Using a conical fermentor

Ive purchased a new 8 gallon plastic conical fermentor. Ive got a few questions about it. The lid doesnt really lock onto the top of conical it just kinda sits there, will this be a problem with contaminents? Also being the fermentor is 8 gal. and I only wanna make a 5 gal. batch will there be any problem with the oxygen in the headspace? If anybody has any experience with these types of setups I could use some advice. Thanks.

P.S.-This is the kind of conical I have:
http://www.highgravitybrew.com/ProductCart/pc/viewPrd.asp?idcategory=159&idproduct=1602

You would think that there would be a tight sealing cap with an airlock, eh? How are you going to monitor CO2 production? Anyway, to answer your second question, I think that the CO2 will displace the oxygen in the headspace. Hope this helps.
jeff

Most conicals have a seal around the top and the weight of the top seals it. But that could just be for SS ones. And as said before CO2 will take the place of the O2 so no worries. Have fun with that.

with that conical you have to rack or transferr after your fermentation is complete, ie 2-5 days down thwe road. It is like doing you primary in a bucket and not in a carboy. The co2 will start to dissapate if there is no air tight seal on the fermentor and there is no active fermentation happening.

I wouldn't worry about the headspace issue, because, as others have said, CO2 will displace it.

But if it doesn't seal, I definitely wouldn't leave beer in there more than a week or two. I wonder if it's actually supposed to seal and they didn't include a gasket or something with your order?

Atticmonkey said:

P.S.-This is the kind of conical I have:
http://www.highgravitybrew.com/ProductCart/pc/viewPrd.asp?idcategory=159&idproduct=1602

Click to expand...

then it seems like this is the kind of gasket you should have:
http://www.highgravitybrew.com/ProductCart/pc/viewPrd.asp?idcategory=159&idproduct=1610

if you want it...

Man as much as I love conicals for ease of dumping off yeast/trub... I hate that there's no "convenient" way to keep them cool. With my fermenters I toss them in a tub of water with some 2liters of ice..

Not so easy with these.

That being said, A member of another brewing board sells these on ebay and offers 10% off to board members.
http://cgi.ebay.com/Homebrew-8G-Con...ryZ38172QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

It's already 165, take another 10% off that.

According to this site the gasket is not nessasary:
http://cgi.ebay.com/Homebrew-8-Gallon-Conical-Fermenter-Gasket-Fitting_W0QQitemZ4440090256QQcategoryZ38172QQtcZphotoQQcmdZViewItem

But what do you guys think? I guess it couldnt hurt, right?

Get the gasket! See if you can devise some clamping mechanism to keep the laid in tight contact w/ the gasket.

Gasket is not entirely necessary. Once the yeast start to metabolise the sugars and put off CO2 you'll be fine.

Not to mention the nasties fall down from the air, they dont zig zag around like a bug. So Unless nasties can take 90 degree turn from falling down and then to under your lid, i think you are fine.