# Building A Sight Gauge Or Sight Glass



## mobrien (14/4/07)

Hi all,

I've had a PM asking me for photos of the sight gauge I built a while back, and since I bought ozbrewers big 80L kettle, I thought I'd build a new sight gauge and document the process.

First step is to get the right equipment.

The general idea is to get a pipe compression fitting to fit the sight glass. In my case I am using a 1/2" polycarb sight glass, so need to get a 1/2" compression fitting. I suggest that you ring around first and found out what you can get - I used 1/2" because that was the ONLY size I could get a polcarb tube AND a compression fitting.

I am going to assume that you have some kind of threaded connection into the HLT or kettle that you want to add a sight guage to. If you don't you need to add one somehow! Either get a weldless fitting, or weld (or get a tame engineer to) weld a fitting to the HLT or kettle. 

In my case I have a 3/4" BSP threaded fitting (male) coming out of my new boiler attaching to the thermometer. The HLT also has a 3/4" BSP threaded fitting coming out to attach the tap. My old boiler (in which the old sight glass imploded) as a 3/4" BSP socket (female). In all we're going to do three sight gauges today!

So off to the store. I came back with 3m of 1/2" polcarb tube ($28) and three fittings. 

The fittings are a little more complex. For the tap and the thermometer, I need a three way T piece with three BSP female fittings. In the top of the T, got a 3/4" BSP male to 1/2" compression fitting. For the tap it needs a 3/4" BSP to 3/4" BSP adapter, so we screw the tap on. The thermometer doesn't need this, as the thermometer has a 3/4" BSP male fitting.

For the old boiler, a simple elbow does the job - 3/4" BSP to 1/2" compression.

All the fittings were $22.

Because a picture is worth a thousand words, here are the fittings - on the left, the T piece with the 3/4" BSP adapter for the tap, and the 3/4" BSP to 1/2" compression adapter for the sight glass. Notice the little nylon olive that makes up part of the compression fitting.

On the right is the elbow for the old boiler - very straight forward.


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## mobrien (14/4/07)

Because it is easy to mix up the adapters, I'll show a photo of the BSP to compression adapter. Notice the PARALLEL threads of the compression fitting, compared to the TAPERED thread of the BSP fitting.


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## mobrien (14/4/07)

OK - so next step is to screw everything togther, with the exception of the sight glass. I use pink plumbers tape, as this is thicker and better than the white bunnings crap. This seals the threads, and means no leaks!

Make sure you get the top of the T pointing up - you need the sight glass to be vertical!

Here is the T piece all attached to the outlet valve of the HLT.


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## mobrien (14/4/07)

Now for the sight glass. Cut it to length, and sand the ends. I always wash everything at this point - any extra dust/shavings will create a leak.

Slide the cap (brass bit) of the compresion fitting onto the polycarb tube, followed by the olive. This should be a REALLY tight fit. If its not, you've got the wrong sizes.


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## mobrien (14/4/07)

Now the sight glass sits into the top of the compression fitting. It should hit the bottom of the fitting and you will need to slide the olive down so it rests on the brass. Now its just a matter of tightening up the nut, which compresses the olive sealing the sight glass!

I've also add the outlet tap in the photo.


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## mobrien (14/4/07)

The next step is to make a scale (and test it doens't leak!). I do this using a fermenter, as its the scale on the fermenter I use when calculating stuff. But its up to you as your source of volume measurements.

With the HLT empty, I fill a fermenter to full at the 30L mark. Then just drain it in until the water shows in the sight glass. I used a piece of white plastic electrical conduit covering as the board for my scale, and at the first sign of water, placed a grey pencil mark, recording the volume.

Then every 5L, I marked the scale in grey pencil.


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## mobrien (14/4/07)

Now using the grey marks as a guide, I did some quick maths to work out the number of mm for every L. Then did the scale properly in perminant marker, and labelled the 5L incriments using my wifes labeller


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## mobrien (14/4/07)

And thats it!

The same process was used for the three way T piece on the temperature port - it just looks a little different.


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## sqyre (14/4/07)

Looks good mate, Wish i knew about that polycarb tubing when i built mine..

Hard plastic is it??

If you have your tap come off the "T" piece you will lose your level reading while the tap is open due to the suction of the flow from the tank.

I did the same thing originaly but got the shits with it as had to turn the tap off and wait for it to relevel to know where i was at. I ended up making the sight glass seperate to the tap and works great now.

My 2 cents..  



Sqyre...


