Advertised tank size vs. actual

[Tamaroak]

We have a new 2019 25’ FC RBT and did a test of our black, grey and freshwater tanks to check the accuracy of our gauges. Imagine our surprise to find that our tanks held 27, 31 and 29 gallons respectively! The advertised gallonage is 35, 37 and 39 gallons. We intend to test again, but this will seriously impact our boondocking ability. Test began from level site, everything drained. Filled grey and fresh with calibrated bucket until they overflowed. Note: black backs up bathroom sink drain, grey into shower drain. Freshwater capacity measured by timing flow, maybe not as accurate. We will test again. Sent info to AS customer service.

[mtbmitch]

Wow, huge difference

[OTRA15]

Thanks for the 8/29/19 heads up. Not good if accurate. Please update us with Airstream's reply and new test results, Tamaroak. Are you still monitoring this thread?

Thanks,

Peter

[billrector]

So bathroom sink is connected to the black tank?

[A W Warn]

Instead of inaccurately measuring the water going into the fresh water tank, fill the tank and drain it into the measuring vessel. This can be drained using the pump through a faucet and/or tank drain in combination. (and recycled for the waste tank test)

Pour the test water through the open toilet flapper for the black tank.
Pour the test water through the shower for the gray tank.
Those are the lowest fixtures, so will give the best result.

The bath sink is connected to the pipe that is the black tank vent. If that pipe extends into the tank slightly from the top, or enters through the side of the tank, it can create a bubble of trapped air inside the tank that can't be displaced with water. Opening the toilet flapper will let some of this air escape, allowing more water in.

A similar bubble condition can occur with the gray tank and fresh water tank (if vent is side entry into the tank).
What this means is: the full volume of the tank is not usable for storage.

[Cyclist]

Originally Posted by billrector

So bathroom sink is connected to the black tank?

It is in our 28. I know our fresh water tank is close to as advertised as I've occasionally filled it, when in storage and not near a tap, by using 4 litre jugs of water and a funnel.

[thewarden]

Originally Posted by billrector

So bathroom sink is connected to the black tank?

On my 2016 27FB Serenity it is. I believe it is the same for the 25s.

[Dremel]

That is a lot off.
Question: was the hot water tank already full? just wandering if that is where all your fresh went to.

[Tamaroak]

I have registered complaints with Ohio Attorney General and the BBB. It looks like Airstream is OK with an unsatisfactory resolution to both. The issue for me is that the blackwater tank has a useable capacity that is only 75% of what is advertised. Their customer service representative told me the purchase a 37 gallon tank and sent me a photo, showing a “37,” and say that they may be installed in a manner that doesn’t allow the full volume to be available. I’m sure that’s the case. Why not advertise the useable volume then so that a buyer could make a fair comparison? And am I supposed to turn the camper on it’s side to get all of the blackwater out before filling? And the only realistic and fair way to judge this is to dump from a level spot and pour a precise amount of water into the toilet until it comes up to the floor, which I have done twice. I’m going to Jackson Center next month and will demonstrate the issue with them before I take further action.

[GMFL]

Have you verified your method for measuring? A 5 Gallon bucket is not very accurate. And are you absolutely sure the tank was bone dry when you tested it. Most of the tanks do not drain completely when you dump due to valve placement.

[Bill M.]

What would be a satisfactory resolution for you?

One of the problems is that it is a long, rectangular tank with only one air outlet and if it is tipped in any direction that will reduce its capacity. Either tipped in installation or in use.

"And am I supposed to turn the camper on it’s side to get all of the blackwater out before filling?"

That is pretty much a yes.

When I want to fully drain the tank, like before storage or when I am going to work on it, I do put blocks under the offside to get it drained. Have to get the liquid over any lip at the valve. And it always flows better with a little tip.

So I think you should do an experiment consisting of raising the off side 3" and dumping and then leveling the trailer and refilling. See if that is actually part of your problem.

We dump as much by odor as by being full. Every 5 to 7 days. The ambient temperature has a lot to do with the frequency.

Have you tried boon docking it it yet? How do you know that this reduction is actually going to affect your usage? Or is there a theoretical daily quantity or what?

Does everything else work correctly? Does the trailer leak? How is the tongue weight?

[Tamaroak]

My tanks don’t leak; it’s a new unit. They are always clean after i dump, so I never had residual materials in the tank to displace my blackwater and affect my measurement. I used a calibrated 2.5 gallon can to fill directly to the toilet. Yes, it has affected our Boondocking because when the blackwater fills up in some parks (Aroostook in Maine, for example) you pack up and look for a dump station, or walk a long ways at night I’m the rain to an outhouse. No dump facility at all. The idea of tipping the AS on its side to get more capacity for Boondocking is ridiculous. Imagine that pumpout line at the dump station at the end of a busy weekend where some turkey is messing with jacks, blocks, skyhooks or ramps to eek out that last part in the tank? I think not.

[Bill M.]

Okay. So what would be a "good resolution" to you from Airstream?

[RAH]

There are lots of limitations on boondocking depending on how you camp.
For us it is usually 5 days due to the battery bank, not freshwater. It is never the black tank. When boondocking we try not to use it too much due to the "smell factor", not capacity. I cannot imagine filling a 27 gallon blackwater tank, and then sleeping in the same trailer.

