I have my electric brewery (http://"https://goo.gl/photos/v3wi6KrnVFeT3Dzq6") ready for testing. I'm going to try programming the PID controllers tonight. I just realised, before I try a brew, I should ensure the probes are calibrated. Does anyone around Central/North Dublin have a thermometer I could use for this ? Ideally, accurate to 0.1C.
John
If your stuck, crushed ice and a small about of water will give you zero and in the spout of a boiling kettle for 100.
Yeah, not a bad idea. Though I'd installed the probes already, so pulling them out for steam would be awkward :-)
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Though, dammit, one of the SSRs isn't getting a signal from the PID controller, so..something is squiffy. Turns out this is harder than expected.
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If you can wait, you should invest in a Thermopen on Amazon. They're only £24 if you don't mind purple or teal.
https://www.amazon.co.uk/Classic-SuperFast-Thermapen-professional-thermometer/dp/B003P63MEW/ref=sr_1_2?ie=UTF8&qid=1472460862&sr=8-2&keywords=thermapen
Pids drift and need to be measured/calibrated one every 6 months or so.
How long do thermapens stay accurate?
So far 12 months
How do you know though?
Ice is OK to check for Zero.
Steam goes higher than 100C though, so the steamy kettle is not going to be accurate IMO.
(Geting cranky in my old age)
John I have a calibrated probe you can borrow.
It's one I "acquired" from work last change over.
Pm me and we can arrange something. I'm only up in northern cross or you can get at next meet up.
Quote from: johnrm on August 30, 2016, 11:33:29 PM
How do you know though?
Ice is OK to check for Zero.
Steam goes higher than 100C though, so the steamy kettle is not going to be accurate IMO.
(Geting cranky in my old age)
http://thermometer.co.uk/content/121-creating-an-icebath
See the table here:
http://www.engineeringtoolbox.com/boiling-point-water-d_926.html
Boiling point varies by a couple of degrees with the weather (0.950 bar to 1.050 bar). Also altitude of course, but I presume we mostly live at sea level in Ireland!
That ice bath method looks a bit hairy, can't touch ice, side of vessel, bottom etc.
Quote from: nigel_c on August 30, 2016, 11:39:32 PM
John I have a calibrated probe you can borrow.
It's one I "acquired" from work last change over.
Pm me and we can arrange something. I'm only up in northern cross or you can get at next meet up.
I might take you up on that, once I'm done..
I'm currently retrofitting silicon seals to the tanks. Looks like the hole that was made for the element is a smidgen big, and it pulled the element through the hole in the tank. Arse.
The other element makes me sad..I left water in it for a few days, to see would anything leak. The feckin' element rusted! I assume that means a manufacturing fault ?
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No the base of the elements can rust when left in water, unless it is also stainless steel. Check out sacrificial anodes on electric brewery or try cleaning and rubbing in olive oil.
soak it in oxalic acid or high concentration starsan and let air dry to repassivate and that will solve the problem.
Is that a camco element? They're notorious for rusting at the base.
Yeah. I thought I was getting a stainless camco one, but must have clicked on the wrong thing. D'oh. Seems like screwing some aluminium plate in somewhere will do the job.
Nnngngn. I am sick of tracking down leaks. Damn, this is ... harder than expected. Possibly not helped by cramped space and lack of plumbing tooling.
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I put a thin aluminium washer (home made) outside the existing washer securing the camco. Aaaand now the nuts won't go back on. (John, breaks down, sobbing)
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You only need one silicone washer on the outside. Have you a big lash of ptfe on your threads?
Fernox lsx if you really get stuck but you shouldn't need it.
Is the hole nice and clean and filed down?
How did you drill it?
I have done 30-40 holes in stainless for brewing now and some can be a complete pita, persevere
Camcos are a pain in the balls to get to be sealed properly. I would advise a fair few turns of ptfe tape on the threads of the camco. I assume that you have the washer and the oring on the outside of the kettle wall between the junction box like in the electric brewery. See the following http://www.theelectricbrewery.com/node/9?page=show
I suspect that your washer is probably not able to compress your oring enough so it not forming a proper seal. Is your washer the same diameter as the outer diameter of the washer. Realistically you want a slightly smaller hole to put the element through so the oring will fit nice and snug around the element and so compress & seal properly.
My brother fitted my camco element & I do remember him complaining that there was insufficient thread exposed on the heating element to get a tight enough compression. I seem to remember him saying he had to pair back some plastic to get sufficient thread exposed so he could get the locknut sealed tightly enough.
Having blundered through three leaking herms pots recently I feel your pain. Best piece of advice I can give is to step back from it for now. Trying to diagnose this kind of problem when frustrated with images it more challenging. If necessary take it apart & take some photos with the different parts e.g. washer, oring, locknut & any electrical housing box & post them on here. Hopefully somebody will spot something obvious that you can fix.