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## mobrien (14/4/07)

And finally - the lebow on the old boiler. Same deal, just using the elbow.

There you go - three sight gauges all done. Hope this helps someone!


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## mobrien (14/4/07)

Finally - a pic of the new look brewery for good measure!


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## mobrien (14/4/07)

sqyre said:


> Looks good mate, Wish i knew about that polycarb tubing when i built mine..
> 
> Hard plastic is it??
> 
> ...




Sqyre,

Polcarb is damn hard plastic, and supposed to be good with heat - we will see!

I have noticed the level on the tap drops - by about 1L with a full HLT and 0.5L when its half full. The eventual plan is to do it with a temp guage in there - just need to get the new BSP port to put it in. Until then. the depressed levels I will cope with - its got to be better than measuring it in 2L lots!

M


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## Keifer (14/4/07)

Hey, so you have a pump? how do you get from the mash tun to the boiler?


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## mobrien (14/4/07)

Keifer,

I haven't actually used the new rig yet, but....

I don't have a pump. At the moment it is gravity fed - mash tun is the blue keep cold cooler, and the outlet is above the 40L mark of the boiler boiler - its no drama to drain it from there into the boiler.

Maybe a pump eventually - for now, I'm willing to keep with gravity!

M


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## Fents (14/4/07)

mobrien said:


> Finally - a pic of the new look brewery for good measure!



:beerbang: Thats mad.


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## Pumpy (15/4/07)

Great Post Mobrien , Thats going to help a lot of people like me who need guidance in life to fit a low cost sight gauge

.well done !!

Pumpy


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## Ross (15/4/07)

Will be interested to see how you go mobrien - i was going to fit one the same way & got advised by several people (& as Sqyre found out) that the false readings whilst drawing water from the tap make it far from desirable to mount like that. My understanding is, you'll have to keep turning it off to let the level settle to see what you've drawn off.
Rig looks good though.  

cheers Ross


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## Batz (15/4/07)

mobrien said:


> And finally - the lebow on the old boiler. Same deal, just using the elbow.
> 
> There you go - three sight gauges all done. Hope this helps someone!




Looks a familiar old kettle there  
Did the old sight glass give it up?

Batz


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## Pumpy (15/4/07)

Ross said:


> Will be interested to see how you go mobrien - i was going to fit one the same way & got advised by several people (& as Sqyre found out) that the false readings whilst drawing water from the tap make it far from desirable to mount like that. My understanding is, you'll have to keep turning it off to let the level settle to see what you've drawn off.
> Rig looks good though.
> 
> cheers Ross




Oh I see Ross is that because of the turbulance caused by using a ball valeve on the end of the Tee .

perhaps it should just be a un-interupted 90 degree bend fitting instead of the tee to the sight gaugue .

Pumpy


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## mobrien (15/4/07)

Yeah - it definitley does effect it having it on the outlet. In my tests yesterday when I checked the calibration scale, I found that when the boiler is full it depresses by around 1L in the sight glass. Half full depresses about 0.5L, and when it gets low - well its almost right.

I've actually set it up so that I can just take the tap off and mount a thermometer there - then just mount the tap elsewhere. I want the tap lower on the HLT anyway - The guys that welded the fitting misread my instructions and put it 50mm from the bottom, not 5!

I'll use it as it is for now - its better than the old measuring way of 2L jug - I'm waiting for the Craftbrewer place to get stainless weldless fittings to add the new place for the tap  

Figure I'll do that the same time as I build the new mash tun - no point in having a 80L boiler, 65L HLT and a 37L mash tun. 57 mash tun coming up me thinks!

M


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## mobrien (15/4/07)

<science lesson>

Pumpy - the depressed level in the sight glass is becaue of the venturi effect. Simply, moving liquid (or gas) past a hole decreases the pressure at the hole. In the case of a sight glass, the pressure decrease means the water is pushed down by atmospheric pressure, reducing the reading. The pressure decrease is propotional to the speed of flow - so when the boiler is fuller, faster flow means more dperessed reading.

Some fish tank pumps have a venturi tube that allows air from the surface to be pushed into the water stream creating bubbles in the outlet.

</ science lesson>


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## mobrien (15/4/07)

Batz - yes that should look very familiar to you!

The old sight glass gave up mid brew two brews ago. It was very spectacular, but some quick thinking had me drain the HLT into the fermenter and then the wort into the HLT. I used the HLT to do the boil, and in the end only lost 1L!