Before our AS days, we rented motorhomes for our trips. I got the bright idea of emptying the kitchen sink water (using a bucket) and dumping that into the toilet each day. My logic was to conserve grey water capacity, which I thought I was low on, and use up black water capacity, which I thought I had extra of. That worked great until day 4. Did I mention it was a really hot weekend? Well that last day the black tank stunk to high heaven, enough to wake a person from a dead sleep. I learned my lesson - a full black tank is not necessarily a good thing.

I just try to enjoy boondocking trips using water and electricity as best we can. I am happy that Airstream's advertised capacities are "close enough" for me.

[n2916s]

Any chance your bucket is marked I’m Imperial gallons? That would account for most of the difference you are seeing...

[uraljohn]

Originally Posted by Tamaroak

We have a new 2019 25’ FC RBT and did a test of our black, grey and freshwater tanks to check the accuracy of our gauges. Imagine our surprise to find that our tanks held 27, 31 and 29 gallons respectively! The advertised gallonage is 35, 37 and 39 gallons. We intend to test again, but this will seriously impact our boondocking ability. Test began from level site, everything drained. Filled grey and fresh with calibrated bucket until they overflowed. Note: black backs up bathroom sink drain, grey into shower drain. Freshwater capacity measured by timing flow, maybe not as accurate. We will test again. Sent info to AS customer service.

You may want to look at a Lance brand trailer. My friend has a 2019 model 1985 (23' plus a nice dinette slid out) and it has 45 gallon tanks for fresh/gray/black water. They are very nice trailers with excellent fit and finish. His model 1985 had a MSRP of $45k and he paid $37k out the door. They are about 1/3 less expensive than an Airstream. If the tank size is that critical to you your going to have to trade out to an SOB. The downside is that the Lance will be worth about 50% of purchase price in 2 years and your Airstream will be worth about 85/90% of its purchase price in 2 years. Pick your poison. Big holding tanks or a great Airstream that will last a lifetime.

[mtbmitch]

Originally Posted by uraljohn

You may want to look at a Lance brand trailer. My friend has a 2019 model 1985 (23' plus a nice dinette slid out) and it has 45 gallon tanks for fresh/gray/black water. They are very nice trailers with excellent fit and finish. His model 1985 had a MSRP of $45k and he paid $37k out the door. They are about 1/3 less expensive than an Airstream. If the tank size is that critical to you your going to have to trade out to an SOB. The downside is that the Lance will be worth about 50% of purchase price in 2 years and your Airstream will be worth about 85/90% of its purchase price in 2 years. Pick your poison. Big holding tanks or a great Airstream that will last a lifetime.

We have a Lance, but were considering an Airstream till we discovered a few things. Plywood floors, single pane windows, heavy for their size, almost no outside storage and limited tank size for boondocking. The AS is beautiful and very modern styling. It just needs to join the 21st century as far as QC and ditch the plywood floors. Lance's value might drop 1/3 in three years yes, then one could buy used. The new 2075 no slide Lance is very similar layout to several Airstreams. The new Escape 23 from Canada might also be promising.

[uraljohn]

Originally Posted by mtbmitch

We have a Lance, but were considering an Airstream till we discovered a few things. Plywood floors, single pane windows, heavy for their size, almost no outside storage and limited tank size for boondocking. The AS is beautiful and very modern styling. It just needs to join the 21st century as far as QC and ditch the plywood floors. Lance's value might drop 1/3 in three years yes, then one could buy used. The new 2075 no slide Lance is very similar layout to several Airstreams. The new Escape 23 from Canada might also be promising.

My friend with the Lance 1985 has had his share of initial build QC issues. Leaking water pipe behind sink due to it being pinched during construction (He hooked up to water at his home and the trailer started to fill with water a few minutes later, this could have been tragic had he not went back out after a few minutes to do some other things and water was running out the door). He fixed the pipe(taking pictures of everything) and Lance customer service was less than enthusiastic about compensating him. He is overall happy with his Lance but the start was frustrating. I think the floor in a lance is a sandwich material of some sort. Only the straight, flat walls of the Lance are made of Azdel. The floor and front cap is still a wood product that moisture will effect. No matter what brand of RV you buy is going to have some issues.

My friends Lance 1985 weighed just 200 LBS less than our previous Airstream, a 2017 International Serenity 23'D model. So given the approximate same size of trailers the Airstream weight was very much aligned with a 23' Lance.

Our 2019 Flying Cloud 25' rear bed twin has 4 outside storage compartments. The one at the rear of the coach is very large. So lots of outside storage on this model. Other Airstream models may not have as much. The twin bed models do have extra nice outside storage.

Did not know that Lance is making a trailer with no slide out. Will check that out. Thanks for info. Happy travels.

[Wayne&Sam]

Meh. We've boondocked for 8 days with no problem in our 25' FC RBT. Could have gone longer.

[A W Warn]

Originally Posted by Wayne&Sam

Meh. We've boondocked for 8 days with no problem in our 25' FC RBT. Could have gone longer.

When boondocking in our 25' Safari, 5 days/4 nights is about the limit of our gray tank with 2 of us taking showers.
Though, the fresh water tank is getting pretty close to dry on that 5th day.
Boondocking, I usually add fresh water using 5 gallon portable tanks, and remove gray water using a blue boy tote or drain gray water on the ground (depending on location).
At 5 days our black tank is ~50% to 60%, so could go 8 or 9 days. If it gets full, it's time to find a dump station (no way do I use a blue boy for hauling black water)