Vacuum rod dryer

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Most of my welding is not stick, so my rods sit for a long time. I can't see affording to run a rod oven for years just to store them. So I played with the idea of vacuum sealing them, either in bags or heavy duty rod holders. The bag system ( like a food storage) probably doesn't create enough vacuum to remove existing moisture, but might keep good rods dry. Using a vacuum (air conditioner recharge pump) on a heavy tube container would definitely keep rods dry, although it may not be enough to suck out existing moisture. Another high vacuum source is manifold vacuum on an engine. On deceleration  you can pull 29" of vac and lock the storage tube.     So I guess the question is, how dry is dry enough? Has anyone else tried vacuum storing rods between usesage? How would I know if they are dry enough? Is it overkill, should they be fine just in the sealed container, maybe a bag a of decateciant or rice thrown in?  So... How dry is dry enough, especially for low hydrogen rods?
Reply:An addition to your idea....If you heated the rods while vacing them would help tremendously.Build a steel rod holder...2" threaded pipe, both ends capped, drill and tap a hole in it for a shredder valve.Put on a vac pump and heat with a torch
Reply:Yeah, my rod goes dry in a heavy sealed plastic one with a shrader now. I pump it down past 29" for a while to remove any moisture. I just don't really know if it even works. The rod holders do hold vac, the bag system is questionable. Heat would probably help too. But is this too much work, I mean if you buy a 50 lb box of rod, it's just wrapped in plastic.
Reply:Originally Posted by blackbartYeah, my rod goes dry in a heavy sealed plastic one with a shrader now. I pump it down past 29" for a while to remove any moisture. I just don't really know if it even works. The rod holders do hold vac, the bag system is questionable. Heat would probably help too. But is this too much work, I mean if you buy a 50 lb box of rod, it's just wrapped in plastic.
Reply:But wouldn't even a very low watt bulb in an insulated container be worth while and cheap to run?
Reply:If you just wanted to keep moisture out you could seal the rods in argon. The gas that comes from the gas company has no moisture in it. That's going to be better than a vacuum. Also you don't need a pressure container to store it in. You could basically put the rods in a plastic bag, purge argon in it so the argon will replace the air and then tie a knot or two on the bag.Other high pressure gases would also work.BTW, a lot of food is stored this way, usually in nitrogen because it's dirt cheap. But the primary issue with food is to keep oxygen away.Last edited by Pete.S.; 04-08-2013 at 07:03 AM.
Reply:Originally Posted by blackbartYeah, my rod goes dry in a heavy sealed plastic one with a shrader now. I pump it down past 29" for a while to remove any moisture. I just don't really know if it even works. The rod holders do hold vac, the bag system is questionable. Heat would probably help too. But is this too much work, I mean if you buy a 50 lb box of rod, it's just wrapped in plastic.
Reply:Never thought of argon. I called them schrader valves, but the ones I experimented with were simple gas valves with AC pump fittings. I could use a light, but I have some specialty electrodes 25 years old or so, I was trying to make a cheap alternative ( maybe that's why some of mine came in boxes) and I'm mainly thinking about the rods I store in my portable rig.     I was told by some AC techs a vacuum pump probably wouldn't pull all existing moisture out even if it pulled for 30 minutes or so.  Although storing them in the vacuum may or may not work. The heavy plastic rod holders seemed to hold full vacuum without crushing.     I just thought it would be an inexpensive idea to have small containers on your truck that after using you just put the under manifold vac before you stored them again.     So, is it that important? Is simple room temp dry good enough? I may have tried to make something more complicated than it really is. Maybe starting off dry then storing them in th small container wit Rick, argon, or a decassient is enough protection.
Reply:I've heard of using vacuum-seal bags to store rods, but vacuum alone will not dry them. The reason that drying rods requires heat above 500*F is that the moisture is chemically combined with the flux, and only sufficient heat will remove it.Rod-Guard canisters cost $6-7 on-line. Just get new, dry rods and put whatever you don't use right away into the Rod-guards. Simple.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:I use rod guard type O ring containers now.  It's probably plenty of protection, just a thought that crossed my mind about the vacuum.  AC techs use full vacuum to pull moisture out of AC systems before recharging them. So my mind went bizerk hoping to make that type of product even better.
