Soldering Custom Element Guard

[Brendan]

Here's another migrated thread on using a custom element guard for a more permanent solution. The parts involved are a 50mm end cap, a 50mm to 32mm reducer, and a 32mm end cap (also a small piece of 32mm pipe, and a cable gland to finish off at the end). The credit for the custom guard idea itself has to go to MacStill, but I am just presenting the soldering and preparation on this here. The element shown in the pictures screws into a 1/2" BSP socket which is welded into the boiler.

Previously, I had mentioned the idea of soldering the end cap for the element guard onto the base of the elements itself. Here's a run-down of what I did for those looking for an effective and permanent solution

Here's the pieces for the custom element guard

When sliding the 50mm end cap over the thread side of the base, I found that I lost too much on the thread and was not able to screw it into the socket in the boiler well enough...it would leak even done up as tight as I could get it, and there was a fair bit of wobble still in the element at this point.

Because the method shown in the previous photo, holds the 50mm cap against the socket...using it on the back of the element base would require it to be fixed permanently...and step in soft soldering an element

[Brendan]

I gave both surfaces a good clean and roughing up with some emery paper, I wanted it to stick real well so I could get the heat in and out quickly

Once soldered, it will go together with the reducer with 2x screw/nut assemblys, one of which will be used to earth the guard

Fluxed up the contact surfaces

pply a light heat to the very side of the copper to avoid burning the flux. I also used the little Bernzo pencil tip torch for this to achieve a slow, soft heat up of the element base. Notice in this pic that I have used some steel wire to hold the end cap in place on the base. The element is being held in a bench vice.

[Brendan]

After soldering, looks a mess but solder flowed nicely and didn't apply too much heat to the area

After a cleanup, nice and neat...

Looking in at the terminals...

The end cap will then be fixed with the use of 32mm pipe, and a cable gland installed at the back of the end cap to keep the cable steady and prevent easy twisting

Then it just screws into the welded socket in the boiler nicely with that extra bit of thread now available, and looks tidy too

[Prairiepiss]

I like the copper. Hope you have a thin wrench to install the element with.

[Brendan]

I like the copper. Hope you have a thin wrench to install the element with.

Thin wrench PP? You just screw it in by hand, they have a silicon washer and you don't want them over tight squashing it...I assumed these were standard internationally; what do you guys use?

These are fairly standard water heater elements here in Aus...

[IrishEnigma]

I suppose you may get some criticism on the silicone gasket.. Id use thread tape to seal it instead of the silicone gasket.

[Brendan]

I suppose you may get some criticism on the silicone gasket.. Id use thread tape to seal it instead of the silicone gasket.

If anyone criticises a 100% silicone gasket in the boiler, I would strongly question their understanding of both the chemical resistance of silicone for starters, and general distilling processes considering that its in the boiler. I have mentioned my experiments with silicone in the vapour path in my build thread, but we're talking in the boiler....

[IrishEnigma]

Well I was kind of thinking that before I posted. So since it's not coming in contact with the vapors is it ok to use it? it's still coming in contact with low alcohol percentage at high temps.

[Prairiepiss]

I suppose you may get some criticism on the silicone gasket.. Id use thread tape to seal it instead of the silicone gasket.

If anyone criticises a 100% silicone gasket in the boiler, I would strongly question their understanding of both the chemical resistance of silicone for starters, and general distilling processes considering that its in the boiler. I have mentioned my experiments with silicone in the vapour path in my build thread, but we're talking in the boiler....

You would then be questioning a lot of members here. And Rule number 8 of the rules we live by.

Standard water heater elements here come with a crappy black rubber gasket. That I wouldn't trust. And many of us have used an NPT threaded mount. So we are sealing the element by the threads. Not the gasket. The elements have a hex head on them for a reason. And hand tight would probably not be sufficient. Not to mention heat expansion and contraction of the dissimilar metals and gasket. Just saying.

[Brendan]

Well I was kind of thinking that before I posted. So since it's not coming in contact with the vapors is it ok to use it? it's still coming in contact with low alcohol percentage at high temps.

Okay IE, now we're treading a fine line in terms of speaking for the HD community. Speaking for myself only, and considering myself as a well educated and overly cautious individual who tries to utilise only the best equipment and practices...I can say that I have done extensive testing on 100% silicon gaskets, and am more than happy to use them even in the vapour path (I wouldn't even think twice about the boiler here).

I may have to post my silicon thread here, but the main potential problem on paper with silicone, is its poor chemical resistance to acetone (not ethanol). Through my own experiments, I concluded that indeed silicone did have a poor resistance to pure acetone, but even in pure foreshots (just the first 50ml straight off the still), showed absolutely no sign of breaking down or leeching over a period of months (can only assume my experiments showed that despite the smell, the percentage of acetone composition in foreshots is much lower than thought). So I personally (only speaking for myself), am happy to use the 100% silicone gaskets which I have tested, in the vapour path for sight glasses in my plated column, and obviously a seal in the boiler doesn't even register a concern due to this. I must stipulate though, that I cannot speak for the community as this is not a material such as SS or glass which is completely inert to solvents. I hope I was able to convey my point while remaining politically correct

edit: to add to this after reading your post PP, these actually seal with the thread too with the 100% silicone gasket resting against the external ridge of the welded socket...however the whole conversation sparked my strong interest and opinion on high quality silicone (for my own use).

[Brendan]

PP, I understand completely on those black gaskets that come with heating elements. I am talking quality 100% silicone clear coloured gaskets here.

Much in line with my previous post, I have a strong opinion on the particular high quality gaskets that I have tested myself, but completely understand that as a community we need to warn people away from these materials in general due to the many sub-par products and partial-silicone components out there. As a general stand, I'm completely there with you...but on close scrutiny of particular high quality 100% silicone products, I have no choice from a scientifically educated background to feel confident to use them.

[Prairiepiss]

That's all fine and dandy. For you. But maybe you shouldn't insult other members. Like you did in your other post. And make your intentions a little more clear.

[Brendan]

That's all fine and dandy. For you. But maybe you shouldn't insult other members. Like you did in your other post. And make your intentions a little more clear.

Yes you are right on my 'questioning their understanding' post. I apologise for that, it may have come across stronger than I intended. Unfortunately, it is a topic that I 'feel' strongly about and have a keen interest in, but just get frustrated by those quick to judge. I will ensure it remains a civil discussion and hope to post some of my experiments up soon for public ridicule

[Prairiepiss]

Just to be clear. My first intentions had nothing to do with the gasket. It was mearly my own experiences with sealing potential fluid leaks. And hand tightening doesn't always cut it. On such a sealing surface. And most time then not. More then hand tight is needed. With or without fluid pressure. Would hate to see you throw a pipe wrench on the copper.

[Brendan]

Not a problem PP, I followed what you meant. Was just trying to answer IE's post while trying to remain politically correct

The elements and sockets we have all been sourcing here in Aus (from accounts on international forums), seal up fine by hand tightening, with the silicon gasket seating it's external plate to the socket.

But you were very right, you would need a thin wrench to get on that!

[Brendan]

You would then be questioning a lot of members here. And Rule number 8 of the rules we live by.

I just read rule number 8, PP.

I think I'll just leave the whole subject alone and be an advocate for the forum's point of view. Sorry, didn't mean to draw you in with my arrogance