I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?

Many thanks

Artie

Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?


My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435


--
Grunff

On 10 Jan 2006 08:37:34 -0800, "Arturo Ui" wrote:

What is the best way of removing the paint and 'scabs' from the keel?

Electrolysis. Google for details. Works beautifully on cast iron.

This is usually done with small parts dunked in a bucket. However you
can also make your own "bucket" from any waterproof bag you can arrange
with thick polythene sheet. The electrolyte is messy rather than toxic,
so spills aren't a disaster.

I've done the arse end of a narrowboat using this technique and half an
old Microvax.

Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

How big is it?

If you can get it off, have it shot blasted. This might
also be possible in situ.

If you want to de-rust it yourself, Grunff's angle grinder
and cup brush suggestion is the way to do it. Wear overalls
and eye protection (important!). N.B. using cup brushes in
a weedy angle grinder will quickly shag it.

"Grunff" wrote in message
...
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?


My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435


--
Grunff

You could always get it sand blasted professionally. It's not as costly you
may fear, and it is quick and 100% effective (I had the fin keel of a 34'
yacht done for £100). It is important though, as with all stripping back to
bare metal, that you get a good coat of primer on straight away, as even a
little bit of rust under the paint will create a weakness which will
undermine any further coverings. It's another reason for getting the whole
thing stripped in one quick go, as working on your own with sanders etc.,
often means leaving it for a while before priming.

Grunff wrote:
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way
of removing it that doesn't take forever and cost a fortune in
abrasive discs? Does on the those 'paint removers' with the spring
steel tines work OK or do they just take off the rust?


My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435

Or this type...
http://www.screwfix.com/app/sfd/cat/...12980&id=16695
--
Sir Benjamin Middlethwaite

The3rd Earl Of Derby wrote:

Grunff wrote:


Arturo Ui wrote:


I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way
of removing it that doesn't take forever and cost a fortune in
abrasive discs? Does on the those 'paint removers' with the spring
steel tines work OK or do they just take off the rust?


My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435



Or this type...
http://www.screwfix.com/app/sfd/cat/...12980&id=16695
--
Sir Benjamin Middlethwaite

or these:

http://www.screwfix.com/app/sfd/cat/...16728&id=32538

Thoroughly recommended - both tough enough to do the job and, if used
with care, gentle enough to feather paint edges.

Pete Styles wrote:
or these:

http://www.screwfix.com/app/sfd/cat/...16728&id=32538

Thoroughly recommended - both tough enough to do the job and, if used
with care, gentle enough to feather paint edges.

I've used those, and while they do work reasonably well, they only last
about 10 minutes in the grinder - not great value.


--
Grunff

"Chris Bacon" wrote in message
...
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

How big is it?

If you can get it off, have it shot blasted. This might
also be possible in situ.

If you want to de-rust it yourself, Grunff's angle grinder
and cup brush suggestion is the way to do it. Wear overalls
and eye protection (important!). N.B. using cup brushes in
a weedy angle grinder will quickly shag it.

Also, sheet the job up well or you could be in for some very expensive
claims from surrounding boats with damaged gel coat.

Graham.

On Tue, 10 Jan 2006 18:20:24 +0000, Grunff wrote:

http://www.screwfix.com/app/sfd/cat/...16728&id=32538

I've used those, and while they do work reasonably well, they only last
about 10 minutes in the grinder - not great value.

How did you get 10 minutes out of one? Catch an edge, or just some
rough crusty rust, and they're worn out in 10 seconds.

"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.



A needle/descaling gun will do the job well. You can probably hire one, but
don't forget the ear defenders

"Nigel" wrote in message
...

"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.



A needle/descaling gun will do the job well. You can probably hire one,
but
don't forget the ear defenders


and a fairly hefty compressor - a needle gun uses a surprising amount of air
if you use it continuously.

Floatything

Have it sandblasted. Remove it if needed. this way you will have all the
loose material gone and the cleanest possible surface to work with. You can
be satisfied your fillers and paints adhere properly with this method.

A needle gun with a compressor would be my 2nd choice. These are great for
removing lumps of rust. Though , you would still need to use a grinder and
wire brush with this method.

DP

"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?

Many thanks

Artie

"Floatything" wrote in message
news

"Nigel" wrote in message
...

"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.



A needle/descaling gun will do the job well. You can probably hire one,
but
don't forget the ear defenders


and a fairly hefty compressor - a needle gun uses a surprising amount of
air
if you use it continuously.

Floatything


A Hilti TE104 is an electric needle gun, works very well.....

Nigel wrote:
"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.



