Heating rods - specifically 7018, Ovens, Etc?

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Originally Posted by FlyFishn

So lets take a 5lb box of 7018 that is not sealed (either not sealed or has been open and exposed to air, either way).

1. What is a proper temperature to bring the rod to?
2. What is a proper time to leave the rod at said temperature?

As an aside to #2 above - the oven temperature can't dictate the rod temperature immediately. So if the oven is at, say, 350deg and the rod is at ambient (we'll call it 75deg) - when you stick the rod in the oven at 350deg it is going to ramp up from 75 to 350 over time. Does that ramp up time detract from #2 above? So lets say it takes 5 minutes for the rod to heat through to 350 degrees and it needs to sit at 350 degrees for 30 minutes. Is that 35 minutes time in the oven? Or 25 minutes at 350deg with the 5 minute warm-up = 30 minutes?

Do the answers to 1 and 2 above depend on weld specs/design specs? Does code call them out? Or are there multiple codes that call for multiple procedures?

Lastly -

Is a 350 degree temperature adequate to "reheat"? If so - how long should the rod soak at that temp? 1 hour? 2 hours? 12 hours/over-night? Is there a time limit so as to not get brittle flux?

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FlyFishn,

Even though everyone is right about you not needing to worry about it, I'll take a stab answering from my opinion as an 'advanced hobbyist', only because if you are a [mechanical?] engineer, then we have a similar mindset in the sense that we at some point had to solve a lot of similar problems in academia.

1. You don't know because you don't know how much moisture (if any) has been absorbed into the flux). You have no way of accurately determining just how bad the rod has or has not been compromised.
2. Cannot be answered because of the answer to question 1.

As for your aside-question, I'd say that the temperature ramp-up time is not included in the requisite time-frame specified to hold a rod at.

Here is some good reading if you can handle it.

Minimizing HIC-HAC In Steel Using Low Hydrogen Electrode for SMAW (International Journal of Engineering Science and Technology
Vol. 2(5), 2010, 1211-1220)

The danger posed by “Hydrogen” in welding un- and low alloyed steels (Böhler Welding)

Weld Cracking - James F. Lincoln Foundation

Control of Hydrogen Assisted Crackng In High Strength Steel Welds (International Journal of Engineering Sciences & Research)


That being said, if you want a rod oven, this place seems to have some at decent prices.

look, your a perfectionist/meticulous (by evidence of your projects/threads), and it will bother you if you dont get one, so i think u shoud buy a used one (and dont worry about its dents/appearance). i myself store the rods in an old fridge w/ a 1" hole on top, and an incedescent light bulb at bottom. then i put them in a capped pvc pipe to transfer them to the job. when i get there the first thing i do is plug in a "10lb phonix rod oven 300 degree". i dont like/do the higher temp rebake either.
99% percent of the time, the inspector is satisfied w/ that. and i'm not saying that 100% correct, and i'm not looking to argue about it, and ill continue doing it that way.

there is/was a member here from bay area calif, but moved outa state, (i cant think of his name right now), that was into basic/crude expermints. he would weld up duplicate testing plates, hit them w/ hammers etc, and count the amount of blows it took to break weld from rod that saw an oven vs. rod that didnt. the rod that didnt, took less blows to break according to him. he was a nice guy, i wonder where/what happened to him?

so keep your eyes peeled for a rod oven

The North Ridge earthquake they check a lot of welds. Any one that did not follow code had at least fines.

Welding codes where change too.
I am glad I followed the rules and codes. My company name was on all my work happy days no knock on my door.

Dave

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Originally Posted by Popeye an old miner

Thats fine if thats what you want to do.

On those construction jobs in the power plants they said the same thing, no welding in the rain preheat evrything to 250 or something like that keep the rods in an oven yadda yadda yadda, when they get behind and that superintendent and that project manager thinks they are gonna lose their bonus for not gettin a certain phase done early all those rules and regs goes in the ****can, you will weld in the rain and if the weld you are gonna do is wet and a weed burner or torch isnt handy weld it anyway, and this here rod can you gave me it aint workin so what just keep it plugged in anyway and make it look good.