Reply:I once made a small vaccuum chamber out of a 4 inch iron pipe nipple with 2 screw on end caps.  I pit a stainless+brass ball valve on one wne to evacuate through.  Pulled it down with a mechanical rotary vane pump (welch)  to about 29 inches (all it would pump)I also had a vac gague plumbed into the other cap.  I came back 2 or 3 weeks later and it hadnt leaked a bit.  Weld some legs on the bottom out of bolts-  I would try using some 110V heating tape arround the body and then wrap it with fiberglass insulation.  I didnt know you had to getit to 500 degrees though.T
Reply:What's your max vacuum?Blackbart29 inches?
Reply:I can get over 29" with an AC pump. My experience is even when you get close to 30" it is hard to remove visible moisture. But I would think that putting already dry 7018 rods in a container, then charging it at 29+" vacuum would keep them as dry as an oven. You can almost get 29" of manifold vac if you use a check valve on max deceleration. I am at 1200' elevation so 30" is to much to ask. In my opinion it would be a cheap alternative to running an oven for months.
Reply:My memory is full vacuum is 29.9" at sea level, but there is more to it than that. AC techs are using micron gauges now and I don't quite get why it's that critical. When I do a car I go to full vac for an hour and assume the moisture is gone. A good AC tech just shakes his head when I say that. I've played around with vac systems quite a bit for other fluid evac systems and sewage trucks.
Reply:In an AC system that uses mineral oil such as R12 or R22, removing the water is mostly to remove non condensable materials from the loop.  In a system that uses PAG oil, water contamination, on even a tiny scale, can cause real damage (R410a comes to mind as a common newly used system where a micron gauge comes in handy).
Reply:Moisture does create havoc in a vacuum but bart, seriously, this is overkill.  A good idea but overkill. It seems to me that some weldors on this site can dry their rods when they strike an arc.
Reply:Wonder how well a pvc pipe container would work for vacuum storage....hmmmmm
Reply:Pvc would work fine.  Basically I have found that most things that hold pressure will hold full vacuum as well.  And it might be overkill, but that was my question in the post. How dry is dry enough?  It is easy to throw a days worth of rods in a plastic rod guard, or PVC tube and give it a quick vacuum charge.  When you study other threads on this site, many are saying low hydrogen electrodes must be stored in an oven.  I would think storing them in a vacuum would be free and easier. Again, I'm talking full vacuum (29"+)  Again,the post on purging the rod guard with argon sounded like a good idea as well. I know throwing a cell phone in rice absorbs moisture if it gets wet, so maybe thats just as good too.    So it boils down to the first question again, how dry is good enough for 7018 for everyday welding? Most welders I know store them in a dry place, but not an oven.
Reply:I would vac pac half of the 50# for long term storage and about ten pounds for short term . My rod oven draws about 6 amps or 0.750KW/hr. It adds up to more than the 7018 is worth based on my usage if I leave it on. I usually turn the oven on about 2 hours before I weld but usually forget to plug the darn thing in.
Reply:So "preheating 7018" is just about as good as storing it warm? I use 50 lbs of 7018 in 5-10 years.
Reply:Originally Posted by blackbartSo "preheating 7018" is just about as good as storing it warm? I use 50 lbs of 7018 in 5-10 years.
Reply:If my oven at 6amps draws 0.750KW per hour at 15 cents per hour, then it cost about $900 per year to leave it on. A 50# box of LINCOLN 7018 is about $100 to $150 more less. They dont come hot from the LWS but if your making money from those low hydrogen rods, then , by all means, leave the darn thing plugged in. I would stick with the vacuum packing idea. Just my two cents.
