Leaky water tank repair

[Ken Shaffer]

My fresh water tank has a crack where the nipple at the bottom connects to tank. Has anyone here tried cutting off that nipple flush with the tank
and tapping threads to insert a brass barbed fitting? Just not sure if the tank is thick enough down there to get good enough threads to seal.

--
Ken Shaffer
Marion Iowa
73 Canyon Lands, 455, Manny Tranny, Custom interior

 

[Ken H.]

Nope. Think what you're proposing to do: Replace a carefully engineered
assembly, which has finally failed, with a kludge using parts not designed
for the purpose. And No, there's probably not enough thickness to allow it
to work even temporarily.

A skilled plastics welder may be able to repair it, or there may be some
suitable adhesive, of which I'm not aware, but most likely replacement is
required.

Sorry,

Ken H.

On Sun, Jun 9, 2019 at 9:42 AM Ken Shaffer via Gmclist <

> My fresh water tank has a crack where the nipple at the bottom connects to
> tank. Has anyone here tried cutting off that nipple flush with the tank
> and tapping threads to insert a brass barbed fitting? Just not sure if the
> tank is thick enough down there to get good enough threads to seal.
>
> --
> Ken Shaffer
> Marion Iowa
> 73 Canyon Lands, 455, Manny Tranny, Custom interior
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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[Jim Hupy]

I had the same (similar) problem with my fresh water tank. Some person had
over tightened the outlet fitting and stripped the female threads in the
tank. I removed the tank from the coach, and took it to Bomar plastics near
Portland, Or. They took a hot knife and cut the old bung out and plastic
welded a new one in place. Took them about 15 minutes. Cautioned me against
over tightening the nipple, and sent me on my way. That was years ago, and
no further issues with that part.
Jim Hupy
Salem, Or

On Sun, Jun 9, 2019, 6:42 AM Ken Shaffer via Gmclist <

> My fresh water tank has a crack where the nipple at the bottom connects to
> tank. Has anyone here tried cutting off that nipple flush with the tank
> and tapping threads to insert a brass barbed fitting? Just not sure if the
> tank is thick enough down there to get good enough threads to seal.
>
> --
> Ken Shaffer
> Marion Iowa
> 73 Canyon Lands, 455, Manny Tranny, Custom interior
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[LQQKatJon]

Ken- in would not cut it off. You are best
To use west systems epoxy to rebuild that.

If there is a skilled
Plastic welder around they can do some fantastic work. Diy plastic welding could work. Buy i made a bigger hole in the last fresh water tank myself
then I started with and had to get a new tank. I have had great luck on pods and a few other plastics, but could not get any filler plastics I
tried to bond(harbor freight rids, milk jug and 5 gallon bucket).

There are some people who will have a used tank I have seen, but the senders have always been garbage on those so factor in in a new oem sender
system you are better buying a new tank.
--
Jon Roche
75 palm beach
St. Cloud, MN
http://lqqkatjon.blogspot.com/

 

[powwerjon]

Ken,
If you want to do it correctly you would need to put a flat washer on the inside of the tank and put a brass nut on after that. Question??? HOW do I get inside the tank?

An addition of a cleanup of your fresh water tank will do two things.
1. Allow you to work on the tank on the inside.
2. Allow you to clean out the tank. You would be surprised how much stuff is on the bottom of the tank, mostly sand.

The Items that you want to purchase is deck plate. They come in a 4” size and a 6” size, I recommend the 6” size. You can get them from West Marine or maybe a local marina.

https://www.westmarine.com/deck-plates

This is what one looks like installed:

http://www.gmcmhphotos.com/photos/interior-rear-construction-detail/p65008-fresh-water-tank-on-passenger-side.html

Great mod for yearly cleanout and sanitizing the tank.

J.R. Wright
GMC Great Laker MHC
GMCGL Tech Editor
GMC Eastern States Charter Member
GMCMI
78 GMC Buskirk 29.5’ Stretch
75 GMC Avion (Under Reconstruction)
Michigan

>
> I had the same (similar) problem with my fresh water tank. Some person had
> over tightened the outlet fitting and stripped the female threads in the
> tank. I removed the tank from the coach, and took it to Bomar plastics near
> Portland, Or. They took a hot knife and cut the old bung out and plastic
> welded a new one in place. Took them about 15 minutes. Cautioned me against
> over tightening the nipple, and sent me on my way. That was years ago, and
> no further issues with that part.
> Jim Hupy
> Salem, Or
>
> On Sun, Jun 9, 2019, 6:42 AM Ken Shaffer via Gmclist <

