Food stainless steel welding on galva or black iron with MIG

[Christophe]

I need to make a homemade "large capacity" anti-ram for our solar pump. In fact it is to limit water hammer when it starts up again when the panels are emptying: this is what can happen when a small cloud briefly hides the sun for example!

So I got a siphon at Emmaüs hoping that the thread is BSP therefore compatible with plumbing ... well no it's the right diameter but not the right step

So I have to weld a part to switch to BSP: a 3/4 nipple fits "perfectly".

So is it possible to weld these 2 pieces (or the nipple in black possibly?) Together with a MIG or do I have to find another bottle?

It is marked "Inox 18/8"

[the middle]

Buy a steel nipple, and everything will be fine for welding.

[Christophe]

Well the galva is steel ...

So a black nipple on stainless steel will you think it will work?

What thread do I take? Stainless steel or Steel?

[Other]

Hello

Your nipple is made of galvanized cast iron preferable a non galvanized black steel nipple (otherwise you have to grind it to remove the zinc)
if momelon in black iron you can weld it with an arc with a stainless steel rod, or with a mig or a TIG medium if it is thin steel and stainless steel it welds very well.

If you want to keep the cast iron nipple preferable to brew it with a strong brew, but a little tricky if you have no experience with stainless steel if you heat the stainless steel a little too much the brew no longer sticks, you need to that you cool and repolish the surfaces.

Personally I weld almost everything with TIG argon

Andre

[Christophe]

Uh are you sure it's cast iron when it's galva André?
I believe that in the 2 case it is steel, one was galvanized by the other ...

But I can be wrong and it may be different in Quebec?

Ok so it is weldable with stainless steel wire! Thank you!

[the middle]

it's a galvanized steel nipple that you have.
It's not the best to weld; it will be kaka boudin

[swift2540]

Correction:
It is a malleable cast iron nipple.
The difference between steel and cast iron is the% carbon, I'm not going to lecture on this.
In plumbing, the pipes are in semi-soft threadable steel, the accessories are in malleable cast iron.
You have to take a raw cast iron nipple to weld it, otherwise you will burn the galvanization (zinc), => release of fumes.
A+

[the middle]

It is a malleable cast iron nipple

Yes, I was wrong, but it's really not great to solder.
It's so simple to take a steel nipple

[swift2540]

Not great to solder, fully agree. Mainly cast iron / stainless steel.
But where to find steel nipples?
Wouldn't it be easier to take a piece of threaded pipe?

[boubka]

given the photo it looks a lot like a 1 "cylindrical (11 threads per inch) if you put a bsp (conical) fitting you take one or even three threads by forcing (sometimes that's enough) otherwise you take a cylindrical stainless steel fitting or cylindrical brass.
or then you are in npt thread (11.5 threads per inch) and you can put a brass bsp cilyndrique fitting by forcing.
it must do
ps: it is not 1 "(8 threads) we can see it clearly on the photo it would be much thinner and moreover it is hardly ever used in piping