Is This Ok For Sealing With

[Keifer]

Hey,

I gotta seal up my mash tun where it leaks and thought this would be ok, what do you rekon?
http://www.selleys.com.au/ItemDisplay.aspx...mID=26#ItemName

And, what would happen if you didn't sparge, just filled my mash tun with the 25 odd litres needed for boil?

Will be doing me first AG tmoro

 

[Sammus]

Hi, I emailed sellys a while ago regarding food grade sealants and the only thing they recommended was multi-purpose knead-it, its food grade and good up to 120C apparently - I never ended up using it...

And re:sparge, have a look at palmers how to brew, I've never done it, but if you want a decent extraction youll have to up your grainbill substantially (its much less efficient)

 

[goatherder]

What sort of mash tun do you have? Esky or SS?

I'd be looking for a sealant that is specifically food grade, I'm not sure if this one is. Also have a look at the curing time for the sealant, especially if you are brewing tomorrow. These sealants will leach compounds into their surroundings as they cure and you probably don't want them in your beer. I'd be wanting the sealant well and truly cured before I brewed on it.

For the second question, not doing a sparge is OK but you will get a lower efficiency in your brew. This will mean either a lower OG or less beer, depending on how you work it. The epic "All in One Brewery" thread covers a lot of the issues involved with the no-sparge method. Also do a search on "no sparge" if you want to go down this path. No sparge is OK, as long as you know what you are up against before you start.

Good luck with the first brew, keep us posted.

 

[dubzau]

Not sure what makes 100% silicone "food grade or not", but it works great as a sealant. I know it releases chemicals as it cures (toxic or not I don't know), so make sure it is fully cured.

No sparge is fine if you have room in your mash tun. Preferable in fact, like extra virgin olive oil (excessive sparging can extract undesirable flavours from the husks). Your efficiency will in all likelihood be down, but if you aren't worried about using some extra grain, go for it. Remember in working out how much water to use, that the grain will soak up a fair bit.

 

[hopmonkey]

DONT SEAL AND MASH TOMORROW!!
Silicone based sealants should be avoided, especially with the prolonged and warm contact we require when mashing. The problem is not with the sealant per se but the by products of curing. All the curing by products are carcinogenic and have well established toxicity levels.
Silicone sealants are food grade when fully cured but i would suggest that would best be achieved by sealing using several thin applications with a week in a dry hot environment between coats.
When full cured run a 'sacrificial' wort through, run off and aerate while hot then let it sit in the tun to remove any leachates from the seal.
Is the leak in the bung hole? if so i know a lot of people who have had sucess with a bung pushed in from the inside to plug the gap! Simple is sometimes best.

 

[Sammus]

I wouldn't use it, I'll say it again, but I spoke to a sellys rep that told me NOT to use their silicone sealants, as there NOT rated as 'safe for contact with drinking water' I got some multipurpose kneadit, which was crap.
If your looking for a seal for a weldless tap setup, go and buy one of those flexible silicone baking trays, they have to be food grade at high temps. If you just want a seal a crack or something kneadit should be ok, im sure there's others out there but thats the only one I could find in my search...

 

[Jez]

if you use Knead it get the Aqua one. I think Ross has used it in his mash tun previously.

Jez

 

[dubzau]

I wouldn't use it, I'll say it again, but I spoke to a sellys rep that told me NOT to use their silicone sealants, as there NOT rated as 'safe for contact with drinking water'

the key here is "NOT RATED" - that is not to say that it is not safe, just that some government body has not certified it as safe and therefore there is a risk of litigation.
When fully cured it should be OK, but don't use it if you're worried about it. I believe that some silicone sealants can emit formaldehyde vapour - which is a potential carcinogen (so is everything else in the world!) - when heated above 150c. You are unlikely to be heating it to that temp.

btw, here is the safety sheet for selleys wet area silicone sealant:
http://www.pscoop.com.au/newweb/msds/Selle...t%20toxicity%22
basically, if you breath the fumes repeatedly and for long enough while it's curing, it might damage your nose. You can eat the stuff when it's cured. Don't burn it and breath the fumes.

 

[len]

I used a silicone sealant to try to seal the tap in my esky-mash tun, leaving it to cure for seven days. It's still leaking though. Not outside, but when I fill it with water, after about 15 minutes, water starts dripping out through the screws holding the esky together, showing that water is getting into the space between the inner and outer walls of the esky.

Has anyone used this setup before? I bought a $45 esky + 2L esky-jug package from Bunnings. I'm going to use the 2L one for mashing a bit of grain for a starter, so that works out well. There was no bung hole in the large esky so I had to drill one out and install a bit of threaded pipe though, with a tap on the outside and a connection to the sparge manifold on the inside. I pumped half a tube of silicone into the gap before installing the pipe, so I thought I'd be set. Apparently not..

 

[Andyd]

Selleys 401 is rated as food grade for occasional contact, and temperature stable up to 260 degrees... I'm inclined to think that once properly cured (and leeched if you're really paranoid) it may be ok.

 

[Jez]

any pic's of your mashtun len?

if your not worried about using brass in your mashtun:

- get 2 brass flanges(?) from Bunnings for a few bucks (not positive thats what they're called. they look like a nut with a washer attached to it).
- Get a silicon cookware baking tray from Woolworths for @$10 & cut out 2 washers.
- Wrap your threaded pipe with pink plumbers teflon tape so it doesn't leak down the thread.
- screw the flanges + silicon washers onto your threaded pipe so they're tight against either side of the inner skin of your mashtun.

I used a similar setup on my keep cold cooler & it doesn't leak.

Jez

 

[len]

any pic's of your mashtun len?

if your not worried about using brass in your mashtun:

- get 2 brass flanges(?) from Bunnings for a few bucks (not positive thats what they're called. they look like a nut with a washer attached to it).
- Get a silicon cookware baking tray from Woolworths for @$10 & cut out 2 washers.
- Wrap your threaded pipe with pink plumbers teflon tape so it doesn't leak down the thread.
- screw the flanges + silicon washers onto your threaded pipe so they're tight against either side of the inner skin of your mashtun.

I used a similar setup on my keep cold cooler & it doesn't leak.

Jez

Jez, I've just had another go at it. I found some brass locknuts and ground off the outside of one until it was 'low-profile' enough to screw into the inside of the threaded pipe - I drilled the hole too close to the esky floor. I had a few aluminium flange-plates around so I've sawed off enough of one to fit into the inside. Screwed the whole thing in until the walls of the esky bowed and now I'm leak testing it. Side bonus is that I don't have to be careful that the torque from turning the tap doesn't twist the threaded pipe!

Cheers,
Len

 

[crozdog]

I have used a Selleys silicon that is safe for "potable water" in my mash tun. It is also safe for aquariums. I think this is what I used. I left it for several weeks to cure, then rinsed it several times before using. There is no smell or taste that I can detect from using this product. My fish are happy too

Don't use kitchen & bathroom silicons as they contain mould killers etc.

Jez's suggestion re the silicon cookware is a good one, I've also used that approach on a number of times, it works well.

Crozdog