Steven9026
Well-Known Member
Would aquarium sealing silicone be considered food grade or safe to use inside my electric HLT to seal around the heating element?
food grade silicone
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Check the MSDS and see if you want to consume the chemicals in the product. I know there are some "food safe" sealants discussed on the forums, but I'm hesitant to reccomend any. In fact, I see no reason to use silicone sealant on a food contact surface when there are better ways to accomplish the same thing; ie. The weldless system that Kal and many others use.
samc
Well-Known Member
Would probably be ok to use, but as Chefkeith points out - you really should not have to seal with it. You either want a silicone o-ring or silicone gasket if needed.
http://www.bargainfittings.com/inde...t&keyword=gasket&category_id=0&product_id=105 not element sized but you get the idea.
http://www.bargainfittings.com/inde...t&keyword=gasket&category_id=0&product_id=105 not element sized but you get the idea.
Steven9026
Well-Known Member
thanks for the info. I need to explain I'm mounting this heating element in the bottom of a igloo cooler, if that makes a difference. I was going to order o-rings to replace the original gasket that came with the heating element, even though others have used it with success. I have a supply of EPDM o-rings where I work. I tried using one of these as a temporary o-ring just for testing, and I could not get it to stop leaking. It just drops a drop about every minute or so.. I know the silicone o-rings are a little softer and maybe they will seal. I've also checked to make sure that the nut I am using on the inside was seating all the way and not bottoming out on the threads.
Steven9026
Well-Known Member
Ok guys. Did another test. I removed the copper washer that I made for the ground and it seems to have stopped leaking now.. I'm now testing it with a full load of water and some time. I placed my washer on the element first then the o-ring just like the diagrams I've seen.. I wonder why mine won't stop leaking with it in place. Is there another way to ground it with using the copper washer on the element?
redalert
Well-Known Member
According to the FDA. 100% silicone is safe for food contact though I trust the FDA about as much as a crack whore.
WPStrassburg
Well-Known Member
Once cured 100% silicone should be food safe. If you want one that has been tested you'll have to look for one that is nsf or fda certified. Dow 732 & 748 look to be listed for FDA & NSF applications.
Laouboy
Active Member
love the crack whore comment 
, but silicone should be food safe, unless your transferring hot wort or mash water then i would use high temp food grade tubing
, but silicone should be food safe, unless your transferring hot wort or mash water then i would use high temp food grade tubing
The problem is that you're not applying 100% silicone. In order to make silicone liquid, some sort of volatile compound must be added. It's the VOC's that may be dangerous, and different manufacturers use different compounds for each line of products. Much of the compound is released into the air causing the silicone to "dry." But I have a hard time believing that you're left with 100% silicone after that, which is why I wouldn't use silicone sealant on any food contact surfaces.
There are, however, silicones approved by the NSF for "food zone areas," but I don't know of any kitchen where silicone sealant is used in direct contact with food.
I'm not saying that you can't find a safe sealant, I'm just saying that I would avoid using it to seal things that come in direct contact with the wort when there are better ways to achieve the same result.
JoMarky
Well-Known Member
Dow Corning 732 is 100% silicone. No solvents, no volatile compounds. How is this different than using a silicone o-ring?
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The volatile compounds should be just that - volatile. The silicone will off-gas for a number of days before it is fully cured. Eventually, those volatile compounds are essentially gone. Nothing like a good test boil to move that process along. I'm betting that the risk from the cured silicone is pretty darn low. Literally. I used White Lightning silicone for my heat sticks. Life entails risk. I'd worry more about driving home.
WPStrassburg
Well-Known Member
I believe o-rings and sheet stock are made in a similar manner as one would seal something up with a tube of silicone, by spreading/extruding/molding the silicone and letting it cure. Yes, as Chefkeith pointed out, the curing agent isn't silicone, but if cured properly should volatilize out of the silicone. I would cure as long as possible and keep whatever is being cured in the driest place possible. Direct contact with water usually slows the curing process,iirc. No less than the mfg recommends, but short of a year...
Vinegar comes to mind as a curing agent and acetic acid may be the fancy word for just that. Anyone know what Ethyltriacetoxysilane and Methyltriacetoxysilane really are?
Vinegar comes to mind as a curing agent and acetic acid may be the fancy word for just that. Anyone know what Ethyltriacetoxysilane and Methyltriacetoxysilane really are?
I would also agree that the risk is low, but people should be aware of it.
Upon further research, Ethyltriacetoxysilane and Methyltriacetoxysilane seem to be slight variations of some of the precursors to silicone which cause cross-links in the polymer that enable it to vulcanize when exposed to the moisture in the air at room temperature; hence room-temperature vulcanization (RTV). So, they may not be volatile organic compounds after all (though I still see brands of silicone sealant that are labeled "low VOC."
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Follow Kals link on www.theelectricbrewery.com and order the FDA approved silicone that is linked to McMaster Carr.
JoMarky
Well-Known Member
The risk of what?
You are correct, silanes can be pre-cursors to silicones. Silicone is a class of compounds, it does not refer to a specific compound. There are many silicones and many silanes. Through hydrolysis, a silane can turn into a silicone, realeasing acetic acid. I ingest acetic acid all the time. Since the acetic acid is released as a gas and removed from the environment of the reaction, and there is an unlimited supply of water vapor(a reactant) in the air, the reaction is able to continue to completion.
I'm not by any means an expert, just playing devils advocate. Seems silicone (unjustly) has been getting a bad rap in a lot of threads lately.
Edit: Please see the wiki on Silicones for a list of its uses, many including high temp food contact.
Scut_Monkey
Well-Known Member
I can't find where he links to this. The only link I can find is for sealing the volt and amp meters with general silicone.
http://www.theelectricbrewery.com/control-panel-part-1?page=11
There are risks involved if the Ethyltriacetoxysilane and Methyltriacetoxysilane aren't fully hydrolyzed, but as they hydrolyze quickly, the risks are low.
After reviewing the 21CFR177.2600 of the Code of Federal Regulations, I believe it's safe to repeatedly use FDA approved silicones on food contact surfaces, though interestingly enough, you can't make baby bottle nipples from these chemicals (see paragraph h).
I'm simply concerned that a lot of people on here are using non-FDA approved silicone sealants which may have a much higher degree of risk. I think this is a valuable discussion to have, and I'm not down on the use of silicone in brewing, in general.
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