Cooler mash tun seal

[Imburr]

I got an old cooler that I turned into a mash tun. The main valve installed fine because the wall of the cooler is slightly thinner there. I drilled a hole through the side to add in a thermometer and for the life of me I cannot get it to seal. The wall of the cooler is very thick so I had to even buy extended nipples to go through. No matter what sort of gasket I use (flat, rounded, skinny, thick), and no matter how tight or Loosely I screw it it leaks.

Can I permanently seal it with some silicone caulk? What are the implications here? If I did seal it in this manner would I seal the inside and outside and let it dry or would I apply the sealant to the inside and the outside and then screw on Two Nuts to hold it in place and let it all bond together?

 

[jheinikel]

You can use food grade silicone. Here is a link to one that supports up to 400F. https://www.amazon.com/dp/B0063U2RWU/?tag=skimlinks_replacement-20

 

[Bobby_M]

There's no reason to use sealant. Teflon tape on the continuous threaded nipple, then the flat gasket backed up with that flanged locknut. Those go on the inside of the cooler. On the outside just a washer and locknut. The key to the seal is teflon tape between the nipple and flanged locknut.

 

[Imburr]

There's no reason to use sealant. Teflon tape on the continuous threaded nipple, then the flat gasket backed up with that flanged locknut. Those go on the inside of the cooler. On the outside just a washer and locknut. The key to the seal is teflon tape between the nipple and flanged locknut.

They dont make continuous threaded nipples long enough, the 2.5" only leaves a tiny bit and not enough to get a hold of on both sides. So I am using the nipple pictured, but only the thread sticks out of the cooler so it is a good size.

I have tried various forms of teflon tape, but I will try what you suggested.

 

[Imburr]

They dont make continuous threaded nipples long enough, the 2.5" only leaves a tiny bit and not enough to get a hold of on both sides. So I am using the nipple pictured, but only the thread sticks out of the cooler so it is a good size.

I have tried various forms of teflon tape, but I will try what you suggested.

Bobby_M, you are the man and correct. By extending the teflon tape on the inside through the nut it fixed the leak. Appreciate the guidance! And appropriately, I got that gear on the table form brewhardware.com