Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?

I am fitting out and old galvanised tank for rainwater harvesting (first
job, glass fibre the inside to hide the rust) and want to arrange an
overflow using a diverter coupler which means the fill pipe will be
below water level before the overflow level is reached.

Water gathered from a 55' x 18' roof so I need the full 68mm size!
--
Tim Lamb

On Sat, 5 Jun 2021 18:12:50 +0100, Tim Lamb
wrote:

Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?

I am fitting out and old galvanised tank for rainwater harvesting (first
job, glass fibre the inside to hide the rust) and want to arrange an
overflow using a diverter coupler which means the fill pipe will be
below water level before the overflow level is reached.

Water gathered from a 55' x 18' roof so I need the full 68mm size!

Failing finding anything suitable off the shelf and if you are
fibreglassing inside the tank anyway (and a good use for it btw g) I
might be tempted to fibreglass a suitable stub of 68mm pipe though at
the same time then you can be fairly sure it will be sealed.

I'd cut several 100 mm long strips of CSM about 20mm wide and with the
stub held securely in place, glass the strips round the pipe like 'L
brackets' and flower petals and do the same again, overlapping the
first layer and then a circular collar over that with the middle cut
like a star (out to the 68mm diameter) and then a band round the stub,
to just pin down any lose ends (woven roving / bandage better than CSM
for that last bit. I probably have some here you can have (stick in
the post etc)).

Cheers, T i m

On 05/06/2021 19:35, T i m wrote:
On Sat, 5 Jun 2021 18:12:50 +0100, Tim Lamb
wrote:

Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?

I am fitting out and old galvanised tank for rainwater harvesting (first
job, glass fibre the inside to hide the rust) and want to arrange an
overflow using a diverter coupler which means the fill pipe will be
below water level before the overflow level is reached.

Water gathered from a 55' x 18' roof so I need the full 68mm size!

Failing finding anything suitable off the shelf and if you are
fibreglassing inside the tank anyway (and a good use for it btw g) I
might be tempted to fibreglass a suitable stub of 68mm pipe though at
the same time then you can be fairly sure it will be sealed.

I'd cut several 100 mm long strips of CSM about 20mm wide and with the
stub held securely in place, glass the strips round the pipe like 'L
brackets' and flower petals and do the same again, overlapping the
first layer and then a circular collar over that with the middle cut
like a star (out to the 68mm diameter) and then a band round the stub,
to just pin down any lose ends (woven roving / bandage better than CSM
for that last bit. I probably have some here you can have (stick in
the post etc)).

Cheers, T i m


Or, for less effort, you could use a 3 inch bulkhead fitting or tank
connector (same thing, two different names) connected with flexible
hose. You might get away with a 2 inch.

I made an interesting discover the other day. I needed to fit some of
this stuff (two inch, actually) over the threads of another fitting that
was just too big. I popped the end of the hose in boiling water for a
minute or two and it became soft enough to push straight on. I secured
it in that case with a few layers of PVC tape as it does not see much
pressure, and small leaks wouldn't matter. I suspect if you used a
jubilee clip, especially when it was warm, it would be very effective.

https://www.machinemart.co.uk/p/3in-reinforced-hose/

On Sun, 6 Jun 2021 10:17:44 +0100, newshound
wrote:

snip

I'd cut several 100 mm long strips of CSM about 20mm wide and with the
stub held securely in place, glass the strips round the pipe like 'L
brackets' and flower petals and do the same again, overlapping the
first layer and then a circular collar over that with the middle cut
like a star (out to the 68mm diameter) and then a band round the stub,
to just pin down any lose ends (woven roving / bandage better than CSM
for that last bit. I probably have some here you can have (stick in
the post etc)).


Or, for less effort, you could use a 3 inch bulkhead fitting or tank
connector (same thing, two different names) connected with flexible
hose. You might get away with a 2 inch.

I think Tim was quite specific in his requirements (if not directly
mateable to 68mm stuff). ;-)

Also, if he does line this tank with fibreglass he might need to glass
in a smooth collar of some sort if using a bulkhead / flanged fitting,
or use some additional sealant to ensure it seals against the back of
fibreglass?

I made an interesting discover the other day. I needed to fit some of
this stuff (two inch, actually) over the threads of another fitting that
was just too big. I popped the end of the hose in boiling water for a
minute or two and it became soft enough to push straight on.

Was the 'discover' doing that on that large a profile or in general?

I secured
it in that case with a few layers of PVC tape as it does not see much
pressure, and small leaks wouldn't matter. I suspect if you used a
jubilee clip, especially when it was warm, it would be very effective.

