DIY Sight Gauge

[ghack]

Friday I put together and installed a DIY sight gauge for my new keggle. I wanted it to be able to survive bumping and dinging without damage so I went with a full attachment at each end.

Materials were as follows, and ran about $25 total (I had the copper pipe)...And I know the regular black o-rings are not the best to use with boiling liquids.

Each of the keggle attachments is:
1/2” copper street elbow
1/2” to 3/8” reducing pipe to male threaded connection
Two 5/8” I.D 1/8” o-rings
two 5/8” stainless steel washers (note photo only shows one, I added another)
3/8” to 1/2” female threaded to pipe connection

The 1/2” to 3/8” reduction provides more material at the connection to bear on the washer and o-ring. The pipe was sweated to the elbows and those to the threaded connections.

The sight glass portion:
12” 3/8” O.D. Borosilicate glass tube
3 3/8” I.D. ½” O.D. silicone o-rings
1/2” copper pipe with 11” slot cut into it

The o-rings were slipped onto the tube, two at the bottom (security), and one at the top, an inch or more from the end. The tube was slipped into the slotted copper and the o-rings were pushed down into the copper pipe. I had to work at it a little to get the ½” of the glass inside the pipe evenly at each end. I used a short piece of split vinyl tubing to work the o-rings along.

I drilled the holes and installed it next to the weldless faucet fitting from Bargain Fittings.

Saturday I calibrated it with measured amounts and it has a clear three and a half to about twelve gallon range. It needed some tightening…

Sunday I fired the whole up for a maiden voyage with a Scottish 60 Shilling ale. Some drips at the faucet and sight gauge, but as things expanded they stopped. Here is the inside view which includes the 3 cups of trub left behind.

 

[McKBrew]

Very nicely done, I like the copper look/old fashioned brewery aspect of it. I had visions of putting copper lids on my keggles until I saw the price.

 

[Couevas]

Nicely done!

Might I ask where you got your glass tube?
I have been wanting to DIY some sight glasses, but the tubing has always been the roadblock.

 

[Drifter]

I have used polycarbonate tubing from McMaster p/n 9176T28 it is $10.08 for an 8' piece.

I use a 90 deg compression fitting and run the tube(cut to length) to the top. I use a s.s. eye bolt to hold it at the top.

Very simple,durable, and inexpensive. The poly tubing is good to 250 deg F

 

[McKBrew]

Bobby_M sells a decent weldless sight tube (link in his posts) for $25 + shipping. Far cheaper than anything else on the market.

 

[ghack]

The glass tube was from McMasters-Carr for less than $5.

I've looked a number of inexpensive ones, but most have the tube fairly exposed. I tend to bang things around so I wanted the tube protected.

 

[McKBrew]

I like the copper look, so I'm going to steal it for my Sight tube protector instead of using the Sanke tube. Hope you don't mind.

 

[mmb]

Agreed. And copper is easier to work with than the stainless sanke dip tube for me.

 

[drunkatuw]

I bought two of these last week and they look like a pretty cheap alternative. I'm still waiting for my step bit to be delivered, so I have not had a chance to connect them to my keggles yet.

Bargain Fittings

 

[ghack]

Just a tip I left out...

Cut the slot in the copper pipe and drill the holes in the keg before you cut the pipe to length. You can then locate the glass portion where you need it and size the pipe on the actual fittings sitting in the holes.

 

[Lil' Sparky]

Nicely done!

 

[amishland]

looks good to me

 

[android]

nice work man. thanks for the ideas.

 

[Bobby_M]

Very cool. You already picked up on the buna N temp problem and of course silicone would be the long term solution. Nice work cutting the slot. I think it's the hardest part.

 

[akmolloy]

Any tips on cutting the slot? Is that something I could attempt with a rotary tool?

 

[defenestrate]

awesomeness, jealous.

 

[ghack]

I rough cut the slot on the table saw with a metal cutting blade; three lengthwise passes to make three parallel grooves stopping short of the 11" length. Then I made a beveled crosscut to define the ends. I cut the grooves last bit to the ends with a hacksaw.

A little light work with an angle grinder to cut away the burrs and smooth it a little. But be careful with the grinder, the copper is soft so you need a light touch. Then I hit it with a couple of mill files and finally some steel wool.

There are a few low spots and divots along the way, but cleaned up you really don;t notice them.

 

[dakamp84]

Love this design but have some questions.

Can this be done in stainless with compression fittings and using the galss tube? If so, what sizes would I need to look for.

Thank you.

 

[Bobby_M]

Yes you can use compression fittings but there are a few considerations. You can't really do it as weldless if you're using a keg because the walls of the keg are not straight. The glass tubing would be not coming into the compression elbow straight so tendency to put stress on the glass or physically make contact with the compression nut is a bad idea. If you weld in fittings, you can get them much straighter. One workaround would be to use a compression fitting that is 1/8" oversized from the OD of the borosilicate glass tube. The inconsistent gaps would be made up with thinwall silicone tubing.