So let’s try another approach.
Yes stainless is best and plastic is slightly less best and personally I can’t stand the stuff and tin plate is at the bottom of the list, but
If all you can afford or have available is tin plate then use it,
Simple rules apply, untreated its best for home consumption only as no one wants you to sell bad honey,
personally I used a 1960’s tin plate 9 frame radial for donkeys years without any issues, all I did with mine is to line the insides and the frame holding mechanisiam, there are several choices you can use , and I expect the doom and gloom lot will of course slate everyone of them as toxic and have me shot at dawn ,,,twice!!
One way it to powder coat the whole lot, for cash and a good job, done out in white you are proberly looking at around the ton mark maybe more or less depending on what’s local, my wine/apple press is formed from a cut down gas cylinder and we have used it for well over ten years now with no problems, let us just put into perspective that we are not storing honey here it is just passing through the system so minimal residual time in it.
No local powder coaters nearby, then lets order something on line then, try any of the fiberglass material suppliers, I won’t name names but the costs and material are all pretty well the same, what we are looking for is some form of “potable water lining system”, anything suggested for water tanks etc is perfectly fine to use , easy to mix up and paint the whole lot, but remember we only have to do the insides only the outsides can be done with normal enamel, this is what I did to use my old extractor, the costs were around about the £50 mark and that’s including delivery,
We can of course just use a food grade quality paint if you wanted to which is even simpler to apply.
As for going onwards why not use it as a template? find a new bestist ever best friend, that also owns a mig/tig welder and can do stainless and use the old on as a template to make a newer and even better version.
Looking to invest in a new one, try thinking for once rather than joining the crown stood outside a uk bee shop try Google translate for” honey extractor” and GERMANY EBAY, I brought a motorized 12 frame stainless steel extractor with delivery and postage for £500 , try finding that quality in the uk for that price!
And just to satisfy the doom and gloom lot who are about to start loading their rifles for the morning, yes stainless is best and plastic is just as good and tin plate is bad