Or a few turns of galvanised garden wire twisted up at the end?

https://www.machinemart.co.uk/p/3in-reinforced-hose/

Yeah, that sort of construction pipe is often used on boats and in
caravans (for waste / bilge pumps, where I have sometime used the
warming trick).

Cheers, T i m

On 05/06/2021 18:12, Tim Lamb wrote:
Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?

I am fitting out and old galvanised tank for rainwater harvesting (first
job, glass fibre the inside to hide the rust) and want to arrange an
overflow using a diverter coupler which means the fill pipe will be
below water level before the overflow level is reached.

Water gathered from a 55' x 18' roof so I need the full 68mm size!

Is the fibreglass tank circular or does it have a flat side?

Can you uses a access connector, with the 'plate' on the inside of the
tank. You would need to cut the access hatch plate to make a suitable hole.

I would have thought, with some silicone sealant, and using the plate
with longer screws, ideally stainless designed for constant immersion,
this would solve your need.

https://www.plasticdrainage.co.uk/ac...ipe-black.html

The access plate would make a handy template for making the holes.

In message , Fredxx
writes
On 05/06/2021 18:12, Tim Lamb wrote:
Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?
I am fitting out and old galvanised tank for rainwater harvesting
(first job, glass fibre the inside to hide the rust) and want to
arrange an overflow using a diverter coupler which means the fill
pipe will be below water level before the overflow level is reached.
Water gathered from a 55' x 18' roof so I need the full 68mm size!

Is the fibreglass tank circular or does it have a flat side?

Can you uses a access connector, with the 'plate' on the inside of the
tank. You would need to cut the access hatch plate to make a suitable
hole.

I would have thought, with some silicone sealant, and using the plate
with longer screws, ideally stainless designed for constant immersion,
this would solve your need.

https://www.plasticdrainage.co.uk/ac...nd-downpipe-bl
ack.html

The access plate would make a handy template for making the holes.

Hmm.. That might do!

The tank is an ancient rectangular 4' x 3'6 x 3'6 riveted galvanised
steel construction I have been using as a secure chemical store after
fitting a hinged lid. The exterior is sound but the inside had some
rusting hence the glass fibre.

The fill pipe could be a sliding fit in the lid and your *hatch plate*
outlet extended and insect proofed above planned water level.

So far, I have not found a bulkhead or tank connector adaptable to 68mm
although I take the point that the plastic can be stretched with the
application of heat.

--
Tim Lamb

On 06/06/2021 12:36, T i m wrote:
On Sun, 6 Jun 2021 10:17:44 +0100, newshound
wrote:

snip

I'd cut several 100 mm long strips of CSM about 20mm wide and with the
stub held securely in place, glass the strips round the pipe like 'L
brackets' and flower petals and do the same again, overlapping the
first layer and then a circular collar over that with the middle cut
like a star (out to the 68mm diameter) and then a band round the stub,
to just pin down any lose ends (woven roving / bandage better than CSM
for that last bit. I probably have some here you can have (stick in
the post etc)).


Or, for less effort, you could use a 3 inch bulkhead fitting or tank
connector (same thing, two different names) connected with flexible
hose. You might get away with a 2 inch.

I think Tim was quite specific in his requirements (if not directly
mateable to 68mm stuff). ;-)

Well the short answer to that, AFAIK, is that the only official fittings
you will get for drain pipe are for gutters, spouts, and tees. And I
agree that the petal approach should work if the penetration has to be
67mm pipe.


Also, if he does line this tank with fibreglass he might need to glass
in a smooth collar of some sort if using a bulkhead / flanged fitting,
or use some additional sealant to ensure it seals against the back of
fibreglass?

There's a choice there, if the tank is good he can seal against the
tank, and then fibreglass over it. Alternatively try to get a smooth
layer of fibreglass that the standard washer will seal against, or
perhaps use a thick washer made from closed cell foam.


I made an interesting discover the other day. I needed to fit some of
this stuff (two inch, actually) over the threads of another fitting that
was just too big. I popped the end of the hose in boiling water for a
minute or two and it became soft enough to push straight on.

Was the 'discover' doing that on that large a profile or in general?

Well, it was on two inch MM pipe that was definitely not going on to the
threaded boss "cold". I've often used the hot water trick on garden
hoses, and on various nylon or PVC "fuel pipe". But I was interested to
find that the reinforcing "spring" in the Machine Mart hose, which is a
very tough thermoplastic, does in fact soften very satisfactorily in
boiling water while still retaining enough strength to grip when pushed
on to the threads. I just thought others might find that information
useful. The pipe looks and feels superficially as though the "spring"
could be metal, in which case of course the approach would not work.

