Tin Coating on old meat grinders


Those old cast iron kitchen hand-cranked grinders, sausage stuffers, etc
are all silver. I have some that the coating is in pretty sorry shape &
they need a re-coat.
Am I correct in assuming it is tin?
How is it applied? Are they "tinned" as in dipping or coating in molten
tin or simply plated?
Thanks!
MikeB
Reply to
BQ340
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It is tin, pure tin. I am sure it is fluxed and dipped in molten tin. Just like galvanizing, using zinc.
My father bought a dairy farm in 1957. The next year he had a bunch of the milk containers re-tinned. A place in Portland, OR did it for him. Can't tell you more than that.
My electronic assembly service uses a lot of lead-free solder for circuit boards going in export products. The solder paste for the surface-mount components is almost 100% tin, Just a few % other metals. Most of the wire solder used to add components by hand is pure tin. In all cases, very active flux is required to clean the area to be soldered.
Molten tin reacts quickly with oxygen to produce a black tin oxide powder that floats on the molten tin. Our CNC selective soldering machine uses nitrogen gas to limit the oxygen getting to the molten tin.
I have not heard of anyone tinning metal parts in a very long time. Perhaps you can find a commercial food processor in your area and ask their maintenance people about tinning their equipment.
Good luck, Paul
Reply to
co_farmer
The better ones are acid dipped then dipped in pure molten tin. Others get plated and some even get metal sprayed.
When I had mine done I talked to a commercial kitchen supply place who gave me a couple of local places that did tin work for them. It cost me a bit less than a new grinder on the #10 and less than half on the #32.
Reply to
Steve W.
Yes.
The old stuff was hot-dipped, like hot-dip galvanizing.
It's not easy to replicate but you can probably do a good job with a torch equipped for metal spraying. Good luck if you try to melt it on like solder.
Or just live with it. I have two grinders, one over 60 years old and with a number of worn spots. I just wash and dry it good and give it a light wipe with medicinal mineral oil.
Reply to
Ed Huntress
assuming it's tin
For what it's worth, I picked up, some years back, some really nice heavy copper pans at a garage sale, but the tin coating on the inside had worn off - I put the pans on the stove, put in a dollop of acid flux, scrubbed that around (with the heat on) until the pan was clean, and then poured in some tin from a bottle of reasonably high purity tin I just happened to have lying around - then when the tin melted, I scrubbed it around until it covered the pan nicely - it's worked well for years - the same approach may work for you, I don't know
Reply to
Bill Noble
I have seen mixing bowls re tinned with a torch,a bar of tin and a wet rag. The bowl would be heated and the tin melted onto the bowl surface. The wet rag would be used to spread the tin over the surface evenly.
John
Reply to
John
Cast iron is tough to coat, John. Copper or steel are a lot easier.
To do a good job with cast iron you need an etch and the right flux.
Reply to
Ed Huntress
You can buy tin ingots on ebay. This seems to be a good deal.
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$24.99 per two lbs.
Use it and resell it back.
i
Reply to
Ignoramus3512
In some old text I've got somewhere, it had how to do it for cast iron. You've got to etch the stuff to get the graphite pockets cleaned out, then use a pretty active flux to get the tin to stick. Presumbably, the graphite surface pockets are still cleaned out on used equipment, all that needs to be done is get the thing fluxed well and re-tin. For repairing milk cans, it was more like tinning for soldering, using a big soldering copper. Tinning cast iron was a dipping process with flux floating on the molten tin bath. So for a fairly large item, you've got to have a pretty big bath and a LOT of tin. Not sure how well sandblasting would work for surface cleaning, you want to have new media and not recycle it. I've done some sweat soldering with small cast iron pieces, not easy even with acid flux.
Stan
Reply to
stans4
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Thanks, Iggy, That's about 1/2 price of what McMaster gets per pound.
MikeB
Reply to
BQ340
Thanks for all the good replies!
I'll get the tin that Iggy found & clean it really well then try just heating it up with the O/A torch. Between adding flux, tin & reflowing what tin is there now it should turn out ok -I hope.
Doing a most likely inferior job for twice the time & money compared to farming it out to the pros is what this group is all about, no?
I'll follow up after I am done.
MikeB
Reply to
BQ340
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Even I got a couple, I will use them for casting tin toys with my kids.
i
Reply to
Ignoramus9512

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