I had actually planned for the scenario, which is what saved me. However, now I have spare end caps for the all fittings - so if it all goes to crap, I can tilt whatever device backwards, remove whatever fitting is the issue, and cap it to keep going.

It also was very worthwhile having a spare fermenter sitting there. Now I also have a 40L crate (clean) just in case also. Don't want to loose any wort!

AS an aside, it looks like I'll be selling the old rig (boiler and the small orange mash tun) shortly - time to start someone else off in AG! I can't actually believe I've outgrown it! it seemed so big when I got it 

M


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## hockadays (15/4/07)

hey mobrien,
nice work and good post, my only question is where in brissy did you find the tubing...??

hockadays


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## mobrien (15/4/07)

Parts list:

PCTI12/9 Polycarb tube 1/2" x 3/8"
$28.60/3m
From Acrylic Rod and Tube supplies
13 Brennan St Slacks creek - PH 32905621

Elbow
016187 Elbow comp brs (Nylon olive) 15c x 15Fl
$7.18

T piece
018119 Tee BRS 15mm
$3.14

Compression nut (for top of T)
017818 Nipple Hex BRS 15mm
$1.81

All brass fittings were from Tradelink - I used Ipswich, but I'm sure product codes would be the same for all.

Hope that helps!

M

P.S. I have left over plocarb tube - around 1m left, which would do two sight glasses. FIrst in best dress - price is pro-rata based on full length.


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## sqyre (15/4/07)

I ended up doing mine a little differently and fed from underneath the HLT. 

This way shows all litres down to an absolute zero but probably not very helpfull unless you wanted to pull up exactly a litre short or something.

But hey, something different... maybe...






Please excuse the filth looking bottom tube..it was the only piece that size i could find to do the job...its stained from when it was used as a blow off valve for the septic tank...Been meaning to replace it..

Beer anyone???  

Sqyre..  


EDIT:changed Kettle to HLT...(Drunk Bastard)


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## Vlad the Pale Aler (15/4/07)

Is it a good idea to have a sight glass on the kettle?
The small amount of wort in the tube may not be boiled fully and could cause problems in the fermenter.

h34r:


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## sqyre (15/4/07)

Vlad the Pale Aler said:


> Is it a good idea to have a sight glass on the kettle?
> The small amount of wort in the tube may not be boiled fully and could cause problems in the fermenter.
> 
> h34r:





Oops. good pickup... typo on my part. should be HLT...

thats what happens when you drink and post.


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## mobrien (15/4/07)

Vlad the Pale Aler said:


> Is it a good idea to have a sight glass on the kettle?
> The small amount of wort in the tube may not be boiled fully and could cause problems in the fermenter.



I actually wondered about this, but solved it (in my head anyway) by waiting until rolling boil, then using a funnel, adding a litre or so of boiling water through the sight glass. This cleans out any froth from the initial boil, and also forces the non boiled wort into the boiler.

During the boil the water in the sight glass often boils anyway - I'm not that worried. Its only got to get about 75 to kill any nasties.

Curious what other people think though?

M


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## mobrien (15/4/07)

The leftover polycarb tubing is sold!

M


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## hockadays (15/4/07)

mobrien said:


> The leftover polycarb tubing is sold!
> 
> M





doh!! :blink: too slow...


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## Velophile (16/4/07)

mobrien said:


> <SNIP>
> 
> Figure I'll do that the same time as I build the new mash tun - no point in having a 80L boiler, 65L HLT and a 37L mash tun. 57 mash tun coming up me thinks!
> 
> M



What vessel is the HLT? 

Where do I find a SS 65 litre drum?


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## Blackfish (16/4/07)

Velophile said:


> What vessel is the HLT?
> 
> Where do I find a SS 65 litre drum?



I second that!
Where do you get those? (apart from behind the pub late at night! h34r: <_< )

FHG


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## Velophile (16/4/07)

fhgwgads said:


> I second that!
> Where do you get those? (apart from behind the pub late at night! h34r: <_< )
> 
> FHG



Its the extra 10 to 15 litres more than a keg shaped HTL I'm after. 

I could have any number of 50 litre 'vessels' some legal, most not & there are a few 100 - 220 HDPE drums around but bugger all 60 - 70 litre ones. 

If I'm spending the time building a new HLT, I want it big enough to grow into.


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## bonj (16/4/07)

mobrien said:


> AS an aside, it looks like I'll be selling the old rig (boiler and the small orange mash tun) shortly - time to start someone else off in AG! I can't actually believe I've outgrown it! it seemed so big when I got it
> 
> M



I'm very interested in your old gear. I'm in the process of making a boiler/HLT at the moment, so your gear would be very handy.

