Sight Glass Project

Testing the waters to see if anyone is interested in a sight glass.

I am going to try and build my own for my setup and McMaster gives pretty good bulk discounts on items.

I don't mind putting them together, as long as people are willing to pay for the materials and shipping....the savings with the bulk purchasing will be enough to me.

If you think you might be interested, PM me and I will get a price sheet together.

Here is a price list with links/part numbers (some are bulk pricing, some are subject to bulk discounts I haven't solidified with suppliers yet):

1 x 1/2" NPT Stainless Nipple: Here is $1.72 per

1 x 1/2" NPT Stainless Female Tee: Here is $3.68 per

1 x 1/2" NPT Stainless Coupling: Here is $2.76 per

McMaster Parts:

1 x 5220K78 1/2" NPT - 1/2"" tubing compression fitting (Brass) $3.14 (Volume)

8585K12 per foot is $1.17, this will depend on the vessel I am making the sight glass for

9396K286 are o rings that will be divided up into each order and a surcharge applied for each.... $.50 cents per o-ring will probably be it at an average of 4 per order.

Parts I need help with:

Stainless Eye-bolts (McMaster is just plain too 'spensive for these)
1/4" tubing - 1/2" NPT compression fitting

So, without those two, I see the total coming to about 20 bucks plus shipping (2-3 bucks per glass) which still puts the total at less than the one that Williams is selling. I plan on taking constructive criticism, suggestions, and sites where some of these things can be found cheaper.

Other parts will be added on a case-by-case basis and I am still trying to figure them out. If you want a sight glass with no tee at the joint, it will all be less expensive, but I am trying to work out a good/cheap choice for a brass compression fitting that allows a thermometer to be fit into the open end of the tee. The inspiration behind this whole thing is coming from Here.

Looks good but that tube's only good to 200 deg F. Fine for a HLT but no good for the kettle. 3723K15 is glass but a whopping $8.65 for 16" when bought in volume (the Williams glass is 15"). Could also eliminate the coupler if you know someone who can weld the nipple to the HLT/kettle.

I think the whole thing could be done for cheaper if you go with smaller fittings. The Williams part says to drill a 3/8" hole for the nipple which implies 1/8" NPT fittings or smaller.

Just FYI, here's a location for Pyrex tubing in 48" lengths. Minimum order is $50, so you'd need to find some people to go in with.

http://www.quartz.com/pyrex.html

Awesome, there we have our supply for the pyrex.

Now I need cooperation from people to request them so I can get these bulk discounts.

Id be interested if I knew about what it would look like and about how much money we're talking.

Check my post above.

It lays out the cost and gives a link to the williamsbrewing website. The one it links to is pretty much a carbon copy of what I am making.

I am still looking for an inexpensive source for SS Eye bolts to stabilize the glass too.

Since we are apparently going to turn the path towards pyrex, I am going to work on some sort of shrouding for the tube to protect it from breaking.

I sold quite a few kits using pyrex and it's much more likely that you're going to break them than not. I know a couple people still using them without a shroud but I bet the numbers are systematically dwindling. A cheap and easy shroud, if you're using both stainless eyebolt and compression fitting is to have some small profile stainless bars tack welded on each side of the glass spanned between the compression nut and eyebolt. Probably not DIY for most. I made one using a slotted sanke dip tube, but that was also a PITA.

If you're still want the pyrex, keep in mind that cutting the tubing is pretty easy in that you have to scribe it with a tubing cutter and snap it but you also have to flame polish the end to keep it from nicking and cracking. I'd find a supplier that will make the cuts and do the polishing. It will be about $7 per glass for a quality piece.

I have done the math out and figured that I will use slightly smaller fittings since a sight glass doesn't really need to have a huge capacity anyways.

I plan on using 1/4" fittings and a 3/8" tube.

I am ordering the parts tonight and hope to have them for the weekend so I can put some prototypes together.

This is a completely weldless design. As of right now, each item will come with a SS tee at the bottom and a plug at the end of the tee. If you want a compression fitting instead so you can use a stem thermometer, PM me and I will put the correct size in there and adjust the cost a few bucks. The sight glass will be plastic. Here is where majority will rule. Since I have reduced the size of the fittings by so much, the sightglass material is open to change. I have narrowed it down to two choices.

#1: 3/8" OD Poly Tubing with 1/16" walls which gives the inner part of the sight glass 1/4" to fill up with.

