Size of hole in water butt for connector

[David]

Wearing my "long time since I did this" hat.

I have a connector kit to join two water butts.

The diameter of the non-threaded bit is 24mm. Outer diameter of the thread is 25.64 mm.

So do you cut the hole to be a tight fit (24 mm) and expect the connector to cut a thread which seals, or do you cut for a loose fit (25 mm or even

26 mm)so the connector just slides in and the seal is on the mating faces with the water butt plastic?

I'm about to go shed diving again, but the cutters at Screwfix are 25mm which might be a hint.

Cheers

Dave R

[newshound]

Depends on the materials of the water butt and the connector kit, and whether or not the butt has a suitable surface finish to make a seal with the supplied seal.

[Chris Hogg]

On my water butt connectors, which are like this,

the threaded portion is a loose fit through the hole in the butt. There is a plastic nut and a rubber washer, and the plastic nut is tightened up to compress the rubber washer against the wall of the butt and achieve a seal. The corrugated hose between the two barbed connectors is a fairly tight push-fit onto the connectors. Softening the hose slightly in hot water before applying, helps. I applied some gutter sealant liberally over the washer, the nut and the barbed connector to ensure a good seal. Didn't bother with hose clips - didn't need them.

[newshound]

That URL didn't work for me.

[Chris Hogg]

Oops! nor me! Sorry.

Trying again:

[Paul]

Paul

[David]

Thanks.

A vote for a loose fit and use the washers to make the seal.

All the cutters I can find seem to be 25 mm which may be a tight fit but will check what the next size up is.

Don't think I can go above 26 mm for the hole and still have enough surface for the washers to seal onto.

The main upside is that the connectors will be right at the top of the water butts so a little leakage will not be a major problem, unlike the taps at the bottom.

Cheers

Dave R

[newshound]

That would be the normal approach using a plastic "tank connector". But, with a metal plumbing fitting in a thick enough thermoplastic tank you can get away with using the fitting as a "tap" in an undersized hole, especially if you have a back-nut for extra security. A sealing washer may not actually be necessary, especially if you put a smear of sealing compound on the threads and the internal and external faces.

You can use the same approach for taps, especially if they have a decent length of thread so that there is plenty of room for a back nut.

[Chris J Dixon]

I take it you have ruled out a permanent syphon between the two?

Chris

[Andy Burns]

Not at the bottom, so they fill and empty in sync?

[Chris Hogg]

Connecting the two butts at the bottom is by far the better way to do it IMO. You only need one tap, and you only need to drill one extra hole, and that in the butt that is going to have the tap, as you use the tap-hole in the other butt for the connector fitting. But you do need both butts to be empty first, on their sides, and the assistance of a small person to crawl inside and screw up the nut. When the nut starts to grip, tightening it from the outside is usually practical, so the small person doesn't have to do it from the inside. Once the two fittings are in place, then the butts can be stood back upright and the linking hose fitted.

[Martin Brown]

That is how I do mine. Small lead weights on each end of the pipe.

Getting it started the first time is fun and then every decade or so after a build up of sludge in the bottom. Weights best off about 6" back from the end of the pipe. I used clear 1cm silicone piping for mine.

[Brian Gaff (Sofa]

Problem is the material of the butt gets hard in the cold weather. I did mine when I had one with screwing it in to a tight hole with it coated in dow Corning eurathane bond. Seemed to last for many years. Brian

[Andy Burns]

Given that various surrey/essex/warwick/tech flanges exist which can be installed into H/W cylinders from the outside, don't suitable flanges exist for water butts?

[PeterC]

Failure-critical though - one detached/damaged link and all the water goes.

I have 3 butts totalling about 550 li that are top-overflow, with no. 3 draining away from the sheds. No. 1 catches most of the crud by acting as a settling tank. The gutters are covered by mesh but ash seeds and pine needles... In the autumn, when demand is low and the rains are starting, I use the water from 2 and 3 then empty and clean out 3, repeat with 2 (after bailing it into 3 if necessary) then bail 1 into 2 until the sediment stirs. Cleaning 1 is the messy part and it needs a scrub as well. I save a couple of gallons from 1 in a bucket so that the resident leeches have a temporary home and the same water. Usually end up with about 200 li left and 3 clean butts.

[PeterC]

Failure-critical though - one detached/damaged link and all the water goes.

I have 3 butts totalling about 550 li that are top-overflow, with no. 3 draining away from the sheds. No. 1 catches most of the crud by acting as a settling tank. The gutters are covered by mesh but ash seeds and pine needles... In the autumn, when demand is low and the rains are starting, I use the water from 2 and 3 then empty and clean out 3, repeat with 2 (after bailing it into 3 if necessary) then bail 1 into 2 until the sediment stirs. Cleaning 1 is the messy part and it needs a scrub as well. I save a couple of gallons from 1 in a bucket so that the resident leeches have a temporary home and the same water. Usually end up with about 200 li left and 3 clean butts.

[Chris Hogg]

Failure is not an option!