Weldless fitting for a water heating element in an aluminum pot?

**cyberbackpacker** · 10-22-2008, 06:19 PM

Any ideas on a weldless fitting for a water heater element in an aluminum pot? The pot is 4mm thick, so would it be possible to find a tap to tap the hole for a screw in element and create a good seal?

There is info for SS, but little on aluminum weldless fittings for these with any real direction/information that I could find.

Thanks.

The Pol · 10-24-2008, 01:35 AM

Or use a 1.25" PVC threaded coupler and tighten it on from the inside with the flange on the outside... this is how I modified my cooler

The Pol · 10-24-2008, 02:56 AM

Here is a pic, hard to see the inside of the cooler, but that is it...

http://www.homebrewtalk.com/f11/new-10-gallon-herms-pics-76773/index5.html

Paco · 10-24-2008, 08:59 PM

I don't know if any plastic readily available as threaded fitting can withstand boiling temperature...

Screw type electric element are, from my investigation, NPS (national pipe straight). All of the brass and copper fittings (NPT) that I've tried don't screw up more than half of a thread. You need straight thread. McMaster have a stainless locknut (4464K586) that should work perfectly.

I'm currently waiting for a reply from Wayne from Bargain fittings to see if can provide me (and others) this particular nut. Since I will be ordering my other fitting sets from him I suggested him to offer this 1"X11-1/2 NPS SS locknut. Let him know you'd like it too!

**GNBrews** · 10-24-2008, 10:08 PM

PVC bulkhead fittings are only rated to 140F. Polypropylene fittings are rated to 200F.

Paco · 10-24-2008, 11:45 PM

Specifications to consider are melting point and the "point-when-the-plastic-get-too-soft"... keep in mind that wort is boiled up to two hours sometime... and mostly don't forget that your are dealing with electricity here. I guess many of us could deal with a leaking fitting without too much problem but when you mix electricity, it can get "tricky"!

**cyberbackpacker** · 10-25-2008, 12:17 AM

Thanks for the input everyone, and Paco let me know about bargain fittings... if we can get them through him, that would be helpful. In my other searches they were about $14 a pop!

**BrewBeemer** · 10-25-2008, 01:11 AM

The OP was for a aluminum pot adding a heating element how did it go to coolers and PVC pipe?

On that pot it's only 4mm thick or .157" too thin to thread besides the radius of the pots OD adds to the sealing problem. A 1/2" or better yet 3/4" thick piece of aluminum with the inner face milled to match the pot OD radius then Tig welded to the pot would be great. Drill then tap for your element to seal on the flat surface as it was intended would be the way to do it correctky. Drill and tap then Tig the inside of the pot to the plate then chase the threads again No leaks now or later and done correctly.

**cyberbackpacker** · 10-25-2008, 02:11 AM

Brewbeemer, now that is an interesting idea I had not considered; it is why I am glad to have the resources and knowledge of this board.

There is a shop that builds short track cars; maybe I will see if there is someone in there who is qualified and would do it for less than my arm and leg.

The Pol · 10-25-2008, 02:29 AM

Quote:

Originally Posted by BrewBeemer

The OP was for a aluminum pot adding a heating element how did it go to coolers and PVC pipe?

On that pot it's only 4mm thick or .157" too thin to thread besides the radius of the pots OD adds to the sealing problem. A 1/2" or better yet 3/4" thick piece of aluminum with the inner face milled to match the pot OD radius then Tig welded to the pot would be great. Drill then tap for your element to seal on the flat surface as it was intended would be the way to do it correctky. Drill and tap then Tig the inside of the pot to the plate then chase the threads again No leaks now or later and done correctly.

It went there because regardless of the material (aluminum or plastic) if you are poking a heating element through the wall of anything, the same principles will apply. Since I converted a cooler and had a nut that worked, and has been used on various other systems, I thought it may be a helpful jumping off point.