DIY Mash Tun and Why I had to use so many washers

[ParkerCantLose]

I just put together my mash tun this weekend and ran into a few problems. Maybe some of you have faced similar problems or maybe I'm missing something.

Right now the tun is sitting with water in it and I'm praying that the leaks have been sealed up.

Problem Description:
I went with the Orange Home Depot cooler and the instructions that go along with converting this. I bought the fittings at Home Depot exactly as described in the threads on homebrewtalk (right down to the same model #'s)

The problem was that the ball valve and hose barb only screwed partially into the nipple (center piece). This left a good chunk of the threaded portion showing.

When I then went to put it put it in the spicket opening in the cooler it was clear that 1 or 2 washers was simply not enough. with 1 or 2 washers the thing was sliding all over the place and completely loose.

I ended up putting 4 washers on each side to account for the extra space. Even when doing this I had to really tighten the thing to get it to not leak. I used two wrenches, hand tightening was not going to get this thing watertight.

It seems to be working but I don't understand what I did wrong that I would have needed some many extra washers? Is it simply that the fittings weren't screwing into one another properly? All of the fittings I tested at Home Depot only screwed in partially and left a good chunk of threading visible.

I assume if the fittings would have screwed together using all the threading that 1 or 2 washers would have done the trick.

Did anyone else have a problem with the fittings not screwing together completely? Or is there something I am missing.

 

[mendesm]

In my case, the 3/8” MIP x 1-1/2” brass nipple (Watts A-786) was too long for the thickness of the cooler where the original tap was installed. A shorter one would've eliminated the need of use 6 washers and a couple of the o-rings.

 

[Toneus]

Since the brass nipple is too long, you are forced to use more washers. This isn't a bad thing because the clearances as you have observed are tight. The leaking is not due to the number of washers though, I expect that you could use two more items and all of your leaking would stop.

First, make sure you have a rubber washer between the inside cooler wall and your first washer. A second one on the outside wouldn't hurt. The next piece which I think is key. Get some Teflon packing from your local hardware store. This stuff is used for packing of leaking valves. Cut a piece about 1 1/2" long, and wrap it around the nipple but inside of the rubber washer. You can stretch and mold it to the length and diameter you need. This will stop the flow of liquid coming down between the nipple and washer. You can put a wrap on the outside as well. The packing will crush into the voids of the coller and washers, and thus stop the leak.

I would suggest trying to limit the twisting of the valve assembly, as I'm sure you have plenty if you have a lot of washers. If the packing is good, the twisting won't matter as long as the rubber and first stainless steel washers aren't turning and are packed well.

Tony