DIY hot dip galvanising

[cheb]

Why not? For small items only, I'm thinking large china mug sized. Spurred by my having to make some cleat plates for a seaweed cutter's boat, it'd be nice not see huge rust streaks down the sides.

The process AIUI is make item, clean back to bare metal, degrease, acid dip, heat to a reasonable temperature, lower into a container of molten zinc, lift it out and leave it to cool. The fumes are nasty so breathing protection etc, it'd be done outside anyway and probably in a breeze.

I can melt the zinc, old anodes being a source of material, in a crucible made from a suitable cut down gas bottle, using old pallets so the cost isn't too much of a worry

 

[Hood]

Would it not be easier just using 316?

 

[cheb]

Yes, if I had a suitable welder and easy access to 316. This is more of a theoretical question rather than me doing it.

 

[Hood]

Ok but for reference stick welding stainless is easy.

 

[8ob]

Its feasible, not sure how much of it @ £40-£50 a kilo you would need to make a vat deep enough to submerse a bracket/plate.

Bob

 

[hotponyshoes]

Its feasible, not sure how much of it @ £40-£50 a kilo you would need to make a vat deep enough to submerse a bracket/plate.

Bob

If it can be do e with old anodes then cheap I would think providing you have a source for them?
I have only ever chucked the old ones away.

Even if you bought new ones then you could make a mold and cast all the unused melt for resale and get most of your money back!

 

[cheb]

Ok but for reference stick welding stainless is easy.

Thanks, I've got a stick welder but haven't yet used it, not even on mild. It's on the learning list.

I was thinking that about making anodes, maybe do PX on the old brackets.

 

[Onoff]

Stainless stick welding is great fun. Aka "dodge the red hot slag that pings off on it's own and arcs through the air, generally in your direction". Makes lovely vapour trails on a misty morning.

 

[Hood]

That is true, lots of little pingers

But occasionally you can make a slag ring that just hops off to the side

 

[Kram]

The fumes are nasty so breathing protection etc, it'd be done outside anyway and probably in a breeze.

Wouldnt say nasty in that, it wont cause any permanent injury or damage, just temporary fume fever. Zinc melts around 420c and has a low vapour pressure until about 600c. I dont know what temp is ideal for HDG but suspect 550c or less will be better. A P3 filter mask is adequate for casting brass with the zinc hot enough to boil, so its not a big problem.
Flame heating has very little control and will have hot spots. Electric heating is much better for avoiding fumes.

Ok but for reference stick welding stainless is easy.

I'd like to disagree. Not sure what I did wrong but made quite a mess of it

 

[Dcal]

If you can stick weld, stainless rods are a gift to use.
I'd look at your setup

 

[RWD3M]

Wouldnt say nasty in that, it wont cause any permanent injury or damage, just temporary fume fever. Zinc melts around 420c and has a low vapour pressure until about 600c. I dont know what temp is ideal for HDG but suspect 550c or less will be better. A P3 filter mask is adequate for casting brass with the zinc hot enough to boil, so its not a big problem.
Flame heating has very little control and will have hot spots. Electric heating is much better for avoiding fumes.


I'd like to disagree. Not sure what I did wrong but made quite a mess of it

Galvanising is usually conducted at between 460 - 480 dec C