I've done various other sorts of bodge on that type of hose before, on
the previous connection I needed to attach it to something like domestic
sink waste pipe, and I did that by wrapping the pipe with Sylglas/Denso
Tape and twisting that inside the MM hose. Followed up with my favourite
wrapping with PVC electrical tape under tension.


I secured
it in that case with a few layers of PVC tape as it does not see much
pressure, and small leaks wouldn't matter. I suspect if you used a
jubilee clip, especially when it was warm, it would be very effective.

Or a few turns of galvanised garden wire twisted up at the end?

https://www.machinemart.co.uk/p/3in-reinforced-hose/

Yeah, that sort of construction pipe is often used on boats and in
caravans (for waste / bilge pumps, where I have sometime used the
warming trick).

Cheers, T i m

On 06/06/2021 21:52, Tim Lamb wrote:
In message , Fredxx
writes
On 05/06/2021 18:12, Tim Lamb wrote:
Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?
Â*I am fitting out and old galvanised tank for rainwater harvesting
(firstÂ* job, glass fibre the inside to hide the rust) and want to
arrange anÂ* overflow using a diverter coupler which means the fill
pipe will beÂ* below water level before the overflow level is reached.
Â*Water gathered from a 55' x 18' roof so I need the full 68mm size!

Is the fibreglass tank circular or does it have a flat side?

Can you uses a access connector, with the 'plate' on the inside of the
tank. You would need to cut the access hatch plate to make a suitable
hole.

I would have thought, with some silicone sealant, and using the plate
with longer screws, ideally stainless designed for constant immersion,
this would solve your need.

https://www.plasticdrainage.co.uk/ac...nd-downpipe-bl
ack.html

The access plate would make a handy template for making the holes.

Hmm.. That might do!

The tank is an ancient rectangular 4' x 3'6 x 3'6 riveted galvanised
steel construction I have been using as a secure chemical store after
fitting a hinged lid. The exterior is sound but the inside had some
rusting hence the glass fibre.

The fill pipe could be a sliding fit in the lid and your *hatch plate*
outlet extended and insect proofed above planned water level.

So far, I have not found a bulkhead or tank connector adaptable to 68mm
although I take the point that the plastic can be stretched with the
application of heat.

IBCs (Intermediate Bulk Container Tank) are cheap and don't rust, plus
if translucent you can see the water level. Just a thought.

Can you insect-proof the top of the drain pipe?

In message , Fredxx
writes
On 06/06/2021 21:52, Tim Lamb wrote:
Snippage.
https://www.plasticdrainage.co.uk/ac...nd-downpipe-bl
ack.html

The access plate would make a handy template for making the holes.
Hmm.. That might do!
The tank is an ancient rectangular 4' x 3'6 x 3'6 riveted galvanised
steel construction I have been using as a secure chemical store after
fitting a hinged lid. The exterior is sound but the inside had some
rusting hence the glass fibre.
The fill pipe could be a sliding fit in the lid and your *hatch
plate* outlet extended and insect proofed above planned water level.
So far, I have not found a bulkhead or tank connector adaptable to
68mm although I take the point that the plastic can be stretched with
the application of heat.

IBCs (Intermediate Bulk Container Tank) are cheap and don't rust, plus
if translucent you can see the water level. Just a thought.

Indeed. 1000L and there are numerous adapters available for piping the
threaded outlet.
However, I already have an almost suitable, larger tank:-) Left over
glass fibre kit and the potential satisfaction of re-purposing a large
lump of otherwise scrap steel.
Currently the collected rainwater goes to a soakaway.

Can you insect-proof the top of the drain pipe?

I have lots of fine mesh plastic netting bought to protect garden
produce for tank vents. Gutter and down pipe not practical but I assume
insects lay their eggs in standing water.



--
Tim Lamb

On Sun, 6 Jun 2021 23:32:19 +0100, newshound
wrote:

snip

Or, for less effort, you could use a 3 inch bulkhead fitting or tank
connector (same thing, two different names) connected with flexible
hose. You might get away with a 2 inch.

I think Tim was quite specific in his requirements (if not directly
mateable to 68mm stuff). ;-)

Well the short answer to that, AFAIK, is that the only official fittings
you will get for drain pipe are for gutters, spouts, and tees. And I
agree that the petal approach should work if the penetration has to be
67mm pipe.

