Posts Made By: Tom Tolla

September 12, 2005 11:18 AM Forum: Home Observatories

Concrete info for....Ivan Posted By Tom Tolla

Hi Ivan,
I see you have plenty of input on this subject already but....

Concrete reaches its maximum strength in 28 days. It should be "damp cured" for at least 7 days before you apply any torque to anchor bolts. Damp cured by Klaus' method is what is accepted in the construction field. This is regardless of what PSI rating the concrete is that you have mixed.

The most important item is the amount of water added when mixing. Concrete mixes are rated in PSI based on the assumption that the person mixing is going to add the instructed amount of water. Too much water will decrease the PSI rating and cause excessive shrinkage (not good)

I know this is a little late, but the best pre-mixed concrete you can buy is "5000 psi Hi-Early Strength".

Sorry about the late post. Maybe someone has posted this info already.

November 1, 2005 02:44 AM Forum: Birding Optics and Photos

Belted Kingfisher Posted By Tom Tolla

Found this guy looking over a tidal pool today. Shot with : 20D and Canon 500mm f4.5 L at 50+ yds then cropped.

I just love the head feathers on these guys

December 6, 2005 10:19 PM Forum: Home Observatories

Roll-over roof (details) Posted By Tom Tolla

So as not to capitalize on a thread by Charles. Here are some other images of my roll-over roof design. It works for me and the space I'm allowed (says my wife ) to take up in the yard.

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