Homemade welding rod oven

[Fastjack]

Hey fellas, I need a welding rod oven, but instead of buying one I am thinking about making one.

Here is my idea... I have a large non-working microwave oven that I am thinking about using. The inner dimensions of the oven are 16.5" x 16.5" x 9.5". My thoughs are to simply remove all the existing electronics and install a small (150 watt) heat lamp.

Does this idea sound practical?

 

[schmuck]

If you find or build something that is insulated it would work better, but there is nothing wrong with your basic idea. The reason for an insulated box is if you plan to leave it plugged in constantly, it would allow you to drop the wattage of your heat source and save you $$$$$.

 

[Fastjack]

Thanks for the reply schmuck. Do you think it would work if I lined the inside of the oven with those thin, foil coated insulation panels that are normally used in house construction? I would lose about 2 inches of my overall inside diameter but I might be able to reduce my heat lamp to a 50 or 60 watt.

 

[schmuck]

I'm not quite sure what your talking about, but I know a typical welding rod oven will run somewhere around 250-300 degrees. It needs to be hot enough to remove the water/moisture. I know a fiberglass-based product would be fine, but as I said earlier I'm not sure what you are referring to. Not sure if this helps ...

 

[Gary from Muleshoe]

I have heard of people using and old refrigerator and wiring the light so it stay on all the time and just putting a 100 watt bulb in it. Does this work well enough to keep rods dry? I am thinking of doing this with an old dorm style fridge from work that has quit working.

 

[Flurette Farm]

What you are talking about using really won't help much.
I think you'd be better off watching for a yard sale or swap meet and picking up a camper refrig.
One point being is it doesn't have to be that hot just warm and well sealed...

 

[LOU from WI]

Just an idea, you could use a damp chaser,(thats the name of them) they make them various size lengths and wattages.They use them in acoustic pianos,closets, for removing moisture and keeping an even humidity in the unit.I've sold quite a few(in piano tuning and repair business).You can order them thru a piano tuner or maybe online.Just thought it might help.No need for a lightbulb, and they have a box you can set the humidity level with,(extra cost),but you wouldn't have to worry about fire and have a 5yr guarantee.
Lou & Victor

 

[Anonymous-0]

Probably don't need a heat lamp, just a 100 watt bulb(maybe even less) unless you're doing critical X-ray work. One thing you need to do is drill a small hole about 3/8 or 1/2 inch it, near the top, so that any moisture has a way to escape. If you look at a Gullco oven, you will see a hole in the door. I think a microwave could work pretty good for a rod oven. Not as big and clumsy as an old fridge. Low hydrogen( xx18) are the only rods that need an oven. 6010 and 6011 actually need a little moisture or they won't work properly. 7014 just need to be dry. 6013 aren't even worth buying.LoL Dave

 

[Anonymous-0]

You don't want a rod oven sealed up. Where's any moisture supposed to go? Dave

 

[Tim Casbolt]

I found that my old refrigerator got way too hot with even a 40 watt bulb, and the bulbs would burn out fairly quickly. (Every few months) Installing a line voltage thermostat solved the problem. Kept it at 70 or so, and the rod was always plenty dry enough for my projects.

 

[guido]

Hello fastjack,
I had one at work but at home i needed to dry just a few rods. I made one with a piece of 2" pipe, capped one end. I put in the rods, and heated the pipe with the torche. If you cover the top as well it retains the heat if you fill the pipe full of rods. Of course the pipe would have to be taller then the rods. Worked for me on a pinch!
Guido.

 

[guido]

Hello schmuck,
Its more like 400 Degrees F. but who's counting.
Guido.

 

[Puddles]

Just a little more detail!

If you’re going to do code work you should follow this! AWS D1.1:2006 :

A5.1 is carbon steel electrodes for SMAW, A5.5 is low alloy electrodes for SMAW. Plain E7018 is an A5.1 electrode.

Clause 5.3.2.1 states that the electrodes must be transferred directly from the hermetically sealed container into a storage oven maintained at 250°F min.

Electrodes must be rebaked after exposure to the environment. Per clause 5.3.2.4, A5.1 electrodes must be rebaked for at least two hrs between 500° and 800°F. A5.5 electrodes must be rebaked at least one hr between 700° and 800°F.

Back to clause 5.3.2.1, electrodes can be rebaked only once and electrodes that have gotten wet shall not be used.

Note that the baking temperatures are way above that required simply to vaporize water... Low-hy electrode coatings are very hygroscopic; they have a very high tendency to absorb moisture. People talk about adding desiccant bags to opened containers, but what makes you think that the desiccant bags are more hygroscopic than the flux? Look at all the surface area the rods have...

That's D1.1 code, and if you are doing D1.1 code work then you should be following these rules. Whether or not you are required to work per D1.1 you should do a little reading about cold cracking, also called hydrogen cracking. Learn how about the conditions that induce cold cracking and how use of low-hydrogen electrodes is one of several tools for preventing cold cracks. That way you can make an educated decision about low-hydrogen electrode storage and determine the requirements for your application.

