Kiln drying STEEL?

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

On Sat, 20 Sep 2008 03:08:39 +0100, Jay Pique wrote
(in article
<7a773144-9f47-4c0c-a2ac-e77c8b41eeb3@z66g2000hsc.googlegroups.com>):


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

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.

On Sep 20, 4:04=A0am, "Steve Lusardi" <[email protected]> wrote:
> It's called hot dip galvanizing. It has been around a long time, it is
> inexpensive and works very, very well.
> 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.

On Sat, 20 Sep 2008 08:51:52 -0400, "J. Clarke"
<[email protected]> wrote:


>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.
>

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

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

Stealth Pilot

On 20 Sep, 12:34, Jay Pique <[email protected]> wrote:

> Could we fabricate the whole chair or table, then take it someplace to
> be dipped? =A0

Here's a worst-case example: lots of thin strip, hot-dipped
afterwards. =A350 (minimum charge) to do a couple of them (or a few
more)

http://jarkman.co.uk/catalog/furnitur/suchair.htm

You can't chrome plate over zinc though

Stealth Pilot wrote:
>
> name the propeller that uses a nickle coating????
>
> Stealth Pilot

I've seen lots of polished spinners, but no polished props.

Jay Pique wrote:

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

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.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Lacquer.

"Jay Pique" <[email protected]> wrote in message
news:7a773144-9f47-4c0c-a2ac-e77c8b41eeb3@z66g2000hsc.googlegroups.com...
On Sep 19, 9:23 pm, Tom Veatch wrote:

>
> 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.

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 <grumble>.

JP

In article
<0808f9c3-40a7-468b-b2e9-d9b2eaa38124@x41g2000hsb.googlegroups.com>,
Jay Pique <[email protected]> wrote:
> 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?

It is normal to dip the complete assembly.

--
Stuart Winsor

For Barn dances and folk evenings in the Coventry and Warwickshire area
See: http://www.barndance.org.uk

On Sep 19, 10:08=A0pm, Jay Pique <[email protected]> wrote:
> On Sep 19, 9:23=A0pm, Tom Veatch wrote:
>
>
>
> > 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.
>
> Now that's interesting. =A0The whole story is this. =A0One of our guys an=
d
> a metalworker built a table for a client. =A0It's made from pieces of
> hot-rolled steel that had further been cold bent into curves. =A0They
> welded together the parts, sanded it and then applied a coat of
> beeswax. =A0And it rusted. =A0So 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. =A0(I know, I know....) =A0In 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. =A0(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? =A0Not much response from the metalworkers <grumble>.
>
> JP

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

Paint it.

John Martin

On Sep 19, 9:23=A0pm, Tom Veatch wrote:

>
> 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.

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 <grumble>.

JP

dpb wrote:
> 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.
>
> 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.
>
> --
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.

"Jay Pique" wrote

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

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

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

On Fri, 19 Sep 2008 14:52:48 -0700 (PDT), Jay Pique
<[email protected]> wrote:

>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.

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

On Sat, 20 Sep 2008 04:34:21 -0700 (PDT), Jay Pique <[email protected]>
wrote:

>On Sep 20, 4:04 am, "Steve Lusardi" <[email protected]> wrote:
>> It's called hot dip galvanizing. It has been around a long time, it is
>> inexpensive and works very, very well.
>> 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?
>
Hell.. Do a flashback and have it chromed.. lol


mac

Please remove splinters before emailing

On Sun, 21 Sep 2008 04:57:52 -0400, "J. Clarke"
<[email protected]> wrote:

>Stealth Pilot wrote:
>> On Sat, 20 Sep 2008 08:51:52 -0400, "J. Clarke"
>> <[email protected]> wrote:
>>
>>
>>> 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.
>>>
>>
>> now where did you get that silly idea from???
>>
>> name the propeller that uses a nickle coating????
>
>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 http://www.flickr.com/photos/goldorak/417313975/.
>The new 8-way that replaced the 54460 on the E2 is another--you can
>see the sheath clearly at
>http://www.flickr.com/photos/kensaviation/1896504667/. 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.
>
>

alright you got me there :-)
hovercraft props!!!!

