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Connecting standard waste to 3/4 hose


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And so on to today's 3 hr conundrum.   I have to install a standard counter top basin and waste, converting a 40mm basing waste waste to 3/4 hose to the skin fitting.   I have the (supplied) "standard 40mm waste" (which measures 1 1/2") to bolt the basin to the countertop via its 40mm/1 !/2" thread, approx 4"  (101.6mm) long.   Anyone know how to link this to a 3/4" 19mm barbed hose fitting?   The old basin had one of these https://www.midlandchandlers.co.uk/products/dls-plastics-waste-sink-1-1-4-90-deg-for-3-4-hose-wd-051 which the old counter inserted-basin had, but I doubt this waste has the length or robustness to hold the counter top sink in place.   This must be an everyday problem  on narrowboats but after 3 hrs, can't seem to find the answer.  Any help or suggestions welcome.   PS advertising a 1 1/2 " thread as 40mm is probably an excellent example of why Brexit occurred.

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What a confusing question!

 

Can we have photos (or links to) please, of 

 

1) The "(supplied) "standard 40mm waste" (which measures 1 1/2") to bolt the basin to the countertop via its 40mm/1 !/2" thread, approx 4"  (101.6mm) long "

 

2) The "3/4" 19mm barbed hose fitting"

 

So we can see exactly what needs connecting to what.

Thanks.

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See how confusing it is.   In all cases of 1 1/2" please read 1 1/4"!

OK.  Not wishing to be sarcastic but to explain things more graphically

How do I fit the arse of this basin to this skin fitting using this waste and this hose? (see pics)  What else do I need and where can I get it?   TIA

I have connected 3 sink wastes in the house without issue, but my question is how to connect 1 1/4"/ ! 1/2" waste system to 3/4" (19mm) outlet.

basin.jpg

skin.jpg

waste.jpg

hose.jpg

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Thanks for that advice,  Rob-M

but the last time I went to a plumber's merchant and asked for a waste to skin fitting, the school leaving serving me got a dress makers tape and measured my stomach! 😉

 

The flowpast ose connector looks promising - many thanks Paul,   I hope it's flo-plast and not flop-last!

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In my opinion (and experience) it's a mistake to reduce a gravity drained waste pipe to a smaller diameter skin fitting because it just encourages restrictions and blockages. That's what I originally did for both my kitchen and bathroom sink waste pipes and a few years later I eventually changed both 3/4" skin fittings to 1 & 1/2" which was a hassle as I had to enlarge the holes.

 

Never had any problems since then.

Edited by blackrose
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8 minutes ago, blackrose said:

In my opinion (and experience) it's a mistake to reduce a gravity drained waste pipe to a smaller diameter skin fitting because it just encourages restrictions and blockages. That's what I originally did for both my kitchen and bathroom sink waste pipes and a few years later I eventually changed both 3/4" skin fittings to 1 & 1/2" which was a hassle as I had to enlarge the holes.

 

Never had any problems since then.

But it still reduces where it connects to the skin fitting as the inside diameter of the skin fitting is a lot less than the inside diameter of the hose.

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6 minutes ago, ditchcrawler said:

But it still reduces where it connects to the skin fitting as the inside diameter of the skin fitting is a lot less than the inside diameter of the hose.

 

A lot less? Only the wall thickness of the brass skin fitting and that's a lot less of a cross sectional area reduction than reducing from 1 & 1/2" to 3/4" - plus the 3/4" skin fitting wall thickness. You can't really avoid the wall thickness of whatever type of fitting you use even if it's a welded in pipe so I don't really understand your point.

 

Anyway as I said, I've never had any problems since I installed the larger diameter skin fittings.