And he's in there fibreglassing 'anyway' etc. ;-)


Also, if he does line this tank with fibreglass he might need to glass
in a smooth collar of some sort if using a bulkhead / flanged fitting,
or use some additional sealant to ensure it seals against the back of
fibreglass?

There's a choice there, if the tank is good he can seal against the
tank, and then fibreglass over it.

I'm not sure I'd like that as you are sorta then relying on getting a
good seal 'outside' the actual water container (now a fibreglass box
inside a galv tank). ;-)

Alternatively try to get a smooth
layer of fibreglass that the standard washer will seal against,

I would finish the glassing with a couple of layers of fibreglass
tissue and then lightly clamp a flat object on top with a layer of
something non-stick in between.

or
perhaps use a thick washer made from closed cell foam.

Yes, or a thicker / softer rubber etc.


I made an interesting discover the other day. I needed to fit some of
this stuff (two inch, actually) over the threads of another fitting that
was just too big. I popped the end of the hose in boiling water for a
minute or two and it became soft enough to push straight on.

Was the 'discover' doing that on that large a profile or in general?

Well, it was on two inch MM pipe that was definitely not going on to the
threaded boss "cold". I've often used the hot water trick on garden
hoses, and on various nylon or PVC "fuel pipe".

Ok.

But I was interested to
find that the reinforcing "spring" in the Machine Mart hose, which is a
very tough thermoplastic, does in fact soften very satisfactorily in
boiling water while still retaining enough strength to grip when pushed
on to the threads. I just thought others might find that information
useful. The pipe looks and feels superficially as though the "spring"
could be metal, in which case of course the approach would not work.

Agreed. It look far less likely that it might all (as you say, inc the
anti-crush reinforcement) respond to heat but seems to.

I've done various other sorts of bodge on that type of hose before, on
the previous connection I needed to attach it to something like domestic
sink waste pipe, and I did that by wrapping the pipe with Sylglas/Denso
Tape and twisting that inside the MM hose. Followed up with my favourite
wrapping with PVC electrical tape under tension.

The trick with all that sort of thing is understanding the mechanics
of what is going on. I've seen people try to join / fix fuel hose with
insulation tape and seem surprised when it more or less melts or
un-glues in front of them or things that instantly burst off out
though because of pressure.

snip

Cheers, T i m

On 07/06/2021 09:25, T i m wrote:
On Sun, 6 Jun 2021 23:32:19 +0100, newshound


But I was interested to
find that the reinforcing "spring" in the Machine Mart hose, which is a
very tough thermoplastic, does in fact soften very satisfactorily in
boiling water while still retaining enough strength to grip when pushed
on to the threads. I just thought others might find that information
useful. The pipe looks and feels superficially as though the "spring"
could be metal, in which case of course the approach would not work.

Agreed. It look far less likely that it might all (as you say, inc the
anti-crush reinforcement) respond to heat but seems to.

I've done various other sorts of bodge on that type of hose before, on
the previous connection I needed to attach it to something like domestic
sink waste pipe, and I did that by wrapping the pipe with Sylglas/Denso
Tape and twisting that inside the MM hose. Followed up with my favourite
wrapping with PVC electrical tape under tension.

The trick with all that sort of thing is understanding the mechanics
of what is going on. I've seen people try to join / fix fuel hose with
insulation tape and seem surprised when it more or less melts or
un-glues in front of them or things that instantly burst off out
though because of pressure.

Oh indeed. Pressure, temperature, chemistry. But I do find you can make
surprisingly effective and also neat-looking connections with tape. For
one of my sink drains, I had to couple solvent weld and compression pipe
where there was no room for a compression coupling. But telescoping the
tubes together and wrapping with stretched PVC tape has worked fine for
25 years. Also, it would be easy to dismantle if I need to.

On Mon, 7 Jun 2021 10:51:04 +0100, newshound
wrote:

snip

The trick with all that sort of thing is understanding the mechanics
of what is going on. I've seen people try to join / fix fuel hose with
insulation tape and seem surprised when it more or less melts or
un-glues in front of them or things that instantly burst off out
though because of pressure.

Oh indeed. Pressure, temperature, chemistry.

And mechanics ... the chances of being able to get access / sufficient
material on the job to stand a chance.

But I do find you can make
surprisingly effective and also neat-looking connections with tape.

And you are likely to be able to cover all the requirements of course.
;-)

For
one of my sink drains, I had to couple solvent weld and compression pipe
where there was no room for a compression coupling. But telescoping the
tubes together and wrapping with stretched PVC tape has worked fine for
25 years.

