37 replies to this topic

[rboe]

I suppose you could take a weather balloon or something suitable, inflate it to the proper size, paper it over, glass it up and there you go (the paper may not be needed but I'm thinking the glass and resin would stick to the paper better than the balloon).

Dan; over in Off Topic a thread on the hovercraft would be great! Hint hint hint! And welcome to Cloudy Nights if you have been given the proper Howdy yet.

[Dragon Man]

Yes, the Paper Mache idea does work!
There is one here in Australia too.

Ron, I considered the idea of f/glassing over a large ball/weather balloon. I found an inflatable ball large enough over there in USA (9 feet diameter) but it was US$700!!!

I'm sure if I went that way (a ball/ballon) I could come up with a cheaper solution, but the cardboard has me intrigued. The rib look doesn't bother me. I think it adds to the appeal, but that's just me.

So many good ideas being thrown in here, keep them coming. I'm always open to new easy ways to get more people into domes. I have several months before I decide which way I will go.


Ken

[rboe]

Check Army surplus - perhaps they're all gone. Another source would be atmospheric physists at your local university. They use small weather ballons to launch radiosonds. Or used to anyway. They may have some old natural rubber balloons rotting away in storage. For smaller domes the air pressure will be fairly low and be totally unworkable.

The way they make cedar strip canoes can be used too. It will be a bit time consuming and it will probably look too nice and it won't be as cheap as one would like. Use cardboard instead of cedar!

Basicaly, a wood armature with massive wood panels the shape of the canoe. You staple/pin/clamp the cedar to the wood panels while inturn gluing the cedar strips edge wise to each other. As the glue dries you remove the staples/pins/clamps and move on. In the end the panels are twisted edge wise and the canoe is lifted off the strong back.

The devil is in the details and there is much sanding and sweat involved, fibreglassing of the outside while on the strongback and again on the inside once it's off.

On the upside it's very messy!

[JerryG]

What a great Idea Strong and light weight I used masonite over my wood frame and it was difficult to work with at best I used cardboard for patterns. They were much easier to work with. I never thought of just applying resin to the cardboard. You may be on to something.

[Paul WB]

With my dome structure (plywood frame), I have been adding some strips of 1/4" plywood (6" width at the base of each strip and then thinning in width towards the top). My plan is to cover this with fibreglass cloth. These strips have curved to the shape of the dome. I'll try to add a picture.

[Dragon Man]

Paul,

some pics of your method would be great, thanks.

Ken

[Paul WB]

I am having a hard attaching pictures to my postings.
Sorry for the delay in posting a picture. Basically, I have made some strips of thin plywood (they are tapered towards the top) to create "ribs". On these ribs, I have attached fiberglass matt ("skin"), and I will apply resin and finer weave, fiberglass cloth.

[nytecam]

Excellent project! Colleague Brian Manning used a similar technique but with 12mm polystyrene sheet in the late 1960's as he described in Small Astronomical Observatories Ed Patrick Moore; pub Springer; ISBN 3-540-19913-6

[Dosster]

Hey seefive,

I love this idea. Do you have any plans?

Living in MN it gets cold. I was set on buying a small scope, for fast easy setup and tear down. After much thought and help from CN bunch I'm now set on getting a big scope and building a observatory. ( I think it will get used a lot more.)

This seems like one of the best ideas for me to tackle.

Was the price of the whole dome only $350?
Who has the best price on fiberglass and resin?
What weight fiberglass did you use?
Cloth or Mat?
Any other tips you could give?

Thanks a bunch

[kiwisailor]

Happy New Year to all Observatory Forum surfers

While browsing for ideas on observatory design and construction I found this page Paper domes and thought I'd update this thread.

SteveH

[Moggi1964]

Where's that "How to.." seefive?

Go on; you know you "want to..."

[kiwisailor]

Where's that "How to.." seefive?

Seconded, all in favour of the motion please say aye

Looking at the pic seefive has posted, he's formed a base ring of ply, and two hoops, then cut three gores for each 1/2 of his dome and then overcoated them with epoxy and glass cloth-be nice to see some more pix tho

Steve