I have a ten year old table saw with an aluminum top. Overall it serves my
needs at this time (and more importantly, my budget), but I've noticed the
surface isn't very smooth. It's flat, but the surface itself feels rough
(sort of like sandstone). I'm starting to get into a somewhat better
quality of woodworking and I'm also seeing it leave some black marks on the
wood (from the table, not the blade), which from the searching I've done
seems to be from rough aluminum.
I know cast iron is the "standard" surface, but a new saw isn't an option at
this time.
I've done some searching about smoothing the top, but mainly what I've found
is to use paste wax (no silicone!) to protect it and make it slick. Before
applying that, I was wondering about possibly a light touch with something
like 0000 steel wool or 600+ wet/dry sand paper. Would something like this
help (or hurt)?
Any suggestions would be appreciated.
Mike O.
I'd like to thank everybody for the comments.
What I ended up doing was a good cleaning with mineral spirits, then LIGHTLY
went over it with some 600grit & water, then, again very lightly with a 1
micron fiber optic polish sheet & water. Let it dry & Johnson's paste wax.
The top feels as smooth as glass.
Thanks again for the responses.
Mike O.
Wax it first and see how that does. If you don't absolutely have to sand a
machine table, don't. If you absolutely must, use a very fine grit and a
flat steel sanding block.
"Mike O." <[email protected]> wrote in message
news:[email protected]...
> Morris Dovey <[email protected]> wrote in message
news:<[email protected]>...
>
> [... stuff snipped...]
>
> >
> > I've smoothed small aluminum parts by burnishing, filing, and
> > sanding. I'd suggest burnishing any rough gouges and scratches
> > first. This lets you work some of the metal back into the top -
> > while simply removing spurs and edges ensures that there will be
> > voids of the same volume.
>
> There's no major gouges or scrapes in it, it just doesn't feel as
> smooth as I think it should, and it's leaving marks on wood.
>
> > After burnishing where it makes sense to do that, sanding with
> > 600 grit (and finer) will help to smooth the surface. I'd look
> > for a flat metal plate to use as a sanding block.
>
>
> Should I wet sand it w/600 grit? If so, with water or something else
> (mineral spirits, acetone, etc.)
>
> >
> > And for a final polishing, you might consider a small amount of
> > WD-40 on typing paper wrapped around your block. Aluminum is soft
> > enough that the typing paper is sufficiently abrasive to do a
> > good final polishing and smoothing.
>
> I've actually got some 1 and 5 micron polishing sheets for fiber optic
> cable polishing that I thought I might use at the end, before waxing
> it.
>
> >
> > When the smoothing is done, I like to do a final cleaning step
> > with acetone and either paper towels or an old T-shirt. Johnson's
> > Paste Wax (a couple of /thin/ coats, renewed periodically) seems
> > to do a good job of protecting the surface.
>
> The plan was to put some Johnson's wax on it, but I figured I'd like
> to get it as smooth as possible before putting the wax on.
>
>
> Thanks for the response.
Mike O. wrote:
> I have a ten year old table saw with an aluminum top. Overall
> it serves my needs at this time (and more importantly, my
> budget), but I've noticed the surface isn't very smooth. It's
> flat, but the surface itself feels rough (sort of like
> sandstone). I'm starting to get into a somewhat better
> quality of woodworking and I'm also seeing it leave some black
> marks on the wood (from the table, not the blade), which from
> the searching I've done seems to be from rough aluminum.
>
> I know cast iron is the "standard" surface, but a new saw
> isn't an option at this time.
>
> I've done some searching about smoothing the top, but mainly
> what I've found is to use paste wax (no silicone!) to protect
> it and make it slick. Before applying that, I was wondering
> about possibly a light touch with something like 0000 steel
> wool or 600+ wet/dry sand paper. Would something like this
> help (or hurt)?
>
> Any suggestions would be appreciated.
I've smoothed small aluminum parts by burnishing, filing, and
sanding. I'd suggest burnishing any rough gouges and scratches
first. This lets you work some of the metal back into the top -
while simply removing spurs and edges ensures that there will be
voids of the same volume.
After burnishing where it makes sense to do that, sanding with
600 grit (and finer) will help to smooth the surface. I'd look
for a flat metal plate to use as a sanding block.