I dont recall seeing the leading edges you mention on commuter turbo
props but I'll believe you.

most props are forged 2025 aloominum with an anodised surface
hardening. the polished prop effect is achieved by wearing off all the
anodising and polishing the remaining aloominum.
the leading edge treatments I can recall are more like icing cuffs or
polyurethane tapes.

seriously though I do believe you on the hovercraft props.

Stealth ( Hovercraft props!?!?) Pilot

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.

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.

--

Jay Pique wrote:
...
> Now for the real question - how do we prevent this table and chairs
> from rusting? Not much response from the metalworkers <grumble>.

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.

--

It's called hot dip galvanizing. It has been around a long time, it is
inexpensive and works very, very well.
Steve

"John Martin" <[email protected]> wrote in message
news:[email protected]...
On Sep 19, 10:08 pm, Jay Pique <[email protected]> wrote:
> On Sep 19, 9:23 pm, Tom Veatch wrote:
>
>
>
> > 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.
>
> 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 <grumble>.
>
> JP

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

Paint it.

John Martin

Jay Pique wrote:
> On Sep 19, 9:23 pm, Tom Veatch wrote:
>
>>
>> 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.
>
> 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 <grumble>.

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.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Jay Pique wrote:
> On Sep 20, 4:04 am, "Steve Lusardi" <[email protected]> wrote:
>> It's called hot dip galvanizing. It has been around a long time, it
>> is inexpensive and works very, very well.
>> 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?

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.

> I can't wait to unload a ration of crap....errr...."inform the
> metalworkers" on Monday!
>
> Thanks all.
>
> JP
> ***********************************
> Just scorping the seats.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

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

"Jay Pique" <[email protected]> wrote in message
news:0808f9c3-40a7-468b-b2e9-d9b2eaa38124@x41g2000hsb.googlegroups.com...
On Sep 20, 4:04 am, "Steve Lusardi" <[email protected]> wrote:
> It's called hot dip galvanizing. It has been around a long time, it is
> inexpensive and works very, very well.
> 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.

Stealth Pilot wrote:
> On Sat, 20 Sep 2008 08:51:52 -0400, "J. Clarke"
> <[email protected]> wrote:
>
>
>> 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.
>>
>
> now where did you get that silly idea from???
>
> name the propeller that uses a nickle coating????

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 http://www.flickr.com/photos/goldorak/417313975/.
The new 8-way that replaced the 54460 on the E2 is another--you can
see the sheath clearly at
http://www.flickr.com/photos/kensaviation/1896504667/. 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.


--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

B A R R Y wrote:
> J. Clarke wrote:
>>
>> 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.
>
> John,
>
> Isn't that section of the prop heated for ice protection?

Centrifugal force takes the ice right off outboard, the prop deicers
are on the inboard end and the spinner On an older commuter airliner
like the DHC-7 you can see the heater as a rubber piece bonded onto
the blade.

In http://www.flickr.com/photos/clearskyphotography/1218007750/ you
can see the heaters on a solid aluminum blade if you look
carefully--there's a foam cuff inboard with a rubber covering, but on
top of that there's a deicer attached--you can see the edge of it
about 1/3 of the way back on the top left blade. The little tab that
sticks up is part of the heater but isn't itself heated. The shiny
strip along the leading edge is likely where dust and rain and whatnot
have eroded the anodize off the blade, although the Dutch may have
painted it for some reason. The tips would have been repainted
recently. http://www.flickr.com/photos/cmphoto/2505031128/ shows a
different model of that prop (both the P-3 and the C-130 use the 54H60
but with different blade tips--nobody ever told me why the
difference). http://www.flickr.com/photos/cmphoto/2530724870/ shows
the heater very clearly. Note the clear tape at the ends of the
heater--that's one that I haven't seen before on that prop but would
bet that it's polyurethane tape that's there to protect the outer edge
of the heater--the outer few inches of those heaters would wear
through long before the rest and the polyurethane tape was an approved
modification on the commuter airliners when I left the company--it's
very likely that someone after me got it approved for that use on the
P-3. http://www.flickr.com/photos/78436618@N00/2497802331/ is another
with a clear view of the heaters--on this one they've been cut back a
little bit--not sure if it's far enough to get into the wires or
not--but that's the area that would wear through.

