Sight Glass Seal

[daveyavey]

Hi all,

I disassembled my sight glass so that I could wrap the silicon gaskets with PTFE tape (x2 times). When I reassembled and tightened as much as I could, the seal between the gasket and glass does not appear to be water tight (i.e. I fill 1/3 height with water, and the water breaches through the glass after a few seconds). Will this be a problem during an alcohol run?

Thanks, Dave.

[CopperFiend]

Yes, it needs to be absolutely water tight. Have you tightened the bolts loads? Is your PTFE taping leaving gaps?

[Yummyrum]

Yup , you need to fix it now because it will leak even more with Alcohol in it . ( it’s got a lower surface tension and will piss out the smallest gap)

How do you define that you have tightened it as much as you could ?

[daveyavey]

I tightened the bolt loads as much as I could with two wrenches. No gaps in PTFE. Hmm... trying to figure out how I can get more torque

[Berserk]

That is odd. I've made the exact same modification to my sight glass.

Have you made sure to loosen the 'inner' bolts before tightening the outer ones? If that ain't it I'm stumped.

[daveyavey]

Yep. Loosened the inner bolts, then worked around each side tightening accordingly. No worries. I might try the heat gun on the gaskets... may be a bit stiff...

[LWTCS]

Swap out the cap nts for regular hex nuts.
If that doesn't let you tighten better.
You may need to replace your rods with some all thread so that you have a longer thread pattern.

[Kindafrench]

Had the same problem. I bought a sheet of „elastic“ PTFE and cut out two gaskets. Sanded the glass tube and wrapped the gaskets and the end of the glasstube with 2 layers of PTFE. Now it‘s fine.

[Birrofilo]

Had the same problem. It is possible that, for the excess torque, one of the "prisoners" is not vertical, it is slightly inclined. Losen everything and tight by hand very slightly the inner bolts so as to keep the prisoners vertical while to tight the outer bolts.

You don't need to apply a strong torque.

Before doing the tightening, watch from above and below and pass a finger on the inner surface, the gasket must be perfectly aligned with the glass, a slight misalignement will create a leak no matter how tight you lock the bolts.

[Boozewaves]

may be better to make 2 everlasting gaskets with thick cardboard than wrap the existing ones .

also as well as replacing the cap nuts like LWTCS said be sure you are tightening the nuts evenly .

imagine the 4 nuts are at a 12 , 3 , 6 and 9 o clock position tighten the 3 a full turn , then the 9 , then the 6 then the 12 , this will pull it all together straight , as it gets tighter do 1/4 or 1/2 turns ,check with a spirit level against the top ferrule too

in my experience this will work but I made hard PTFE sheet gaskets after a while using a holesaw to cut the groove for the glass , they are not perfect but work well enough

if all else fails and it starts leaking during a run, flour paste works well , last time I ran I had to do this

[StillerBoy]

The issue is you are not tighten the cap nuts evenly, and nuts on the rod are stopping from sealing properly..

Loosen the the nuts on the rod as they are there to just lock the cap nuts in place once the whole unit is tight.. once the nuts are loosen some, tighten the cap evenly from both end by hand, holding the rod with pliers if the rod wants to turn.. doing this until all four rods have been tighten as hard as one can by hand.. then holding the rod with pliers, torque each cap nut a quarter turn at a time, once all cap nuts have received a quarter, give each cap nut another quarter turn.. then once that done, lock the cap nut in place using the nut..

Mars

[30xs]

I agree with the torquing the in the sequence of 3, 9, 6, 12 but doing 1/8-1/4 turns on each. Starting from finger tight you could use a vise, or clamp, to press squarely on everything and sneak up on the torque evenly that way. If you go finger tight on the first bolt with slack on the assembly you are going to start out office of square from the beginning and never be able to seal.

[daveyavey]

Thanks for the advice all. I'll revise my strategy as per the posts. I was hand tightening the 12 nut, followed by 6, 9 then 3. .Then turning over and repeating the process on the other side. Understand now that I may have been slightly off line from the get go. Ill try your technique mars.

Hey, if it all doesn't work out. Then flour paste sounds easy enough.

[StillerBoy]

Hey, if it all doesn't work out. Then flour paste sounds easy enough.

It will work out.. flour paste is not the solution..

What need to be remembered.. the nut is there only to lock the cap nut in place nothing else, as they(the nuts) are the ones stopping you from properly tighten the unit.. it just a failure to understand the concept of a stud and cap at both ends..

Mars

[LWTCS]

Ah right you've got plenty of threads to spare.
Run the lock nuts down the rods a turn or two and make sure the face of the flanges are level/parallel/squared to the face of your glass as recommended by others.

The back up/lock nuts do provide structural integrity so don't rely on the chimneys to bear any weight.

[Snackson]

I typically measure from inside the flange on one side to inside on the other side to ensure I am tightening them evenly. I also mark them so the same rods go back into the same holes on the flanges. Take it slow and ensure even threads on both sides and you'll get it back to normal soon.

[daveyavey]

Thanks for all the help. Took it slow and ensured that I slowly tightened the lock nuts.

Proof is in the pudding. Both sides held without any water loss. Success!

Dave

[StillerBoy]

You finally got it.. that's good.. learned some thing new..

When taking a slight apart, always start by unlock the cap nut by loosening the nut first, then loosen and remove the cap nut..

Putting it back together is a just the reversal of the process.. if done properly, by tighten the cap nuts by hand first, the glass will a line the base ends..

Mars