Reply:Note that the 6 Amp draw is a maximum. Once the oven warms up, its thermostat will cycle on and off to keep it at the set temperature. The average draw is probably around 1 or 2 Amps depending on the oven.Still not economical for the hobbyist or occasional user.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:I dont think it has a thermostat. It just warms up and keeps going. I think it only gets to about 280F on the IR thermometer. Its great if you dont have to pay for the electric. Figure $80/ month x two months is about the cost of a 50# box of 7018.  An oven that has a themostat would probably cost alot more than buing new rod.
Reply:Using a 60 watt incandescent bulb: One hour  of use is 1.44 kWh Take your electric utility Kwh cost  Or  use an average of  say - -  $0.10 per KwhSo If I can do the math ~ ~ ~ ~  a doubtful proposition on the best of days ~ ~ ~ ~ ~ then:$0.10 x 1.44 kWh = $0.144   per hour A light bulb is pretty cheap to runHey~!! It's a hobby. It's not supposed to make sense~!!Originally Posted by RaulUsing a 60 watt incandescent bulb: One hour  of use is 1.44 kWh Take your electric utility Kwh cost  Or  use an average of  say - -  $0.10 per KwhSo If I can do the math ~ ~ ~ ~  a doubtful proposition on the best of days ~ ~ ~ ~ ~ then:$0.10 x 1.44 kWh = $0.144   per hour A light bulb is pretty cheap to run
Reply:Originally Posted by MinnesotaDaveI could be wrong -
Reply:Vacuum is free and once a 10 lb tube is evacuated it can be carried around till needed. I just don't really know if it works. How would you know?  I know it holds the vacuum, but Is there an obvious difference when welding with a perfectly dry 7018 and one that has a small amount of moisture in it?  Anyone else have thoughts on the argon idea ? If I used SMAW every day it would be one thing, but I don't use the process often.
Reply:Originally Posted by blackbartMy memory is full vacuum is 29.9" at sea level, but there is more to it than that. AC techs are using micron gauges now and I don't quite get why it's that critical. When I do a car I go to full vac for an hour and assume the moisture is gone. A good AC tech just shakes his head when I say that. I've played around with vac systems quite a bit for other fluid evac systems and sewage trucks.
Reply:For me it comes down to if a person actually needs 7018 then new ones should be bought for the job and/or use an oven - my .02, no offense intended.For mild steel 7018 is not needed so an easier rod to store would work out better.  I like 7014 because it runs similar to 7018 and no oven needed. I like papaharley's idea of backfilling with argon through a schrader valve - cool But, Argon can contain moisture (I recently learned that from this video.)[ame]http://www.youtube.com/watch?v=8fjZOkWm0PQ[/ame]I have never used rods from an oven - but I have used super old 7018 for practice and they weld good but no longer have low hydrogen properties. Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Originally Posted by papaharley03diffusion oil pump,
Reply:I was hoping for an answer in english..........
Reply:Originally Posted by blackbartI was hoping for an answer in english..........
Reply:I'm sure their wouldn't be any google hits.  I'm trying it just because I can't see why it wouldn't work.  I just don't know how to tell. If it's just a matter of keeping them from moisture, again, rice or a decaseant should work in my mind.  Also like one suggestion, a shot of argon or nitrogen might work.  I did build a vacuum chamber once to try to dry radios when our employees dropped them off of marinas.  It did not work, and I still don't know why.  Vacuum loweres the boiling point of moisture to room temp so I would think it would vaporize and be evacuated at the vac pump. A top notch AC tech told me why, but it still didn't makes sense to me.
Reply:What about putting rods under vacuum in a container as you said, and maybe test them in a month with one of those moisture detectors like they use around home inspections.For personal use like mine, it would not matter. For code welding say xray quality, rods have to be kept in an oven and the oven has to be inspected from time to time. They weld on high pressure boiler tubes at work and this is how it is done there.They even have an oven in the shop labled "not for code welding" because it does not follow under this criteria but is okay for non code type welding.
Reply:Originally Posted by blackbartI'm sure their wouldn't be any google hits.
Reply:How do you know when these things are done? Do I need to stick a fork in until it comes out dry and fluffy?   Attached Images
Reply:Yeah, I think I should have a shiskabob party the day before using 7018. I'm thinking my high vacuum idea sucks,Yuk yuk! Those rods look medium rare, but I broke a tooth trying the last batch.
