a question about Dao Vua.

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a question about Dao Vua.

Post by Marzipan »

it's been repeatedly said on reddit that some of their knives have lead in the metal. is there any substance to this claim or is it elitists trying to poo poo a company with potential that makes Japanese knives but aren't Japanese?

can anyone here share any info between the leaf spring steel and pipeline steel? what are the biggest differences and how the 52100 they've sourced from the US compares to them?

many thanks!!!
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Re: a question about Dao Vua.

Post by taz575 »

52100 is a nice steel for the kitchen when heat treated properly; it takes a holds a nice edge and is pretty tough. 5160 (leaf spring) is a bit tougher, but with much less carbon, so it won't hold the edge as well as 52100 will. I would say the US Sourced 52100 will be a lot better steel wise, assuming they do the proper heat treating process for it?
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Re: a question about Dao Vua.

Post by jmcnelly85 »

http://www.zknives.com/knives/steels/st ... hp?nm=5160

https://www.zknives.com/knives/steels/s ... p?nm=52100

I’m not seeing lead in either of these two, I’m not sure what steel is used for the pipeline series.
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Re: a question about Dao Vua.

Post by taz575 »

From what I remember, people tested a few knives with the cheap home lead testing swabs. The swab showed lead present. Many people say that the cheap swab kits are constantly showing false positives and the 3M are the only reliable ones. Lead can be from anywhere; it can be in brass fittings (especially recycled brass. Lead is often added to brass and other metals to make it easier to machine), coal ash (from forging since coal is made from organic materials that may have absorbed heavy metals), or in the recycled steel itself as a contaminate from the recycling process with other contaminated metals). So if someone used some brass fittings to make a guard, it may contain lead. If there was lead in the water used to wash the blade before the test, lead will show. If the coal came from an area that had lead polution, the coal itself will test positive for lead. People are claiming that knives from Pakistan, China, Vietnam, etc contain heavy metals, along with lead. Something to be aware of, but I do not know how much of a problem it is?

Leaf spring is not always 5160, either! I would rather use a known steel, but environmental factors can add lead to a knife. The kits test for any trace of lead; it isn't saying that lead is a primary component of the metal being used for the blades.
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Re: a question about Dao Vua.

Post by Jeff B »

Marzipan wrote: Fri Nov 25, 2022 11:45 pm it's been repeatedly said on reddit that some of their knives have lead in the metal....
Internet drama queens and reddit, I wouldn't expect anything less. :roll:
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Re: a question about Dao Vua.

Post by Marzipan »

thanks for the responses. I put up a post on r/chefknives asking about sleeper brands / makers and mentioned Dao Vua as one of them and a few people responded with hostility. I countered with some reasonable thoughts and while they were thumbs up those posts were thumbs down. how dare I question elitists and rock the boat, LoL!

also, it makes no sense for a US company to import knives with lead when the US is a very litigious country and would likely have their asses sued off them for putting their customer base at risk once discovered.

I know their knives are pretty rough and how sharp and defined their edges are out of box is spotty, but I quite like the rustic look and support an underdog and peoples who are trying to make a living. especially because when the craftsmen are trying to get better at their trade. they're on wha t appears to be generation 4...leaf spring...pipeline...classic v2 and now the 52100.

oh, question about the 52100. can you adjust or redo the heat treatment if you get one that's questionable?
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Re: a question about Dao Vua.

Post by taz575 »

Its a process to redo a heat treat. On a knife that is already ground and thin, it is a risky process and can lead to warps and cracking due to the thin areas. The handles also need to be removed. You would want to normalize, anneal and re heat treat fully. Better off starting with a properly heat treated blade?
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Re: a question about Dao Vua.

Post by TheLegalRazor »

I have a leaf spring small cleaver and have read the Reddit commentary about lead in the steel. None of the individuals raising these claims cite any supporting authoritative sources. I don't know if leaf spring steel has any lead. I do know that what I've read on Reddit so far is speculative and not factual.
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Re: a question about Dao Vua.

Post by ChefKnivesToGo »

I’m willing to send one to a lab to settle this. Anyone know of one in the US?

Here’s the melting point of 52100: 2595 F
Here’s the melting point of Lead: 621.5 F

So my question is how could you heat treat a knife with lead without it melting away?
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Re: a question about Dao Vua.

Post by timos »

hey maybe larrin @ knifesteelnerds would tackle this one. seems like a decent topic for one of his articles.
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Re: a question about Dao Vua.

Post by taz575 »

Mark, I don't think there is actual lead deliberately used in the knives as a component on it's own. 1500-1600 degrees (most simple carbon steels are heated to this point for heat treating) would liquefy any lead in the blade. However, I believe lead may be a contaminate in the metal alloys themselves from using recycled metals/pipe steel. I doubt recycling places clean their machines after each batch of metal is processed, so lead can work it's way into recycled steel batches. Many pipes in the US and Canada have lead in them still, too. Lead can even be found in the coal used in forging if the wood the coal is made from had absorbed lead at some point. From what I saw on the posts about lead in Chinese, Pakistan and Vietnam knives, the cheap Amazon tests are NOT accurate, but others said the 3M home tests are supposed to be pretty accurate. But I think you will find lead in many places you don't realize! Many of these posts are trashing products from these countries to promote blades from other areas. One person even went so far as to claim that these knives were tempered in lead baths??? Reddit isn't known for factual information!!

52100 from the US should be OK.

