Drying hot-rolled steel in kiln for wood?

I saw a guy going over some hot-rolled steel bar with a blow torch
recently. When I asked what he was doing he said he was evaporating
the moisture from it. Sure enough - I watched it myself. The process
is that he'll fabricate the chair, blow torch the whole thing, then
rub beeswax all over it. Seems pretty labor intensive. I'm wondering
if we couldn't just put the whole dozen chairs in our wood kiln for a
few days and achieve the same effect. Any thoughts?
(Note: our kiln has a dehumidifying unit, but only reaches temps of
maybe 100F.)
Also posted to rec.woodworking.
Reply to
Jay Pique
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When you initially point a torch at cold metal the water vapor from the combustion may condense on the surface, and then as the metal heats the moisture visibly evaporates. Unless he left the chair outside in the rain or dew there is no real moisture to evaporate off.
What the blacksmith is doing (whether he know it or not) is getting the metal hot enough to melt the beeswax to allow it to flow in to all the cracks and crevices of the chair leaving an attractive and to some extent rust inhibiting finish. I don't think your 100F kiln will get the chairs hot enough to do the same thing.
Reply to
Carl Boyd
I work with high vacuum stuff, so there's some truth to it, but not enough to matter. Every material used for construction has some degree of porosity to the surface, and high vacuum draws out all moisture (the worst culprit in high vacuum) embedded into the pores and surface texture of the steel. The bigger issue using a flame is all most torch fuels have water as a byproduct of combustion, so he's actually putting moisture back on the surface of the steel, and as a matter of fact, he's driving it deeper. If he wants to dry the steel, he needs to first clean it thoroughly with solvent to remove the oils, then heat it in a dry atmosphere. The hotter it gets the faster you'll dry it, but 100F will be fine as long as you're willing to wait awhile. How long I have no idea.
The problem is that you have to immediately, and I mean immediately, seal up the surface, which will be difficult unless you're willing to spend time in the same environment while you're doing the sealing, as bringing it out into the atmosphere will result in immediate deposition of water onto the surface from condensation (including your breath.) This is sort of extreme, but I have to pick around for the flyshit sometimes, so I thought it might be worth throwing out.
When car bodies (I don't do bodywork, so this is second and third hand knowledge) get stripped to bare metal, the surface has to be wiped down with solvents and immediately coated with primer, one small section at a time. You will inevitably trap some moisture in the metal, but if there's not enough moisture and iron getting together, you're not going to cause any damage to the paint bond line.
And now for some information you most likely won't care about, but I felt like being wordy: When most new high vacuum assemblies are completed, there's a process of baking out that may be necessary depending on the vacuum level. A high vacuum is drawn with all pumps going full blast and the entire assembly is heated up to drive out moisture, hydrocarbons, and other contaminants. When heat is applied, the vacuum takes a huge dive when all the molecules are pushed out. Molecules flying around in high vacuum systems are bad, and you don't want molecules of water or whatever getting in the way of high power electron or proton beams (like the Large Hadron Collider) as they have a habit of putting beam particles in places you don't want them.
Reply to
Carl M
If he was pointing out the moisture to you, he was putting you on. Other posters have told you why. I use beeswax regularly to finish "traditional" products that I have when I demonstrate to the public. There are at least two ways to do it: 1. Heat the metal just enough to melt the beeswax and cause it to flow evenly onto the work. I'd usually rub it with a rag during this process. It leaves the finish pretty much the same color as it was before I started. 2. Heat the metal up to soemwhere between 300° and 500° or so, F. Then rub the piece of beeswax onto the part. At this temp, some of the volatiles in the beewax start to vaporize. This is really evident if the part is hot enough so the beeswax ignites when applied. Anyway, this "richens" the carbon content of the beeswax. That raw carbon is "baked on" to the part along with the liqufied components of the beeswax that didn't volatilize and produces what I call "black blacksmith paint".
Pete Stanaitis -----------------------------------------------
Jay Pique wrote:
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