A needle/descaling gun will do the job well. You can probably hire
one, but don't forget the ear defenders

And how much will it cost to hire this gun? bearing in mind the op is
looking for the cheapest reliable method.

--
Sir Benjamin Middlethwaite

Arturo Ui wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?

Unquestionably shotblasting as others have said, you will get the whole boat
cleaned and primed in a day.
However if you have a few weeks /months free time and wish to spend a
similar amount of money using an angle grinder (disks at £5 each) you could
take pictures and claim an ididit diy award.


-

Andy Dingley wrote:

On Tue, 10 Jan 2006 18:20:24 +0000, Grunff wrote:



http://www.screwfix.com/app/sfd/cat/...16728&id=32538


I've used those, and while they do work reasonably well, they only last
about 10 minutes in the grinder - not great value.



How did you get 10 minutes out of one? Catch an edge, or just some
rough crusty rust, and they're worn out in 10 seconds.

I got the whole of my keel (Bavaria 32 - quite a lot of rust) cleaned up
with one and a bit, and I'd have thought that uner 10 quid a keel wasn't
bad value.

"Pete Styles" wrote in message
...


The3rd Earl Of Derby wrote:

Grunff wrote:

Arturo Ui wrote:

I've a cast iron keel
snip
Does anyone removed this type of rust before? What is the best way
of removing it that doesn't take forever and cost a fortune in
abrasive discs?

My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435


Quite effective, but the brushes can be picked up much more cheaply than
that - I usually stock up at autojumbles. Beware the flying brush
bristles - they sting like hell, and you find them stuck in your clothes
for days afterwards. These brushes can catch and kick back at you -
keep a good hold of the angle grinder and don't get dangly bits of body
or clothing too close.


Or this type...
http://www.screwfix.com/app/sfd/cat/...12980&id=16695
--
Sir Benjamin Middlethwaite


Predictably useful advice: taking a keel to a bench grinder seems an odd
way to do the job, to me.

or these:

http://www.screwfix.com/app/sfd/cat/...16728&id=32538

Thoroughly recommended - both tough enough to do the job and, if used
with care, gentle enough to feather paint edges.

Hmmm. Excellent devices, but perhaps not for this purpose. Great for
large areas of paint, for example stripping a car bonnet, where their
non-clogging and fine finish are an advantage, but, as Andy says, you
can shred one in seconds on a thick rust scab or a sharp edge. Again,
Screwfix aren't the cheapest (we're saying that a lot, these days, I
think) - try a motor factors specialising in refinishing materials.

The OP doesn't say where the boat is, or how transportable it is, but
commercial grit-blasting might be the best way forward, provided it can
be immediately re-coated. It's even messier than using a cup brush,
though, if the boat's in his living room (or vice versa).

Do any special precautions need to be taken with the dust from
anti-fouling paint?


--
Kevin Poole
**Use current month and year to reply (e.g. )***
Car Transport by Tiltbed Trailer - based near Derby

I found that attacking the local defects / rusty 'scabs' with a proper
hardened welders chipping hammer (the kind with a point and industrial
quality) was very effective. The localised corrosion cells appeared to me,
as if they might have been inclusions, voids or defects in the original
casting some of which were roughly filled and faired at the time. Agree
with others angle grinder with that cup brush is very effective for surface
rust and a grinding disk for fettling any high spots. Automotive rust
'killers' such as "Kurust" seem effective at preventing recurrence and they
convert any remaining rust to a black primed finish.


"Autolycus" wrote in message
...

"Pete Styles" wrote in message
...


The3rd Earl Of Derby wrote:

Grunff wrote:

Arturo Ui wrote:

I've a cast iron keel
snip
Does anyone removed this type of rust before? What is the best way
of removing it that doesn't take forever and cost a fortune in
abrasive discs?

My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435


Quite effective, but the brushes can be picked up much more cheaply than
that - I usually stock up at autojumbles. Beware the flying brush
bristles - they sting like hell, and you find them stuck in your clothes
for days afterwards. These brushes can catch and kick back at you -
keep a good hold of the angle grinder and don't get dangly bits of body
or clothing too close.


Or this type...
http://www.screwfix.com/app/sfd/cat/...12980&id=16695
--
Sir Benjamin Middlethwaite


Predictably useful advice: taking a keel to a bench grinder seems an odd
way to do the job, to me.

or these:

http://www.screwfix.com/app/sfd/cat/...16728&id=32538

Thoroughly recommended - both tough enough to do the job and, if used
with care, gentle enough to feather paint edges.