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

Stealth Pilot wrote:
> On Sun, 21 Sep 2008 04:57:52 -0400, "J. Clarke"
> <[email protected]> wrote:
>
>> Stealth Pilot wrote:
>>> On Sat, 20 Sep 2008 08:51:52 -0400, "J. Clarke"
>>> <[email protected]> wrote:
>>>
>>>
>>>> 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.
>>>>
>>>
>>> now where did you get that silly idea from???
>>>
>>> name the propeller that uses a nickle coating????
>>
>> 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
>> http://www.flickr.com/photos/goldorak/417313975/. The new 8-way
>> that
>> replaced the 54460 on the E2 is another--you can see the sheath
>> clearly at http://www.flickr.com/photos/kensaviation/1896504667/.
>> 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.
>>
>>
>
> alright you got me there :-)
> hovercraft props!!!!
>
> I dont recall seeing the leading edges you mention on commuter turbo
> props but I'll believe you.
>
> most props are forged 2025 aloominum with an anodised surface
> hardening. the polished prop effect is achieved by wearing off all
> the
> anodising and polishing the remaining aloominum.
> the leading edge treatments I can recall are more like icing cuffs
> or
> polyurethane tapes.
>
> seriously though I do believe you on the hovercraft props.

I think that the term for the sort of commercial aircraft that would
have Hamilton props is "regional" airliners these days.

The C-130 and P-3 have 7075 blades (note, not 707_6_--Hamilton props
are about the only place that 7075 is used and Alcoa used to have to
run special lots for Hamilton). The Hamilton commuter props have a
fiberglass or Kevlar shell over an aluminum spar, which may be 2024--I
honestly don't recall what they were using on those spars. The 54460
on the E-2 had a fiberglass shell over a steel spar--don't know what
they're doing on the new 8-way. If you look at the photos of that
prop on flickr you'll see that inboard of the nickel sheath the
leading edge is smooth--the deicer is molded into the fiberglass--the
wires are stitched into place during layup. The 24PF had a glue-on
rubber heater, but the newer ones have gone to the integral heater.

Here are a few that show the sheathes more or less well:
http://www.flickr.com/photos/thomasbecker/2290167447/
http://www.flickr.com/photos/kensaviation/398359395/sizes/o/
http://www.flickr.com/photos/redteam/2384048553/
http://www.flickr.com/photos/mrottler/2112446280/
http://www.flickr.com/photos/capitals_of_tin/448098062/sizes/l/

Good clear prop close-ups are rare.

By the way, those polyurethane strips--I'm the guy who got the first
one certificated, for the 24PF on the DHC-7.


>
> Stealth ( Hovercraft props!?!?) Pilot

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)

In article <7a773144-9f47-4c0c-a2ac-e77c8b41eeb3@z66g2000hsc.googlegroups.com>,
Jay Pique <[email protected]> wrote:
<...snipped...>
>Now for the real question - how do we prevent this table and chairs
>from rusting? Not much response from the metalworkers <grumble>.
>
>JP

For ordinary hotrolled mild steel? The traditional solution is paint. If
you want the bare steel look I suppose you could use varnish or laquer.




--
Better to be stuck up in a tree than tied to one.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org

J. Clarke wrote:
>
> 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.

John,

Isn't that section of the prop heated for ice protection?