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Hi,

I've finally decided that I've had enough carting my astro gear in and out of the house everything I want to do some imaging/observing.  I'm also going to buy a heavier mount in the near future  so I'm not sure if I'll even be able to carry it out.

We are going to do some work on our garden in the spring which includes having a new patio laid.  The boss has given me permission for a permanent pier as we can't fit an observatory in.  I intend making a concrete pier and have seen a number of similar projects, but I can't find out which type of concrete to use.  I've seen multi-purpose, fast set, postcrete etc.

I've worked out that I need 8 x 20kg bags of concrete I just need to know what type.  Can anyone advise me.

Thanks

Doug

 

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I assume you are talking about cement, concrete = cement + aggregates like sand and stone.

You would probably be ok normal multipurpose cement, but I would be inclined to go for sulphate resistant cement for anything that is below ground level.  I would also use a damp proof membrane between the concrete and earth to prevent it absorbing ground water.

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11 minutes ago, scitmon said:

I assume you are talking about cement, concrete = cement + aggregates like sand and stone.

You would probably be ok normal multipurpose cement, but I would be inclined to go for sulphate resistant cement for anything that is below ground level.  I would also use a damp proof membrane between the concrete and earth to prevent it absorbing ground water.

Thanks for the advice

Doug

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I just used a one in three cement and builder's sand mix plus some drain pipe. I know mine was for an obsy but the principal is the same whatever you put around it. Underground cable run up through the middle. Remember to put a gap between the piller and surrounding patio, etc.

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Not an expert on this but...

I was mixing a washing up bowl half full of fast setting and water with an electric hand cake mixer (as you do), and went inside for two minutes to wash my hands, went back out, and it had set in the bowl! Had to bin the lot. 

 

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6 hours ago, Doug64 said:

Hi,

I've finally decided that I've had enough carting my astro gear in and out of the house everything I want to do some imaging/observing.  I'm also going to buy a heavier mount in the near future  so I'm not sure if I'll even be able to carry it out.

We are going to do some work on our garden in the spring which includes having a new patio laid.  The boss has given me permission for a permanent pier as we can't fit an observatory in.  I intend making a concrete pier and have seen a number of similar projects, but I can't find out which type of concrete to use.  I've seen multi-purpose, fast set, postcrete etc.

I've worked out that I need 8 x 20kg bags of concrete I just need to know what type.  Can anyone advise me.

Thanks

Doug

 

Any standard concrete mix in bags like Wickes stuff, just give it time to dry completely.

That's all I used for my pier and my 35foot hamradio mast.
The mast has been in the ground since the early 90s and no problems.

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When I built my observatory I used standard cement and small ballast mix (sand and stone) in a 1:3 (1 shovel of cement to 3 of ballast).  The pier was a standard 6" plastic drain pipe, which was then filed with rebar and concrete to the same mix

 

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Yeah, I don't think that anything special is required.  For smaller jobs I often get a dumpy bag of 20mm "all in" ballast from the builders merchant (20mm stone down to sand, basically) and use standard cement.  I can't really suggest a mix though I'm afraid.  I tend to throw a dozen large shovels of ballast and half a bag of cement into the mixer and then add a bit more ballast and water until it "looks right" :)

James

Edited by JamesF
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