Edited by blackrose
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Just to clear things up, I took all the crap from the old and new sink and showed the nice lady in Screwfux (who was absolutely brilliant and knowledgeable) and she spent over an hour trying to help.   One thing that didn't help was that my sink drain that is 1 1/4 BSP is described as "40mm" in the manufacturers catalogue and a 1 !/2" BSP to 3/4" spigot (which is exactly what I'd need if I had a 1 1/2" system) is described as 40mm on the packet. Meanwhile the Screwfux catalogue states that "bathroom sink items are described as 'basins' and are always 32mm  &  kitchen sink items are 'sinks' and are always 40mm"   It then displayed a basin sink waste of 40mm.
I wouldn't have believed it was this difficult.  All chandlers sell 1 1/4" fittings AND 3/4" fittings but not the things to mate them together.   All narrowboat blogs say connect your sink using standard fittings and 'simply' connect to an outlet hose.     Any other brilliant ideas apart from drilling a vast hole in the side of the boat, or letting it spill into the bilge and let the bilge pump take car of it!

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3 hours ago, Rob-M said:

I went to a plumbers merchant with the fittings I had and they worked out a number of adapters to go from sink to skin fitting.

I did exactly the same thing. It involved glueing a piece of pipe in iirc. Much easy than pissing around.

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31 minutes ago, Cal Ando said:

I wouldn't have believed it was this difficult.

I would.

 

I feel your pain, having been down the same path. Unless you are fluent in the gobbledygook speak of plumbing fittings and take a chance of what you think is right, its better to seek the knowledge of someone who speaks BSP. If you don't you just end up buying loads of random bits in the hope that cobbling them together will get you the result you need.The resulting left overs need a whole cupboard on the boat for themself, and will probably never be used again.

 

Plumbing fittings are much harder than they should be. Probably intentionally.

 

This is the hideous abomination that I eneded up with. If you do come up with a simple one piece solution, please, please let me know so I can reclaim some of my cupboard space.

 

This image will be deleted in 24 hours, as its such an embarrasment.

 

 

IMG_20230514_173137254~2.jpg

Edited by rusty69
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40 minutes ago, Cal Ando said:

Just to clear things up, I took all the crap from the old and new sink and showed the nice lady in Screwfux (who was absolutely brilliant and knowledgeable) and she spent over an hour trying to help.   One thing that didn't help was that my sink drain that is 1 1/4 BSP is described as "40mm" in the manufacturers catalogue and a 1 !/2" BSP to 3/4" spigot (which is exactly what I'd need if I had a 1 1/2" system) is described as 40mm on the packet. Meanwhile the Screwfux catalogue states that "bathroom sink items are described as 'basins' and are always 32mm  &  kitchen sink items are 'sinks' and are always 40mm"   It then displayed a basin sink waste of 40mm.
I wouldn't have believed it was this difficult.  All chandlers sell 1 1/4" fittings AND 3/4" fittings but not the things to mate them together.   All narrowboat blogs say connect your sink using standard fittings and 'simply' connect to an outlet hose.     Any other brilliant ideas apart from drilling a vast hole in the side of the boat, or letting it spill into the bilge and let the bilge pump take car of it!

Any help..

https://www.screwfix.com/p/floplast-push-fit-reducer-white-40-x-32mm/12833?tc=VA6&ds_rl=1249404&gclid=CjwKCAjwjYKjBhB5EiwAiFdSfgIf6amA6sAYPbDP1gbxzhuPq0JNebv5jL8nBTtNEf8pxGofi1w-2RoC_NkQAvD_BwE&gclsrc=aw.ds

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35 minutes ago, rusty69 said:

I would.

 

I feel your pain, having been down the same path. Unless you are fluent in the gobbledygook speak of plumbing fittings and take a chance of what you think is right, its better to seek the knowledge of someone who speaks BSP. If you don't you just end up buying loads of random bits in the hope that cobbling them together will get you the result you need.The resulting left overs need a whole cupboard on the boat for themself, and will probably never be used again.

 

Plumbing fittings are much harder than they should be. Probably intentionally.

 

This is the hideous abomination that I eneded up with. If you do come up with a simple one piece solution, please, please let me know so I can reclaim some of my cupboard space.

 

This image will be deleted in 24 hours, as its such an embarrasment.

 

 

IMG_20230514_173137254~2.jpg

We have something similar but with brass fittings.