Hmmm. Excellent devices, but perhaps not for this purpose. Great for
large areas of paint, for example stripping a car bonnet, where their
non-clogging and fine finish are an advantage, but, as Andy says, you
can shred one in seconds on a thick rust scab or a sharp edge. Again,
Screwfix aren't the cheapest (we're saying that a lot, these days, I
think) - try a motor factors specialising in refinishing materials.

The OP doesn't say where the boat is, or how transportable it is, but
commercial grit-blasting might be the best way forward, provided it can
be immediately re-coated. It's even messier than using a cup brush,
though, if the boat's in his living room (or vice versa).

Do any special precautions need to be taken with the dust from
anti-fouling paint?


--
Kevin Poole
**Use current month and year to reply (e.g. )***
Car Transport by Tiltbed Trailer - based near Derby

In article .com
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Shipyards use needle guns for descaling - whether it's worth hiring one
depends on the size of the job and how much you value your time.

"Rob Morley" wrote in message
t...
In article .com
Arturo Ui wrote:

Shipyards use needle guns for descaling - whether it's worth hiring one
depends on the size of the job and how much you value your time.

Needle guns are very inexpensive to buy from the likes of clarkes machine
mart etc ( although I haven't actually used one of theirs) but I think
quite a large capacity compressor is required.

On Wed, 11 Jan 2006 11:22:03 -0000, "ChrisR"
wrote:

Needle guns are very inexpensive to buy

70-odd quid, which is quite expensive for an air tool.

I guess you're posting from a sailing group 8-)

"Andy Dingley" wrote in message
...
On Wed, 11 Jan 2006 11:22:03 -0000, "ChrisR"
wrote:

Needle guns are very inexpensive to buy

70-odd quid, which is quite expensive for an air tool.

I guess you're posting from a sailing group 8-)

£35.19, uses 4cfm, Machine Mart.

"Rob Morley" wrote in message
t...
In article .com
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Shipyards use needle guns for descaling - whether it's worth hiring one
depends on the size of the job and how much you value your time.

Ah the sounds of many a cruise ship refit, wandering back from the nearest
bar to the melodic song of the night shift needle guns shooting th S**T out
of the upperworks !

Oh the joys
just dont think about trying to make a phone call afterwards
Doug

Do any special precautions need to be taken with the dust from
anti-fouling paint?

Kevin Poole
**Use current month and year to reply (e.g. )***
Car Transport by Tiltbed Trailer - based near Derby

Yip, phone your local undertaker

Arturo Ui wrote:

I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?

Many thanks

Artie

Whatever method you use if you end up with bright metal it is important to
prime it VERY quickly before the salt air gets to it.

I was chatting once to a surveyor who had supervised the antifouling of a
large ship. He noticed that a layer of ferrous chloride was forming less
than 2 hours of shotblasting.

"Grunff" wrote in message
...
Arturo Ui wrote:
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?


My preferred method of rust stripping is a wire cup brush in an angle
grinder, such as:
http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14326&ts=11435


--
Grunff

Just a word of caution and something to be checked if using rotary brushes.

Blakes state that such brushes polish the metal and can cause adhesion
problems for blacking. I know we are probably talking antifouling here but
to be sure I think I would follow the brush up with a grinding disk to give
the keel surface a key. This should be fairly fast and remove the worst of
any surface corrosion that took place after rotary brushing.


--
Tony Brooks
www.TB-Training.co.uk

On Thu, 12 Jan 2006 15:45:50 +0000, Tony Brooks wrote:
Just a word of caution and something to be checked if using rotary
brushes.

Blakes state that such brushes polish the metal and can cause adhesion
problems for blacking. I know we are probably talking antifouling here
but to be sure I think I would follow the brush up with a grinding disk
to give the keel surface a key. This should be fairly fast and remove
the worst of any surface corrosion that took place after rotary
brushing.

a grinding disk will do exactly the same thing!

its the raw speed at which the disk/brush passes over the metal that
causes the polishing. A grinding disk may leave a scored surface, but
inside the grooves the metal will still be polished (even more so)

You really need to use an etch primer to get a good bond after attacking
metal with a grinder, this eats into the metal a little bit and anchors
itself to any voids.

regards,

--
http://maps.google.com/maps?q=irelan...244,0.0822&t=k

"Iain Hibbert" wrote in message
news
On Thu, 12 Jan 2006 15:45:50 +0000, Tony Brooks wrote:
Just a word of caution and something to be checked if using rotary
brushes.