And for a final polishing, you might consider a small amount of
WD-40 on typing paper wrapped around your block. Aluminum is soft
enough that the typing paper is sufficiently abrasive to do a
good final polishing and smoothing.
When the smoothing is done, I like to do a final cleaning step
with acetone and either paper towels or an old T-shirt. Johnson's
Paste Wax (a couple of /thin/ coats, renewed periodically) seems
to do a good job of protecting the surface.
--
Morris Dovey
DeSoto, Iowa USA
Mike O. writes:
> I have a ten year old table saw with an aluminum top. Overall
> it serves my needs at this time (and more importantly, my
> budget), but I've noticed the surface isn't very smooth.
<snip>
Why not make a sled and get on with it.
With a sled, who cares what the table looks like?
--
Lew
S/A: Challenge, The Bullet Proof Boat, (Under Construction in the Southland)
Visit: <http://home.earthlink.net/~lewhodgett> for Pictures
Morris Dovey <[email protected]> wrote in message news:<[email protected]>...
[... stuff snipped...]
>
> I've smoothed small aluminum parts by burnishing, filing, and
> sanding. I'd suggest burnishing any rough gouges and scratches
> first. This lets you work some of the metal back into the top -
> while simply removing spurs and edges ensures that there will be
> voids of the same volume.
There's no major gouges or scrapes in it, it just doesn't feel as
smooth as I think it should, and it's leaving marks on wood.
> After burnishing where it makes sense to do that, sanding with
> 600 grit (and finer) will help to smooth the surface. I'd look
> for a flat metal plate to use as a sanding block.
Should I wet sand it w/600 grit? If so, with water or something else
(mineral spirits, acetone, etc.)
>
> And for a final polishing, you might consider a small amount of
> WD-40 on typing paper wrapped around your block. Aluminum is soft
> enough that the typing paper is sufficiently abrasive to do a
> good final polishing and smoothing.
I've actually got some 1 and 5 micron polishing sheets for fiber optic
cable polishing that I thought I might use at the end, before waxing
it.
>
> When the smoothing is done, I like to do a final cleaning step
> with acetone and either paper towels or an old T-shirt. Johnson's
> Paste Wax (a couple of /thin/ coats, renewed periodically) seems
> to do a good job of protecting the surface.
The plan was to put some Johnson's wax on it, but I figured I'd like
to get it as smooth as possible before putting the wax on.
Thanks for the response.
Andy Dingley <[email protected]> wrote in message news:<[email protected]>...
> On Wed, 15 Sep 2004 22:34:11 -0400, "Mike O."
> <[email protected]> wrote:
>
> >I have a ten year old table saw with an aluminum top.
>
> I wouldn't take abrasives to an aluminium top unless I was prepared to
> re-anodise it afterwards, or if it had already lost any anodised
> surface. Unless you live in a desert, aluminium can quite easily
> re-develop a poor surface just from ongoing surface oxidation - don't
> leave it unprotected.
This is probably a dumb question, but how can I tell if has any
anodized surface? It just has a grey "brushed" aluminum look (the
same as it's always had); there's never been any color to it.
Mike O.
>
>This is probably a dumb question, but how can I tell if has any
>anodized surface? It just has a grey "brushed" aluminum look (the
>same as it's always had); there's never been any color to it.
>
>Mike O.
>
Anodizing is extremely thin. If it has any wear on it, you've already gone
through the anodizing.
John Martin
On 16 Sep 2004 18:25:47 GMT, [email protected] (JMartin957) wrote:
>>
>>This is probably a dumb question, but how can I tell if has any
>>anodized surface? It just has a grey "brushed" aluminum look (the
>>same as it's always had); there's never been any color to it.
>>
>>Mike O.
>>
>
>Anodizing is extremely thin. If it has any wear on it, you've already gone
>through the anodizing.
>
>John Martin
not all anodizing is colored. it comes clear too. once you wear
through it you'll be able to see the difference.
[email protected] wrote:
> On 16 Sep 2004 18:25:47 GMT, [email protected] (JMartin957) wrote:
>
>>>This is probably a dumb question, but how can I tell if has any
>>>anodized surface? It just has a grey "brushed" aluminum look (the
>>>same as it's always had); there's never been any color to it.
>>
>>Anodizing is extremely thin. If it has any wear on it, you've already gone
>>through the anodizing.