-Bonj


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## Darren (16/4/07)

M obrien,

I am wondering why you hav added a sight glass to your kettle. Does it not worry you that it will never be sanitary?

If it were me I would have "plugged" the hole off. After all you can see into your boiler and use a dip-stick for levels.

Otherwise looks pretty good.

cheers

Darren


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## sqyre (16/4/07)

Velophile said:


> Its the extra 10 to 15 litres more than a keg shaped HTL I'm after.
> 
> I could have any number of 50 litre 'vessels' some legal, most not & there are a few 100 - 220 HDPE drums around but bugger all 60 - 70 litre ones.
> 
> If I'm spending the time building a new HLT, I want it big enough to grow into.





I do double batches (aim for 45-48 litres) and have so far never had to boil more than about 25-30 litres at any given time.

My mash tun is approx 42 litres and my kettle 50 litres.

I boil each "addition" of water seperatly...and having small amounts with a large heating element (3600watt) it only takes about 20 minutes to bring around 25litres of hot water out of the tap up to about 90 degrees. (if need be)

This also gives me greater control on sparge water temps.

Perhaps a more powerful HLT is another option to a bigger HLT?

Supose it all comes down to how big you think you are going expand.

More Food for thought...

Sqyre...


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## Doogiechap (17/4/07)

Another way of interfacing polycarbonate tubing into 1/2" BSP fittings. Salvage the ends off your mash tun braid hose. They have an approx dia of 8mm on the barb ends. Carefully heat the end of the 6mm (inside diameter) polycarb tubing and voila ! You have a skinny sight glass  . These fittings have a rubber seal and make a good fingertight seal so are easy to pull apart to clean if needed. It's also a great way of interfacing beer line to general plumbing setups.
Sorry about the dodgy piccy !


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## devo (17/4/07)

I thought about installing a sight gauge for some time but ended up opting for the dip stick solution.


BTW this is my 500th post so now I can personalise my avatar name  i think? :huh:


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## Blackfish (17/4/07)

Doogiechap said:


> Another way of interfacing polycarbonate tubing into 1/2" BSP fittings. Salvage the ends off your mash tun braid hose. They have an approx dia of 8mm on the barb ends. Carefully heat the end of the 6mm (inside diameter) polycarb tubing and voila ! You have a skinny sight glass  . These fittings have a rubber seal and make a good fingertight seal so are easy to pull apart to clean if needed. It's also a great way of interfacing beer line to general plumbing setups.
> Sorry about the dodgy piccy !



Nice work Doogie! I knew I didn't throw those ends out for nothing. 

Something from nothing is like my favourite thing in this world!! :super: 

FHG


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## mobrien (17/4/07)

Hi everyone,

A few people are asking about my 65L drum. I bought that 5 years ago from Visypack in Bulimba (Brisbane). Its a 60L 316 stainless open top drum (but holds 65). I paid cash for it - $150.

I have also heard that Rheem Australia, also at Bulimba, sell a similar thing.

No idea about current prices.

Hope that helps!

Matt


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## mobrien (17/4/07)

Darren,

I posted this earlier in the thread:



mobrien said:


> I actually wondered about this, but solved it (in my head anyway) by waiting until rolling boil, then using a funnel, adding a litre or so of boiling water through the sight glass. This cleans out any froth from the initial boil, and also forces the non boiled wort into the boiler.
> 
> During the boil the water in the sight glass often boils anyway - I'm not that worried. Its only got to get about 75 to kill any nasties.
> 
> ...


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## mobrien (13/5/07)

An update on this thread.

I've done three brews since I put the sight guages on the brewery, and there is no going back. Everything is so much easier.

The glass on the outlet of the HLT works perfectly. People were concerned about false readings, but in practice this is nothing but good. When filling the HLT from the bottom, the reading is elevated above what is *really* is, which means I don't overflow the HLT. When draining out to underlet on the mash tun, the reading is depressed, but this is excellent also - I do a temperature check and stir before adding the last litre, just to make sure its all good - then add the final litre. Its perfect - if I was doing it all again, I'd still have the sight glass on the outlet of the HLT.

The guage on the boiler is also really good. This is on the thermometer port, so no depressed readings here. There was some concern about the sanitation of it, but my "add boiling water till no colour is in the sight glass" method works well, and all brews have been fine. I like having the sight glass on the boiler, as I can ensure I meet the volumes I want easily.

