Short Sightglass?

[vallonswayla]

If a sightglass isn't quite long enough, does that cause any problems like liquid leaking out of the top of the sightglass? I am looking at getting something that appears to have an enclosed top. The lengths are 11"(might be an inch or two short of top of my kettle) or 16" which would be 3-4 inches above my kettle. I'd prefer shorter rather than longer.

 

[Auger]

If your sightglass is shorter than your kettle walls, and the liquid level is filled higher than the top of the sightglass, then yes, liquid will overflow the slightglass.

 

[vallonswayla]

even with something like this?
https://www.proflow-dynamics.com/pr...sight-glass-brewing/weldless-sight-gauge.html

 

[kh54s10]

The top of a sight glass cannot be closed otherwise it will be full of a big bubble. If your sightglass is shorter than the volume of the vessel you cannot fill above the top of the sightglass. In fact your volume of liquid will expand about 4% so you cannot even fill to the top of the sightglass. Get the 16 inch one and find a way to trim off the top. Or find another supplier that has one that is 12 -13 inches. Remember that you cannot put the glass right at the bottom of the kettle.

 

[kh54s10]

even with something like this?
https://www.proflow-dynamics.com/pr...sight-glass-brewing/weldless-sight-gauge.html

That one as in all others will be open on the top. If you find one with a return to the pot at the top it will not overflow but you can also not read anything that is higher than the top end.

Again, find one the right length for your pot. Remember that the bottom end will be above any curve in the bottom of the side of the pot. Mine is a little above where the one gallon mark would be.

 

[vallonswayla]

i have a spike kettle that already has a welded coupler that i can thread the sightglass into. the kettle is about 16 inches tall, and the coupler is an inch or two off the bottom of the pot. maybe i will just do something that has it return to the pot.

 

[kh54s10]

i have a spike kettle that already has a welded coupler that i can thread the sightglass into. the kettle is about 16 inches tall, and the coupler is an inch or two off the bottom of the pot. maybe i will just do something that has it return to the pot.

I still suggest that you get one that goes to within 1/2 inch of the top of the kettle. If you go too low you lose the ability to measure above that. For instance if you heat once for a brew that needs 10 gallons of water but your sight glass only goes to 8 gallons you will be forced to add water for the sparge. This works but you will be heating cold water for the sparge. If you have enough for the mash and the sparge you can decide to heat the sparge from what it drops to, or just use the somewhat still hot water.

 

[vallonswayla]

do you think a heat shield is necessary?

 

[kh54s10]

It depends. If a lot of heat is coming up the side of the kettle it would be a good idea. I added a piece of aluminum to my burner that is under the sightglass when in position. $.50 - $1.00 fix.

 

[vallonswayla]

thanks for the replies - much appreciated : )

 

[Auger]

Another option would be to find a short piece of vinyl tubing that has an ID close to the OD of the sight glass tube, and slip it over the top of the sightglass while brewing to extend it enough that it won't overflow, and then pop it off again if you're worried about it sticking up too far to, say, store the kettle upside down or something.