>
> not all anodizing is colored. it comes clear too. once you wear
> through it you'll be able to see the difference.
Since the Mike O. said his top was leaving black marks on wood
being cut, I assumed that the anodizing has been at least partly
worn away.
It didn't occur to me to suggest checking for dirt/grease/oil/etc
before doing anything else.
In my experience (IMX?) the smoother the surface, the less effort
required to maintain and keep clean.
--
Morris Dovey
DeSoto, Iowa USA
On Thu, 16 Sep 2004 19:32:35 GMT, [email protected] (Doug Miller)
wrote:
>But once the layer of oxide is formed, the oxidation process _stops_.
No, the oxidation continues. A randomly formed oxide layer just isn't
adequately impermeable.
>Hogwash. It protects perfectly fine. I have an aluminum-frame greenhouse in my
>back yard that's _at_least_ thirty years old, with no protection from the
>elements other than the protective film of aluminum oxide that naturally forms
>on any aluminum surface in an oxygen-rich atmosphere.
If not anodised at the factory, then it was at least passivated.
--
Smert' spamionam
On Thu, 16 Sep 2004 12:58:52 GMT, [email protected] (Doug Miller)
wrote:
>What you describe is the result of corrosion, not oxidation.
What's the (practical) difference ? For aluminium in workshop
conditions, the form of corrosion most likely to occur _is_ an
oxidation. Steel bolts through aluminium in damp conditions might show
galvanic corrosion, stressed forgings in machine tools can break owing
to intergranular corrosion. Tabletops though are going to do it by
surface oxidation.
>the thin surface layer of aluminum oxide _protects_ the
>underlying metal from further oxidation.
The trouble is that randomly formed aluminium oxide doesn't protect
very well. It's thin, it's porous and it's permeable. Surface
oxidation is ongoing. If you want an impermeable oxide film, you have
to make it yourself. The same applies (to a lesser extent) to
stainless steel in kitchens - if you don't passivate it deliberately,
there can be all manner of staining problems as it slowly does it
itself.
If you have a damp workshop (I certainly do), then white powdery
surfaces on aluminium are the natural state of things, unless you take
precautions (But then, I have as much stock in my workshop that's
scrap aircraft parts and old engines as I do for raw timber).
Much depends on the alloy. Alloys used for extrusion or casting (and
thus most sawbench tops) are admittedly less likely to show powdery
surface corrosion than alloys for barstock and machined components.
Lots of cast tabletops (those gridiron ones) still do it though -
goodness knows what's in the alloy.
The problem with sawbenches particularly isn't that the top is likely
to disintegrate, but that the corrosion that is there isn't compatible
with being a sawbench. It can leave discolouration on timber. It's
also so soft that just sliding timber over it is enough to be
abrasive, removing one layer and introducing another.
>Aluminum unprotected by any surface finish such as paint,
>lacquer, etc will survive continued outdoor exposure for _years_ because it
>forms its own protecting layer.
This depends on the alloy. Most castings will disappear entirely if
left outside. Look at an old aircrash site sometime - there's a big
oval patch of bare earth, because the aluminium that's still there as
hydroxides is a powerful weedkiller. Aircraft (and Landrovers) are
mainly aluminium / magnesium alloy and the stuff practically vanishes
while you watch.
--
Smert' spamionam
On Wed, 15 Sep 2004 22:41:38 -0500, Morris Dovey <[email protected]>
wrote:
I've had a shopsmith mark V for a lot of years... part of my "twice a
year, if I remember" maintenance is to go over the alum. table tops
with new 3M abrasive pad (one of those green thingies) glued to a
piece of scrap 1x6...
I go over it lightly, looking to remove any burrs or whatever and old
wax buildup..
After washing with soap and water and rinsing well, I put 2 coats of
old fashion paste wax on the table top and it feels like a new saw..
note.. you're polishing the table, NOT resurfacing it, so keep the
pressure light and use something straight and flat to back up your
abrasive pad...
>Mike O. wrote:
>
>> I have a ten year old table saw with an aluminum top. Overall
>> it serves my needs at this time (and more importantly, my
>> budget), but I've noticed the surface isn't very smooth. It's
>> flat, but the surface itself feels rough (sort of like
>> sandstone). I'm starting to get into a somewhat better
>> quality of woodworking and I'm also seeing it leave some black
>> marks on the wood (from the table, not the blade), which from
>> the searching I've done seems to be from rough aluminum.
