Winter shelter using MDPE pipe

Poignard

Poignard

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I need to make a winter shelter to enable me to work on refurbishing a wooden coachroof, and other jobs on deck. It needs to be high enough so that I can move about under it; crouching room would do. The boat is 28' loa and 8' beam (8.5m x 2.5m).

I have read about shelters using hoops made from MDPE pipe which should have the advantage of cheapness and lightness. It is available in 20, 25, 32, 50, 63 mm outside diameters.

What is the best size of MDPE pipe to use for this job? It has to be a compromise between ease of bending into a hoop and having sufficient rigidity to keep its shape in a gale.

Any other ideas for framing a winter shelter would also be appreciated.
 
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50mm direct onto stanchion bases, with a rope either side and at top to prevent 'swaying'

works a treat!

86715d32ab94f332cb1eb92d032553e5.jpg
 
Phoenix of Hamble said:
50mm direct onto stanchion bases, with a rope either side and at top to prevent 'swaying'

works a treat!

86715d32ab94f332cb1eb92d032553e5.jpg
Click to expand...

+1 Mine was shrink wrapped in an identical manner using the same tubing here in Argyll a couple of years ago. It stood up to 70mph winds no problem. My only complaint was the door flap's zip failing after a few months.
 
Looks like that is a good, simple solution.

How did you secure the MDPE pipe to the pulpit and pushpit?

My pushpit is only about 4'6" across and the widest distance between the sides of the pulpit is even less (about 3'). Would 50mm take such a tight bend?
 
the pipe will bend round fairly steep bends, but when it collapses, it does so without warning. For a really strong structure, I'd put some 8mm re-bar inside the pipe to support the curvature.

Also, if waterproofness is really critical, perhaps consider transparent builders' scaffolding tarpaulin from e.g. Monarflex. It is very very tough and tear resistant, with grommeted holes for tie-downs.

http://www.monarflex.com/Products/Weather protection/Scaffold sheeting.aspx
 
parsifal said:
Was shrink wrapping expensive?
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Yes, for my 36' ketch - about £500 inc the tubing, shrinkwrap, gas and labour but did enable me to get on with removing and overhauling the front windows, sorting out the surface rust under the treadmaster and painting the topsides regardless of the weather. So the expenditure was a necessary evil rather than money well spent!
Ian
 
As you say, money well spent. I have been reading up on this technique and it's very widely used in the USA, especially in the North where the winters are very severe. I'm surprised it isn't used more here.
 
On my last boat I made a frame from 32mm plumbing pipe and it worked well for many years. However repeating the scheme on the current boat in Corfu from 2004 using Greek sourced pipe the whole thing ended up in the harbour as the components succumbed to UV degradation.
 
I'm using 32mm at present. It's OK as long as you've got decent, straight, 'longitudinals'. My mast is on deck so that gives a solid mid-line fixing point for the arches. I think it takes more design and building than the thicker pipes.
 
A three pipe problem, Watson!

Yesterday I went to City Irrigation Ltd, Bromley, to have a look at various sizes of MDPE pipe and to try and get an idea of how easily it would be to bend it over my skinny boat (max beam = 2.5m = 8’; distance across forward stanchions = 1.5m = 5’).

Here’s my ‘report’!

It was a very cold day and the MDPE pipe was stored outside, so it was quite stiff. However, I need the shelter soon and warm days are unlikely.

50mm MDPE pipe as used by Phoenix of Hamble would be very strong but I’m not sure it would take such tight bends as my boat needs. Available in coils of 50, 25 metres or 6 metre straight lengths.

40mm o/d MDPE pipe seems a better bet for my size of boat (8.5m = 28’) but for some reason they only sell it in 50 metre coils which is more than twice what I need.

32mm o/d MDPE pipe would be much easier to handle but would presumably need bracing, as alahol2 says. (I’d be interested to know if Steve Cronin found he needed it). It has an i/d of 26mm so it would not fit over the 1” (25.4mm) guardrail stanchions because it would snag the grommets for the guardrail wires. It would have to be lashed to them with cable ties or hose clips.

