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Paint for Pulsar Observatory


varius21

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6 hours ago, varius21 said:

thank you both for the reply. I just feel like Green will look better in my garden and match the surroundings. :) If anyone can point me to the right direction on what kind of paint I should be looking at.

Check out a boat supplies company for paint suggestions.
You will probably have to abrade the surface all over to get a key. Nasty!

This dome colour problem is far more complex than you might realise.
White domes are traditional for one very good reason. Solar heat rejection.

I painted my raised, plywood dome with white primer before it quickly became sage [not grass] green.
Grass green stands out just like white! There is no grass green in nature. 😱
The white dome was visible for as far as the eye could see. Sage green, much less so.

 Round things are a blot on the landscape! White, round things are rarely seen in the countryside.
Yet white caravans are relatively huge but pass almost unnoticed. Even in quantity.
Caravans are white for a reason. To stay cool in summer when they are most used.
A green caravan would be intolerable! It would fry the occupants.


Now I am building an even larger dome [4.3m /14'] in grass green coloured GRP. Yuck!
Green GRP gets very hot in direct sunshine.
I have repeatedly measured 150F/66C surface temperature with my laser guided thermometer.
BUT, I still can't paint it white for "carbuncle" reasons. It would be seen from space!

 So I plan to paint only the shutters white.
Then park the dome with its green back to the public view when inactive.
This will also help to keep the dome cool when I am solar imaging.
The bi-parting shutters also shield lots of dome surface from the sun when open.
Pulsars have "up and over shutters" so don't have this advantage.

Bottom line: Keep it white.
Cover it with a camouflage net. Or even horticultural shade netting when inactive.

Here are some images to give you a better idea than 1000 words. :wink2:

 

 

P1340939 dome white rsz 600.JPG

IMG_2316 dome rsz 600.JPG

P1263544 green dome rsz 600.JPG

P1470869 rsz green dome snow rsz 600.JPG

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I made my fibreglass dome from scratch and used a green gel coat. The colour is British Racing Green. Its a dark shade and will be familiar to anyone who has seen an old lawnmower. It blends in so well with our trees and grass that visitors often don't notice the observatory!

It does get hot. I've since insulated the inside with foam, about 30mm thick. I installed a thermostat controlled extractor fan to exhaust hot air.

You will have to go over the whole white surface with sandpaper to provide a key.

Then any proprietary fibreglass paint of the right colour will work.

Dsc01811b.jpeg

Edited by AstroKeith
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49 minutes ago, Rusted said:

Jeremy. I have to ask:

Why did you think my post was funny?  :)

Well, the whole thing had me chuckling but the piece de resistance was the phrase “there is no grass green in nature”. Which is spot on. I also enjoyed the sage green photoshop mock-up.

My dome is “British Pulsar Green”. Chosen so it wouldn’t offend my wife’s artistic eyes. However, I soon realised any huge fibreglass dome in a small back garden sticks out like a sore thumb. Especially if it resembles a giant above ground septic tank 😊

Edited by JeremyS
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I used fibre glass primer and top coat paint, applied with a brush, just googled fibreglass paint suppliers. I rubbed the white gel coat with 400 grit paper to give the primer a key. Try and complete the task in dry weather, I was impatient and lost the gloss on the top coat and and had to apply another coat. Here is how it looked shortly after completion, 3 years on it’s still looking OK.

I wish I had a sky like that every night…☺️

6B9D056C-2C1C-43C7-88E7-E236802D8BFE.thumb.jpeg.50af9181d4739cb31ae42df04f246a7b.jpeg

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It’s off topic discussing Pulsar’s new design on this thread but it does look more 21st century.

I guess the recessed flat sections on each quadrant make the fabrication and installation of the side pods easier, and there is now an almost flat door.

I think white does help with heat reflection, but Mrs Tomato wasn’t keen on having what she described as a massive piece of sanitary ware in the back garden, so green it became.

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9 hours ago, tomato said:

It’s off topic discussing Pulsar’s new design on this thread but it does look more 21st century.

I guess the recessed flat sections on each quadrant make the fabrication and installation of the side pods easier, and there is now an almost flat door.

I think white does help with heat reflection, but Mrs Tomato wasn’t keen on having what she described as a massive piece of sanitary ware in the back garden, so green it became.

When I were a lad... you could buy sanitary ware in all sorts of hideous colours. 😱
They look horribly dated now IMO but white seems to have become the norm again. :thumbsup:

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Nice dome, the larger diameter of both observatory and shutter aperture would have suited me better than the 2.2  m Pulsar dome, but the Superscopes observatories are quite rare onto the market these days, I believe.

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