>>
>> I know cast iron is the "standard" surface, but a new saw
>> isn't an option at this time.
>>
>> I've done some searching about smoothing the top, but mainly
>> what I've found is to use paste wax (no silicone!) to protect
>> it and make it slick. Before applying that, I was wondering
>> about possibly a light touch with something like 0000 steel
>> wool or 600+ wet/dry sand paper. Would something like this
>> help (or hurt)?
>>
>> Any suggestions would be appreciated.
>
>I've smoothed small aluminum parts by burnishing, filing, and
>sanding. I'd suggest burnishing any rough gouges and scratches
>first. This lets you work some of the metal back into the top -
>while simply removing spurs and edges ensures that there will be
>voids of the same volume.
>
>After burnishing where it makes sense to do that, sanding with
>600 grit (and finer) will help to smooth the surface. I'd look
>for a flat metal plate to use as a sanding block.
>
>And for a final polishing, you might consider a small amount of
>WD-40 on typing paper wrapped around your block. Aluminum is soft
>enough that the typing paper is sufficiently abrasive to do a
>good final polishing and smoothing.
>
>When the smoothing is done, I like to do a final cleaning step
>with acetone and either paper towels or an old T-shirt. Johnson's
>Paste Wax (a couple of /thin/ coats, renewed periodically) seems
>to do a good job of protecting the surface.
Mac
On Wed, 15 Sep 2004 22:34:11 -0400, "Mike O."
<[email protected]> wrote:
>I have a ten year old table saw with an aluminum top.
I wouldn't take abrasives to an aluminium top unless I was prepared to
re-anodise it afterwards, or if it had already lost any anodised
surface. Unless you live in a desert, aluminium can quite easily
re-develop a poor surface just from ongoing surface oxidation - don't
leave it unprotected.
--
Smert' spamionam
In article <[email protected]>, Andy Dingley <[email protected]> wrote:
>On Wed, 15 Sep 2004 22:34:11 -0400, "Mike O."
><[email protected]> wrote:
>
>>I have a ten year old table saw with an aluminum top.
>
>I wouldn't take abrasives to an aluminium top unless I was prepared to
>re-anodise it afterwards, or if it had already lost any anodised
>surface. Unless you live in a desert, aluminium can quite easily
>re-develop a poor surface just from ongoing surface oxidation - don't
>leave it unprotected.
>
What you describe is the result of corrosion, not oxidation. In the absence of
any corrosive agent (e.g. salt or acids), unprotected aluminum oxidizes
rapidly -- and the thin surface layer of aluminum oxide _protects_ the
underlying metal from further oxidation. There just isn't a problem with
"ongoing surface oxidation" in aluminum, unless the oxide layer is repeatedly
abraded away. Aluminum unprotected by any surface finish such as paint,
lacquer, etc will survive continued outdoor exposure for _years_ because it
forms its own protecting layer.
--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)
Get a copy of my NEW AND IMPROVED TrollFilter for NewsProxy/Nfilter
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On 16 Sep 2004 10:13:51 -0700, [email protected] (Mike O.) wrote:
>Morris Dovey <[email protected]> wrote in message news:<[email protected]>...
>
>[... stuff snipped...]
>
>>
>> I've smoothed small aluminum parts by burnishing, filing, and
>> sanding. I'd suggest burnishing any rough gouges and scratches
>> first. This lets you work some of the metal back into the top -
>> while simply removing spurs and edges ensures that there will be
>> voids of the same volume.
>
>There's no major gouges or scrapes in it, it just doesn't feel as
>smooth as I think it should, and it's leaving marks on wood.
don't worry too much about polishing the aluminum. just get it flat
and reasonably smooth.
>
>> After burnishing where it makes sense to do that, sanding with
>> 600 grit (and finer) will help to smooth the surface. I'd look
>> for a flat metal plate to use as a sanding block.
>
>
>Should I wet sand it w/600 grit? If so, with water or something else
>(mineral spirits, acetone, etc.)
use the minimum amount of abrasives. if the table has been anodised
you want to preserve as much of that as you can for as long as you can
>
>>
>> And for a final polishing, you might consider a small amount of
>> WD-40 on typing paper wrapped around your block. Aluminum is soft
>> enough that the typing paper is sufficiently abrasive to do a
>> good final polishing and smoothing.
>
>I've actually got some 1 and 5 micron polishing sheets for fiber optic
>cable polishing that I thought I might use at the end, before waxing
>it.
probably overkill, but it probably won't hurt. the wax is the main
thing.
>
>>
>> When the smoothing is done, I like to do a final cleaning step
>> with acetone and either paper towels or an old T-shirt. Johnson's
>> Paste Wax (a couple of /thin/ coats, renewed periodically) seems
>> to do a good job of protecting the surface.
>
>The plan was to put some Johnson's wax on it, but I figured I'd like
>to get it as smooth as possible before putting the wax on.
the wax will wear out fairly quickly. you'll be reapplying it
regularly. try to get in the habit of doing it before the black marks
become a problem. if you think you have to go through the whole
rubbing out/ polishing sequence first it will probably be less likely
to be done. most of the time it will just need a quick wipedown with
the paste wax.
>
>
>Thanks for the response.
In article <[email protected]>, Andy Dingley <[email protected]> wrote:
>On Thu, 16 Sep 2004 12:58:52 GMT, [email protected] (Doug Miller)
>wrote:
>
>>What you describe is the result of corrosion, not oxidation.
>
>What's the (practical) difference ?
The practical difference is that aluminum oxide, once formed, is not subject
to further oxidation. It doesn't behave like iron in the presence of oxygen
and water.
> For aluminium in workshop
>conditions, the form of corrosion most likely to occur _is_ an
>oxidation.
But once the layer of oxide is formed, the oxidation process _stops_.
>Steel bolts through aluminium in damp conditions might show
>galvanic corrosion, stressed forgings in machine tools can break owing
>to intergranular corrosion. Tabletops though are going to do it by
>surface oxidation.
Iron tabletops, sure. Not aluminum.
>
>>the thin surface layer of aluminum oxide _protects_ the
>>underlying metal from further oxidation.
>
>The trouble is that randomly formed aluminium oxide doesn't protect
>very well. It's thin, it's porous and it's permeable. Surface
>oxidation is ongoing. If you want an impermeable oxide film, you have
>to make it yourself. The same applies (to a lesser extent) to
>stainless steel in kitchens - if you don't passivate it deliberately,
>there can be all manner of staining problems as it slowly does it
>itself.
Hogwash. It protects perfectly fine. I have an aluminum-frame greenhouse in my
back yard that's _at_least_ thirty years old, with no protection from the
elements other than the protective film of aluminum oxide that naturally forms
on any aluminum surface in an oxygen-rich atmosphere. If what you say is
correct, it should have disintegrated long ago. It hasn't, and probably will
outlive either of us.
>
>If you have a damp workshop (I certainly do), then white powdery
>surfaces on aluminium are the natural state of things, unless you take
>precautions (But then, I have as much stock in my workshop that's
>scrap aircraft parts and old engines as I do for raw timber).
If that's happening to aluminum in your workshop, then you have some source of
corrosive fumes. Water alone will not cause aluminum to acquire a white
powdery surface.
>
>Much depends on the alloy. Alloys used for extrusion or casting (and
>thus most sawbench tops) are admittedly less likely to show powdery
>surface corrosion than alloys for barstock and machined components.
>Lots of cast tabletops (those gridiron ones) still do it though -
>goodness knows what's in the alloy.
I had a Sears tablesaw with an aluminum top that, over the years, as I changed
residences, lived in two different garages (both unheated) and two different
basements -- and it never exhibited a white powdery surface. If this is
happening to you, it means that you have some source of corrosion present
_other_than_ water and oxygen.
--
Regards,
Doug Miller (alphageek-at-milmac-dot-com)
Get a copy of my NEW AND IMPROVED TrollFilter for NewsProxy/Nfilter
by sending email to autoresponder at filterinfo-at-milmac-dot-com
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On Thu, 16 Sep 2004 21:21:52 GMT, Badger <[email protected]>
wrote:
>Birmabright old chap, birmabright (land-rovers)
Indeed so.
Have you ever looked at L-R's officially recommended flux for gas
welding it ? "Hari-Kiri No 2", from some place in Birmingham. I'd
love to get a tin, just for the name.
Mind you, it's probably full of fluorides, so the name isn't
unreasonable.