Re: [ATM] RE: How hot is your scope

["Rod Shea" <RodShea@comcast.net>]

Dan,

I was thinking that some increase in flexibility would make the parts less 
brittle, potentially a problem with CF anyway, but too much is a huge 
problem...  Your "hotbox" sounds like a good idea.  Post curing seems like a 
good way to do this, it looks like you go for a temp 40 degrees F below 
T-sub-g.    I have been digging around the net looking for the T-sub-g of 
different resin-hardener combinations, and getting some info.  What kind of 
resin and hardener did you use?

Thanks,

Rod


----- Original Message ----- 
From: "Daniel Fundo" <fundo@bellsouth.net>
To: "Rod Shea" <RodShea@comcast.net>
Sent: Tuesday, October 12, 2004 1:35 AM
Subject: Re: [ATM] RE: How hot is your scope


> <<...I had not known it was more flexible, which would be a plus.  >>
>
> Rod,  ???  Why would you want flexibility in the components of a
> telescope, where alignment is critical?
>
> Polyester resins are cheaper, but they need protection from UV.  They
> are also a third as strong as epoxy.  Room temperature epoxies can be
> post cured after they have set up by heating them to 150-175 degrees.
> After that, they won't "creep" unless they are subjected to a temp
> higher than that.  I made a fork mounting from fiberglass and epoxy over
> a foam core.  I did the post cure by building a wood frame box and
> covering it with aluminum foil sprayed with a flat black paint.  The
> temp inside got to 155 degrees when the outside temp was 95 here in
> Memphis.
>
> *****-----
> Dan F.
> Secretary/MAS
> Memphis, TN
> 


_______________________________________________
ATM mailing list http://www.atmlist.net/