Welding question unrelated to everything

BullwinkleII

Does anyone know if the kind of welding you might do on two bits of mild steel would be food grade?

I have a new idea for a thing to cook flat bread, and need to weld a few bits that will come into contact with the food.

BullwinkleII

BullwinkleII wrote:

Does anyone know if the kind of welding you might do on two bits of mild steel would be food grade?

I have a new idea for a thing to cook flat bread, and need to weld a few bits that will come into contact with the food.

I could use 3 or 4 bolts instead if that would be safer. I presume I can buy mild steel nuts and bolts.

I also presume it's mild steel I want.

I've really thought this through, haven't I

I'm going to revise the question...

Is it mild steel that you might use in something like an old style wok, or a heavy frying pan?

Can you weld it whatever that stuff is?

Would the welds be food grade?

Would it be food-safer to use nuts and bolts?

There

superdave50

I don't know if it's considered food grade but, people around here have long used "expanded metal" (mild steel) for building BBQ grills and used regular 6011 or 6013 Welding rod. You just get it real hot before you use it the first time to burn off any crud then season it with oil like a skillet. Most frying pans are made of cast iron, can be welded but not easily. I've seen people make woks from old tractor disc blades too (mild steel). As for the bolts, I've never seen them without galvanized coating which wouldn't be good for cooking. Probably safer then your homemade anchovies
:bootyshake:

BullwinkleII

Thanks superdave

Traditionally we used a plow disk as a hotplate in Oz so I'm sure I'm being too fussy, but...

Anyone else?

Will I die if I eat off a weld?

Charlie

Most home made outback bbq's ive ever eaten from have been welded with basic mild steel arc welding rods, usually a 16TC. You need to season the steel as you would do any metal or cast before cooking.

Now that I'm a little older and wiser I personally use a weld-all stainless arc rod. Very easy to use on most steels but is a little more expensive but will last forever with the added benifit of being food friendly.

Growing up, we all ate from fabricated mild steel BBQ plates with mild steel or mig welding joins. But hey, we didn't wear seat belts and smoked in restaurants so.....

BullwinkleII

Does that mean something called a "weld-all stainless arc rod" is actually classed as food grade?

I wont hold you to it, but is this an avenue I need to explore to get a product to market?

ie is there a food grade welding path I should look at following?

superdave50

Ah ha the hidden agenda! :smile:

BullwinkleII

Eh?

I'd love to think I was holding something back

Perhaps the "hidden agenda" is the secret path of Tripiṭaka or something.

Mrs Bullwinkle would love it if I stopped giving ideas away as well, but what did I do this time?

If I have a hidden agenda, I'll share it with you, and ask only 1% regardless of whatever it was

Actually this is a genuine appeal. I have an idea or two that I want to take to market, but I'm too scared to do a kickstarter or whatever, just because "I'm too messed up. But if there is anyone out there in South Oz that feels they could take an idea further, can you let me know. I'm even willing to release an idea for free to the world if that's what floats your boat.

I just need someone who can take an idea, and not vomit when required to pitch it.

superdave50

Well I was just looking fun and to be fair it was more of an assumption on my part then a hidden agenda. When I read the original post I thought "why the concern with food grade? Just build it." But it became clearer when you later mentioned brining product to market. If you're serious about marketing, you should probably get your patent application started and then talk to a manufacturer they'll know the specifics. Definitely not my area of expertise though

David - WI

You can weld two pieces of mild steel together without adding anything at all but heat... so the welded item wouldn't be any more or less "food grade" than the parts you started with. The "bad" things come when you solder or braze the parts together... which can add things like lead, cadmium, zinc, etc.

If you can make the item out of pieces of (proper grade) stainless steel and weld them together using (if needed) stainless filler rod, then your item will be much more corrosion resistant and more resistant to high temperature.