Blakes state that such brushes polish the metal and can cause adhesion
problems for blacking. I know we are probably talking antifouling here
but to be sure I think I would follow the brush up with a grinding disk
to give the keel surface a key. This should be fairly fast and remove
the worst of any surface corrosion that took place after rotary
brushing.

a grinding disk will do exactly the same thing!

its the raw speed at which the disk/brush passes over the metal that
causes the polishing. A grinding disk may leave a scored surface, but
inside the grooves the metal will still be polished (even more so)

You really need to use an etch primer to get a good bond after attacking
metal with a grinder, this eats into the metal a little bit and anchors
itself to any voids.

regards,

--

http://maps.google.com/maps?q=irelan...244,0.0822&t=k

Cutting tools do not polish unless they are dull and rub. Wire brushes can
be kept sharp

Cutting tools do not polish unless they are dull and rub. Wire brushes
can
be kept sharp


How do you sharpen/keep sharp a wire brush. I have a both cup and dish? type
wire brushes for my angle grinder, it has never ocurred to me their
sharpness was under my control. Is the same true of grinding discs.

On Fri, 13 Jan 2006 00:19:34 +0000, ChrisR wrote:

Cutting tools do not polish unless they are dull and rub. Wire brushes can
be kept sharp

who said anything about cutting tools?

a grinder with a grinding disc is not a cutting tool

a grinder with a cup wire brush is not a cutting tool

a grinder with a sanding disc is not a cutting tool

For cutting, you would probably want some kind of saw. Please try to keep
up.

--
http://maps.google.com/maps?q=irelan...244,0.0822&t=k

"Iain Hibbert" wrote in message
news
On Fri, 13 Jan 2006 00:19:34 +0000, ChrisR wrote:

Cutting tools do not polish unless they are dull and rub. Wire brushes
can
be kept sharp

who said anything about cutting tools?

a grinder with a grinding disc is not a cutting tool

a grinder with a cup wire brush is not a cutting tool

Without getting too involved with technical explanations both are cutting
tools.

A proper hardened wire cup brush on an angle grinder can be sharpened and
fettled on a grindstone by an experienced tradesman if it has been allowed
to dull by rubbing. If you examine the end of an individual wire on an
effective brush there will be a sharp corner at the end of each wire on an
ineffective brush the end will be rounded and or bent over so there is no
sharp edge. One problem with "as cast" finishes, cast iron keels for
example, is that there will be a chilled (iron carbide) skin that is very
hard and will dull a hardened brush very quickly reulting in rubbing. The
brush is only really effective at removing material on the cast iron skin in
this case. Rubbing the iron skin itself will not be terribly effective as it
will merely glaze and polish. Depending on the grade of iron below the skin
a soft grey iron is relative soft and machjineable, quite a different of
course.

A grindstone or grinding disk consists of hard grit embadded in a softer
usually polymeric matrix. The grit will be hard with randomly disposed sharp
cutting edges. As the exposed sharp edges of the individual pieces of grit
dull they are shed exposing new grits with sharp cuting edges. The
composition of the wheel or disk must be matched to the material being
ground if the wheel is not to glaze or clog. Lubricants canbe very effective
to aid cutting and cooling some materials.
A blunt brush or grinder is just as useless as a blunt knife.

I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.
What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.
Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?

Whatever method you use if you end up with bright metal it is important to
prime it VERY quickly before the salt air gets to it.
I was chatting once to a surveyor who had supervised the antifouling of a
large ship. He noticed that a layer of ferrous chloride was forming less
than 2 hours of shotblasting.

And after all the responses, and with the keel now laying very heavily next
to my boat at the sailing club, I think a shotblasting and epoxy coating is
the way to go - many thanks to all who responded!

Artie

I'd use rust converter. You can never be sure that you've removed all the
old rust otherwise.

"Arturo Ui" wrote in message
oups.com...
I've a cast iron keel that has been rusting quietly under my boat for
the last few years. Most of the antifouling paint on the keel is on
rusty 'scabs'.

What is the best way of removing the paint and 'scabs' from the keel?
Ways I've considered so far include a circular sanding device (in an
electric drill) and an angle grinder.

Does anyone removed this type of rust before? What is the best way of
removing it that doesn't take forever and cost a fortune in abrasive
discs? Does on the those 'paint removers' with the spring steel tines
work OK or do they just take off the rust?

Many thanks

Artie

In article
glenn P wrote:
I'd use rust converter. You can never be sure that you've removed all the
old rust otherwise.

And you reckon that will penetrate right through to sound metal?

No, it will not penetrate to bare metal, but the coating it provides will
protect the remaining steel from rusting.

glenn P wrote:
No, it will not penetrate to bare metal, but the coating it provides will
protect the remaining steel from rusting.

Whatever are you talking about, glenn?