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2 hours ago, Cal Ando said:

All chandlers sell 1 1/4" fittings AND 3/4" fittings but not the things to mate them together.   

 

Depends on the chandler. 

 

What about buying a 32mm & 19mm hosetail fitting and connecting them with a 1" BSP female sleeve? Not cheap but it would do the job.

 

https://www.ebay.co.uk/itm/265788736054?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=B1UfzYA4Tci&sssrc=2349624&ssuid=SV_sF0T7SiS&var=565574411939&widget_ver=artemis&media=COPY

Edited by blackrose
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2 hours ago, Cal Ando said:

Just to clear things up, I took all the crap from the old and new sink and showed the nice lady in Screwfux (who was absolutely brilliant and knowledgeable) and she spent over an hour trying to help.  

I was in the very long queue behind you

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5 minutes ago, Tacet said:

I was in the very long queue behind you

 

Strange, our local Screwfix is pretty well staffed and there would always be others to serve.

6 minutes ago, MtB said:

 

Quite. 

 

This is exactly why proper plumbers' merchants are trade only. 

 

 

 

 

Luckily some places are quite happy to help DIY'ers and help us stop getting ripped of by 'proper' so called trades people.

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9 hours ago, Cal Ando said:

PS advertising a 1 1/2 " thread as 40mm is probably an excellent example of why Brexit occurred.

40mm and 32mm are the standard metric sizes for plastic sink, bath and washing waste pipes using push fit, compression or solvent welded fittings.

The sink, bath and basin fittings have a screw thread of the type referred to as BSP (British Standard Pipe) thread. These were originally developed in this country and defined using imperial dimensions. They are now set out in international standards; the dimensions are unchanged but they are now specified in metric units (and therefore not round numbers in mm).

Strictly the inch units have been dropped from the standard, so your sink waste thread is properly referred to as '1 1/2 BSP' and not '1 1/2 inch BSP', with the 1 1/2 simply being a size reference, not a dimension. But most people still include the inch.

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10 hours ago, David Mack said:

40mm and 32mm are the standard metric sizes for plastic sink, bath and washing waste pipes using push fit, compression or solvent welded fittings.

The sink, bath and basin fittings have a screw thread of the type referred to as BSP (British Standard Pipe) thread. These were originally developed in this country and defined using imperial dimensions. They are now set out in international standards; the dimensions are unchanged but they are now specified in metric units (and therefore not round numbers in mm).

Strictly the inch units have been dropped from the standard, so your sink waste thread is properly referred to as '1 1/2 BSP' and not '1 1/2 inch BSP', with the 1 1/2 simply being a size reference, not a dimension. But most people still include the inch.

OK I understand this.  What I can't understand is what people mean when they say "40mm" or "32mm" connector.   A bathroom screw thread is 1 1/4 BSP.   If this is measured in metric it's (approx) 41mm. dia   It should mate with a 32mm system.   So when people talk about a '40mm' thread, do they mean 1 1/4 BSP, for bathrooms,  a kitchen tap push fit to thread converter, the thread for Kitchen systems ???

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3 minutes ago, Cal Ando said:

What I can't understand is what people mean when they say "40mm" or "32mm" connector. 

 

I think it refers to the plastic pipe size, and just to make matters worse the true size of the pipes depends upon what type of fitting you are using, glue or push fit. Glue uses a pipe with a thicker wall so has a greater OD. So called compression waste fitting  fits both size pipes.

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On 14/05/2023 at 17:22, captain birdseye said:

Screwfix do ones like this

image.png.e3773db3cd04fc967cd1996c6e051f2d.pngimage.png.e3773db3cd04fc967cd1996c6e051f2d.png

Thanks for trying Capt Birdseye.   Just for the record I got one of these connectors which screwfix advertise as to fit 40mm system with 1 1/2 BSP internal screw thread and its BRILLIANT apart  from TWO TINY FLAWS   1) it's not 40mm and 2) it's not 1 1.2 BSP   It is in fact 1 3/4 BSP which again is BRILLIANT if anyone else in the world used 1  3/4"BSP as a standard waste fitting.

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