Thread: 10" F4 build
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Old 16-04-2012, 10:44 AM
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alistairsam
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Quote:
Originally Posted by ZeroID View Post
2" Focusser and the secondary is a generous one. I only need about another 3-4 mm but that is already stacked up on the adjusters so I will pull some of the neoprene supports out and use the box section to get it into position.

I think the sealant is better because it is designed for some thickness and setting as a volume whereas the adhesive works better as a thin film. The thickness is part of the flexible no-stress support structure. You would lose that with a thin film I'd think.

I've seen no corrosion problems with Alum and Sealant but if you want to be sure of a hold drill a hole where the sealant will be and squeeze a 'button' through to lock it on the far side. I did this with my lateral side supports. In fact I drilled the hole and set the support about 2 mm from the side and then squeezed the sealant through the hole to the mirror edge tofill the gap, very tidy looking.
Hi Brent,

yes I noticed the side sealant, but did you use spacers while it cured? else won't it tend to pull the mirror sideways?

I found this sealant that works well on glass and aluminium
http://www.selleys.com.au/sealants/silicone/glass
specs mention it doesn't shrink while curing. But does mention its not suitable for roofs and gutters as it will cause corrosion. should be fine for Al.
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