Hot dip galvanized at home?

[julianf]

I watched a video on galvanising yesterday, which reminded me quite how 'cool' the dip is. Vid said 450c.

I mean, if I don't pay attention, our Rayburn hotplate can start to glow. That's maybe 650c and sitting in my kitchen, so 450 is nothing really.

Which got me wondering if anyone had tried it at home. Plenty of people doing alloy sand casting etc. and that is hotter again.

I'm talking small parts, not chassis.

 

[Shox Dr]

I think it needs something like tin floating on the top other wise the zinc oxidises very quickly. Causing problems.
And then there’s the fumes

 

[julianf]

On the video I watched (years old - a 4x4 is born) they're were constantly skimming the top.

Would a layer on top even work? It would be the first thing to coat the job on dip, and the last to cling to it on lift?

I know welding zinc is crazy, but I think the chaps in the vid were not wearing air fed or anything, so maybe at a lower temp then weld temps it does not fume in the same way? Or maybe it does, but it would only be as bad as 2k.

I'm (probably) not actually considering doing this at all - but I reckon it would be quite possible.

 

[Kayos]

I think melting the zinc might be the easy bit

Prep chemicals and explosion risk would be my concern

 

[Hitch]

You can buy it in a spray can for small bits....

 

[rcx132]

You can buy it in a spray can for small bits....

I never thought that's the same. Hot dips melts itself into the metal forming a physical bond and is very thick and is pure zinc. A spray can won't compare, it still relies on a shoddy chemical bond created by the thinner drying off.

 

[Hitch]

I never thought that's the same. Hot dips melts itself into the metal forming a physical bond and is very thick and is pure zinc. A spray can won't compare, it still relies on a shoddy chemical bond created by the thinner drying off.

Properly hot dipped galv item, agreed...but only if the pretreatments are carried out properly.
The caustic dips, the pickling acid dipping... if its not done properly, I'd think the zinc-iron oxides dont form properly, and the coating isnt perfect.
I'd think just dipping a few bits in a saucepan full of hot zinc would probably be on a par with a good quality film applied galv, such as Zinga.

 

[Revs1972]

When I was working for a subby drawing office, we drew a lot of galvanised structures for an American Fabricator. They still weld a heck of a lot of their connections when erecting. I spoke to a couple of their "ironworkers" and asked how they repaired the galv after welding. They clean up the area then heat it up with a blowtorch then use a stick of zinc and heat that then rub it all over the joint.
Speaking to a couple of old boys over here, they said they used to use it years ago , but it was banned.

 

[merryman]

Millers Oils, Zilt. I must have used hundreds of sticks when I was getting Galvanised stuff ready for powder coating, that was round about 2000. I suspect it was mostly tin, but if I needed to fill a dent I rubbed Zilt on then melted a drip, (that had fallen off something) into the dent, followed by grinding and sanding with the 4" grinder.

 

[optima21]

in the mid 1980's when I worked a a metal pressing company they did hot tin dipping in house for electrical contacts, which was basically putting the contacts into molten solder. I think they may have spun the parts in wire baskets to remove the excess tin (solder)

 

[rcx132]

If you want to do hot dip you can probably get a book about it. You can easily do the acid pre dip and prep work. Galvanising technology was developed decades ago and hasn't changed much so an old text book is fine and gives all the info you need. I did electro plating for a while but found its only worth while for small one off parts.