Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×

Thread Tools Search this Thread Display Modes
Old 11-08-2015, 05:44 PM   #1
1981 25' Excella II
Mesa , Arizona
Join Date: May 2005
Posts: 8
Black tank outlet crack

Hi, All.
I recently purchased a 1981 Excella II 25 footer with a front kitchen. I've had a few Airstreams in the past but I've never seen this floor plan. I really like it. It will need some restoration but I plan to keep it a long time so I want to do the best I can.
First project is the waste system. It was dripping at both Thetford valves and from the black tank outlet where the PO "fixed" it with electrical tape. Not!!!!!
The black tank sits above the floor in the rear. The outlet drops from the bottom through a hole in the floor.
There is a 3" abs elbow that slips into the outlet. The outlet has a 1-2 inch crack causing the leak. I attempted to plastic weld the crack with the tank still installed but when fitting the abs pipe into the outlet it split apart again. When the pipe is installed the crack is pretty wide.
So the question is; has age caused the plastic to shrink? Is there a way to repair this or do I need to replace the tank?
I appreciate any advice.
karisk12 is offline   Reply With Quote
Old 11-08-2015, 06:30 PM   #2
Rivet Master
J. Morgan's Avatar
1972 31' Sovereign
1975 31' Excella 500
Currently Looking...
Benton , Arkansas
Join Date: Mar 2013
Posts: 5,868
Images: 11
It could be repaired, I am almost sure of that, however, the easiest, surest, and maybe even the cheapest fix might well be a new tank from the get go.

Brevi tempore!
The fact that I am opinionated does not presuppose that I am wrong......

J. Morgan is offline   Reply With Quote
Old 11-08-2015, 06:50 PM   #3
Rivet Master
cwf's Avatar
1999 34' Excella
Currently Looking...
Hillsboro , Texas
Join Date: Feb 2013
Posts: 6,394
Images: 2
Originally Posted by J. Morgan View Post
It could be repaired, I am almost sure of that, however, the easiest, surest, and maybe even the cheapest fix might well be a new tank from the get go.

Brevi tempore!

Fix it, don't repair it...if you want to try to repair.... Have you thought of epoxy??? Might work..b there are some real exposures.. Not the store brands..
Peace and Blessings..
WBCCI# 30676
cwf is offline   Reply With Quote
Old 11-11-2015, 06:15 AM   #4
1981 25' Excella II
Mesa , Arizona
Join Date: May 2005
Posts: 8
I removed the tank over the last 2 evenings. I called Airstream and they had no information on an above floor tank in 1981. I'd sure like to see a manual for that year. I had to remove the toilet, sink, plastic countertop, sink cabinet and plastic cover over the tank to get to it. I was expecting rivets but it was all screws. Further disassembly of the cabinetry and closet would have been all rivets but it was unnecessary. There was one hidden screw that had no access and caused me to break a 1" piece of the countertop. It will be hidden again so I'm not worried about it. I consider myself a mechanic not an artist or carpenter so I plan to put it back together the way it was. The tank is very unique and I can't find an exact replacement. Now that its out I'll try again to repair it or take it to Phillp's Plastic in Tempe where they've quoted me $125-150 to repair it.
karisk12 is offline   Reply With Quote
Old 11-11-2015, 07:46 AM   #5
Rivet Master
robwok's Avatar
1964 26' Overlander
Richmond , Virginia
Join Date: Feb 2011
Posts: 790
Images: 35
Plastic repairs can be tough. You really want to find the solvent that works. I take a paper towel and rub acetone on it, and then rub that on the tank. That'll tell you fiberglass vs polyethelene vs some type of ABS. If ABS, it will soften and stick to the towel. Polyethelen will be whitish usually, and you should be able to see some glass in fiberglass. Its probably an ABS type material. I would get a polyethelene bottle, like a glue bottle and squirt it in the crack to clean it (after you've tried blasting it with water and soap and rinse) then, look for some extra plastic - like at a seam, or flange or something and scrape that into a glass jar, then mix with acetone or MEK to create a paste. Use that to fill the crack. I would widen it first, then fill, then compress, and leave the squeezeout there until cure, and leave it if it doesn't cause a problem. there is also this great new tape at Lowes and HD that has a curing component in it - they sell it in the plumbing section. Not sure where the issue is on your trailer. The other option is after the repair, scuff up the plastic, then wrap in fiberglass and glass it. I've had fiberglass bond very well to ABS in my trailer for some plastic parts - like a cover piece that was in a closet.
robwok is offline   Reply With Quote
Old 11-11-2015, 08:00 AM   #6
Rivet Master
BambiTex's Avatar
1955 22' Safari
1967 26' Overlander
1955 22' Flying Cloud
Clear Lake Shores , Texas
Join Date: Nov 2013
Posts: 1,342
Tank color should tell you the material. Black is ABS, milky white is polyethylene. Best repair method is to use parent material combined with a solvent which will cure and be as strong as the original.
BambiTex is offline   Reply With Quote
Old 11-12-2015, 05:21 PM   #7
2 Rivet Member
terrencecolp's Avatar
1976 25' Tradewind
Tulsa , Oklahoma
Join Date: Jun 2013
Posts: 96
Images: 1
I've got the exact same design of bathroom in my 76 Tradewind. Black tank on top of floor. My tank cover cracked so I'm looking at a job just like yours only stopping when I get the cover off.
terrencecolp is offline   Reply With Quote
Old 11-12-2015, 05:37 PM   #8
1981 25' Excella II
Mesa , Arizona
Join Date: May 2005
Posts: 8
I will be happy to share my lessons learned. Send me a picture so I can see if it's the same
karisk12 is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Plastic Welding 310 MH Black Tank Outlet Auretrvr Waste Systems, Tanks & Totes 4 08-02-2014 07:54 PM
Black Tank, Grey Tank, New Tank, Old Tank Bunkroom Waste Systems, Tanks & Totes 3 07-22-2014 08:35 PM
Easy fix, or not? Black tank/outlet pipe leak Bex Waste Systems, Tanks & Totes 0 09-06-2010 02:03 PM
What glue should I use to fix a small crack in my freshwater tank? JimGolden Fresh Water Systems 4 06-11-2009 04:22 PM
Argosy holding tank crack blondie3265 Waste Systems, Tanks & Totes 8 07-14-2007 11:09 PM

Featured Campgrounds

Reviews provided by


This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.

All times are GMT -6. The time now is 10:48 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.