Recycled leaf spring or pipe line steel may be where the contamination would be found. Places that recycle steel (actually re smelt/re process completely the steel) may not know there is lead present since lead can pretty much be anywhere or they may not be able to remove all of the impurites when recycling the steel if they actually smelt it down. If Daovua buys their steel (ie buys a huge section of old pipe line or a stack of leaf springs from a scrap yard), they may have no idea what contaminates are in the steel itself from the place that made the pipe/spring or what was able to leech into the steel over time as pollution/contamination. Lead was commonly (and still is) added to various pipes/fittings to improve ease of machining and used to be in a lot of different solders, too. Lead can be in any organic substance, such as plants and trees (which coal is made out of) or inorganic substances like brass, steel, iron, etc. Lead is commonly added to brass to make it more machineable and those fitting/parts are often labeled as not being for drinking water. Your garden hose will probably have some lead in brass fittings, yet most of us drank out of a garden hose as kids. Hoses for drinking water are now often made from non lead containing materials, but it seems there is always some new contaminate that pops up on the radar every few years!

My mom worked with stained glass for many years. Her fingers were taped to prevent cuts, but she still used lead channel on all of the glass pieces over numerous years (10+)and soldered the lead. My brother and I worked in the same place as a summer job during most of High School and College too and we handled the pieces. My brother and I used to chop down the long lead channel pieces (8' long) to smaller sizer to be used by the people making the pieces. I remember her hands would be black when she worked at home and she would wash her hands when she was done. So she was exposed to a lot of lead on the skin for many years and has no lead related issues. My brother and I were also exposed and have no lead issues. I wasn't always the best about washing my hands before eating, either!
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Re: a question about Dao Vua.

Post by ChefKnivesToGo »

timos wrote: Mon Nov 28, 2022 7:48 am hey maybe larrin @ knifesteelnerds would tackle this one. seems like a decent topic for one of his articles.
That's a good idea. I'll email him.
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Re: a question about Dao Vua.

Post by FisherMAn1298 »

Marzipan wrote: Sat Nov 26, 2022 7:54 pm thanks for the responses. I put up a post on r/chefknives asking about sleeper brands / makers and mentioned Dao Vua as one of them and a few people responded with hostility. I countered with some reasonable thoughts and while they were thumbs up those posts were thumbs down. how dare I question elitists and rock the boat, LoL!

also, it makes no sense for a US company to import knives with lead when the US is a very litigious country and would likely have their asses sued off them for putting their customer base at risk once discovered.

I know their knives are pretty rough and how sharp and defined their edges are out of box is spotty, but I quite like the rustic look and support an underdog and peoples who are trying to make a living. especially because when the craftsmen are trying to get better at their trade. they're on wha t appears to be generation 4...leaf spring...pipeline...classic v2 and now the 52100.

oh, question about the 52100. can you adjust or redo the heat treatment if you get one that's questionable?
Those elitist drama queens don't know how to have an open dialogue let alone have an open mind about much of anything, they're rude and attack anyone who doesn't agree with them. No matter how many pure facts you lay at their feet they will continue their onslaught unabated without fail. Where are the moderators when you need them? BTW, I got a 240 Gyuto in 52100 and am working on as close to a mirror polish as I can get on it. Once I sanded the surface down a bit she sharpens with ease and produces a very quick, wire like burr. Having lots of fun and she's starting to look beautiful.
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Re: a question about Dao Vua.

Post by salemj »

Thanks for this thread. It is easy for everyone to have an opinion, but it is helpful for people to open their ears and listen to one another and learn from each other. Mark, thanks for making the effort to listen and provide us all with a basis for understanding the nature of things here by sending out product to be tested!
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Re: a question about Dao Vua.

Post by ChefKnivesToGo »

salemj wrote: Wed Nov 30, 2022 10:54 pm Thanks for this thread. It is easy for everyone to have an opinion, but it is helpful for people to open their ears and listen to one another and learn from each other. Mark, thanks for making the effort to listen and provide us all with a basis for understanding the nature of things here by sending out product to be tested!
I agree. I'm interested to know what's in their steel anyways, so I think it will be a good learning experience to test one. Also, we get many customers on reddit and get a lot of positive comments from them daily. The market is growing and there is room for everyone. I haven't heard back from Larrin yet, but I did find this outfit in Illinois that might be suitable to send a knife. They said they could do a optical emission spectroscopy test on it for a $200.

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For those of you that want to check us out there we have a reddit page that is growing nicely since I started it at the beginning of the year.
https://www.reddit.com/r/Chefknivestogo/
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Re: a question about Dao Vua.

Post by taz575 »

I guess I gotta join reddit now! This should be interesting!

I am curious to see what comes back from the lab testing!
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Re: a question about Dao Vua.

Post by XexoX »

Well, that Mr. Mark is on reddit does explain how the "seconds" knives sold out so fast.
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Re: a question about Dao Vua.

Post by Jeff B »

XexoX wrote: Thu Dec 01, 2022 3:15 pm Well, that Mr. Mark is on reddit does explain how the "seconds" knives sold out so fast.
He posted that sale on FB and Instagram too...he definitely got the word out.
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Re: a question about Dao Vua.

Post by ChefKnivesToGo »

Hi guys,

Here is the lab testing results for the daovua leaf spring knife I asked them to analyze.

As expected, no lead.
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Re: a question about Dao Vua.

Post by ChefKnivesToGo »

Here it is again. Not sure if the other one can be downloaded.
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