Mash Tun Manifold: Cut Slots or Drill Holes?

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jerichobill

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I'm retrofitting a coleman cooler for my mash tun. Please let me just drill holes in my CPVC manifold, I really don't feel like pulling out the hacksaw. What are the pros and cons? Also, if holes are okay, what size? Also, should I drill holes (or cut slots) on the shorter cross pieces? I heard somewhere that would increase the likelihood of channeling. Any truth to that?

Thanks in advance!
 
I just finished building mine so I think I can be of help. I started with a hack saw and gave up within a few minutes. I then fed my roommate a beer and had him hold the assembly steady while I went to town on the manifold with a sawsall (metal blade.) So, if you have access so a sawsall or a dremel tool I say that's the way to go. I'm not sure about drilling holes though, it seems to me that if the holes are on the bottom you're not going to get much flow.
 
The slots will keep more open area when grain is touching it. Grain particles, especially lopped off ends are like little round cones just looking for a hole to plug. I don't think for a second that drilling holes is any easier than making slots.
 
Beside the plugging part, I would think you would need quite a few holes. I would go with the hacksaw slots, especially if you are using the PVC, it should be nothing to cut into. I made mine of copper, put probably 50 slots into it, using a jigsaw, and it took me about 45 minutes. I think you would be faster putting 50 slots with a hacksaw than putting 200 holes with a drill.
 
After I marked where they should go and fired up the dremel with a little cutoff wheel it took me all of 10 minutes to cut the slots in the copper manifold for my rectangular 48qt. MLT. Only way to go IMO. I shudder to think how long drilling would have taken! I also did put slots in the two short cross pieces in the center. Everything got slotted except the joints.
 
I just finished mine this past weekend and cut and then filed the slots and ran a round file thru the center. It took a lot of effort, beer and time but I'm happy with the results. I did drill holes for the sparge manifold in the lid, which was much easier.
 
Slits with a hacksaw are a pain in the @$$ ...... I gave up on that after about 5 minutes. I have some pics of the 2 mash tuns that I built over my almost 3 year brewing career (all of which was all grain). Since I didn't have a dremel I explored the hole route (I did have a drill). I used 5/64th's bit for the holes in both of my tuns.

This is my original tun. You can't see the holes very well on the picture but I only drilled 3 or 4 holes about every half inch. I never had a stuck sparge in this thing. It drained full bore and never even slowed. The only reason I built a new one was that the cooler didn't hold temp well. I ended up giving it to a buddy who still uses it

oldmashtun.jpg


The new tun I went a little crazier on. I started with the slits ONLY (I borrowed a dremel for this build). I brewed two batches both of which stuck like crazy. Having never had to deal with a stuck sparge this pissed me off beyond belief. I spent half a day drilling holes between all the slits. No more stuck sparge.

I'm not saying that the slits suck (obviously I used to thin of a dremel wheel in retrospect). Just saying that holes work just as well. Never had a stuck sparge since adding the holes.


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Yes ......... the vinyl tubing has since been replaced with silicone.......
 
I built 2 mashtuns with slots, a 5 and a 12 gallon. I had problems with stuck mashes on both. I didnt change any parts, I just got out the drill and punched a bunch of holes. I havnt had a problem since. So I say BOTH.
 
I recently built a copper manifold and drilled holes, mainly because I have a drill and don't have a reciprocating saw or Dremel. It works great. About 5 batches with it so far and zero problems. Can't remember what size bit I used though. Something small enough that grain wouldn't have an easy time making it through, but large enough that a single husk wouldn't clog a hole.
 
I drilled mine, but I used a CNC to drill on even measurements and rotated by hand after each line of holes. If I had to drill all of those by hand... Yuck.
 
Both holes and slots does sound like a good idea because it's conceivable that some grist shapes are more prone to clogging either and you sort of hedge your bets. I think holes are great as long as they are small enough and you have enough of them. I just know what my false bottom looks like when I pull it out after a brew. About 1/4 of the holes are plugged really solidly.
 
Could be a grain weight thing also bobby ...... with the holes pointed downward in the manifold vs. upward with false bottom. Grain and water weight pushing down might mean more jammed grain pieces in false bottom than manifold holes which aren't supporting the weight of the grain bed???? Just a guess.... never used a false bottom.

I pull my manifold out and spray it off with hose. No grains to poke out of the holes or anything.
 
I used a miter saw. took a piece of pvc, and just went up and down up and down with miter saw, moving pvc about 1/2" to an 1" each time. did it in about 2 minutes.
 
I used stainless steel braid and hose clamps for my manifold and used it to brew 3 all grain batches last weekend, worked like a charm. No stuck sparges and no collapsing filter braid and it was real easy to clean afterwards.

The braid is reinforced with a coil made from 12 gauge copper wire to prevent it from collapsing.

coilwire4.jpg


screwytunfilter1.jpg
 
I second the stainless braid. I don't have a reinforcement coil, and have yet to have it collapse or get a stuck sparge. Costs $12-15, and if you hose clamp it to a 45* elbow and a length of cpvc to near the bottom it will suck up all but a tiny amount of wort. Mine leaves behind about 1.5 cups...

I've been using this one for 1.5 years with no problems and no complaints:

Ok, here's how I set mine up. I also noticed when I just took it aprt, that my hole is just through two layers of plastic (inside and outside). It looks like the manufacturing process for these powerade coolers sorta welds the two parts together at this point and they just punch a hole through that for the spigot.

Anyway, I was a little inaccurate on my previous post on a few details...Everything is still 1/2" cpvc, but the angles are 45's and I only used one washer on the inside and outside. I had to dremel out the hole in both washers to get it to fit easily (they must have been 3/8"), and I bent the inside washer to fit the curve of the cooler.

Here's what it looks like put together (loosely)
IMG_4997.JPG


Here's a shot of it taken apart.
IMG_4995.JPG


Here's a close up of the brass nipple...notice the curve on the right washer?
IMG_4999.JPG


The black rubber washer sits about in the middle of the smooth part of the nipple, and the stainless washer (right), is about all the way on the smooth part.

Here it is tightened down
IMG_5001.JPG


My cooler wall is maybe twice as thick as the space left over, so everything cinches down nice and snug. This configuration works well for my cooler, but I don't have to deal with the walls collapsing any. You could used the OP configuration and just sub the cpvc in for the metal part. This might save some wear and tear on the plastic cooler walls, as the whole thing only weighs just shy of 273g (~10 oz.)
 
thx for the help! i'm going to make two varieties (one with holes, one with slots) and try them both since my manifold is just loose fit. i've gotten distracted now by the bulkhead through the cooler drain. i have the guys at lowe's w/smoke coming out their ears. i'll post pics when i'm done...
 
I've built two mash tuns, one 5gal and one 12gal, both modeled after ChemE's super efficient mash tun thread. The only difference is that I didn't install a manifold for sparging. I get great efficiency with these and have yet to have anything close to a stuck sparge. I cut my slots with a hacksaw slightly less than halfway through the pipe and spaced them out a 1/4" and couldn't be happier with the performance.
 
I agree with the hacksaw, I just used a vise and only slotted the long dimension, one at a time, took me 10 mins. Mine was CPVC, not sure if copper would take longer.
 
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