Reply:Originally Posted by polarred21How do you know when these things are done? Do I need to stick a fork in until it comes out dry and fluffy?
Reply:LOL, great thread. And some creative vacuum/argon storage ideas. Hobbyist, 10# of 7018 is about a 10 year supply. New, it burns great. But even stored in a Rod Guard, it absorbs enough moisture that it wont run properly when I need it. Spits, sticks, goes a little ways, sticks again. Almost unusable. Baking it for 4 hours at 400 degrees in the oven (after wife goes to bed...) seems to restore normal performance. But a year later when I finally use it again, its picked up moisture, same problems.So we'll experiment. Will bake my current supply, then vacuum package it into "single servings", maybe 10 rods per pack, sealed packs will go back in the Rod Guard. Results posted in about a year...Hobbyist - At what point is a "hobby" out-of-control?
Reply:Just buy it in 10# quantities, and bake it when you need it.If you're doing something really critical, just crack open a new can.IW Local 580 NY, NY
Reply:Simple terms:If the flux coating absorbs water like a sponge does, a vacuum would remove the moisture. It might take quite some time as the vacuum being pulled will be the 'worker' doing the boiling.  This would show up as not being able to pull as low of a vacuum on the container full of damp rods as you can pull on an empty dry container.  Over a few hours the vacuum would eventually get down to the same level as the dry empty container as the water is removed.  For AC systems you pull a vacuum, then wait 15 min and see if it has gone up. If it has, then there is still moisture in there evaporating and reducing the vacuum.If the flux coating absorbs water via a chemical attraction like some of those odd chemicals from the chemistry lab back in college, chances are it takes heat to remove the moisture. Once heated to remove the moisture, long term storage in a vacuum should maintain the same level of dryness though.I suspect since there is a specified procedure to dry rods that involves 500 odd degress for however long that the coating is hrdroscopic (http://en.wikipedia.org/wiki/Hygroscopy) and a vacuum to dry them will not work, but would be fine for long term storage of already dry rods.miller syncrowave 250hobart handler 140home made 400 amp engine driven in progress...
Reply:My main idea was not to remove moisture from contaminated rods.  I Just thought I could make a moisture free storage system by precharging it with a full vacuum in a rodguard type of plastic container. I still think it would work, but feedback seems to disagree. It seems like it would be a lot cheaper than an oven.
Reply:If vacuum just maintains the moisture free state, and any leak conpromises that state - then wouldn't it be simpler to just purge a rod container with argon/co2 and store in that?
Reply:Bart.   You said rice works for a cell phone, why won't it workk for 7018?
Reply:Originally Posted by DeuceTrinalIf vacuum just maintains the moisture free state, and any leak conpromises that state - then wouldn't it be simpler to just purge a rod container with argon/co2 and store in that?
Reply:Originally Posted by polarred21How do you know when these things are done? Do I need to stick a fork in until it comes out dry and fluffy?
Reply:If you guys spent as much time welding as you guys spend worrying about whether you welding rod is wet or not you should really be some real good welders. If a box of 7018 sets out to the air like mine does and you dont use it all up fast enough then you wont be in practice enough to run a good pretty bead with it anyway. So who cares. If you only use a few rods at a time then leave them lay on the shelf. If you want to seal up something then seal up the nickel and aluminum. The spendy ones. If you are a good welder then the price of rod aint that much.
Reply:Welderskelter, I don't do that much stick. I was just thinking once I opened a can of, whatever, I could put it a rod guard type container, charge it with vacuum, and it should be the same as leaving it in an oven.  I'm talking about dry rods, just trying to keep them dry for a year or so.
Reply:I don't see a need to keep them in an oven unless you are welding something that requires dry rods. When you need dry rods buy a 10lb can.If you are a hobby welder, you prob don't really need dry rods. JMOAirco Ac/Dc 300 HeliwelderMillerMatic 200 (stolen)Miller Maxstar 150STLMiller AEAD200LE (welding and generating power) Hobart MIG