Fitting tanks between frame

[bwaysteve]

I am having to replace my black tank and install a gray tank.I have the frame exposed and am having trouble finding a stock tank with the depth of the frame.
How much leeway do I have past the bottom of the frame when it comes to reinstalling the bellypan?
In otherwords I have about 6 " of depth.Can I go 8 and make the bellypan fit over the additional? How do I plan this out? 65 Ambassador.

[Inland RV Center, In]

Originally Posted by bwaysteve

I am having to replace my black tank and install a gray tank.I have the frame exposed and am having trouble finding a stock tank with the depth of the frame.
How much leeway do I have past the bottom of the frame when it comes to reinstalling the bellypan?
In otherwords I have about 6 " of depth.Can I go 8 and make the bellypan fit over the additional? How do I plan this out? 65 Ambassador.

I wouldn't unless you severely beef up the shell to frame hold down at the rear.

Andy

[bwaysteve]

Andy, The plan is to install a gray tank behind the rear axle.The frame space is only 5 in. deep.Can't find anything that shallow to fit that is long enough.I did find 2 10 gallons that were 4in. Maybe I could daisy chain together?Does this need a pan or could straps be used?Wnen doing my tearout the black tank was sitting on a 2x4.Was a pan originally used on a 65?
I know Inland has the stock black at least.Any advantage to tying the gray into the black with a gate valve for flushing through the black or is this just asking for trouble? Thanks

[silverleeper]

You can order a custom tank. This is one place I found. Plastic-Mart. You can use straps to hold the tank up. The black tank on a 2"x4" does not sound factory. My 67 black tank was in a galvanized steel box supported by two L-bars.

[Chuck]

as with everything, "it depends"....on your budget, among other things. Yes, you can get a custom tank to fit that area; it'll cost 2-3x what a "stock" tank costs, and still won't be all that big. well...again, that depends on just how much room there is in your trailer; in mine, the x-members in the frame are equally spaced. in others, they are not. Some people have re-located x-members to accommodate a larger tank; that wouldn't be practical with my particular trailer.
My personal opinion: buy a stock tank, big enough to be worthwhile (another subjective judgement. mpo: less than 25g="why bother?" ), and let it hang below the frame, cut a new belly pan to fit. (see RJ's restoration at Vintage Airstream Home for an example). Nobody's going to see it under there, anyway.
I may do this, but stack a 3" c channel below the existing c-channel frame (which is essentially how sub-floor tanks are supported on old and new trailers), creating an 8" deep space. then cover it up w/ new belly pan, enclosing everything. it won't look original, but it'll still look "factory". or "factory-like".
and of course, as Andy says, beef up the frame-floor-shell attachment as appropriate to handle the extra weight.

[vinstream]

One black tank between frame rails should do! (should be around 25 gal) However, one grey tank maybe a little small! I would put two grey tanks (45 to 50 gal) in and not go past the bottom of the frame rails! The bellypan in this vintage of trailer is part of the structure of the trailer!!! It helps keep the frame rails in line and helps the entire frame from excess movement. Do not cut below the frame would be my advice!!!

Todd

[Chuck]

Originally Posted by vinstream

The bellypan in this vintage of trailer is part of the structure of the trailer!!! It helps keep the frame rails in line and helps the entire frame from excess movement. Do not cut below the frame would be my advice!!!

Todd

Really??? thats the first I've ever heard of that. I'm no "vintage airstream structual engineer", though. But it would seem to me that if rigid plywood bolted to, and welded steel x-members can't keep the frame rails straight, a thin sheet of aluminum isn't going to do much.

[VIKING]

One of the most popular grey tanks for '60s Streams is the Inca plastics H517. It will hang below the pan where the drain is located, which it must do in order for you to drain it. You may fit a bigger tank than this due to your increased frame depth(mine is 4").

Rich the Viking

[Inland RV Center, In]

Originally Posted by vinstream

The bellypan in this vintage of trailer is part of the structure of the trailer!!! It helps keep the frame rails in line and helps the entire frame from excess movement. Todd

Todd.

The underbelly that Airstream uses, "DOES NOT" keep the frame from doing anything.

It does well to take care of itself, let alone support or hold together the chassis.

That is true at least for the 1936 and up to and including the 2011 models.

The underbelly, if nothing else, is considered a cover, and helps the trailer to be more aerodynamically clean.

Andy

[vinstream]

It very much is apart of the structure!!! It makes the intire frame more ridged! No by itself it does not do much but in combination with the rest of the parts it does make a differance! If you place only the belly pan on a bare frame like I have the entire flex of the frame from back to front is cut by a solid 1/3! When the floor and belly pan are on there it is even a further reduction of flex! It is no differant than the walls of the trailer!
Todd