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Dascro
01-19-2008, 07:05 AM
I searched the forum and found some good information on storing electrodes, but wanted to ask a more specific question related to 7018 electrode storage.

If 7018 rods are kept in the plastic container they came in and stored in a heated basement, can I just use them as is, or should I heat them first? I would be using them for hobby and farm use, so no critical service.

And while I'm asking questions ;), is that a generally acceptable way to store my other rods (6013 and 7014) too?

Thanks for any help or guidance.

Dave

k.a.m
01-19-2008, 07:49 AM
at my home for my shop i store my 7018s in the closet in my bedroom my other rods i store over my refigerator in an unused cabinet, i always store my 7018s by themselves.

Knowledgeworker
01-19-2008, 01:04 PM
Moisture is the big killer of the 7018's. Each brand of electrode has their own reccomendation, but they all boil down to keeping them dry. I usually keep mine in the original container until right before I use them. I do try to keep some of those activated carbon-silica gel packs in the containers that have been opened.

Just my 2 cents worth.

Jim

TOMWELDS2
01-19-2008, 03:49 PM
I keep 7018 in a rod tube..never had a problem. When doing a 'structural' type weld, i buy a fresh pack.

Dascro
01-19-2008, 07:23 PM
Thanks for the responses.

Sounds like I'm OK storing them in the original container in our dry, warm basement.

Dave,

6010
01-20-2008, 10:45 AM
I noticed an experienced welder where I used to work do this to get the moisture out of 7018. We had a rod oven where the rods were kept but occasionally he would be using the portable welder and need to used some rods that were stored in the open for some time that remained stored on the welder. He would take some lineman's pliers and break off a little of the rod coating at the end and then stick the end to the metal and let the rod really heat up. HE would then Wait a little while and then start his weld. I can't imagine much moisture being in the rod after he heated it like this. Does anyone else do this ?? I know you wouldn't want to use this method in production welding but he was getting pair by the hour ;)

enlpck
01-20-2008, 11:03 AM
This method of 'drying' isn't a good idea. It takes time to get the moisture out of the flux (it is chemically bonded in-- the chemist's term is that the flux forms a hydrate, like concrete), and getting it hot enough to do it fast will damage the flux in other ways. It is not reliable, and is not recommended.

jerryo
01-20-2008, 10:30 PM
The 7018 rod is designed to operate with little or no moisture in it. Moisture (h2o) when heated turns to gas and will cause porosity in the weld. 7018's are designed to weld w/o causing porosity, therefore they must be kept in a heated oven at around 300 degrees when not in use. New sealed cans of rods can be used right from the can for a few hours but must be returned to an oven within several hours. Some 7018-xx rods are more moisture resistant and can remain out of the oven for longer periods (hours) than other types of 7018's. This procedure of keeping the rods in an oven is for code specific welds.

For just general welding the 7018 rod can be used, as long as its dry, for most welds that can tolerate some porosity and do not need to be full strength. I have done bend tests on 3/8 " plate with rods from room storage and they bent just fine. I have done general welding with 7018 rods from a 50 lb. can that has probably been open for years with no problem. These were not code welds though. I ran some beads with a few 7018 rods that had been left out in my carport all summer, rust was showing through the flux, but the beads looked great. Probably full if internal porosity though.

The procedure of keeping these rods in a box with a light bulb on or shorting them out to heat them up before use is basically useless in driving any moisture from the rod if code type welds are to be made.

Sparkeee24
01-21-2008, 08:28 AM
Howdy Howdy!

I thought the lightbulb box was great for MAINTAINING 7018 fresh dry rods, in their original state, as in freshly opened can, but that once taken out for more then 15 minutes, or 15 seconds here in the great northwet, that you would have to use a real rod oven to bring them back to dry. I would think that the lightbulb heat would be fine for dry stroage, but not for re-drying. I may be wrong. I do know, that there are several different types of heat settings and time frames neaded for both redrying wet rods as in rainy day structural welding, and re drying open air sunny day (several day old "dry" rods). But I don't have those numbers memorized.

I have a 7ft red tail boa with a 150 watt ceramic heat bulb for, and I've been thinking about how fast the water evaporates in her tank. Iv'e also thought about building a small rod box, where all the wasted heat is transferred to her tank. Since I have the heat setup anyway. The idea is to keep them warm and dry, unfortuneately, it's a wstefull process just using juice like that.

To me, what most people like, is the way 7018 runs, and most don't use it for it's metalurgical properties, even though they may be trying to use it for metalurgical reasons cause they've heard it's better. Especially since so many 7018 welds are not metallurgically up to standards, simply because they are not dried correctly. I use 6010 instead. I just got better with it, and practiced. Theres a reason why 6010 is so accepted in the industry. (not that 7018 isn't) but I think people who use 7018 cause it runs nice, but have had an opened package for months, probably don't have as sound a weld as 6010 rod been stored the same way would produce, even if it's uglier.

6010, 6013, 7014, 7024... these can be stored in plastic containers at room temp, indefinately. so I've read anyway. Good luck! Brian Lee Sparkeee29

enlpck
01-22-2008, 04:04 PM
Howdy Howdy!

I would think that the lightbulb heat would be fine for dry stroage, but not for re-drying. I may be wrong. I do know, that there are several different types of heat settings and time frames neaded for both redrying wet rods as in rainy day structural welding, and re drying open air sunny day (several day old "dry" rods). But I don't have those numbers memorized.

