How close can I solder a fitting next to another?

[Nemanach]

I have a pull through fitting for a ball valve on my kettle and I want to add a surface soldered weld spud to add a temp probe. How close can I solder the fitting without worrying about the other fitting’s solder melting and falling out? I want them close so the probe tip is between the dip tube and the element.

The attached are 2.5” from each other center on center. If I leave the ball valve, diptube and wrap the old fitting in a wet towel do you think that would be enough of a heat sink to not worry about that fitting melting?

 

[Vale71]

Are you actually going to solder it or do you mean welding?

 

[Nemanach]

Solder

 

[Vale71]

Stop using that kettle immediately. You have lead in your beer and that is a known poison. Either get a professional to actually WIG-weld the parts to the kettle or throw it away. I'm not kidding.

 

[Soulshine2]

it could be lead-free silver solder meant for potable water . Not all solder has lead in it.
OP- is it one of these?
https://search.myway.com/search/GGm...9508e085d34&searchfor=lead free solder&st=tab

 

[Nemanach]

It is silver solder from brewhardware.com, there is no lead in it. I wouldn’t use lead electronic solder on plumbing either.

 

[Soulshine2]

how close you can solder to another soldered fitting is up to the skill of the person soldering,but if I may critique yours....your finished solder looks a bit cold and rough. a proper solder joint should be smooth flowing in appearance. which means the heat was enough for the solder to penetrate the joint enough. Use plenty of lead free flux and pre-heat before touching the solder to the joint.
But the point Vale was trying to make is with a stainless steel kettle you really should be having a port tig welded in by an experienced welder, not soldered. If at one point you should heat an empty pot, that solder will most likely fail.

 

[Vale71]

If it's NSF compliant lead and cadmium free solder than I withdraw my warning but still I would consider this at best a temporary fix and look into having everything professionally welded for durability.

EDIT: just checked the documentation on the manufacturer's site and this product is clearly not meant for food applications. It could still contain up to 0,1% Pb and 0,1% Hg. I definitely wouldn't use it.

 

[etk29321]

Harris stay brite is lead free and NSF certified. Here’s the data sheet: https://www.harrisproductsgroup.com...ldering/Lead-free-Solders/STAY-BRITE8Spec.pdf

I’d be shocked if Bobby were selling anything that wasn’t.

 

[Vale71]

They're certified to NSF standard 51. Lead-free is either 61-G or 372.

 

[IslandLizard]

To answer your main question, you need to leave enough vessel material between the holes, to maintain integrity, IMO.

 

[day_trippr]

I think the proposed spacing will be fine, there is a lot of kettle wall to suck up heat from soldering the new fitting. Wrap wet towels around the existing fittings on both sides if unsure.

The original soldering job should be redone as it looks like an amalgam of cold solder blobs. Not enough heat when flowing the solder....

Cheers!

 

[Nemanach]

The first fitting was hot enough to have solder melting out the other side of the fitting. I think it looks like that because I kept feeding solder into it after it cooled a bit. I’m concerned trying to reheat it as it is currently holding water fine, I don’t want to screw it up and I don’t have any more solder to pull it out and start over.

I was able to get the fitting installed where proposed. No problems with the original melting. I did have a tough time getting the fitting leak proof but the 3rd try did it.

As far as the solder I was under the impression that silver soldering was a fairly widely accepted way of installing them. If I have problems in the future I will look into welding them but I suspect it will be expensive enough that I don’t want to do it for the sake of doing it if there isn’t a problem.

Stay brite 8 is listed as lead free and I don’t see any mention of lead in the data sheets. I would be interested in seeing where the 0.1% pb and 0.1% hg is coming from.

 

[Vale71]

That's from the European safety data sheet. In the EU the product is declared compliant with 2011/65/EU Annex II which states those 0,1% limits. Here is the source, just pick the language of your choice:

https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=celex:32011L0065

 

[wilserbrewer]

Just my opinion, I think you are over concerned...

You can typically reheat and reflow a solder joint without damaging the previous work. You could easily reflow the previous fitting while adding the new one.

A wet paper towel should easily avoid you’re first joint from re flowing.

There is no need to add solder as it cools, it’s not like welding where you want to build a bead for strength, the kettle and fitting should be hot enough that once touched with the solder it is quickly sucked in to fill the joint.

Once you see a bead of solder around the joint, that’s plenty of solder. Strength comes from the mating surface...

 

[IslandLizard]

That! ^
Soldering is a "surface alloy" process.

 

[kh54s10]

IMO, even if there was a trace of lead in the silver solder, there isn't enough surface area exposed to the wort to cause a problem. No regular electronic solder would be another story.

 

[etk29321]

Here's the 'typical compliance certification' for the spool Bobby sells: http://typicalcerts.harrisproductsgroup.com/Default.aspx?partno=SB31

It does list NSF 61/NSF 372 compliance there.