Physopto

I am glad for you. Now tell us the same in a months time Derek

Looks like you have enough left over soil for a rockery ! Been there and done it (14 x 8 ton skips ) and mostly dug by hand. Alarm cable? Derek

Why didn't you just weld a pier to the drain cover and save all that backache?

Good luck and have fun. Ouch me back!

Try this website for more info. http://gbr.sika.com/en/builders-merchants-diy/builders-merchants-diy/02a024/02a024sa02.html You do not need their expensive sand just well washed sharp sand. Your local builder may be able to supply it. Often they tell you it is washed but sometimes in WHAT, as it sure as heck is not fresh water. Wicks can supply washed sharp sand. Any salts will cause a track for water or moisture to penetrate and will leave white deposits on the surface after a while. What ever you do, do not use dish washing detergent to act as a plasticiser, as it will add salt!!! If you want that get the correct additive. At this time of year best to use a frostproofer. just be sure it is Sika friendly if you use it. +4 deg and rising is spot on advice. Ice starts forming even before the air temp gets to freezing as the ground radiates heat into space. As the temp falls Ice crystals grow in size. If I can remember my physics, this takes place from 0 deg down to about -4 deg. Which is what causes the cracking of newly setting concrete/cement. A frost proofer retards the ice formation to below these temperatures. (not sure exactly what temps though, may vary by manufacturer). Best of luck. Derek

Now that is an idea for Billy's observatory.........Warm feet Ooooooh!

The site looks great. Nice outlook. I will watch you posts with interest. I am sure you will have thought about it but just in case you haven't as yet, you can waterproof the concrete mix with Sika 1. I think it may be called Sika Proof now. It stops water penetration. In the presence of water it forms a waxy layer in the concrete and becomes a barrier to moisture. Also as you are pouring at this time of year I would use an accelerator if Sika allows,( I cannot remember). A few years ago I put in new foundations and tanked the internal walls of the house. If you only use washed sharp sand it can be waterproofed that way. Yellow sand cannot as it is porous. Finally if you have spare fibreglass insulation and a tarp cover it for a week to keep frost off the surface as it will destroy the finished surface. (I have included a pic on of some the foundation work). I will be very interested in your progress. I only have a base down as now not going to finish mine as moving. Best of luck with the build. Derek

Why not just stick a camera on it and forget the steps. Come join the dark side Damian. Derek

If the gap is under the dovetail bar, then that is correct. The bar should be clamped at the sides by the dovetails in the mount clamp when properly tightened. The EQ8 has three clamp bolts and holds the dovetail very tightly. It may be also preferable to tighten them by hand, then a fraction more using a spanner, carefully! You can also use a socket on a small ratchet. Remember only a slight bit more on the tightening, no more than a tenth of a turn. Derek

Hi Scorpius, That is definitely starting to look good. I will be interested to see the finished item. I especially like the guard dog, really fierce looking! Derek

Over here the original wall ties ( in the distant past ) were just iron/steel bars splayed at the ends. Many houses have had to have them cut out as they rusted and rust is 40 times the size of the steel it replaces. So they found that the bricks were being forced apart and structural damage resulted. The galvanised wall ties replaced the steel ones around the 1910/20s I believe. But theses have also been found to have corrosion problems over the years and just rusted away in the cavities. This meant the inner and outer walls were not tied together and so could either bow apart or cause collapse problems. So now all mortgage providers require that they are replaced with stainless steel replacements. Hot galvanised metal in the past was of much better quality and much heavier deposit than the presently used processes that attempt to save money. Just have a look at barbed wire that has been wetted over the years. You will see the rust. It was just a suggestion that may be a bit over the top, but it is what I would do to preempt any failure. Derek

What is holding the roofing felt on the walls? Are they galvanised nails? If so could I suggest you paint each one with some protective rubber solution. May sound like over doing it but any moisture over a period of time (could be a long time) will eventually cause corrosion, especially if there is not a good air flow to dry out the moisture. Here in the UK we have found that galvanised ties in our house walls have been the causation of house sales being very expensive. Mortgage companies now ( in the last 20 years ) want them all replaced with stainless steel ties before they will allow the sales to go ahead, simply because of corrosion tie failure. This has happened in properties as young as 10/15 years old. Costs are around £2000 per property. Why take the chance if it can be prevented. Your build looks really nice. It will be good to see the end result. Derek

Hi Scorpius, I think it is the same sort of stuff, the "low expansion" is very important or it may cause bending of structures. You cannot use ordinary expanding foam. it will come down to availability and cost. Soudal stays soft to the touch and you get about 25 litres from a tube. It can be bought in several different forms. One is as in the video you pointed out. But you get less out of a can and it is way more expensive. The other methods require a foam gun and a cleaner for the gun. (Use immediately or the gun is very difficult to clean!!!) About £25 here so around $40 over at your end. The guns come in two types. Bayonet and Screw. Initial cost higher because of the guns. But if you use a lot it works out cheaper. You can use the foam for insulation in the cavity between walls. You are on the right track. Derek

Hi Damian, OK, so Mike and I have cancelled the big event, Grand Opening, ( rope lines, banners and pay booth) for Galloway this Autumn but are now reorganising for Galloway, Spring next year. Fees none refundable, just a slightly later date! We can talk about your cut, or lack there of, at John's Mirror event Derek

Make sure the wireless receiver for the game pad is not shielded by the steel pier. Game pads are prone to interference problems if not in direct line of sight. Also if too close to reflective surfaces, i.e. metal or metalised surfaces. I gave up with my wireless game pad because of problems, it was a Logitech one. I have used that make of mouse for years without any problems but the game pad was useless. You may be better off with a wired version. There are one or two other threads here on SGL that mention problems. If you have only three sides to your pod I would suggest a heavy curtain between the pod and observatory. It will keep you warmer and light out of the observatory from computer screens. A door and curtain may have been better. Friend here on SGL uses a curtain and it works well. USB3 can and does cause wireless interference to equipment. It operates on similar frequencies about 2.4 Ghz, plenty of info on the web! So good idea to stick to USB2 for the present methinks. Looks a great project, watching with interest. Derek

They won't get stuck on it so it won't hurt them. But they will not like getting covered in the goo. I like mices but not in my gear.

Mices love duct tape

If you did that you would have to ensure that pieces of gravel could not get jammed between the pier and the wood or you would definitely loose isolation! It would make it difficult to get at the junction boxes as well. Looking at the pictures again you could just fill all around the gap between the pier concrete and the wood joists for the floor.

You could use silicon sealant in a very thin layer at the pillar to wood and soft foam inside. Soudal make a silicon called Silirub, silly name I know but decent stuff. They also do a sealant that is over paintable called "Soudal Fix All " but it does not like UV light. No problem underneath but it is not as flexible as silicon. The alternative is to fit a two piece floating wood cover fixed to the pillar, so that it overlaps the hole by some amount. with a very small clearance to the bottom of your observatory. It may be difficult as there is very little clearance from your pictures. You could do it in one piece dropped down from the top. I suspect that there is not enough clearance though, so that is why I suggested foam. One last point is to paint the pillar bottom with anti- vandal paint, the really gooie type that never dries. Best of luck in whatever decision you make. Derek

Hi Scorpius, You could spiral wind a small wire around the power conduit and earth it using an earthing rod at one end. That would shield the com conduit from any interference. The gap can be filled with a soft expanding foam. We have some over here manufactured by Soudal called Flexifoam. It does not harden like most gap filling foams but stays soft. It can be used to fill around door frames or behind plasterboard without forcing it apart. It is a good insulator as well. Or you could use silicon filler. I'm not a fan of silicon as it will not bond to itself. So if it goes wrong it cannot be repaired without a lot of work. By the way Soudal Flexifoam can be used to encase any delicate equipment in a case. You just need to wrap the item in cling film then support it on small blocks underneath the item to allow the foam to get under it in the case. Fill the case with the foam half way, Wait for it to set then trim it flat to the half way mark. Then do the rest with cling film over the first half. Obviously shutting the case lid and awaiting it to expand fully and set. You will end up with a purpose made foam compartment for your gear. Derek

Hi Damian, As much as it is nice to read your updates, they are not the be all and end all of your build. We can wait, more important to concentrate on feeling good about your own work on the mirror or the shell of the scope. For your own sake forget us and just take your time. It is not our time, money and effort, it is yours and we are just the interested bystanders. Feeling rushed is probably the worst thing. Just take it easy. I built a model boat a long time ago (nearly 30 years ago). Took me 3 years and £2000+, every time I rushed it went wrong!!!! Derek

I've not tried my Loadstar for this type of use so far but this opens up possibilities. Excellent read full of information. Thanks to both you and Paul. Derek

Hi Damian, Not sure what I'm looking at there. But I you think it is better, good. You need a bit of good luck. Derek

Just a thought Damian, are you bringing your mirror for us to practice on ? . . Mike will bring the car polisher and I will bring the Brasso !

Aye, maybe summit strong enough to hold the Titanic. Nice!