Sealing a bulkhead?

[bkwudzjeep]

I am finally making some ground on my set-up and just did a leak test with the plumbing to find one bulkhead is leaking.

I have heard of some people using silicone grease to lubricate the gasket. Where can find this stuff?

Ace Hardware had 90% silicone grease....is that what I am looking for? Home Depot kept leading me to the lithium grease, and I know that's not what I need!

 

[drparker]

Yes that will work, but I've never had to use it. Make sure the rubber gasket is on the side of your glass with the flat flange and not side with the nut.

The only two time I've had one leak was when the gasket was on the wrong side or when a nut cracked.

 

[littleoldme]

You shouldn't need to grease the bulkhead, which side of the bulkhead are you putting the gasket on, it should be on the wet side of the tank (flange side). Anyhow any grease for potable water should do it, look in the plumbing section where the pvc glues are or where the replacement cartridges are for faucet repair.

 

[greenmonkey51]

Can you tighten it anymore. I had bulkhead that kept leaking. I took the tank to a lfs and they used a big pipe wrench to tighten it down and no more leaks.

 

[drparker]

<a href=showthread.php?s=&postid=12492172#post12492172 target=_blank>Originally posted</a> by littleoldme
You shouldn't need to grease the bulkhead, which side of the bulkhead are you putting the gasket on, it should be on the wet side of the tank (flange side). Anyhow any grease for potable water should do it, look in the plumbing section where the pvc glues are or where the replacement cartridges are for faucet repair.

It does not have to be on the wet side. But does have to be on the side with the main part of the bulkhead not on the nut side. One of my applications required the bulkhead be place reversed with the nut on the inside (wet) and when I placed the gasket on that side it leaked.

However when the gasket was moved to the dry side next to the flat flange of the main bulkhead it never leaked again.

 

[bkwudzjeep]

The gasket was on the wet side (opposite the nut), I made that mistake on my last tank

Before I loosened it up, I tighted it as much as I could by hand, and it kept leaking. I have some plumbers wrenches, but they are so big, I can't get it in the space I have.

 

[bkwudzjeep]

Would the 90% silicone grease I found at Ace be the right stuff?

 

[ricks]

I would not put any silicone grease on the gasket... Is the bulkhead sch 40 or sch 80???

 

[bkwudzjeep]

It is not that bulky, so I'd say sch 40.

 

[drparker]

Is there a bur or a scratch on the bulkhead? Could the bulkhead be too small for the hole? Old brittle rubber?

 

[bkwudzjeep]

No burrs that I can see......1" bulkhead for a 1" drain line. I actually just stretched the gasket over the top and inspected and it looks fine (no cracks, not brittle).

One thing I did notice is that one side of the gasket has a small lip running all the way around the middle of the gasket, and it was facing the flange side of the bulkhead, maybe it is supposed to face the glass?

I found this stuff online:
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=9708
and
http://www.waterfiltersonline.com/detail.asp?product_id=Dow_111_5oz_Silicone_Sealant (seems pricey)

Here is the stuff I found at Ace Hardware.... http://www.acehardware.com/product/...w=silicone+grease&origkw=silicone+grease&sr=1

 

[xJake]

Look on the back of the silicone grease. If it says anything about being food-grade or FDA approved then chances are it's alright to use.