Quote:

Stainless steel is the preferred general use metal for food contact surfaces because of its corrosion resistance and durability in most food applications. However, not all stainless steel is equal.

http://edis.ifas.ufl.edu/fs119

Cast iron works for cooking, but it's not really weldable and has to be kept oiled to keep it from rusting; although it's more heat resistant than mild steel (holds it's shape when hot).

Example: grates for cooking over open fire... stainless or cast iron will keep their shape even when red hot while mild steel will warp, sag, or even melt.

(I guess should say "in my experience" that's how it works.)

BullwinkleII

Thanks for the input everyone.

The device would need to sit as flat as possible so it could be used on my new induction cooktop I just bought (yay - We have an electric stove in our rental so I often cook with a little portable gas burner, but just bought a little portable induction burner)

I guess that means I want cast iron.

I presume cast iron is just done in a mo(u)ld...thus the cast bit to the name. If so, that means I can add the shape as required at that stage.

As I type I've just had an idea.

I'll make a prototype by cutting some plates of mild steel, and just heat bend tabs into place as required. That should at least tell me if the idea works.

BullwinkleII

superdave50 wrote:

Well I was just looking fun and to be fair it was more of an assumption on my part then a hidden agenda. When I read the original post I thought "why the concern with food grade? Just build it." But it became clearer when you later mentioned brining product to market. If you're serious about marketing, you should probably get your patent application started and then talk to a manufacturer they'll know the specifics. Definitely not my area of expertise though

I wish there was a company that took your idea, gave you 1% and ran with it.

I know someone who gets things made of cast iron in China so he might be good for part of the process.

I have to see if the thing works before I do much else, so now I need a forge, or at least a decent burner to bend a little steel.

David - WI

You can bend pretty thick mild steel "cold" unless you have some complex shape you're trying to achieve. Just need probably a vice and a hammer and sometimes a big adjustable wrench works good to slip snugly over the edge and bend with.

For small quantity "production" cast iron you would have a pattern made, usually out of aluminum... basically it's a flat plate with half of you part sticking out the top of the plate and half sticking out the bottom. They pack sand on the top & bottom then remove the pattern leaving a perfect impression of your part that fills with iron. If you need to have holes & such for perhaps a bolt or rivet, they would set a sand replica in place to make the void.

Attachment:

100_1286.jpg [ 305.87 KiB | Viewed 4224 times ]

There will be a void in the upper and lower sand molds for them to set the separate sand "cores" into before they put the halves together; so that the holes for the bolt & rivet won't fill with iron.

SeanD

Perhaps casting iron can be one of your skills you learn along this journey!

There are a few different ways to weld things together, the choice of method will have an impact as to the impurities that will be present.

Spot welding just uses electricity to create heat, not real strong but it holds your car together.

Mig welding uses wire and an inert gas (normally argon, or an argon CO2 blend). Depending on the wire it should have low/no dangerous impurities.

Arc welding burns the outside of the electrode to create the inert pocket around the electrode. Probably the nastiest (yet easiest to do at home)

Tig uses an inert gas and a filler rod rather than a wire. Should also be fairly clean.

If it's a proof of concept you could consider making it out of mild steel and arc welding it as a demonstration piece to sell the idea.

From a production line perspective if it's to be a mass produced product I'd imagine the cheapest options will be casting the item or stamping it out with a press.

Lastly, most welding items have an MSDS sheet available which should help you with your decision making process.

EG:

http://www.boc-gas.com.au/en/sheq/msds/index.html

http://www.cigweld.com.au/literature-videos/msds/

I had a quick skim through this MSDS http://www.boc.com.au/shop/en/au/cigweld-ferrocraft-12xp-mma-electrode---5kg-pack-ferrocraft-12xp-50 for a pretty generic electrode and as scary as it all sounds, it seems that most of the nasty stuff is in the fumes rather than the product that is left behind.

Personally I think there are more important things to worry about than eating off something that's been welded, if it's seasoned then the food wont actually be in contact with the weld anyway.

BullwinkleII

Excellent info (as always).

Thanks people.

Backyard Aquaponics
A place to discuss aquaponics