? for you electrical tech guys

[Graham Cracka]

Hey guys,
I do a little bit of welding on the side and want to make a "rod oven" for storing some of my electrodes to keep the moisture from destroying them. Basically what I want to make is an insulated box with a 100w light bulb in it. My question is, how would I rig up a thermostat and fan or vent to keep the internal temp. around 100-120 deg F.? I want to do this as inexpensively as possible (and as simply). Can this be done with 110v or low voltage? Any input or ideas would be appreciated. I can purchase a commercial one for $1,500, but that is out of the question for just a hobby.

[[JiF]KellysHero]

You could always buy desiccant (granuals) and store the rods in a desiccator.

http://en.wikipedia.org/wiki/Desiccator

What's nice is you can take out desiccant, put it in the oven and drive off the moisture and reuse it. Not sure about the cost effectiveness though.

[Graham Cracka]

You could always buy desiccant (granuals) and store the rods in a desiccator.

http://en.wikipedia.org/wiki/Desiccator

What's nice is you can take out desiccant, put it in the oven and drive off the moisture and reuse it. Not sure about the cost effectiveness though.

That is what I am doing now. I find that it really does not make much difference, versus no desiccant. It may be because I dont use the rods fast enough. I find that after 3 months I need to put them in the oven at 550 deg for a couple of hours (the wife apon that). I figure that I might as well run a light bulb all year 24-7 and use less electric. Thanks for the idea and quick response. I need some help with the electrical side of this project. How could I use (possibly) a 12v computer fan and a household thermostat? Do I need a transformer of some kind?

[Shalghar]

Computer fans will run un 12V DC not AC so you´ll need no transformer but a small Power supply with DC output.
This wont solve your problem though. Using heat to drive humidity out just increases the chance of corrosion, when some humidity remains and additional airflow punps in more and more "contaminated" - humid - air.

You could try to get your compartment flooded with nitrogen, in addition to good desiccant (unused silicagel or you might try kitchen salt mixed with rice). The problem with the salt/rice is some kind of corrosion with some metals generally at direct contact but in some cases even without direct touch, all being dependant on temperature, airflow and humidity (again;) ).

My choice would be some kind of filter paper, coffee filters would be too airtight though, arranged like two layers of paper with salt/rice in between. This filter section must be the only way for air to flow.

Then you could rig up the bulb without the fan, as thermal contraction will move the air anyhow so all you might need is a thermoswitch. This could either be realised the electronic way (PTC or NTC with thyristor or transistor/relais in series for example) or simply by a bimetal switch. You could even try out some mechanical timers, though this would be quite unprecise.

Well anyhow, i hope that some ideas might prove useful. have fun .

[[JiF] General WarHawk]

Why not just store them in a good old can, like the one some toys come in, or gourmet crackers. It's pretty airtight, and as long as it doesn't get submerged in water it won't rust.

[Graham Cracka]

Thanks for the ideas and tips guys. I found these http://www.goldenroddehumidifiers.com/index.htm and I think I am going to give one a try. They should be safer than a light bulb.