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Rod oven

Posted: Tue Apr 12, 2011 3:58 pm
by kermdawg
So the more I weld the more serious projects I take on, and my 7018 rods that I keep in a 5 gallon bucket with a bunch of desicant packs aint cuttin it anymore. I dont have the money to buy a rod oven, but I do have an old dishwasher sitting in my garage that I think would convert into a makeshift rod-oven nicely.

Ive heard about people converting refrigerators, so shouldnt be that differant. My question was about the heat. The refrigerators Ive seen just used like a 100 watt lightbulb. What temperature should my makeshift rod oven aim for too keep my rods moisture under control? Secondly, does it have to be kept on 24/7, or only when I'm actually using the rod.

Re: Rod oven

Posted: Tue Apr 12, 2011 5:11 pm
by GWD
I would think that Las Vegas is dry enough most of the year to not worry about moisture in the 7018 rod flux. In Florida or anywhere back east that may be another story.

Put them on a cookie baking sheet in the sun on a day with single digit humidity.

I just use a old extra large electric fry pan. Just make sure the corner-to-corner measure is 14" or whatever your rod length is. It will hold over 5 lbs.

The day before I'm going to use the rod it is heated overnight at about 400 degrees. Then the rod is used hot out of the pan. Seems to work fine.

Re: Rod oven

Posted: Tue Apr 12, 2011 10:31 pm
by Otto Nobedder
7018 is a "low hydrogen" rod. If they absorb moisture, and you then drive it out with heat, you have still defeated the purpose. That is why they are sealed so well when you buy them. You can cook the moisture out of the flux and they will weld fine, but you've still opened the door to hydrogen embrittlement in your weld.

On a jobsite where performance is critical, 7018 should be used within four hours of opening the can (or removal from the rod oven).

Every rod oven I've pulled 7018 from was set at about 275-350 degrees F. (Above the boiling point of water.)

Anything you can do to keep the rod temp well above the dewpoint will help, but you will not be able to economically hold a dishwasher above around 180 degrees, as this is what they are designed to hold (for short periods).

My best suggestion for a rod oven would be to start with a small electric oven, and modify it for size and insulation level. It would be a good hobby project. You can probably buy a small rod oven for far less than the time you'd have in a homebuilt, though. Seriously, how much rod will you have open at a time? The smallest oven I've seen would probably hold 20#.

Steve

Re: Rod oven

Posted: Tue Apr 12, 2011 10:40 pm
by Otto Nobedder
Here's one for $50 that'll hold 5#.

http://www.rodovens.com/products/keen-k5-holding.htm

Steve

Re: Rod oven

Posted: Tue Apr 12, 2011 10:42 pm
by Otto Nobedder

Re: Rod oven

Posted: Tue Apr 12, 2011 11:59 pm
by kermdawg
Ya ive looked at those. I usually buy 5 pound boxes, and at any one time I usually have 4 boxes open, 1 7018 3/32, 1 7018 1/8, and 1 of each 3/32 and 1/8 6011. Right now I keep the rod in the original boxes, with as much plastic on em as possible, desicant pouches inside, sealed up and kept in a 5 gallon bucket. The main reason I ask is because I'm getting some porosity with my 7018 rods and I'm pretty sure its cause they got some moisture in em.

Las Vegas actually gets a great deal of humidity for short periods due to thunderstorms/monsoons. It'll be sunny until noon, then itll pour rain for 15 minutes, than itll be sunny the rest of the day, with the 100 degree plus heat rapidly evaporating the ground water, creating a rather large amount of humidity for a short time, just enough to ruin some rod probably.

Should I rather look at a better means of rod storage then? If I do end up buying a rod oven do I have to have it on 24/7 to keep the rods from getting moisture?

Re: Rod oven

Posted: Wed Apr 20, 2011 7:30 pm
by rickbreezy
I dont think that you have to keep it on all the time, just enough time to de-humidify the rods before use. In an ideal situation, yes, rods would be kept in a rod oven 24/7 and then removed one by one as you use them. But come'on, this is the real world right?

-Rick

Re: Rod oven

Posted: Wed Apr 20, 2011 8:34 pm
by Longshot379
I use a old refrigerator shell with two 100W light bulbs wired in parallel. They ran at half power and keep the refrigerator at a little over 100 degrees. Bulbs last for a long time, usually several years.

Re: Rod oven

Posted: Wed Apr 27, 2011 10:00 am
by nadogail
I think the refrigerator, being insulated, would be superior to a dishwasher for cnversion to a improvised rod oven.

Re: Rod oven

Posted: Wed Apr 27, 2011 11:02 am
by kermdawg
Oh I agree, problem is I got the dishwasher sittin in my garage, and I dont have a frige :) This isnt about which one is superior, Im just wondering if it is capable or if im wasting my time money. if I wanted a real rod oven I would just go by one for 100 bucks or so. Its just a thought I had cause I got this POS dishwasher and dont wanna throw it away and I thought I might have a little project to make it somehwat useful.

Re: Rod oven

Posted: Thu Apr 28, 2011 11:08 am
by nadogail
OKAY, Heating element, thermal switch (thermostat), high temp wire, and a roll or two of fiberglass insulation. I have scrounged insulation from the haul away boxes at remodel projects.

I would imagine in hot weather, they will save you the insulation and load it for you if you bring the crew some cold cokes.

Re: Rod oven

Posted: Thu Apr 28, 2011 11:59 am
by kermdawg
Not a bad idea. Wonder what they would give me for some cold beers :p Thanks nadogail

Re: Rod oven

Posted: Fri Apr 29, 2011 1:13 am
by nadogail
kermdawg wrote:Not a bad idea. Wonder what they would give me for some cold beers :p Thanks nadogail
The beers might get you run off & banned by the boss. Beers can lead to bad judgement and accidents.

Another casualty of our present society seeking to avoid personal responsibility and shift blame.

Re: Rod oven

Posted: Fri Apr 29, 2011 7:27 am
by jpence38
nadogail wrote:
kermdawg wrote:Not a bad idea. Wonder what they would give me for some cold beers :p Thanks nadogail
The beers might get you run off & banned by the boss. Beers can lead to bad judgement and accidents.

Another casualty of our present society seeking to avoid personal responsibility and shift blame.
Yeah Kermdawg, what were you thinking!!!! :o :roll:

Re: Rod oven

Posted: Fri Apr 29, 2011 10:00 am
by kermdawg
Lol, guess Im just a litle old school :p