Material for mocking up a tubular frame.

[Simondjuk]

I want to build an arch/davits for my boat, but want it to look really right. Consequently, before I start cutting, bending and welding relatively expensive lengths of stainless tube, I want to mock the arch up on the boat, try a few different shapes and layouts, have a good look at it from all angles, and maybe even use it as a pattern of sorts

I could do with something along the lines of giant bendy straws to use as a quick, cheap and easy way of making a readily modifiable pattern, but they don't exist. I considered plastic conduit, but I'm not sure if it will hold the bends even if heat is used, but it's possible.

So, before I go out and buy something which won't work or may not be the best compromise of usefulness to cost, does the panel have any genius ideas of the ideal material to use for such a purpose? I'm not too bothered about it being exactly the same diameter as the final tube, but something similar would be good to give a reasonable representation of the finished article.

 

[Wansworth]

you can buy plastic wáter pipe with various joints that can be glued ......probabkly in B&Q

 

[Simondjuk]

I considered that but really want to get a feel for the look of the curves I might use, which I won't be able to replicate with angled fittings.

The pipe alone is another potential candidate for shaping with heat along the lines of the conduit idea. Perhaps I'll get a piece of each and see if they can be made to take a set. Thanks for the thought.

 

[PlankWalker]

I mocked up one using conduit and glued on bends, the bends have too small a radius , but it gives you something to work out the final dimensions.

Plank

 

[Simondjuk]

Hmmm, thinking about it, I suppose I could rough in the curves with a flexible material inside a more angular pipe/conduit frame. The corners outside the curves may be a little distracting, but perhaps not too bad. Thanks.

Still got this nagging feeling that there's something rebendable by hand which is the ideal stuff though. Like a convoluted conduit which clickety clicks into bends and stays put. Not sure if I've actually seen similar or just imagined it.

 

[boatmike]

Assuming that you have a bending machine for the stainless, you could consider using thin wall copper pipe as a mock up first.... You only need to use this for the bends and then attach plastic pipe to that.......

 

[geem]

I want to build an arch/davits for my boat, but want it to look really right. Consequently, before I start cutting, bending and welding relatively expensive lengths of stainless tube, I want to mock the arch up on the boat, try a few different shapes and layouts, have a good look at it from all angles, and maybe even use it as a pattern of sorts

I could do with something along the lines of giant bendy straws to use as a quick, cheap and easy way of making a readily modifiable pattern, but they don't exist. I considered plastic conduit, but I'm not sure if it will hold the bends even if heat is used, but it's possible.

So, before I go out and buy something which won't work or may not be the best compromise of usefulness to cost, does the panel have any genius ideas of the ideal material to use for such a purpose? I'm not too bothered about it being exactly the same diameter as the final tube, but something similar would be good to give a reasonable representation of the finished article.

Go to your local stell stockholder and buy some 1/4 inch rebar. This will hold its shape and is stiff enough to give nice long slow bends. You will need to tape the ends so they dont scratch the deck but they will do what you want cheaply.

 

[pvb]

I'd use flexible plastic corrugated conduit with steel rod inside to hold the shape. You can get conduit in white and 25mm diameter, so it will look quite like the finished arch.

 

[nigelmercier]

You can bend plastic pipe with a little heat ...

 

[Grampus]

I used 15 mm copper plumbing pipe and Yorkshire solder fittings. Being copper it took and held the free hand bends and bows and the standard Yorkshire fittings give lots of freedom as well as strength. For really weird bits I Just slotted part way through the tube with lots of cuts, bent to shape and filled the slots with solder. If needed just solder on extra braces where required.
galps

 

[Hadenough]

Use copper tube and weigh it in when you have finished. Easier to work and probably will work out cheaper than plastic.

 

[sarabande]

standard black alkathene water pipe from an agriclutcheral supplier, with a length of 8mm rebar inside.

Can be bent by hand, and will take up the required curve by manual adjustment.

 

[gordmac]

One of my friends mocked up a roll cage for a rally car using plumbing pipe insulation.

 

[Poignard]

Plastic pipe from Wickes etc and return any unmarked items for a full refund afterwards.

 

[Simondjuk]

Thank you one and all, some excellent suggestions there. I'm sure with a combination of them that I can rig an mock-up which can be easily adjusted until it looks and functions as I have in mind, can be used as a pattern, and at reasonable cost, especially if most of it can be returned for a refund later.

I'm now imagining the funny looks I shall attract as it appears that I'm using plastic pipe and conduit, cooper tube, rebar and all sorts of other random materials to construct some monstrous structure on the back of my boat.