#2: 3/8" OD Poly Tubing with 1/8" walls which will give the liquid 1/8" of space to fill up but will be MUCH thicker.

The tubing should be fine (even though it is listed as 200 degree stuff) in a boil kettle since the wort in the tubing will not be boiling...it will be away from all of that.

I plan on placing an order for both tubes when I place the order tonight and boiling each one when I have them to see how well they hold up to the abuse....(If anyone has done this and knows the result...please chime in and save me the hassle.)

As it stands, each one should run about $18 plus shipping (I will choose the cheapest method to get it to you unless otherwise specified.) That price will be subject to adjustment depending on the "options" you choose to include.

Again, I plan to order these supplies tonight and have some prototypes built for the weekend. I am just going to wait a little while for people to respond to this thread and give some ideas.

Sounds great. Good point about the 200 deg F limit being fine given the location of the sight tube outside of the boil. I'm stoked to see the prototypes. I'll probably get two if they look good.

Just placed the order.... bulk pricing required a REALLY bulk purchase... so if I get this entire forum in on the requests, maybe I will make that kind've order....but with that kind of volume, I will need a vendor account

Just a note, these will not include a SS eyebolt. Because of the wide use of different kettles, coolers, etc, supplying an eyebolt with the kit would be counter productive.

If you are going to be putting this through a wall of anything thicker than a bot/keggle, let me know, since I will have to source a longer nipple to attach each end.

Do they have the eyebolts that would work at Lowe's/Home Depot? It'd be ideal to put it through the upper "skirt" of the keg, then you don't need to worry about SS.

I'd like to be considerred for 2, and would probably stick thermometers in there, or temperature probes.
(sent PM)

I suppose its your choice. The sight tube will be 16", so if it will reach that far up, its all you. The SS hardware that DOESNT come with the assembly kit is all at home depot/lowes.

I also wanted to make sure everyone knows:

The compression fittings will be brass. If you want SS, I can get them, but you can kiss the $18 price tag good bye. EVERYTHING ELSE IS SS

Nipple: SS
Tee: SS
Coupling: SS
Plug (Square Head): SS

I'm really interested to see some pictures of your prototypes.

Oh....theyracomin

I HOPE that everything gets here by thursday so I can put them together by friday since I plan on taking advantage of the holiday (long) weekend by leaving my house for long long time

I suppose while I have everyone's attention as well, does anyone have a suggestion on a bit to use to drill through SS (keg in particular)

I need to drill 2 size holes, one to allow a 1/2" NPT nipple to go through it, and the other to allow a 1/4" to go through it. I THINK I need a 3/8 and 5/8 bit to do each hole, but I was wondering what brand/material to use and if its something I should do on my drill press or if it could be done with a hand drill.

Use a step drill bit (Unibit). I tried drilling through me keggle this past weekend with a regular steel bit and it didn't work to well. The step drill bit worked like a charm. Oh, and I'm interested in two, all SS though. I'd like to see them before I commit though.\

Cheers,
Mike

I'll probably take one (or 2) if the prototype turns out. I've been looking for some, seems that Bobby_M isn't selling them anymore. Plus I'd like the 'T' for a temp probe.

I am putting together a list of people interested and the quantity they are interested in. Just PM me or post here and I will add you to the sheet. The sheet is strictly tentative and I am using it to get a rough idea of how many I need to build. Its plently easy to delete your row in excel if you don't like the way they look

New sight glass guy is going to learn pretty quickly why old sight glass guy stopped putting them together. Coordinating the whole thing is painful, parts, shipping, boxes, ugh. I wasn't it in for profit at all. I liked what I put together for myself and wanted everyone to have one but it just got to be too much.

I go to school full time and work full time, it pretty much adds up to not much of a life outside of those. This is a way for me to use my spare time to polish up my mechanical DIY skills and let everyone get in on what I assume will be a great find.

I can tell by the activity I have seen so far that this is going to be a popular item. I also hope that once I get prices all figured out with the parts in front of me that I can lower the price a little (except for those all SS ones, which are still just outrageous what they charge for their Comp. fittings)

I was closely watching and sniping lots of SS fittings on Ebay in order to keep the cost down but you're right about the ridiculous retail pricing on them.

The elbows aren't terrible, but the two compression fittings I would need for the tube and the temp gauge are 14 each!

I didn't feel like scouring ebay to get the parts I was telling people i could get for X amount...since they aren't a fixed price marketplace.

Now that everything (almost) has arrived, I put the prototypes together.