So in conclusion - all is working well - I highly reccomend it!

Matt


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## lokpikn (10/6/07)

I thought i would re do my site tube today while i was in the shed and thought i would take a few photos to show as i thought this was quite easy to do.

I did get this 90deg bend welded in but you could use a weldless fitting but i dont think i would cost much different.




I have used polycarbonate tubing and some heat proof glue which is on the outside only so it will not touch the water in the HLT.



This thing ( I dont know what to call it )was the perfect fit and you can buy it as is there was no modification at all to any bits in this setup.



And all that is left is to wait for the glue to dry (or use 5min araldite which i ran out of  ) and screw in into the 90deg bend and once it is on the HLT you can draw up all the marks.


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## nabs478 (25/9/07)

I was looking at compression fittings at my local bunnings, and they only had ones with copper olives.

Has anyone used these compression fittings with polycard tubing with sucess?


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## niceshoes (25/9/07)

Pip. said:


> I was looking at compression fittings at my local bunnings, and they only had ones with copper olives.
> 
> Has anyone used these compression fittings with polycard tubing with sucess?



Hi Pip,

I've used Bunnings brass compression fittings with plastic (polypropylene??) olives using polycarbonate.
Never tried the copper olives but I do know you can buy the plastic olives separately in a bag of 20 or so.


Ian


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## afromaiko (27/8/08)

mobrien said:


> Parts list:
> 
> PCTI12/9 Polycarb tube 1/2" x 3/8"
> $28.60/3m
> ...



Anyone know where to get this in half inch in Melbourne? I've only been able to find 19mm stuff on the Geordi website so far.


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## TidalPete (27/8/08)

Pip. said:


> I was looking at compression fittings at my local bunnings, and they only had ones with copper olives.
> 
> Has anyone used these compression fittings with polycard tubing with sucess?



Yes! you will have no worries there but be careful not to scratch the poly when you put them on.

Afromaiko,
Any plastics shop worth their salt will stock poly tubing.

TP :beer:


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## schooey (27/8/08)

Try Dotmar Plastics

30-32 Garden Boulevard, Dingley VIC 3172

(03) 9552 4444

1/2" x 3/8" x 3m length is $26.16 +GST

Maybe do a share buy with someone?

oh.. no affiliation yatter yatter


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## afromaiko (27/8/08)

Excellent, thanks guys.


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## enoch (27/8/08)

Having read this thread I might update mine which is a bit bodgey to be sure... 
Vinyl hose with the top held by whats left of the top keg chine.


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## Cortez The Killer (27/8/08)

How do you take measurements are there markings somewhere?

Cheers


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## enoch (28/8/08)

Cortez The Killer said:


> How do you take measurements are there markings somewhere?Cheers


As its only the HLT I am primarily using it to make sure there is enough water in to avoid cooking the element. Other than that its a case of eyeballing it. 
I use a steel ruler in the boiler and work it out from a chart.


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## sanders4_ (8/5/09)

There has been some bad press regarding polycarbonate use in food grade applications lately - so glass may be a better way to go. After hunting around for some 1/2 inch (12.7mm) glass tubing i could use with a compression fitting, I located a glass blowing place in Sydney that had some 13mm glass tubing that they will cut to length. 

Bit pricey - but they had exactly what i needed, they do mail order, and have very fast, friendly service. Highly recommend them:

Custom-Blown Glassware

Address: 12 Mary St, St Peters, NSW, 2044 
Phone Number: (02) 95172916

I got two 450mm length, 13mm outer diameter glass tubes for $45 delivered - so not cheap - but perfect for the job and completely inert. Nylon olives fit over the top with no modification - but the 1/2 inch compression fitting (from bunnings) required a slight drilling to increase its diameter slightly.


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## muckanic (8/5/09)

sanders4_ said:


> There has been some bad press regarding polycarbonate use in food grade applications lately



Yeah, I scrounged one of those upside down polycarbonate water coolers a while back, with a view towards using it as a more permeable secondary fermenter than HDPE. Then I started reading about BPA.  Heat and alkaline conditions seem to be the worst combination for plasticiser leaching. Dunno about heat and acidity, nor alcohol for that matter, but I have a feeling the cooler may be going back whence it came.


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## muckanic (11/5/09)

An afterthought on ploycarbonate. Whether you believe the BPA scare or not, it is instructive looking at the damage that acetone does. Extrapolating, I can't guarantee my brews don't contain diacetyl. Wiki also suggests that several higher-weight esters are incompatible.


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