buytel tape to seal a water tank inspection port

[woodster]

i have now got my aluminum tank welded up ......i put a 1 1/2 inch nipple in for the water fill hose...3/4 nipple for the water to pump line and a 1/2 inch nipple in the top of the tank for vent hose....i also have 2 ..4 1/2 inch holes in the top for inspection and clean out ...i am useing beckson 4 inch ports for this...fastend with ss machine screws with nylon locking nuts...

now will butel tape work as a sealant or do i need to use silacone or 5200 or 4200....beckson says silacone only on there plastic products but if i can use butel tape that would be great .......what do you say would be the best for this purpose......

obtw..... the tank is made out of 6063 aluminum 1/8 inch thick and the fit up was great from the sheet metal shop friend of mine ...i did all the welding my self in a about 3 hrs.....havent done this in a while and found out that i may have gotten a little older than i though i was as i am not nearly as uniform as i once was ...and that is a little hard to swallow for me being that i remember when ...but i have no leaks and am proud of that ......

regards

woody

 

[RichH]

Butyl tape is NOT rated for use with potable water.
Sealants and caulks used with potable water tanks should be FDA or NSF 'rated' for compatibility for *potable* water.
The 'best' for such service is 'food grade' silicone or BUNA rubber -- gaskets or O-rings.

Food Grade or 'potable water' rated ensures that the material does not or has very small amount of 'chemical leachables' or chemical 'emission' in contact with water.

 

[woodster]

Butyl tape is NOT rated for use with potable water.
Sealants and caulks used with potable water tanks should be FDA or NSF 'rated' for compatibility for *potable* water.
The 'best' for such service is 'food grade' silicone or BUNA rubber -- gaskets or O-rings.

Food Grade or 'potable water' rated ensures that the material does not or has very small amount of 'chemical leachables' or chemical 'emission' in contact with water.

thanks for the response Rich...wasn,t sure about the butyl..i will geta pieace of Buna and do it that way and make a reinforcing ring for the inside of the tank where it nuts go....

regards

woody

 

[RichH]

Suggest you look for 40 durometer - an indication of the rubber's 'softness' or compressibility. Typical industrial grade duromter is 70 and takes a lot of force to 'seal'.
Try a local source that caters to the 'dairy' or food industry. The better Food grade rubbers arent 'black' but are 'almost clear'/amber or whitish in color.