Yeah. I have similar in place that have been there on years (not on
any plumbing as it happens) even when often it was only going to be
temporary. ;-)

Also, it would be easy to dismantle if I need to.

Generally yes. I'm not sure if the adhesives used in 'the old days'
were chemically better (even if not for the environment etc) but you
do also get those where you try to un-peel something and it all flies
undone because the adhesive has failed / dried throughout or it's all
bonded together (like self amalgamating tape).

Cheers, T i m

On 07/06/2021 08:46, Tim Lamb wrote:
In message , Fredxx
writes
On 06/06/2021 21:52, Tim Lamb wrote:
Snippage.
https://www.plasticdrainage.co.uk/ac...nd-downpipe-bl

ack.html

The access plate would make a handy template for making the holes.
Â*Hmm.. That might do!
Â*The tank is an ancient rectangular 4' x 3'6 x 3'6 riveted galvanised
steel construction I have been using as a secure chemical store after
fitting a hinged lid. The exterior is sound but the inside had some
rusting hence the glass fibre.
Â*The fill pipe could be a sliding fit in the lid and your *hatch
plate*Â* outlet extended and insect proofed above planned water level.
Â*So far, I have not found a bulkhead or tank connector adaptable to
68mmÂ* although I take the point that the plastic can be stretched
with theÂ* application of heat.

IBCs (Intermediate Bulk Container Tank) are cheap and don't rust, plus
if translucent you can see the water level. Just a thought.

Indeed. 1000L and there are numerous adapters available for piping the
threaded outlet.
However, I already have an almost suitable, larger tank:-) Left over
glass fibre kit and the potential satisfaction of re-purposing a large
lump of otherwise scrap steel.
Currently the collected rainwater goes to a soakaway.

Can you insect-proof the top of the drain pipe?

I have lots of fine mesh plastic netting bought to protect garden
produce for tank vents. Gutter and down pipe not practical but I assume
insects lay their eggs in standing water.

A film of oil tends to stop that! It does mean the overflow must dip
below the surface and have a anti-syphon feature

In message , Fredxx
writes
On 07/06/2021 08:46, Tim Lamb wrote:
snip
Can you insect-proof the top of the drain pipe?
I have lots of fine mesh plastic netting bought to protect garden
produce for tank vents. Gutter and down pipe not practical but I
assume insects lay their eggs in standing water.

A film of oil tends to stop that! It does mean the overflow must dip
below the surface and have a anti-syphon feature

Yes. I had forgotten that. Reduced surface tension so the wrigglies
can't hang there to breathe?

The plan is to use the water for garden/greenhouse irrigation so it may
empty in long dry spells.

--
Tim Lamb

On 07/06/2021 21:59, Fredxx wrote:
On 07/06/2021 08:46, Tim Lamb wrote:
In message , Fredxx
writes
On 06/06/2021 21:52, Tim Lamb wrote:
Snippage.
https://www.plasticdrainage.co.uk/ac...nd-downpipe-bl

ack.html

The access plate would make a handy template for making the holes.
Â*Hmm.. That might do!
Â*The tank is an ancient rectangular 4' x 3'6 x 3'6 riveted
galvanised steel construction I have been using as a secure chemical
store after fitting a hinged lid. The exterior is sound but the
inside had some rusting hence the glass fibre.
Â*The fill pipe could be a sliding fit in the lid and your *hatch
plate*Â* outlet extended and insect proofed above planned water level.
Â*So far, I have not found a bulkhead or tank connector adaptable to
68mmÂ* although I take the point that the plastic can be stretched
with theÂ* application of heat.

IBCs (Intermediate Bulk Container Tank) are cheap and don't rust,
plus if translucent you can see the water level. Just a thought.

Indeed. 1000L and there are numerous adapters available for piping the
threaded outlet.
However, I already have an almost suitable, larger tank:-) Left over
glass fibre kit and the potential satisfaction of re-purposing a large
lump of otherwise scrap steel.
Currently the collected rainwater goes to a soakaway.

Can you insect-proof the top of the drain pipe?

I have lots of fine mesh plastic netting bought to protect garden
produce for tank vents. Gutter and down pipe not practical but I
assume insects lay their eggs in standing water.

A film of oil tends to stop that! It does mean the overflow must dip
below the surface and have a anti-syphon feature

Paraffin is more usual than lubricating oil. Diesel would do equally
well. Not so much that it prevents egg laying, it stops mosquito larvae
from breathing through their snorkels when they hatch.