As for me in the here and now doin what I do and having done it most of my life since I was a kid I have a pretty good idea what works and what dont work. Ive welded 4inch thick dragline lips on buckets, lips on loaders moldboards on dozers and probly 500 tons of wear plate any where from 1/2 thick to 2 inch thick over the years and never had a failure and never used a rod oven and welded in the rain snow when it was 10 below zero and colder. I did preheat religously.

Im not braggin about just tellin you what I know and what works for me, and I do care or I wouldnt be havin the work that I still have today with the same people over the years.

But this kid is way out of line sayin that no one cares when they tell him to just burn the rod and forget it. Number 1 he needs to learn how to weld before he can rightly say no one cares and number 2 he needs to get a weld hood on his noggin and learn what a puddle is supposed to look like and what it supposed to do before he turns welding into rocket science inside his head...learn the basics first before you try to analyze and argue with folks that been doin this probly before his mommy and daddy got puberty

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Originally Posted by yellowfin

There are a lot of things with welding stuff, gun upgrades, high end knives, etc. that can be summarized with the following: when you get to the point where you REALLY need it, there will be no doubt or need to ask. Short of that the answer is usually no.

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Nailed it.

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Originally Posted by 123weld

look, your a perfectionist/meticulous (by evidence of your projects/threads), and it will bother you if you dont get one, so i think u shoud buy a used one (and dont worry about its dents/appearance). i myself store the rods in an old fridge w/ a 1" hole on top, and an incedescent light bulb at bottom. then i put them in a capped pvc pipe to transfer them to the job. when i get there the first thing i do is plug in a "10lb phonix rod oven 300 degree". i dont like/do the higher temp rebake either.
99% percent of the time, the inspector is satisfied w/ that. and i'm not saying that 100% correct, and i'm not looking to argue about it, and ill continue doing it that way.

there is/was a member here from bay area calif, but moved outa state, (i cant think of his name right now), that was into basic/crude expermints. he would weld up duplicate testing plates, hit them w/ hammers etc, and count the amount of blows it took to break weld from rod that saw an oven vs. rod that didnt. the rod that didnt, took less blows to break according to him. he was a nice guy, i wonder where/what happened to him?

so keep your eyes peeled for a rod oven

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CEP (Washington) did all the break tests and posted results but might have been on a different forum. He hasn't been on this forum for awhile so hope he is OK.

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Originally Posted by Welder Dave

CEP (Washington) did all the break tests and posted results but might have been on a different forum. He hasn't been on this forum for awhile so hope he is OK.

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Jeez, now that I think about it, you're right. Shoutout to CEP! Anyone heard from him?

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Originally Posted by 123weld

look, your a perfectionist/meticulous (by evidence of your projects/threads), and it will bother you if you dont get one, so i think u shoud buy a used one (and dont worry about its dents/appearance).

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Thank you for replying and the info.

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Originally Posted by 123weld

i myself store the rods in an old fridge w/ a 1" hole on top, and an incedescent light bulb at bottom. then i put them in a capped pvc pipe to transfer them to the job. when i get there the first thing i do is plug in a "10lb phonix rod oven 300 degree". i dont like/do the higher temp rebake either.
99% percent of the time, the inspector is satisfied w/ that. and i'm not saying that 100% correct, and i'm not looking to argue about it, and ill continue doing it that way.

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I won't start an argument or discussion, but just to make a statement - that is precisely in-line with the lower end of the "board" of methods I've read about. If it takes close to 600deg to break some of the hydrogen bonds in the flux on a "reconditioning cycle" then that amount of hydrogen would always be present in the rod flux at any temps under. As to how much - no idea. I'm sure somewhere some place, organization, individual, testing lab, etc, etc has studied that. But that is the root of my post - I don't consider the fridge/light bulb method "proper" based on what I've read so I'd like to find a "proper" method.

I don't even think, right now, that a "portable rod oven" that stores 10-15lbs of rod is proper. It might be proper as part of a system, but by itself I am not sure that it is - they don't get up to close to 600deg, I don't believe (maybe there are some that do, haven't looked all that hard).

Quote:

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Originally Posted by 123weld

there is/was a member here from bay area calif, but moved outa state, (i cant think of his name right now), that was into basic/crude expermints. he would weld up duplicate testing plates, hit them w/ hammers etc, and count the amount of blows it took to break weld from rod that saw an oven vs. rod that didnt. the rod that didnt, took less blows to break according to him. he was a nice guy, i wonder where/what happened to him?

so keep your eyes peeled for a rod oven

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I've heard of the "hammer tests" and maybe I saw a youtube video or two that described that type of test and results.

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Originally Posted by Oscar

FlyFishn,

Even though everyone is right about you not needing to worry about it, I'll take a stab answering from my opinion as an 'advanced hobbyist', only because if you are a [mechanical?] engineer, then we have a similar mindset in the sense that we at some point had to solve a lot of similar problems in academia.

1. You don't know because you don't know how much moisture (if any) has been absorbed into the flux). You have no way of accurately determining just how bad the rod has or has not been compromised.
2. Cannot be answered because of the answer to question 1.

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Thanks for the "stab" Oscar. Good stuff.

Your 1 and 2 are somewhat humorous answers, but 100% "correct". They just aren't very descriptive.

I'm sure that does factor in to what the recommendations/codes are on rod storage - in that they likely take the high end of starting moisture content because if they do then moisture contents under that would be included in the (I imagine) higher heating times. So if a rod that is at 15% saturation takes 20 minutes vs a rod that is at 93% saturation taking 52 minutes, if they spec 1 hour the 15% rod is going to be "dry" just as well as the 93%.

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Originally Posted by FlyFishn

Your 1 and 2 are somewhat humorous answers, but 100% "correct".

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Oscar got a star for his correct answers from the teacher! Yay!

OP, shouldn't you be shooting welding instructional videos for youtube by now?

What is point of using a using costly low hydrogen rod if do not heat the rod to drive out the H2O.

Dave

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Originally Posted by FlyFishn

Thanks for the "stab" Oscar. Good stuff.

Your 1 and 2 are somewhat humorous answers, but 100% "correct". They just aren't very descriptive.

I'm sure that does factor in to what the recommendations/codes are on rod storage - in that they likely take the high end of starting moisture content because if they do then moisture contents under that would be included in the (I imagine) higher heating times. So if a rod that is at 15% saturation takes 20 minutes vs a rod that is at 93% saturation taking 52 minutes, if they spec 1 hour the 15% rod is going to be "dry" just as well as the 93%.

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Lincoln Excaliber E7018 H4R. The H4 designates a diffusible hydrogen level of <4.0 per mL/100g weld material. (There are H8 & H16 specifications also, but the H4 seems most common & meets the other two specs). R - Designates that it will meet low moisture absorbing limit in 80F/80% humidity for not < 9 hours.

Electrodes with the R designation removed from sealed packaging/rod oven are supposed to be good for 9 hours with out re-heating per code.

Electrodes without the R designation are good for 4 hours with out re-heating per code.

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Originally Posted by smithdoor

What is point of using a using costly low hydrogen rod if do not heat the rod to drive out the H2O.

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Even if it absorbs some H2O sitting in an unsealed, unheated container, 7018 still makes welds that are a lot tougher and more ductile than any other rod I've found.

There are also low moisture pick up 7018 (often says MR, moisture resistant)) but of course it is more expensive. No shop stores rods anywhere near 600 deg's. They take new rods and put them in an oven at 200-250 deg's. depending on how critical of work they do. Shops that don't really require an oven often lower the heat a little because they are easier to handle. Hot rods burn a little nicer. Most of the time if rods are used within 15 or 20 minutes they're fine. Critical jobs will call for having a portable 10lb. rod oven at the weld source to take rods from. A 7018 weld with non heated rods is still the strongest weld of all mild steel rods by a longshot, even if it has a little porosity. This is just getting really redundant. You have to learn how to weld before need to worry about doing code quality welds. To learn how to weld you need to have the hood down a lot more than up.

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Originally Posted by FlyFishn

Thanks for the "stab" Oscar. Good stuff.

Your 1 and 2 are somewhat humorous answers, but 100% "correct". They just aren't very descriptive.

I'm sure that does factor in to what the recommendations/codes are on rod storage - in that they likely take the high end of starting moisture content because if they do then moisture contents under that would be included in the (I imagine) higher heating times. So if a rod that is at 15% saturation takes 20 minutes vs a rod that is at 93% saturation taking 52 minutes, if they spec 1 hour the 15% rod is going to be "dry" just as well as the 93%.

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You need to look up some of the scientific papers written on this subject.
In them you will find the charts equating: relative humidity - to time - to affect on rods - to diffused hydrogen in the weld.

After you read them until your eyes are blurry for a few days, 99% of your esoteric questions will be answered I believe. ;)

There is no data for H2O in 7018
Almost all rod has a limit to the H2O
If want to use 7018 do so
If want to use 7018 right heat per spec.

Dave

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Originally Posted by Kelvin

Even if it absorbs some H2O sitting in an unsealed, unheated container, 7018 still makes welds that are a lot tougher and more ductile than any other rod I've found.

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Originally Posted by Welder Dave

There are also low moisture pick up 7018 (often says MR, moisture resistant)) but of course it is more expensive. No shop stores rods anywhere near 600 deg's. They take new rods and put them in an oven at 200-250 deg's. depending on how critical of work they do. Shops that don't really require an oven often lower the heat a little because they are easier to handle. Hot rods burn a little nicer. Most of the time if rods are used within 15 or 20 minutes they're fine. Critical jobs will call for having a portable 10lb. rod oven at the weld source to take rods from. A 7018 weld with non heated rods is still the strongest weld of all mild steel rods by a longshot, even if it has a little porosity. This is just getting really redundant. You have to learn how to weld before need to worry about doing code quality welds. To learn how to weld you need to have the hood down a lot more than up.

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Yep, we only use Lincoln Excalibur 7018 MR rods keep them in sealed containers. We have a small rod oven but only use it for critical work when required and in that case we open a new container and preheat in the oven.

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Originally Posted by smithdoor

There is no data for H2O in 7018
Almost all rod has a limit to the H2O
If want to use 7018 do so
If want to use 7018 right heat per spec.

Dave

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Curious what welder qualification(s) you have. Journeyman, pressure, etc. 7018 is the strongest mild steel rod by a longshot in any condition other than being completely soaked in water and all the flux came off. There is a lot of truth in the statement that a bad(within reason)7018 weld is still better than a good 6013 or 7014 weld in a high stress weldment.

Let's see a table on 7018 with H2O AKA no heating the rod.

There tables when the rod is heat over 250°F

Dave

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Originally Posted by Welder Dave

Curious what welder qualification(s) you have. Journeyman, pressure, etc. 7018 is the strongest mild steel rod by a longshot in any condition other than being completely soaked in water and all the flux came off. There is a lot of truth in the statement that a bad(within reason)7018 weld is still better than a good 6013 or 7014 weld in a high stress weldment.

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To the OP:

Look at Lincoln holding, and reconditioning specifications.

Look at AWS holding, and reconditioning specifications.

The internet has it all my friend, all's ya gotta do is reach out and grab it.

You hold yer rods at 250*, and keep them in a hotbox when they're transferred from the oven to the jobsite.

"R" designated rods keep humidity at bay for extended periods after removal from a sealed container. If you're working in extreme humidity, and the work is fairly critical, use a hotbox to keep the rods dry. I have a little Phoenix that I use during days when the dew point is in the 70's.

Hydrogen cracking occurs when the weld is made. It doesn't become evident immediately in many cases............it sometimes manifests itself up to 48hrs after the weld is completed.

Preheating, which effectively reduces the cooling rate, is the best way to avoid hydrogen cracking. Interpass temps are also critical. The idea is to relieve stress during the cooling process. Elevate the temp prior to welding, and you've reduced the time the temperature comes down after the weld is completed. The slower cooling rate keeps the weld from contracting too fast, which reduces overall stress.

That's it in a nutshell.

Unless ya enjoy dragging it out in a long discussion, this is about all you have to know.

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Originally Posted by smithdoor

Let's see a table on 7018 with H2O AKA no heating the rod.

There tables when the rod is heat over 250°F

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A comparison would be interesting, and it seems like just the kind of test CEP would have done with his BFH. Paging CEP to the white courtesy phone! :waving:

A search of the forum using CEP's name might even turn up something.

Yes the rod is hot, but welding work is very hot.
You may want to wear gloves getting the rod out.

This what used can be found at Lincoln in DC
https://store.cyberweld.com/lincoln-...oln%20Shopping

Any one does not heat the is wasting money .
Rod that is not low hydrogen is has chemical/flux to remove the hydrogen.
Low hydrogen rod does not have this chemistry/flux.

If do not want to heat the rod use a rod like 7014 or 6012

In high humidity all rod needs to be heated too.

If you doing farm repair how cares

Dave

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Originally Posted by farmersammm

To the OP:

Look at Lincoln holding, and reconditioning specifications.

Look at AWS holding, and reconditioning specifications.

The internet has it all my friend, all's ya gotta do is reach out and grab it.

You hold yer rods at 250*, and keep them in a hotbox when they're transferred from the oven to the jobsite.

"R" designated rods keep humidity at bay for extended periods after removal from a sealed container. If you're working in extreme humidity, and the work is fairly critical, use a hotbox to keep the rods dry. I have a little Phoenix that I use during days when the dew point is in the 70's.

Hydrogen cracking occurs when the weld is made. It doesn't become evident immediately in many cases............it sometimes manifests itself up to 48hrs after the weld is completed.

Preheating, which effectively reduces the cooling rate, is the best way to avoid hydrogen cracking. Interpass temps are also critical. The idea is to relieve stress during the cooling process. Elevate the temp prior to welding, and you've reduced the time the temperature comes down after the weld is completed. The slower cooling rate keeps the weld from contracting too fast, which reduces overall stress.

That's it in a nutshell.

Unless ya enjoy dragging it out in a long discussion, this is about all you have to know.

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Originally Posted by smithdoor

Any one does not heat the is wasting money .
Rod that is not low hydrogen is has chemical/flux to remove the hydrogen.
Low hydrogen rod does not have this chemistry/flux.
.
.
In high humidity all rod needs to be heated too.

Dave

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I would respectfully disagree with you, non low hydrogen rods do not remove the hydrogen with chemistry/flux.
If it did, low hydrogen rods wouldn't be needed.
Also, if you weld with a non low hydrogen rod (or any rod that is left out of a heated storage box) and drop the weld into mineral oil, you will see the hydrogen bubbles escaping the weld.

https://www.youtube.com/watch?v=H4aSkugbcaA

Interesting video, Dave, thanks for posting.

What puzzles me is how the hydrogen comes out of solution from the steel after the steel has cooled and hardened.
After the steel cools and hardens, I would have expected the hydrogen to be "frozen in place" like CO2 bubbles in the ice cores drilled out of ancient glaciers.
Are there microscopic "pores" or "tubes" in the weld deposit from which the hydrogen escapes?

I'll add a couple more questions. Is it actually hydrogen that is observed? Is what we see related to the water quench,which might speak to the condition of the surface of the welds?
Proper recommended treatment of electrodes can seldom be wrong.

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Originally Posted by Kelvin

Interesting video, Dave, thanks for posting.

What puzzles me is how the hydrogen comes out of solution from the steel after the steel has cooled and hardened.
After the steel cools and hardens, I would have expected the hydrogen to be "frozen in place" like CO2 bubbles in the ice cores drilled out of ancient glaciers.
Are there microscopic "pores" or "tubes" in the weld deposit from which the hydrogen escapes?

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Quantum tunneling is the natural conclusion ;)