I have a 7ft red tail boa with a 150 watt ceramic heat bulb for, and I've been thinking about how fast the water evaporates in her tank. Iv'e also thought about building a small rod box, where all the wasted heat is transferred to her tank. Since I have the heat setup anyway. The idea is to keep them warm and dry, unfortuneately, it's a wstefull process just using juice like that

A lightbulb won't do it. The issue isn't condensation and evaporation, it is hydration. Wen water condenses and evaporates, there is a physical change, but no chemical change. Hydration is a chemical process, wherein (oversimplified) the water becomes chemically bonded into the structure. This is how concrete sets up, and this is how the flux on 7018 get moisture. It will still look 'dry' even when the flux has enough moisture in it to make the rods very tough to run. The flux will take in moisture at temperatures up to about 100C (212F) , and will not release it until temps of about 320C (about 600F), hence the storage requirements being store at about 250F, and the rebake being about 700 to 800F

Porosity isn't the only concern, or the major one in most cases. In the arc, the water molecules will be broken down to hydrogen and oxygen, and the hydrogen is very soluble in the liquid metal, and is pretty soluble in the high temperature structures (such as austenite), but not very soluble in low temperature structures (such as ferrite). As the material cools, the hydrogen can lead to cracking as it comes out of solution between the grains. Worse with higher strength steels, thicker base metals, some alloy steels, higher cooling rates (among other things, lower cooling rates decrease the hardness of the metal, as well as permit more time for the hydrogen to diffuse out of the metal... diffusion rates are higher at higher temperature)
(see http://files.aws.org/wj/supplement/Park2-02.pdf, for example)

crawler
01-23-2008, 11:18 AM
Since my oven won't get up to 600 degrees, can I use my propane powered BBQ grill to heat up the 7018 rods before use?

enlpck
01-23-2008, 02:44 PM
Since my oven won't get up to 600 degrees, can I use my propane powered BBQ grill to heat up the 7018 rods before use?

No. Several reasons:
1) the temperature needs to be controlled
2) one of the byproducts of burning propane is water vapor. As the temp of the rods comes up, they will hydrate, and unless you hold at the rebake temp for an appropriate time, the water will be there forever.

You don't need to heat fresh rods before use... you only need to store them heated if they will not be used within four to eight hours of opening the can. Those that won't be used in that time frame should go right into the oven. If the work you are doing is noncitical (not structural, not to a code, all low carbon steel with relatively light welds), it isn't a major concern to store them heated.

I work in a code shop, and we keep the rods in the oven. The oven will hold several hundred lbs of rod and take about 100 to 200W (average) to maintain heat once temperature is achieved. Obviously, opening the door, putting in fresh (cold) rods, etc increase this. We do a fair bit of welding (non-code) with rods that arn't properly stored... they never go back in the oven once removed, so we have a seperate storage for these rods for general (non-code, non-critical, like padding up a bucket, tacking on brackets for electrical boxes, etc) use, and they are fine. Just don't use them for work where there may be impact loading, low temp service, etc, or for code-regulated welds.

crawler
01-23-2008, 10:45 PM
No. Several reasons:
1) the temperature needs to be controlled
2) one of the byproducts of burning propane is water vapor. As the temp of the rods comes up, they will hydrate, and unless you hold at the rebake temp for an appropriate time, the water will be there forever.

You don't need to heat fresh rods before use... you only need to store them heated if they will not be used within four to eight hours of opening the can. Those that won't be used in that time frame should go right into the oven. If the work you are doing is noncitical (not structural, not to a code, all low carbon steel with relatively light welds), it isn't a major concern to store them heated.

I work in a code shop, and we keep the rods in the oven. The oven will hold several hundred lbs of rod and take about 100 to 200W (average) to maintain heat once temperature is achieved. Obviously, opening the door, putting in fresh (cold) rods, etc increase this. We do a fair bit of welding (non-code) with rods that arn't properly stored... they never go back in the oven once removed, so we have a seperate storage for these rods for general (non-code, non-critical, like padding up a bucket, tacking on brackets for electrical boxes, etc) use, and they are fine. Just don't use them for work where there may be impact loading, low temp service, etc, or for code-regulated welds.

Thanks for the explanation. I have some 7018 rods that have been stored in the garage and they seem to work okay.. I'll make sure they're used for non-critical stuff.

JTMcCracken
01-24-2008, 10:49 AM
Billions and billions of tons of 7018 have been used successfully over the years without storage in a rod oven. Usually in a single pass or limited thickness welds.

But when you get into heavier sections that require many passes, or higher strength materials, you can have much more probability of having crack problems related to hydrogen pickup so code work requires proper storage and like several people have said that doesn't include a fridge with a light bulb, it means a real rod oven. And non code work with those same materials/welds will call for proper storage as well.

JTMcC.

thingy
01-25-2008, 08:09 PM
low/hy rods,,,,storage,,always a good question,,,so,,,aws code says to store them at 250 degrees minimum,[I think],,some say this is too hot,,some say store them hotter,,,always something,,I know that not all 7018's are created equal,,,sometimes the coating on a batch will be not uniform,,some rods burn better it seems,,but the bottom line is if they run good,no porosity,etc,,than thats a good thing,,[they might not be low/hy any mores],,use 6010 and you ain't got to worry about it,,,thingy

cpurvis
01-26-2008, 09:11 AM
Here's a dumb question...why store them at all?

Buy what you need to do the job, discard what's left over.

New job comes up, buy some more.

There's gotta be a reason why this won't work.

Bob the Welder
01-26-2008, 10:03 AM
Economics. It's much cheaper to buy 50lbs. of 7018 than to buy 3lbs. Also much more convenient. I've never bought less than 10lbs. at a time.