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Old 07-03-2010, 04:14 PM
Wavytone
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Wavytone is offline
 
Join Date: Jul 2008
Location: Killara, Sydney
Posts: 4,147
Quote:
Originally Posted by DavidTrap View Post
Too much heat too quickly could cause something to go bang!
Unlikely. Years ago I found the ultimate solution to stop a C8 dewing over, and bear in mind I had a plastic dewcap* on the front that stuck out maybe 50 cm.... the same would work well on a dob.

Point the scope down.
Set up a camping gasring beneath.
Put the billy on top and add water.
Light the gas.
The rising steam and hot air will make the whole OTA quit warm.
Bring the water to the boil, turn off the gas, add tea and make a cuppa, including friends.

By the time you've drunk the cuppa, 20 minutes later the tube currents inside will have settled down enough for a look through the scope and it will stay that way until it's time to repeat the process

A lot quieter than hairdryers, it won't flatten your car battery (so you can still drive home afterwards) and best of all you're warmed up and hydrated. The blue gas flame is pretty benign, it shouldn't bother the photogs.

*if the dewcap melts, time to turn the gas off.

Last edited by Wavytone; 07-03-2010 at 04:45 PM.
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