Sight Glass Seals "SILICONE"

[Thelegion]

Well I have been kicking this over for some time now and ready to pose the question here.

I see many people using the silicone seals on their stills, yet when I search for advice on using silicone it's a "no no". If I use a pre made seal of 100% silicone then why can't I make my own from the same material in the tube form. I have found many "food grade" commercial sealants in the liquid form for use in the food equipment industry. A lot of these RTF Silicones (100%) are widely used in the food industry and are recommended for food contact and temperature rated. I have also looked at "many" aquarium sealants and they are the same composition as the food sealants.

So why the taboo on the DIY silicone seals? just Wiki look up copper and see how toxic it can be to the human body.

The reason for this is that my current build has sight glasses that are non standard to the seals sold on the distilling sites. Everything has it's warnings on this planet and the mere fact that alcohol is a toxin to the body I don't see how the silicone can be an issue, especially when your making seals from the same material that the seal manufactures are making them out of and selling them for this very application.

Having said all this I certainly would not use the same silicone used to hold the oil pan on my car.

[Brendan]

Here's an experiment I did on 100% silicone baking sheet...

Silicon Baking Sheet

I think the test wrapped up abruptly, but I found that the only problem with 100% silicon is that it has low chemical resistance to acetone (not ethanol)...the problem being that we know acetone is a compound in foreshots...but how much?

The test showed in pure acetone that there was indeed chemical breakdown as expected, but when tested on pure foreshots from the still, there was no breakdown over a month or so...therefore I'm happy to use 100% silicon myself :handgestures-thumbupleft:

Oh and it has no problems with ethanol or methanol, it's only acetone in question.

[bt1]

Howdy,

have used the silicon baking sheet for seal for bout 50+ runs on smaller glass still and found no issues. They feel the same, look like the original sheet have no mechanical wear that's noticeable.

I'd recommend them based on what I've seen, time used. Liquids I can't speak for ...did take a look see but could not find a food grade that was ok with solvents like ethanol.

Might need a fair bit of testing to be sure.

bt1

[Brendan]

Liquids I can't speak for ...did take a look see but could not find a food grade that was ok with solvents like ethanol.

Silicone has a high chemical resistance to ethanol...the problem is acetone as silicone's chemical resistance is rated as very poor.

Silicone also has excellent chemical resistance to Methyl Alcohol (Methanol), and good resistance to Ethyl Acetate...although there may be other compounds that it is not resistant to like acetone, I found the compounds just don't make up enough of the foreshots even to cause any breakdown effect...

[Thelegion]

thanks all,

When building a one off distilling apparatus we tend to build what we can find to keep the costs down. I have found some 2 inch lenses from commercial halogen lights and the best part is there free and there are plenty of them around and they will take the heat too. They fit so perfect inside a 2 inch pipe there's less than a mil free play, so I'm sealing them on the outside with a copper flat washer and a tiny bead of silicone under the copper washer. (that's the plan) To find a commercial (alcohol tolerant) proper washer is next to impossible for the odd sized stuff. I have tried the everlasting gasket and I'm just not getting a proper seal.

I'll post some pics soon..

Legion

[Thelegion]

here are some some picks, I'm planning on a "tiny" bead of silicone where the glass meets the pipe opening and using the washer to flatten out the seal.

Legion

[kiwikeg]

I would suggest this instead a everlasting ptfe gasket .... http://homedistiller.org/forum/viewtopic.php?t=24199 sorry for the off site link :oops:

[Yummyrum]

Hey Legion, I'm all ears on what you are doing .Can you give more specifics on where you scored these glasses from.

Make model etc.

I also like the samohon everlasting gasket..I have several of them in my Rig but are also tending to think the silicon road is as safe as any :handgestures-thumbupleft:

[Potmash Boka]

:text-+1: :text-imwithstupid: where does one get these glasses?

[Thelegion]

Here's the skinny on those sight glasses,

The lenses came from a commercial establishment that used halogens and the lenses were the safety cover for the light, I ended up with a couple of dozen of them. I haven't looked and never thought to look at the local lighting store until now, I imagine they can be had in a variety of sizes, and the best part, halogens are HOT. I just finished an everlasting gasket and it takes the whole roll to get a proper seal on the way I have the glass set up.

Legion

ps, they might be called "fire breaks" to give the light extra life in the case of a fire, to light up the escape route.

[Yummyrum]

Nice... Does that writing come off them or is it etched in somehow

Everlasting gaskets do use a lot of tape...but they do compress and make a nice seal...I find that everyso often I have to wrap another few layers on them but eventually they compact into a firm gasket.

[Thelegion]

Nice... Does that writing come off them or is it etched in somehow

Everlasting gaskets do use a lot of tape...but they do compress and make a nice seal...I find that everyso often I have to wrap another few layers on them but eventually they compact into a firm gasket.

I have tried to remove the writing with nail polish remover but didn't work, straight acetone might work. I'll try a few different things and post if I find one that works.

[Smbjk]

Nice... Does that writing come off them or is it etched in somehow

Everlasting gaskets do use a lot of tape...but they do compress and make a nice seal...I find that everyso often I have to wrap another few layers on them but eventually they compact into a firm gasket.

I have tried to remove the writing with nail polish remover but didn't work, straight acetone might work. I'll try a few different things and post if I find one that works.

Recon a stanly knife blade would work :think: