Kiln drying STEEL?

[Jay Pique]

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.

JP

************************************************* Also posted to rec.crafts.metalworking

[dpb]

Don't see why not if he's not counting on the torch flame doing something--certainly the kiln heat would be sufficient for surface moisture.

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[Keith nuttle]

Could he be burning the milling oil from the steel before he paints it? That would be the quickest way I could think of to get rid of it completely.

I don't think the blow torch would be hot enough to remove the stress from the metal in the recent fabricated piece.

[Tom Veatch]

My thoughts are that if it's moisture you're trying to get rid of, just set 'em out in the open sun for a couple of hours. Refinished some lawn furniture recently. Used a pressure washer to knock off loose paint. Left them out in the sun for a couple of hours to dry, set them in the shade for a couple of hours to cool off, sprayed them. No problems.

But, I don't think it was moisture the guy with the blowtorch was after. Like another poster surmised, it was probably mill oil he was burning off.

Tom Veatch Wichita, KS USA

[Jay Pique]

Now that's interesting. The whole story is this. One of our guys and a metalworker built a table for a client. It's made from pieces of hot-rolled steel that had further been cold bent into curves. They welded together the parts, sanded it and then applied a coat of beeswax. And it rusted. So now the metalworker thinks that if he heats the steel really well it will evaporate trapped moisture and then they'll seal it out with beeswax. (I know, I know....) In any event, since it sounds like it's not moisture they're burning off anyhow, the whole question of whether a kiln would work is pretty much moot. (Obviously wouldn't be hot enough to burn off oil, either.)

Now for the real question - how do we prevent this table and chairs from rusting? Not much response from the metalworkers .

JP

[dpb]

Jay Pique wrote: ...

Has to be an impervious coating of some sort.

Depends on what look is wanted, cold bluing could do or powder coat or even painting.

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[John Martin]

Not much response from the metalworkers because they're laughing too hard about the moisture "trapped" in the steel.

Paint it.

John Martin

[Lee Michaels]

"Jay Pique" wrote

Now for the real question - how do we prevent this table and chairs from rusting? Not much response from the metalworkers .

**********************

My comments on working with metal.

Hot rolled steel is a lower quality steel and it will rust in a second. Particularly if you weld it. Cold rolled steel is smoother and does not rust as easily. If I absolutely did not want it to rust, I wirebrushed it with an angle grinder and immediately primered it. You can get primers for both clean metal and rusty metal.

Steel tends to rust if heated anyway. One secret to a good paint job is similar to applying any kind of finish on any kind of surface. That is to make the surface absolutely clean and bare. And if it sits for a day or two, it will not be clean and pristine anymore.

I used at least two angle grinders with wire brushes on them. I then used a hand wire brush. I then used some emory cloth. Then I got the primer on it.

I used to make gym equipment. I was always being offered hot rolled round stock for cheap. The cold rolled stuff was at least half again as much and in some diameters, twice as much. The hot rolled crap would pit, rust and generally degrade before your eyes.

Any piece that went out with hot rolled stock came back and had to be replaced. Other shops actually gave me a bunch of the hot rolled stock. I used it to build jigs, etc. I never used it personally in any of the good stuff I built.

One good reason to make good welds is that there isn't any pits or cracks for the rust to grow in. Which is why all welds were ground if necessary. There is little need to grind a good weld. And the rust starts growing right next to the weld where the steel was heated.

Rust is the enemy of any metal piece that must be smooth and/or must look good. Enough care in building it and a good clean up before painting helps a lot.

HTH

[Morris Dovey]

Clean 'em, polish 'em, gold-plate 'em. Apply a heavy coat of epoxy paint to protect the gold. :-)

Suggest they use stainless for the next set.

[Steve Lusardi]

Not much response from the metalworkers because they're laughing too hard about the moisture "trapped" in the steel.

Paint it.

John Martin

[J. Clarke]

To how to keep it from rusting, Rust-Oleum works quite well. If you want something better, any automotive paint shop should have a wide range of systems intended specifically to work on steel and can match just about any color. Or you could go with the full MIL-SPEC system with MIL-T-8514 etch, MIL-P-23377 epoxy primer, and a MIL-PRF-85285 topcoat. If it has to have a metallic appearance then paint it with a metallic paint.

If it is _all_ steel with no plastic or wooden or other parts, or if it can be dissasembled and all the non-steel parts removed, and if you can find a plating shop with a tank set up that is big enough to hold it then you could have the whole thing chromed (or plated with another metal of your choice, but don't count on anything but chrome being available without a significant set-up charge). This is going to be an expensive option, but will leave you with a durable shiny metal surface.

Oh, and if the "metalworker" is one of your employees, you need to have a long talk with that boy.

[Bored Borg]

On Sat, 20 Sep 2008 03:08:39 +0100, Jay Pique wrote (in article ):

Simple. Galvanize it. (or hot-dip it in zinc )

Powder coat? Red lead paint? I presume, however, that we want a "bare metal" industrial look to this otherwise we'd not be doing this kiln-drying and furniture polish thing? so galvanizing it is.

Or nickel plate if it's a smooth polished look that's wanted- don't forget to specify over copper plate though else it'll get woodworm...

Or keep it in a pure nitrogen environment if that's simpler, 'cos rust is caused by phlogiston escaping into impure atmospheres and contamination from bodily fluids umm..

Remake everything in stainless steel?

Alumininuminum?

Wood?

meanwhile - beeswax? really? Where did these guys go to school? Oh......

I'll get me coat.

[Jay Pique]

Could we fabricate the whole chair or table, then take it someplace to be dipped? Or do we have to assemble it from pre-dipped steel - in which case I gather we'd have rusting issues at the welded joints, right?

I can't wait to unload a ration of crap....errr...."inform the metalworkers" on Monday!

Thanks all.

JP

*********************************** Just scorping the seats.

[Stuart]

It is normal to dip the complete assembly.

[J. Clarke]

You need to call around to your local plating companies and find out what size tanks they normally have set up. I'd go with chrome over galvanized--hot dip galvanize isn't all that pretty a finish and plated zinc isn't very hard. Nickel is _very_ tough (it's used as protection on aircraft propellers) but doesn't stay shiny without regular polishing. How large a piece can be handled depends on how big a tank is available.

If the tanks are large enough they should be able to do the whole table, although they may need to do some fiddling to get the electrodes placed for even coverage. Welding up from precoated steel means that you've lost the protection at the welds. A better option might be to make it in several subassemblies that can be bolted together--note--if you're using tapped holes, either tap them _after_ plating or plug them for plating.

This really sounds like you might be ahead of the game to use stainless.

[Steve Lusardi]

Jay, There is also another option, which may also be possible in your area. Not only can you hot dip in molten zinc, you can sandblast and metal spray with zinc. It is not as robust as hot dip, but allows the piece to be then powder coated in any color of your choice. Of course you can can also powder coat after hot dip as well. You will find that all 3 processes are very inexpensive and compete cost wise with quality paint, when all material and labor costs are included. Steve

Could we fabricate the whole chair or table, then take it someplace to be dipped? Or do we have to assemble it from pre-dipped steel - in which case I gather we'd have rusting issues at the welded joints, right?

I can't wait to unload a ration of crap....errr...."inform the metalworkers" on Monday!

Thanks all.

JP

*********************************** Just scorping the seats.

[mac davis]

Hell.. Do a flashback and have it chromed.. lol

mac

Please remove splinters before emailing

[EXT]

Lacquer.

Now that's interesting. The whole story is this. One of our guys and a metalworker built a table for a client. It's made from pieces of hot-rolled steel that had further been cold bent into curves. They welded together the parts, sanded it and then applied a coat of beeswax. And it rusted. So now the metalworker thinks that if he heats the steel really well it will evaporate trapped moisture and then they'll seal it out with beeswax. (I know, I know....) In any event, since it sounds like it's not moisture they're burning off anyhow, the whole question of whether a kiln would work is pretty much moot. (Obviously wouldn't be hot enough to burn off oil, either.)

Now for the real question - how do we prevent this table and chairs from rusting? Not much response from the metalworkers .

JP

[Stealth Pilot]

now where did you get that silly idea from???

name the propeller that uses a nickle coating????

Stealth Pilot

[J. Clarke]

Hamilton-Standard 54460 and 24PF are two examples that use a bonded-on sheath over the outer portion of the blade leading edge. You can see them on a 54460 at

The new 8-way that replaced the 54460 on the E2 is another--you can see the sheath clearly at Those sheathes are plated on a mandrel then removed from the mandrel, trimmed, and bonded to the blade. There is also a process involving plating nickel over conductive rubber--the rubber prevents cracks in the nickel from propagating into the blade. Don't recall where all that was used--some 54H60 variants for hovercraft use had it and I recall vaguely that it was used on the 63E60 in a similar application--it's been a long time and the 63E60 was past its prime when I was working at Hamilton.

If you ever fly on a propeller-driven commuter airliner, look closely at the blades and you'll see the sheath unless it's been painted over, which it's not supposed to be except along the edges. Carbon black in the paint, which is electrically conductive to bleed static off the blade, tends to corrode the nickel.

As to how I happen to know this, my first job out of college was as a project engineer in the Blade Group at United Technologies Hamilton Standard and my area of specialization was erosion protection.