Manifold Questions

[Matt12398]

I built my manifold today to fit into my Igloo Icecube coolbox. I haven't cut the slots yet but the image is shown below.



I've gone with the advice John Palmer gives of having the distance from the pipes at the edges of the coolbox being half that of the distance between the pipes. This means that with having 4 pipes it gives a distance of 7 cm between the pipes and 3.5 cm at the edges. The question is whether the distance between the pipes and the cooler wall is enough to avoid channeling around the edges.

[hotmog]

That looks excellent to me . However I'm a little puzzled. Since you decided to base your design on John Palmer's recommendations, why do you question it/them now? If you increased the gap around the edge you would have to reduce the overall size, thus reducing efficiency. I think what you have now will achieve optimum results.

My own bespoke design for my 48l Coleman coolbox is very much more simplistic. I have not read John Palmer's views on the matter, so my only consideration was to minimise the amount of dead space. To do that, I decided to run the pipework along the outer edge where there is a channel so it would sit as low as possible. I have never noticed any any problems with channelling, but then I batch sparge so it's irrelevant anyway.

[fordpopular]

Looks good to me, Channelling is only a problem if you are fly sparging and a minor one at that in my opinion my manifold touches all 4 walls which helps to keep it in place as I batch sparge I dont want to disconnect the manifold from the outlet whilst I mix the grist between sparges

[Matt12398]

I didn't realise it was only an issue for fly sparging. I intend to batch sparge so hopefully it won't fall apart as I don't intend to solder it. I do plan to very slightly crimp or punch the joints though with the aim of creating a very good push fit. I guess it might be good in case I ever decide to try fly sparging in the future.

The reason I ask even though having read John Palmer's advice is that reading gave me a good idea of what I need to do but I wanted to be sure I had interpreted it correctly.

Thanks for your feedback guys.

[orlando]

I didn't realise it was only an issue for fly sparging. I intend to batch sparge so hopefully it won't fall apart as I don't intend to solder it. I do plan to very slightly crimp or punch the joints though with the aim of creating a very good push fit. I guess it might be good in case I ever decide to try fly sparging in the future.

The reason I ask even though having read John Palmer's advice is that reading gave me a good idea of what I need to do but I wanted to be sure I had interpreted it correctly.

Thanks for your feedback guys.

I think you are spot on with that. My experience with a similar set up in the boiler is that you don't really need to crimp the joints, I sometimes struggle to get mine apart for cleaning as it is, crimp them and you might not. Try it without for awhile you can always do it later if you need to.

[hotmog]

I didn't realise it was only an issue for fly sparging. I intend to batch sparge so hopefully it won't fall apart as I don't intend to solder it. I do plan to very slightly crimp or punch the joints though with the aim of creating a very good push fit. I guess it might be good in case I ever decide to try fly sparging in the future.

The reason I ask even though having read John Palmer's advice is that reading gave me a good idea of what I need to do but I wanted to be sure I had interpreted it correctly.

Thanks for your feedback guys.

I think you are spot on with that. My experience with a similar set up in the boiler is that you don't really need to crimp the joints, I sometimes struggle to get mine apart for cleaning as it is, crimp them and you might not. Try it without for awhile you can always do it later if you need to.

What I would do with yours is just solder the upper and lower horizontal short straights to the elbows and T-joints, leaving the 5 long vertical straights (including the outlet return that is not shown) unsoldered. That way it all comes apart easily for cleaning, but the structure is quite rigid and not liable to get dislodged when stirring the mash. Also it guarantees permanent correct bottom-facing orientation of the slots in relation to the elbows and T's; you only need to worry about getting that right with the four long straights when re-assembling. Don't forget, however, that the centre T-joint in the top section needs to be angled upwards slightly before you solder it, so that the return is able to engage with the outlet which is above the level of the floor-pan. You will need to assemble the whole thing first and connect the missing return pipe between the T and the outlet to ensure you get that angle correct.

I took a similar approach with mine, only soldering one elbow to each straight and leaving the other end of each joint unsoldered.