>
>> My fresh water tank has a crack where the nipple at the bottom connects to
>> tank. Has anyone here tried cutting off that nipple flush with the tank
>> and tapping threads to insert a brass barbed fitting? Just not sure if the
>> tank is thick enough down there to get good enough threads to seal.
>>
>> --
>> Ken Shaffer
>> Marion Iowa
>> 73 Canyon Lands, 455, Manny Tranny, Custom interior
>>
>>

 

[Ken Shaffer]

I plan on checking to find a plastic welder locally. I do like the idea of creating an inside access that would allow a rubber washer and nut on the
inside of the tank. Concerned that with the original nipple located in the corner of the tank that I could get a flat enough surface for washer to
seal against. S
--
Ken Shaffer
Marion Iowa
73 Canyon Lands, 455, Manny Tranny, Custom interior

 

[Matt Colie]

> I plan on checking to find a plastic welder locally. I do like the idea of creating an inside access that would allow a rubber washer and nut on
> the inside of the tank. Concerned that with the original nipple located in the corner of the tank that I could get a flat enough surface for washer
> to seal against. S

Ken,

Do Not try to tap that antique Polyethylene tank. Before you can get enough load on the threads to make them seal, the tank material will crack.
Plastic welding is about your only hope. This is particularly true on the bottom of the tank where the water draw is located.
(Do I have to add BTDT?)

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[jesse farr]

Love the clean out port, just wonder why I didn't think of it.

Has anyone tried bondic on these tanks?

www.bondic.com

jesse farr
74, 76 & 78 GMCs

----- Original Message -----
From: Ken Shaffer via Gmclist
Reply-To:
To:
Cc: Ken Shaffer
Sent: 6/9/2019 3:18:37 PM
Subject: Re: [GMCnet] Leaky water tank repair
________________________________________________________________________________

I plan on checking to find a plastic welder locally. I do like the idea of creating an inside access that would allow a rubber washer and nut on the
inside of the tank. Concerned that with the original nipple located in the corner of the tank that I could get a flat enough surface for washer to
seal against. S
--
Ken Shaffer
Marion Iowa
73 Canyon Lands, 455, Manny Tranny, Custom interior

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[ghickey]

I would be weary of using Bondic. It is not an FDA food safe plastic.
Might be fine, but who knows if it is giving off any interesting molecules.

--
Gerard Hickey / WTØF IRLP:3067/Echolink:529661
hickey DMR: 3102272
425-395-4554

> Love the clean out port, just wonder why I didn't think of it.
>
> Has anyone tried bondic on these tanks?
>
> www.bondic.com
>
> jesse farr
> 74, 76 & 78 GMCs
>
>
> ----- Original Message -----
> From: Ken Shaffer via Gmclist
> Reply-To:
> To:
> Cc: Ken Shaffer
> Sent: 6/9/2019 3:18:37 PM
> Subject: Re: [GMCnet] Leaky water tank repair
> ________________________________________________________________________________
>
> I plan on checking to find a plastic welder locally. I do like the idea of creating an inside access that would allow a rubber washer and nut on the
> inside of the tank. Concerned that with the original nipple located in the corner of the tank that I could get a flat enough surface for washer to
> seal against. S

 

[jim kanomata1]

Gearld is correct in addressing that it is not always about if it works,but
how it will comply.
We have customers that are willing to take us to court for small things
like this and do not like to recommend to people.
I like hearing about new products and appreciate you bringing them up.

On Fri, Jun 14, 2019 at 1:03 PM Gerard Hickey via Gmclist <

> I would be weary of using Bondic. It is not an FDA food safe plastic.
> Might be fine, but who knows if it is giving off any interesting molecules.
>
> --
> Gerard Hickey / WTØF IRLP:3067/Echolink:529661
> hickey DMR: 3102272
> 425-395-4554
>

> > Love the clean out port, just wonder why I didn't think of it.
> >
> > Has anyone tried bondic on these tanks?
> >
> > www.bondic.com
> >
> > jesse farr
> > 74, 76 & 78 GMCs
> >
> >
> > ----- Original Message -----
> > From: Ken Shaffer via Gmclist
> > Reply-To:
> > To:
> > Cc: Ken Shaffer
> > Sent: 6/9/2019 3:18:37 PM
> > Subject: Re: [GMCnet] Leaky water tank repair
> >
> ________________________________________________________________________________
> >
> > I plan on checking to find a plastic welder locally. I do like the idea
> of creating an inside access that would allow a rubber washer and nut on the
> > inside of the tank. Concerned that with the original nipple located in
> the corner of the tank that I could get a flat enough surface for washer to
> > seal against. S
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502