 

[Anonymous-0]

They don't need to be 400 deg. They are hot to hold even with welding gloves though. You take them out and put them in a rod holder right away so you don't burn your hands. I think you're supposed to use them within 20 minutes from removing from the oven. You can buy smaller portable rod ovens that can be plugged in right where you're working, so you don't have to keep going back for more. Dave

 

[Puddles]

7018's are changed out every 4 hours on code jobs, 8018's every 2 hours, 9018's every hour and 10018's every 1/2 hour. :wink:

 

[RodinNS]

I guess it could work OK.
I just use an old 15 cu ft fridge. A 25 W bulb wired to run steady is sufficient to keep it warm and dry. I started with a 100W but quickly found out it was too hot.
It may be that the rods like to be 400 degrees but personally I'd be worried about the risk of fire in having cardboard boxes and such cramped into a PVC fridge or microwave at 400 degrees. Something is going to melt or burn... so tone it down to 25 W or so for safety's sake. You'll still need to change the bulb every couple of months tho.


Rod

 

[Anonymous-0]

Bottom line.most of us never do any xray or code work so we dont need a rod oven.Power used would be costly for an individual.I do wonder why hydrogen isnt burned up in the arc.

 

[Anonymous-0]

I couldn't remember, maybe it was 2 hours? A lot of places prefer if you keep them in a portable oven right beside you so they stay hot all the time. Rods are taken out of the box when stored in a rod oven. I'm glad they don't have to be 400 deg., you'd need some really thick gloves just to take them out of the oven. 250 deg. is plenty hot. The very first welding job I got, I had to do a job test. We never needed an oven in school so when the foreman told where the rods were I darn near burned my hands getting them. Ouch. Luckily they kept their oven cooler than 250 deg. or I'd probably still have blisters. LoL Dave

 

[Fastjack]

Thanks to one and all for the comments, I have learned a litte from each of you!

My microwave is completely made out of sheet metal -- both the outside cover and inside stove body. I completely disassembled the microwave and removed all the existing electronics.

In the area of the oven that contained all the former electronics I drilled a one inch (1") hole into the oven area itself and installed a light fixture. I, then, completely insulated the microwave -- between the outter metal cover and the inner metal oven area. I used half inch insulation panels and sealed all the cracks with metal duct-tape (used for heating and AC ducts). I did, however, leave a small vent hole at the top for mosture evaporation. In the light fixture I installed a 60 watt heat lamp.

I plugged it in and left it one all night and then checked the tempature the next day. The tempature was just a little over a 120 degrees.

My "new" rod oven cost me $9.00 -- for the 60 watt heat lamp -- and it will hold about 70 pounds of rods. It is definately not up to code standards and I will not pretend that it is, but I am hoping that it will help protect my monetary investment in rods by keeping them dry until I have a chance to use them. If not, I have learned from the experience and it only cost me nine bucks.

 

[Fastjack]

You are very correct, most of us do not do code work. Never-the-less, we all invest money in the rods we buy and want to keep them in good shape until we need them.

Also, hydrogen can be a cause of both porosity in the weld bead and even subsurface cracking. Most of the hydrogen is burned out from the high temperature of the arc but if your rod has too much mosture in it or your base metal is too cold the hydrogen will be trapped or absorbed into the heat-affected ares next to the weld. This "produces a condition of low ductility known as hydrogen embrittlement" (Principles of Industrial Welding, pp. 6-4 & 5). In short this causes tiny cracks under the weld bead and/or in the toes of the weld.

Because I know this I should probably go ahead and spend the money for a real rod oven. But since I don't do code work (at least not as of yet), I just want to protect my rods from possible moisture contamination until I need to use them.

 

[Anonymous-0]

I keep my rods in plastic tubes with screw caps.Most rod is kept in the attic over the kitchen.100 degrees in summer and 50% humidity in winter.I dont use 7018 much and there havent been any weld failures on farm equipment Ive built in 45 years.All my welding is done outside.I keep my rod dry and have no problems.

 

[Puddles]

Fastjack I think your makeshift rod over is going to work great! :wink:
I worked the majority of my career in bridge construction. I can’t tell how many times I had to pour water out of a can of 7018 because a carpenter type left the lid to the gang box open. All I would do after cursing their first-born :lol: was install the rod in the electrode holder stick the rod to the beam, (no arc) and let it warm up. Then start welding. Now this was only while welding what is called falsework, which is supports for the concrete forms. I’m sure you’ve seen the spaghetti of iron that is placed under a concrete bridge during the building process. I would never do this little trick with code work or in a testing situation! For the average guy all 7018 has to be is warm to the touch to weld comfortably.

 

[eastexan]

Good to know!
Thanks, Puddles.

 

[Anonymous-0]

Checked rod oven electrical use.An oven that holds 15 pounds uses 1200 watts per hour.This would cost 20 cents per hour 5 bucks a day.150 bucks a month.As Ive said only a company can afford to run a rod oven.My wood burning cook stove would be the best way to dry rods.Looks like the old Home Clarion is the best rod dryer going.