[Matt12398]

The fittings are a little looser than I would liked so I think I might have to do something to get them to hold together better. I wanted to avoid soldering if I could partly because I've never soldered before.

The return pipe, that's not shown, is the frustrating part. I bought this from someone as new and unused which made me think it wouldn't have the drain hole already drilled but it does and it's higher than I would have liked it. I contacted the seller and they insisted it came with a pre-drilled hole and drain bung but every example of this coolbox I have ever seen has the recessed area allowing you to cut a hole but never actually cut. This has given me a headache because if it was not drilled already I could just cut the hole exactly level with the manifold and push fit a piece of pipe into the bulkhead and then push it into a tee on manifold with no problem. Because the hole is higher than the manifold I'm going to try solving this problem by turning the manifold 180, having the outlet tee at the opposite end and then connecting the manifold to the bulk head with a piece of flexible silicon pipe because it should form a good seal between the bulkhead and manifold and hopefully maintain the siphon effect as far as the connection to the manifold.

[StrangeBrew]

Mine is a similar design to yours, fitted to an Igloo Ice Cube only with slightly less distance between copper pipe and coolbox wall and I don't suffer any noticeable channeling.
Run off can be a little slow at times but this is a common problem with copper manifolds.
I've part soldered mine enough to help hold it together duing the mash but it still breaks down in to six pieces for ease of cleaning.
The centre 'T' piece is unsoldered where it joins either side to the manifold and so still moves up and down to allow easy connection to the outlet.

[hotmog]

The fittings are a little looser than I would liked so I think I might have to do something to get them to hold together better. I wanted to avoid soldering if I could partly because I've never soldered before.

The return pipe, that's not shown, is the frustrating part. I bought this from someone as new and unused which made me think it wouldn't have the drain hole already drilled but it does and it's higher than I would have liked it. I contacted the seller and they insisted it came with a pre-drilled hole and drain bung but every example of this coolbox I have ever seen has the recessed area allowing you to cut a hole but never actually cut. This has given me a headache because if it was not drilled already I could just cut the hole exactly level with the manifold and push fit a piece of pipe into the bulkhead and then push it into a tee on manifold with no problem. Because the hole is higher than the manifold I'm going to try solving this problem by turning the manifold 180, having the outlet tee at the opposite end and then connecting the manifold to the bulk head with a piece of flexible silicon pipe because it should form a good seal between the bulkhead and manifold and hopefully maintain the siphon effect as far as the connection to the manifold.

If you turn it 180 it looks like a tight squeeze to fit in a right-angled connection between the T and the outlet that would be right above it. An alternative approach is to do as I did and move the T to the side, allowing a right-angle connection to be made with copper pipe - more durable than flexible silicon and with no risk of failure in the longer term.

Soldering is quite easy really - I always used to use pre-soldered joints when doing the odd plumbing job around the house. However I used unsoldered ones when making my manifold out of 22mm pipe.

Clean the end of the pipe with a bit of wire wool. This also creates a roughened surface for the solder to bind to. Apply some flux around the end with an old toothbrush. Push on to the elbow or T you are soldering it to. Heat with blowtorch until the flux starts to bubble, then apply the solder to the top of the joint on the pipe side. As soon as it melts, it will run all around the joint and also be sucked inside forming a complete seal. At this point, remove the blowtorch immediately, and leave to cool. If you are connecting a T, it is best to have all 3 pipes in position and solder them all together, otherwise solder can run down the inside and then set, making it difficult or impossible to push the next pipe fully into place once it has cooled without reapplying the blowtorch, which could then weaken the first joint.

Have a few practice goes first with some tubing off-cuts, then you'll wonder what all the fuss was about!

As long as the pipe you connect to the outside tap extends below the bottom of your mash tun, then you will have no problem with maintaining the siphon effect. I found that I needed to restrict the diameter to 10mm at the end, however, to prevent air bubbling back up the pipe once the flow starts to reduce as it empties, so I use this:

[seymour]

...Channelling is only a problem if you are fly sparging and a minor one at that in my opinion...

