[Public-list] Portlight Frame Replacement Options

[Don Campbell]

Hi Todd;
    Stainless does not obviate electrolysis. Because it is an alloy, 
usually with nickel in it (which is very close to zinc on the activity 
scale), it is very prone to electrolysis and in stainless they call it 
crevice or tunnel corrosion. There have been examples of it in keel 
bolts (found at Bristol Marine in Bronte, Ont) where they have twisted a 
1" bolt off with less than 50 lbs of torque because the centre of the 
bolt was completely gone. Tunnel corrosion in stainless is certainly one 
of the main things one needs to be concerned about if  buying an older 
boat, and one needs a really good surveyor to look for that.
   
Don
#528

Todd Redhead wrote:
> Maybe even get them made out of stainless?  No more electrolysis.
>
> Todd
> Strathgowan #400
> www.weliveonaboat.com
>
> On 3/26/07, George Dinwiddie <gdinwiddie at alberg30.org> wrote:
>   
>> C.B. Currier wrote:
>>     
>>> Well I removed the frames as delicately as possible today and found that
>>> many of the frames were extensively deterioriated from electrolysis(SS
>>> screws & salt water& aluminum). Several cracked and fell apart upon
>>> removal from the portlight(no extereme bending was involved). Arrgh! SO
>>> now I need to find a replacement not only for the lexan but also for the
>>> aluminum.
>>> I have a source for the lexan ... no need for help there.
>>> But I do need some advice on what to do about the frames.
>>>       
>> You could probably take one to Washington Aluminum Company (or similar
>> place) and get them to cut new ones.  I think you'll want to bevel the
>> edges, but a flat back should work fine.
>>
>>   - George
>>
>>
>> --
>>   ----------------------------------------------------------------------
>>    When I remember bygone days                         George Dinwiddie
>>    I think how evening follows morn;            gdinwiddie at alberg30.org
>>    So many I loved were not yet dead,           http://www.Alberg30.org
>>    So many I love were not yet born.
>>                 'The Middle' by Ogden Nash
>>   ----------------------------------------------------------------------
>>
>>
>>
>> _______________________________________________
>> These businesses support your Association:
>> http://www.alberg30.org/store/A30supporters.html
>> Please support them.
>> _______________________________________________
>> public-list mailing list
>> public-list at lists.alberg30.org
>> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>>
>>     
> _______________________________________________
> These businesses support your Association:
> http://www.alberg30.org/store/A30supporters.html
> Please support them.
> _______________________________________________
> public-list mailing list
> public-list at lists.alberg30.org
> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
>                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
>
>   

 1175002718.0