[Healeys] Windscreen scratches

[Bob Spidell]

Same with any grinding compound: The components are selected for their 
shape, hence 'cutting' ability, hardness, purpose, cost, etc. A compound 
with large particles with sharp edges will cut deeper and faster than 
one with particles of a softer and/or more rounded shape. The kit I 
bought came with a paste consisting of rhyolite and whatever semi-liquid 
was used to make it a paste; it appears aluminum oxide is also used.

A coarser compound will remove deeper scratches, but leave its own 
scratches. You can start with a coarser compound to remove larger 
scratches, then switch to a finer compound to remove smaller scratches, 
and so on; just like you might start rubbing paint--or filler--with 
320grit sandpaper, then 400, then 600, 1200, etc. Some polishing 
compounds do that 'automatically,' they start with larger particles 
which themselves break down to smaller particles and successively smooth 
the surface. McGuiars (sp?) has several compounds, all graded on a 
thermometer-like scale for their cutting (deep) or polishing (fine) 
characteristics.

I appears the lapidary (mineral-polishing) crowd has lots of discussion 
re: best compounds. Cerium oxide is mentioned a lot, rhyolite some, but 
I didn't see any mention of zinc oxide. Zinc is a soft metal and may not 
lend itself to being a good polishing compound, for glass anyway. Cost 
will (always) be an issue, rhyolite may be a better compound than cerium 
oxide but may cost more, or vice versa.

bs


On 9/30/2023 9:46 AM, llennep at verizon.net wrote:
> What is special about cerium oxide?  Why not use zinc oxide?
>
> On Saturday, September 30, 2023, 04:20:50 AM EDT, Mark Donaldson 
> <ardmorebusiness at xtra.co.nz> wrote:
>
>
> Ira,
>
> I have a spare windscreen with wiper blade ‘rainbow’ scratches on both 
> sides.  To remove them I have purchased some CERIUM OXIDE to make a 
> paste and hand-polish them out.
>
> The people at the glass company told me the process will be slow (a 
> lot of elbow grease) but applying it to a soft rotary pad will speed 
> up the procedure.
>
> My cost equates to about US $15 for 4 ounces.  That amount should do 
> the whole windscreen.
>
> Here is a useful YouTube link: https://youtu.be/4ZJPPC1ak50 
> <https://youtu.be/4ZJPPC1ak50>
>
>
>
> I hope this will help.
>
> Mark
>
> Ardmore
>
> NZ
>
> *From:*i erbs <eyera3000 at gmail.com>
> *Sent:* Saturday, 30 September 2023 5:08 AM
> *To:* Bob Spidell <bspidell at comcast.net>
> *Cc:* Ahealey help <healeys at autox.team.net>
> *Subject:* Re: [Healeys] Windscreen scratches
>
> I got nothing to loose. Might as well give it a try. BTW, this is on 
> my 67B. Those windscreens are spendy to replace
>
> Ira Erbs
> Milwaukie, OR
> 1959 Austin Healey 100-6
> 1967 MGB Roadster
>
> On Fri, Sep 29, 2023, 9:06 AM Bob Spidell <bspidell at comcast.net> wrote:
>
>     I used a kit with some sandpaper, a mild abrasive and an
>     attachment for a drill to polish my BN2's windshield. IIRC, I got
>     it from Eastwood:
>
>     https://www.eastwood.com/glass-polishing-kit-for-deep-scratches.html
>
>     The 'rule-of-thumb' is if the scratch can be felt with a
>     fingernail it can't be removed, but my car had mostly mild wiper
>     wear and the kit did the job well enough I can live with it.
>
>     Bob
>
>     On 9/29/2023 3:41 AM, Robert Markovich via Healeys wrote:
>
>         There are some some places that polish windshields. But
>         ultimately it may be more cost-effective to simply replace.
>         Triplex is the brand to use; an OEM manufacturer that supplied
>         them back then. The rest often don’t fit right and eventually
>         crack from stress points, as I’ve found.
>
>         Sent from the all new AOL app for iOS
>         <https://apps.apple.com/us/app/aol-news-email-weather-video/id646100661>
>
>         On Friday, September 29, 2023, 2:01 AM, i erbs
>         <eyera3000 at gmail.com> <mailto:eyera3000 at gmail.com> wrote:
>
>             Howdy all
>
>             Is there any proven way to remove wiper blade scratches
>             from a windscreen?
>
>             Thanks all
>
>             Ira Erbs
>             Milwaukie, OR
>             1959 Austin Healey 100-6
>             1967 MGB Roadster
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/healeys/attachments/20230930/bd7b423a/attachment.htm>