Scratched aluminum block

Ashton Crusher wrote:
>
> On Wed, 25 Mar 2009 21:53:27 +0000 (UTC), Brent
> > wrote:
>
> >On 2009-03-25, runderwo > wrote:
> >> On Mar 25, 12:39 am, Ashton Crusher > wrote:
> >>> > So what can I use to smooth it down flat without
> >>> >wrecking the rest of the surface finish?
> >>>
> >>> Small ball peen hammer.
> >>
> >> Can you elaborate on the technique you're suggesting? Just some light
> >> tapping all around the groove?
> >
> >He's messing with you.
> >
>
> only half joking. I've got a little metal hammer from a fire
> extinguisher box that I'd be tempted to try. I really don't like the
> idea of filing or otherwise abrading on the heads.

Right. Check for high spots with a machinists straight edge and a light
behind it. Tap down the high spots so that they won't hold the mating
surfaces apart and make a worse seal.

The scratch itself isn't that big a deal as long as it doesn't create a
connection between two systems that aren't supposed to be connected.

--
Paul Hovnanian
------------------------------------------------------------------
Don't let your mind wander -- it's too little to be let out alone.

Don Bruder wrote:
> In article >,
> Nate Nagel > wrote:
>
>> Brent wrote:
>>> On 2009-03-25, runderwo > wrote:
>>>> On Mar 25, 12:39 am, Ashton Crusher > wrote:
>>>>>> So what can I use to smooth it down flat without
>>>>>> wrecking the rest of the surface finish?
>>>>> Small ball peen hammer.
>>>> Can you elaborate on the technique you're suggesting? Just some light
>>>> tapping all around the groove?
>>> He's messing with you.
>>>
>> yup
>>
>> I'd be tempted to simply try to dress it down with a stone like you use
>> to sharpen your pocketknife. CAREFULLY. don't remove any more material
>> than you have to.
>>
>> nate
>
> I'd be real tempted to try using a machinist's scraper, a plane iron, or
> even just a decent quality knife that has a straight edge. Set it down
> at one end of the scratch, angled slightly across it (like they angle
> the blade of a road grader), tilt the top slightly in the direction
> you're going to move it, then draw it down the length of the scratch
> with enough steady pressure to "catch" the ridge. Repeat as needed to
> get the ridges gone without digging into the deck.
>

I'm with Don on this. I'd use a gasket scraper with a fresh razor in it,
and I'd very carefully "shave" any curl of aluminum from the scratch
that might stick above the deck. I wouldn't polish with any power tool,
and I sure wouldn't use sandpaper. *Maybe* a light touch with
scotch-brite wrapped around my index finger. But really, I'd just use
the scraper to remove any lip of metal that might have gotten pushed up,
then hope it seals. You can't put metal back in the scratch, and
removing any metal around the scratch just lowers the compression on the
gasket in that area when everything's assembled.

In article >,
Steve > wrote:

> Don Bruder wrote:
> > In article >,
> > Nate Nagel > wrote:
> >
> >> Brent wrote:
> >>> On 2009-03-25, runderwo > wrote:
> >>>> On Mar 25, 12:39 am, Ashton Crusher > wrote:
> >>>>>> So what can I use to smooth it down flat without
> >>>>>> wrecking the rest of the surface finish?
> >>>>> Small ball peen hammer.
> >>>> Can you elaborate on the technique you're suggesting? Just some light
> >>>> tapping all around the groove?
> >>> He's messing with you.
> >>>
> >> yup
> >>
> >> I'd be tempted to simply try to dress it down with a stone like you use
> >> to sharpen your pocketknife. CAREFULLY. don't remove any more material
> >> than you have to.
> >>
> >> nate
> >
> > I'd be real tempted to try using a machinist's scraper, a plane iron, or
> > even just a decent quality knife that has a straight edge. Set it down
> > at one end of the scratch, angled slightly across it (like they angle
> > the blade of a road grader), tilt the top slightly in the direction
> > you're going to move it, then draw it down the length of the scratch
> > with enough steady pressure to "catch" the ridge. Repeat as needed to
> > get the ridges gone without digging into the deck.
> >
>
> I'm with Don on this. I'd use a gasket scraper with a fresh razor in it,
> and I'd very carefully "shave" any curl of aluminum from the scratch
> that might stick above the deck. I wouldn't polish with any power tool,
> and I sure wouldn't use sandpaper. *Maybe* a light touch with
> scotch-brite wrapped around my index finger. But really, I'd just use
> the scraper to remove any lip of metal that might have gotten pushed up,
> then hope it seals. You can't put metal back in the scratch, and
> removing any metal around the scratch just lowers the compression on the
> gasket in that area when everything's assembled.

I think you've got the general idea, Steve, but the way you say it, I
think you've got what I meant backwards - The action needs to be more
like using a putty knife to "mash material into the gap" than "trying to
get under a gasket".

Trying to "get under" the ridge is pretty much guaranteed to make things
worse than they are now. You want to scrape the top of the ridge off
until it's flush with the main deck, not "cut it out".

--
Don Bruder - - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
somewhere, any message sent to this address will go in the garbage without my
ever knowing it arrived. Sorry... <http://www.sonic.net/~dakidd> for more info

Don Bruder wrote:
> In article >,
> Steve > wrote:

>> I'm with Don on this. I'd use a gasket scraper with a fresh razor in it,
>> and I'd very carefully "shave" any curl of aluminum from the scratch
>> that might stick above the deck. I wouldn't polish with any power tool,
>> and I sure wouldn't use sandpaper. *Maybe* a light touch with
>> scotch-brite wrapped around my index finger. But really, I'd just use
>> the scraper to remove any lip of metal that might have gotten pushed up,
>> then hope it seals. You can't put metal back in the scratch, and
>> removing any metal around the scratch just lowers the compression on the
>> gasket in that area when everything's assembled.
>
> I think you've got the general idea, Steve, but the way you say it, I
> think you've got what I meant backwards - The action needs to be more
> like using a putty knife to "mash material into the gap" than "trying to
> get under a gasket".
>
> Trying to "get under" the ridge is pretty much guaranteed to make things
> worse than they are now. You want to scrape the top of the ridge off
> until it's flush with the main deck, not "cut it out".
>
Your second paragraph describes what I meant. "Shave" any up-turned
metal so that its flush with the remaining good surface, NOT "dig" under
anything. A gasket scraper held very nearly parallel with the block deck
will do that, just like you want to "shave" stuck gasket material off,
not "dig" under it.

I appreciate all the thoughtful replies! I think I have the general
idea now. I just need to get myself a decent straight edge so I can
do more than guess at what is actually going on at the edge of the
gouge.