Backyard Aquaponics
A place to discuss aquaponics

I've designed a google Sketch-Up 2D plan for a cover that I can cut out of a sheet of greenhouse film (like the redpath duratough4 - polyethylene) for a 6m diametre geodesic dome PVC greenhouse. I'd like to give this design a go because it means I can cut it out in one piece and just drop it over the frame and attach it to a timber frame around the base (not sure how I'm going to do the door yet ). This is a pic of the flat plan:



(if you want to print it and cut it out it folds into a cool little paper dome )

The diagram is to scale and the dimensions can be changed in Sketch-Up depending on how big you want the dome. As it is now it has a height in the middle of three meters... If anyone wants a copy of the sketch-up files Pm me.

Anyway, you can see that the net pattern needs cutting out at some points. Has anyone had a go at joining this polyethylene film? I'm thinking a tape of some kind might be useful???

Have you thought about not cutting it but just making some folds in the film?

You can get away with some folds but you can`t fold them all

Maybe the easiest way is to use 5 seperate cover sections with folds and taped joins. The 5 main sections can be taped together with the joints running mostly vertical. The pic is for a 5/9 dome, just ignore the row of triangles below the pentagons.

After some practice.. it is possible to heatseal long pieces of poly using a domestic iron and baking parchment (silicon stuff) to prevent it from sticking.
I would be a bit wary of pvc tube in high temperates, it soon loses its strength and permanently deforms.

Edit: I just noticed yours is a 2 frequency design not a 3 frequency as in the pic ..its early here. The same covering technique can be used though.

Yes this is a 2V dome - not 3V.

Using the iron is a good idea - plastic welding... hmmmmmm.



I had been reading of this and the word on the net is that if you use a film that has a UV filter then it preserves the integrity of the PVC. Initially I was going to make a tunnel house and this was an issue with them. I guess I could use galvanised pipe and flatten the ends to make connectors that way too...

Hair straightening tongs are quite effective for narrow widths and edges especially if they have digital temperature control..just don`t let the wife catch you

Hmmm. That's cool

I used pvc glue to stick some plastic on a greenhouse once. Try a few methods and see what works best.

Do you mean that green (well the stuff i have is green ) solvent based PVC cement for joining pvc plumbing that melts the pvc temporaily then resets solid - like a plastic weld?

Not worried about my wife... it's my daughter I'm scared of

Yes the solvent based pvc cement.

If a hair straightener would work that might be faster.

OzV, i can relate to that.. i have two teenage daughters

Don`t forget to use the baking parchment even with teflon coated plates. I made that mistake joining some 1000g black dpc together...devil of a job scraping the "tyre marks" off the plates