On Sep 19, 2:55*pm, Jay Pique wrote:
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.)

JP
*************************************************
Also posted to rec.woodworking.

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
fly**** 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.