Re: Newtonian Sonotubes


"Starlord" <starlord@xxxxxxxxxxx> wrote in message
news:h8KdncBKB_5EhNHfRVn-tQ@xxxxxxxxxxxxxx
> I have seen old ( 10years+ old ) Dobs that are sono tube and they have
NOT
> weaken at all and hold their collimation just fine.
>

I agree. I have owned several Sonotube Dobsonians, and STILL own one that
is over 20 years old with NO sign of deterioration ANYWHERE. In fact, I
would say that, aside from a few scratches (which I promptly seal to keep
out moisture) from much use over the years, that it's tube is as healthy
today as it was when new. The ONLY reason these tubes weaken in areas
such as around the focuser or mirror cell, is because someone who didn't
know what they were doing cut into the tube, and made changes without
sealing the cut. This allows moisture to enter at will, and WILL result
in damage over time. This is NOT a fault of the material. It is the
fault of the person who did the work without taking the time to do the job
right.

--
Jan Owen

To reach me directly, remove the Z, if one appears in my e-mail address...
Latitude: 33.662
Longitude: -112.3272

>
> "DustyMars" <dustymar@xxxxxxxxxxx> wrote in message
> news:MPG.1cb5be7a4c70f470989785@xxxxxxxxxxxxxxxxxxx
> Plus, after
> > years of use, the paper tubes began to weaken in the
> > focuser and mirror cell areas, therefore rendering collimation nearly
> > impossible to handle.
>
>


.

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