Shanna
Saw some really clever nuts recently where there is a groove in the body of the nut for the silicone washer to prevent it from jumping out from behind the washer and allowing it to make a uniform seal
Quote from: CH on September 04, 2016, 03:53:40 PM
Saw some really clever nuts recently where there is a groove in the body of the nut for the silicone washer to prevent it from jumping out from behind the washer and allowing it to make a uniform seal
Good tip also is resist the urge to tighten the nut to the absolute Max as it can cause the oring to distort & several the seal.
Shanna
Absolutely, hand tight and one extra turn does it
Quote from: Shanna on September 04, 2016, 04:15:50 PM
Quote from: CH on September 04, 2016, 03:53:40 PM
Saw some really clever nuts recently where there is a groove in the body of the nut for the silicone washer to prevent it from jumping out from behind the washer and allowing it to make a uniform seal
Good tip also is resist the urge to tighten the nut to the absolute Max as it can cause the oring to distort & break the seal.
Shanna
I've a bunch of problems.
One, is that it's insulated...so I can't really get tools in through the external hole to get a good grip on things. I don't think I've any silicon O rings on the inside - there isn't really room on the camco thread. I've a single heavy washer, a 0.5mm aluminium washer, and the nut. Any more, and it'll slip off before it bites. Maybe if I had some sort of tool that could push the side of the tank flat, while I was working on it...but I don't have enough hands :)
I didn't actually drill the holes, it was done by the guy who sold me the pots. Oddly, one element fit nicely, the other's rubber seemed to slip through the hole when I started to tighten it.
Maybe better fitting washers would help. I'm also wresting with trying to loosen/tighten things while the bloody great herms coil is in the way. Or maybe I should go back to just buying beer :)
John
Quote from: bigvalen on September 04, 2016, 11:44:21 PM
I've a bunch of problems.
One, is that it's insulated...so I can't really get tools in through the external hole to get a good grip on things. I don't think I've any silicon O rings on the inside - there isn't really room on the camco thread. I've a single heavy washer, a 0.5mm aluminium washer, and the nut. Any more, and it'll slip off before it bites. Maybe if I had some sort of tool that could push the side of the tank flat, while I was working on it...but I don't have enough hands :)
I didn't actually drill the holes, it was done by the guy who sold me the pots. Oddly, one element fit nicely, the other's rubber seemed to slip through the hole when I started to tighten it.
Maybe better fitting washers would help. I'm also wresting with trying to loosen/tighten things while the bloody great herms coil is in the way. Or maybe I should go back to just buying beer :)
Johny
Are you trying to fit more than one element? If you can't get a spare set of hands try jimmy something against the opposite wall of the pot to hold it in place. Are you running the element through the wall of a project box & the through the wall of the pot (like in the diagram from the electric brewey link)?
If the oring is going through the hole either your over tightening the nut or else the hole is too big. If you can get something like this https://www.amazon.co.uk/Sealey-6-inch-Digital-Vernier-Caliper/dp/B000RODA10/ref=lp_1939084031_1_21?s=diy&ie=UTF8&qid=1473059265&sr=1-21 measure the outer diameter of the element and the diameter of your hole to see are they the same. If the hole is too big then that is going to be your problem. You want the element to snug so that the oring can get purchase on the wall.of the pot. One other thing to check is whether the curvature of the pot is causing some kind of misalignment that is causing the oring to be pulled through on one side. You might want to building a rug out of wood that you can attach some clamps on to. One at the top of the pot and the other at the bottom. That would release your hands for dealing with the lockout.
Shanna
My camcos have no washers. Just a silicon oring on the outside that makes a compression seal.
My herms is still dented from trying to tighten the damn thing!
Looking at the rusted pic, you just don't have spare thread. Id say remove a washer, have an oring in the nut and try that way.
I got my housing from brewpi so there was no messing around and it was still a task, especially as my drill had no slow setting to drill the holes, making them a real mess.
If it's a double skin you need to cut your self some access holes, before I bought those element shrouds from brew builder I had stainless nuts and no way was I going to be able to have them tight without a good grip.
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Huh. I have a 1.5" element wrench, which is good for external access. It's internal that's a pain. I went out to start work again tonight, and was demotivated when I discovered the element was rusting again. Check this out...you can also see the aluminium washer behind it is starting to corrode to...after two days sitting in a wee bit of water. This seems suboptimal.
Time to go find some stainless ones ?
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Did you soak it and re passivate?
I wouldn't be letting my elements sit in water though.
I'd send element back to supplier. Who was supplier?, couple of the guys on Jims reporting rusty elements and just had them swapped out
Try bar keepers friend on the element, that should sort out the rusting, it did with my stainless elements
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