but it will append the quoted text with some html code that tells the web server to make a quote out of it. I can't type the html code exactly, because if the server sees that, it'll make a quote out of something, and you won't see what it was that I typed. so...the first character is "[". then the text as follows: quote=smokelessjoe. then this character: ] closes the command. When the server sees that, it'll make a "quote" out of the text that follows, until it sees [ followed by / followed by quote, and ending with ].

go ahead and find any post by anyone, and click the "quote" button, as if you're going to reply with quoted text, and you'll see what I mean.

So, if you want to use multiple quotes, all you have to do is type out those same commands on either side of the text you want to quote. type your response after the [ / quote ] . start the next piece of quoted text with [ quote=whoever ]. highlight and delete the text you don't want. when you're done, click on the "preview post" button, and that'll show you how it will look to others. if it all looks right, click "submit reply".

Originally Posted by smokelessjoe

I think a tire blow out would wreck the body and the flimsy plastic wheel well covers before the compartment.

yes, I'd say that looks secure. But I'm not just talkin' airstreams...SOB's, too. one friend of mine had this happen to him on his Winebago MH. Seems that ALL rv manufacturers just let that fragile, yet very important stuff just hang out there, inches above the road. any good speed bump or pothole could take it right out.

Originally Posted by SmokelessJoe

Having a deep tank at the rear is probably not good for all the reasons you suggest: clearance, weight, moment-arm.

I think you should go as shallow there as you can.

yep. but the thing I'm thinking is that for the 3" drain pipe to get past the frame, it should hang below it. so, an 8" tall tank would fill the cavity (5"), and the pipe could come straight out and still clear the frame. That way, a back-flushing device could spray water straight into the tank. any bends in the output of that tank would minimize the effectiveness of that sort of "power flush". (check out "the sewer solution", if you're not already familiar). Of course, your design more than compensates for that, but with added complexity and expen$e.
As for the weight issue way back there, I'm thinking:
a) don't drive around w/ a full tank. (we almost never boondock, anyway, so there's almost always some sort of dump facility available).
a1) beef up the shell to frame attachment when I'm in there tearin' it all apart. (I have damaged floor to replace back there, as well, that needs to be addressed).
b) use a smaller tank, and just mount it lower. as long as the outlet is just under the bottom of the frame rail, there's no need for the rest of the tank to completely fill that cavity.

of course, I call this my "plan"; it would be more appropriately called a "fantasy", because Lord only knows when I'll actually have the time or gumption to undertake such a project. I'm all talk.

But hey, I know how to use the "quote" function on the forum. that's gotta be worth somthing.

[Chuck]

wanted to just add: this pic sums it all up...with an explanation.

it is of the middle of the 3 frame cavities that are aft of the axles. Pic is shot facing the street side of the trailer. The p-trap is the shower drain. Its drain heads toward the curbside, bangs a left, and goes aft to the existing sewer outlet. That pretty much excludes most of the space here for any other use.
The forward bay would house the gray tank. The axle tubes don't interfere here at all; they cross at the next forward bay, so a tank could be installed/removed as necessary without much trouble. The drain pipe in the background that slopes right to left is the galley drain; it could easily be dropped into that forward bay, into the top of a tank, and provide the vent.

I can't really expand that forward bay by moving the cross members, because as you may see in the pic, right above it is a gusseted floor seam. the cross member is shorter by 3/8" to accomodate that seam, which is exactly 4' forward of the back of the trailer. (first 4x8 sheet of plywood ends here). the cross member on the other side of this bay (not seen in the pic) is too close to the axle tube.

the cross member on the left of this center bay is the one to which the BAL stabilizer jacks are attached. So if I want to keep those, (and I do), that one can't be moved. (also, the legs of the jacks swing down from the belly, and that precludes running any drain lines beneath the belly pan in this area). So I think I'm pretty much stuck with working within this alloted space.

So, my fantasy is to get a 8" grey tank that slopes to a center aft-facing drain. (Ameri-Kart H882 http://www.kart.com/rv_catalog/14_H%..._29_Gallon.pdf). The drain would hang just below the belly pan, and a drain pipe could run down the center line of the trailer, so as to go in between the jacks. Then I put a 90-degree elbow and head for the streetside corner area to tie into a sewer outlet.
a black tank could fit in the aft bay, with an outlet that points straight out to the streetside.

OR, I could skip the black tank, and just have that grey tank drain meet up with the existing sewer drain, which is located in the center of the trailer, just forward of the rear. (it doesn't exit in the aft streetside corner, like most campers, airstream or sob). The existing black tank sits on the floor, inside the trailer, and its drain just goes straight down through the floor and belly pan.

another option would be to get the type of tank that's lowpoint would be located toward the streetside, (6.5 or 8" deep, so the drain is just below belly pan level) with an outlet pointing aft. (H052, same link as above). I could snake the drain line to the outside of the frame rail through that gap between the axle mounting plate, and the frame extension (who's purpose is completely unknown; there isn't one on the other side of the trailer; its much lighter guage metal than the frame c-channel...doesn't appear to do anything, or protect anything. the hole in it is for the acutator of the BAL jack to stick through to the outside) with a couple of elbows, and follow along the frame member to a rear corner sewer outlet. But more of the system would be exposed...visible (ugly) and in the line of fire of blown-out tire.

the pic: