TARDIS observatory

[The14thDr]

I'm amazed at how quickly this is all coming together! I can tell she's going to be a beauty when she's finished - you make it all look so easy!

[galacticprobe]

I agree with 14th; she's looking a real beauty so far!

And this...

I have found that a hook-shaped floor cutting tool (for carpet, vinal etc) does a fine job of scouting acrylic as well...

For those looking to possibly get one of those tools, they're called "Linoleum Knives", and they're not expensive. (Be very careful when handling them; the are razor sharp and their points are like hypodermic needles!)

Dino.

[alistair]

For those looking to possibly get one of those tools, they're called "Linoleum Knives", and they're not expensive. (Be very careful when handling them; the are razor sharp and their points are like hypodermic needles!)

That's the beastie and yes, they are sharp. The plastic part of the packaging seems to hold mine quite well so I'm keeping it in that to protect my fingers while rummaging in my tool-box. On a related note, if you are using chisels, or indeed anything sharp, make sure you use any provided edge protectors when storing them and ensure they can't come out of the protector and end up with a razor edge pointing up. I now use a piece of wire to keep the chisel in its holder.

Stay safe people!

[russellsuthern]

Alistair,

Your build is coming along really well!
Your safety advice has made me think it might be wise to have a whole section on safety tips to help keep us all in one piece....
I think I'll have a quick search round the forum to see if there is anything of the sort on already...
If not I might get something started....

Russell

[Volpone]

In addition to linoleum knives (and Scarfwearer's glass cutter) there's a cutting tool for concrete-based backer board (the brand name is Hardibacker), used for things like shower stall areas.  You attach it to the studs instead of drywall and then you do your thinset and tile onto it. 

Anyhow, they make a cutting tool for it (because it dulls sawblades and knive blades very quickly).  It's basically a handle with a little point facing each way (like the top of a serifed "I").  I want to say there's diamond in the points, but I think it may just be hardened steel, where the backside is sharpened at an angle like armor piercing longbow arrows.  You bury the point into your Hardibacker and then you drag it back towards you, scoring the board repeatedly until you can snap it.  I've found it works relatively well for plexiglass too (although I've always had a problem cutting corners in anything but the thinnest plexi). 

[alistair]

The doors fit (sort of). The whole thing leans a bit to the right, which will be 'fun' to correct!

[alistair]

Just looking at ventilation mechanisms and I saw a suggestion of a solar powered fan. I've found this:

http://www.solarshop.co.uk/solar-fans#!/Solar-Fan-Kit-12cm/p/66514869/category=19615152

I was going to cut some ventilation slots behind the 'Police ^public_call Box' signs on each wall. But now with this, I am thinking just one 12cm square hole on one wall with the fan covering the hole and blowing out might do the job. What do you guys think?

[Volpone]

It seems like it would work.  I don't think anyone's ever tried it before. 

I must be getting old and closed-minded, because I have a hard time suggesting anything but the way I did mine.  And I can definitely see how someone would find flaws in the way I did it, but I'd probably ignore them. 

The good thing is you should be able to try it and if it doesn't work, you can try something else.  I don't know how many things I tried before I got something I thought worked. 

[galacticprobe]

It seems like it would work.  I don't think anyone's ever tried it before.

I think I've seen other outside builds with fans for ventilation before, but they used powered (either mains or a DC fan, like those used to keep computers cool). I don't think I've ever seen a solar-powered fan yet, so it will be interesting to see how it works. Since it would run during the day, it would draw out any dampness that set in during the night. (If the fan runs at night it could draw in that damp air and cause condensation, so this solar fan has its merits.)

I must be getting old and closed-minded, because I have a hard time suggesting anything but the way I did mine.

Nothing wrong with making that suggestion, Steve. It could be something that a new member hasn't thought to try yet, and it might work for him. Look at it this way... if a dozen people suggested just their ventilation methods, then that would be a dozen choices the member would have to look at, and then be able to decide which of those would work best, or be the easiest for him to implement. If you never suggest your method, that would be one less idea on the table.

So, no; you're not closed-minded. You're just contributing the method that worked best for you.

And I can definitely see how someone would find flaws in the way I did it, but I'd probably ignore them.

Possibly find flaws... (be positive ). And if someone did find flaws, that someone might have an idea on how to modify your method to eliminate those (hypothetical) flaws, which would benefit both the other builder and you, if you're able to modify your ventilation method. So all ideas are workable, and all are good.

The good thing is you should be able to try it and if it doesn't work, you can try something else.  I don't know how many things I tried before I got something I thought worked.

If you know where in your Diary your ventilation method is, could you post a link to it here so alistair could have a read through it (if nothing else, for his reference)? It's always nice to have a "Plan B" just in case.

Dino.

[alistair]

Started work on the roof at the weekend. This is the area that will differ most obviously from the 'real' thing: it will extend right over the top of the posts and only has one 'step'.





I am wondering whether I will need some more supporting ribs but I reckon I could probably get away with just the diagonals.

[russellsuthern]

You should be ok with just the diagonals, that's all I used.
Your wood looks nice & thick so it should last!

Russell

[Volpone]

That roof is built like a tank! It should be fine.  The one thing I would have suggested (a bit late, since it looks like you're got the triangles on) is putting on metal flashing--especially with the flat plywood bit.  Basically, it would be sheet metal that covers the flat plywood, then bends 90 degrees to run up the roof step before bending back 90 degrees so its top end is under the angled part of the roof (actually maybe not quite 90, maybe 85 for reasons to follow).  That way, rainwater runs off the sloped roof and instead of pooling on wood it hits metal and has no way to attack the wood and cause rot.  The problem with flashing is, if you don't do it right instead it guides water to the wood and traps it there, accelerating rot. 

All that said, I forget if you're somewhere that gets a lot of rain and extreme weather.  I get a lot of rain and don't have any flashing on my build.  I also don't value it enough to try and retrofit it--bending metal, cutting around the rim to get the top edge under the sloped roof, etc.  So I just keep an eye on my roof, make sure to paint it when needed and add roof patching compound when needed. 

[alistair]

Actually, I have not yet attached the trapezoid pieces, they were just laid on there for the photo. So I could go for the flashing, it's not something I had considered. I suspect though that if I tried then I would probably make a mess of it and end up creating a nice hidden space for water to pool in, especially in the corners!

I am thinking instead of some sort of rubber/bitumen coating like Cromapol Acrylic Roof Coating(http://amzn.to/2thNnr8) or Acrypol + Waterproof Roof Coating(http://www.acrypolproducts.co.uk/products/acrypol-plus.html). I'm thinking it needs to be in white, or at least grey, for the subsequent paint colour to match. I'm just trying to find out at the moment whether either of those products can actually be painted!

I'm in the west of England so we get fairly wet weather but it's not 'extreme': no hurricanes or monsoon! I'm also thinking about being able to check the condition inside that roof section. Maybe I can drill some ventilation holes in the base of the roof (probably a good idea anyway) and poke a web-cam up them every now and again.

Sorry for all the musings, I'm just trying to make sure I don't make any stupid errors and the advice of you guys is really helpful.

[Volpone]

Yeah, that's kind of my thoughts too.  And I've really been impressed with the rubber roof patching compound--I think that's the same stuff you guys call bitumen.  If you use that and just keep an eye on things, you should be fine.  And as an added bonus, since you're using yours as an observatory, you'll be inside it a lot more often than mine, which is just storage of stuff I never use, so you should be able to notice any leaks before they become a problem. 

[galacticprobe]

There's also Darph Bobo's "Flex Seal Liquid":

(Direct link: https://www.youtube.com/watch?v=_NygbA9UYPw)

They show it covering a roof, and supposedly no matter the weather, it won't crack or leak. And I think it comes in colors now, not just black, white, and clear. I think it's also available in blue and red, but don't quote me on that.

I hope this is helpful.

Dino.