I disagree. Whether you fly sparge or not has nothing to do with it. The purpose of the slotted channels is to suck the sugary wort from the entire mass. If you only have outlets around the edges, and none underneath the vast majority of your grainbed, there is no possible way you're extracting as much as you could. A fluid takes the path of least resistance, so it will flow along the edges of the box more freely than down through the grainbed, thereby leaving lots of potential fermentability behind. I don't mean to criticize anyone's hard-work, but if the whole point of going to the effort of building a mash/lauter tun is to extract as much sugary wort from a quantity of grain as possible, then why would you knowingly handicap it? Will the design shown work, and can you make good beer from it? Of course. But will it give the most efficient extract rate possible from your hard-earned money? No, but that's easily improved upon with a few extra copper runs.

[hotmog]

...Channelling is only a problem if you are fly sparging and a minor one at that in my opinion...

I disagree. Whether you fly sparge or not has nothing to do with it. The purpose of the slotted channels is to suck the sugary wort from the entire mass. If you only have outlets around the edges, and none underneath the vast majority of your grainbed, there is no possible way you're extracting as much as you could. A fluid takes the path of least resistance, so it will flow along the edges of the box more freely than down through the grainbed, thereby leaving lots of potential fermentability behind. I don't mean to criticize anyone's hard-work, but if the whole point of going to the effort of building a mash/lauter tun is to extract as much sugary wort from a quantity of grain as possible, then why would you knowingly handicap it? Will the design shown work, and can you make good beer from it. Of course. But will it give the most efficient extract rate possible from your hard-earned money? No, but that's easily improved upon with a few extra copper runs.

Of course a fluid takes the path of least resistance - that is why channelling is an issue if you fly-sparge. Because the sparge water is added in a continuous gentle sprinkle over the top of the grain bed, it will not get to soak through the grain bed properly dissolving the remaining sugars as it goes, but will run straight off out through the channel instead, so you lose efficiency.

However, what you do not seem to appreciate is that with batch sparging, the volume of sparge water added to the mash tun is given a thorough mix with the grain once more before being left to settle, so most of those sugars the sparge is seeking to extract are already in solution when it is drained off. Thus it matters not whether the route the sparge wort takes to the boiler happens to be via a channel within the grain bed or by soaking through it. Any residual sugars still remaining are then extracted through a repeat of that process in the second batch sparge.

[seymour]

I know what batch sparging is, I use it too. Of course everything is in one stirred solution. Even so, when the time comes to open the valve, I still contend that all the suction will be pulling at the edges and more sugars will be left behind, bunched in the center compared to a simple design modification with a few extra vents underneath the main grain mass, which would permit a more evenly distributed suction.

[Matt12398]

If you turn it 180 it looks like a tight squeeze to fit in a right-angled connection between the T and the outlet that would be right above it

I think I may have confused things slightly in what I said because in the orientation shown in the photo this is in the 180 turn orientation. The problem you suggest about having enough space is exactly why I turned it 180 and the photograph shows how it will be in use.

Thanks for the advice on the soldering. I might consider soldering some of it if for no reason other than ensuring a seal on some of the sections to ensure continuity of the siphon effect.

I think based on all the comments, I've negated any challenging issues because I've allowed enough space between the cooler walls and the manifold. I think also I've covered a good portion of the base of the cooler so hopefully I'll get an efficient extraction from all of the grain bed.

Thank you all for your comments.

[hotmog]

If you turn it 180 it looks like a tight squeeze to fit in a right-angled connection between the T and the outlet that would be right above it

I think I may have confused things slightly in what I said because in the orientation shown in the photo this is in the 180 turn orientation. The problem you suggest about having enough space is exactly why I turned it 180 and the photograph shows how it will be in use.

In that case, you could still use copper pipe rather than flexible silicon tubing for the return from the central T to the outlet. It would just need to be bent slightly in the middle, and the 'T' angled upwards to meet it, which is what I envisaged you were going to do in the first place.

[Belter]

I was there yesterday helping him do this. That was the originaal idea but due to the height the previous guy cut the hole the pipework doesn't fit above the pipe below the outlet