I accidentally brain farted and bought 1/4" o-rings while I was ordering 1/4" everything else, so I will need to order another couple sets of those, but luckily, those are not crucial to putting the prototypes together...you can use your imagination and figure out where they belong (two of them will replace the fitting over the tube in the compression fitting to assure a better seal against the plastic tubing)

Here they are.... I am pretty pleased:









A couple things to keep in mind:

You will need a SS eyebolt to hold the assembly steady near the top of the vessel you mount this on

Every joint will be teflon taped to prevent leaking

The sight tube part of the assembly is 16" which should be the tallest anyone needs and can be cut to size when you get the sight glass.

You can request an additional compression fitting with the unit for a small additional charge for mounting a temp gauge through the horizontal opening in the SS tee. I will just need to know the size you need.

All other questions/comments/suggestions would be appreciated.

You will need a 1/2" hole drilled at the entry point of the vessel in order for the nipple to fit through it. I am toying with the idea of adding a SS washer on each side of the wall...but im not sure its necessary.

Did you forget the silicone Orings for the weldless portion going into the kettle? I do think you'll need a washer on the inside and outside (or maybe a couple or three on the outside without a locknut)

Like in mentioned, I brain farted on the o-rings.... they are going to get ordered this weekend and given McMaster's prompt shipping, I should have them monday/tuesday. I actually have to get a bag of 1/2" ID and 3/8" ID. The 1/2" is for the bulkhead and the 3/8 would be for the compression fittings.

I was a bit surprised that none of the threads fit together better than are shown....but I guess the most important thing is that its watertight.

As far as the washers are concerned....the SS tee should act as a locknut and the coupling on the inside should provide enough pressure against that to make a watertight seal. I dont have time to drill into my kegs tonight so I will test that over the next couple days. I am not worried about those details though, since washers and o-rings are easily sourced and add next to no cost to the overall project.

If this is the same material as a racking cane it will break like nobody's business.

I was going to use a piece of 1/2" ID beverage tubing with a compression fitting and then put an outer sleeve around it with a cut out to keep it erect.

If its Glass it will be more sturdy as well

Its probably the same MATERIAL as a racking cane, but the walls are 1/8" thick....so its not breaking any time soon, I can ASSURE you of that.... I did some initial rigidity testing and that won't be an issue. Since its 3/8" OD tubing, its 1/8" wall --> 1/8" open air (for water/wort/etc to flow) --> 1/8" wall, quite sturdy!

Yeah I just tested it on a raking tube and it was really brital

racking tubes are usually at MOST 1/16" thick... double that and you get an item a lot stronger. Besides, the thing is for reading fluid levels, not crossing the hudson bay... how strong does it really need to be?

I might be interested in one when you get the details all sorted out. Looks good so far.

If I had to guess, I think racking canes are acrylic and a lot more brittle. Polycarbonate is more flexible in general and less brittle which is why it's used as bulletproof glass.

The problem trying to make the seal between the coupling and tee is that the thread penetration is really low. You'll crank down hard and still leave a 3/8 to 1/2" gap and the Orings will not be compressed. You can either make up the gap with a brass locknut on the outside or several washers. Without washers on the inside, the Oring will squeeze out and over the coupling, maybe not on the tee. You'll have to play with it.

Like I mentioned, this weekend is a bad weekend for experimentation. I am going to try to find a step bit I can use to drill through these things while I am away this weekend and then I will let everyone know how the seal holds up.

Well, after scouring everywhere for the last couple days, I have resorted back to my trusty thread for advice. I am trying to find a source for stainless steel washers to finish these sight glasses up. I am going to be ordering the o-rings tomorrow and don't want to place that order until I have exhausted all others for the washers. McMaster is too expensive for these... it would just drive the price up too much. Since these don't come into contact with beer, I am thinking about scrapping the SS idea, but I thought I would check here first. Can anyone else find them for me?

How about fastenal.com?

Done and done.... hopefully those get here pretty quickly and I can get the prototypes up and installed this weekend/later this week.

What's your final price without shipping?

Right now, I am looking at $16.... thats barring any other changes that need to be made. As of right now, I am recommending that anyone who wants to use this with a temp. gauge should buy the thermometer, measure the stem, and go to home depot or lowes and buy the compression fitting that fits their gauge. These things are too non-standard and for the same reason I am not stocking the eyebolts, I am not stocking the temp gauge compression fitting. They are pretty cheap and pretty common at those stores.