Somewhere on the internet I found a statement that the minimum bending radius of MDPE pipe is 20 x outside diameter.

Blue MDPE pipe is subject to u/v degradation and black should be used if the pipe is exposed but most people seem happy to use blue, presumably because it is more readily available.

http://www.cityirrigation.co.uk/acatalog/MDPE-Waterpipe-and-fittings.html

http://www.cityirrigation.co.uk/acatalog/MDPEsize.html
 
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parsifal said:
Blue MDPE pipe is subject to u/v degradation and black should be used if the pipe is exposed but most people seem happy to use blue, presumably because it is more readily available.
Click to expand...

I believe the pipes are identical (both are PE80 MDPE) but the black prevents light ingress thereby preventing bug growth in the pipes, and presumably blue is used in the ground so you can hopefully see it before cutting through it when digging holes!
 
mdpe is commonly used for polytunnel type greenhouses. I've seen 32mm used and would think it would be quite satisfactory for a 30' boat. Bending radius is sometimes quoted as 12 x OD but it depends on temperature at the time of bending.
BTW blue is for potable water, yellow for gas, black for non-potable water so that if you dig one up, you know what's in it.
 
I stole some glass fibre bendy poles from a knackered tent. I had trouble getting them to stop in one place but I think I'll have another go securing them to the mast down the middle, never thought to do that before. I have a clear mono filament tarp from Bradwels, good for letting light through but it hasn't lasted as long as I thought it would.
 
parsifal said:
Yesterday I went to City Irrigation Ltd, Bromley, to have a look at various sizes of MDPE pipe and to try and get an idea of how easily it would be to bend it over my skinny boat (max beam = 2.5m = 8’; distance across forward stanchions = 1.5m = 5’).

Here’s my ‘report’!

It was a very cold day and the MDPE pipe was stored outside, so it was quite stiff. However, I need the shelter soon and warm days are unlikely.

50mm MDPE pipe as used by Phoenix of Hamble would be very strong but I’m not sure it would take such tight bends as my boat needs. Available in coils of 50, 25 metres or 6 metre straight lengths.

40mm o/d MDPE pipe seems a better bet for my size of boat (8.5m = 28’) but for some reason they only sell it in 50 metre coils which is more than twice what I need.

32mm o/d MDPE pipe would be much easier to handle but would presumably need bracing, as alahol2 says. (I’d be interested to know if Steve Cronin found he needed it). It has an i/d of 26mm so it would not fit over the 1” (25.4mm) guardrail stanchions because it would snag the grommets for the guardrail wires. It would have to be lashed to them with cable ties or hose clips.

Somewhere on the internet I found a statement that the minimum bending radius of MDPE pipe is 20 x outside diameter.

Blue MDPE pipe is subject to u/v degradation and black should be used if the pipe is exposed but most people seem happy to use blue, presumably because it is more readily available.

http://www.cityirrigation.co.uk/acatalog/MDPE-Waterpipe-and-fittings.html

http://www.cityirrigation.co.uk/acatalog/MDPEsize.html
Click to expand...

What I used was good quality OSMA ABS pipe and push-fit 45 & 90deg unions and tees so there was no bending nor stress' The uprights were PVC taped to the stanchions and the a double layer of Bradshaw's bestpolytarp with bubble wrap interspaced was used as the cover. The Greek version failed because their drastically inferior plumbing fittings were destroyed by the UV and their small size waste pipe was only 29mm. Brought back what I could salvage and have subsequently used it as a data cable and power lead ducting in the garden.

I now have a vinyl canvas all-over laying up cover made by a mental defficient and his wife who operate from MainSt Kondokali. With some persuasion it can be made to actually fit in a few places but only a few. As many friends have pointed out "You should have gone to Anthony Giatras" I WILL next time!
 
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Steve C Cronin said:
What I used was good quality OSMA ABS pipe and push-fit 45 & 90deg unions and tees so there was no bending nor stress' The uprights were PVC taped to the stanchions and the a double layer of Bradshaw's bestpolytarp with bubble wrap interspaced was used as the cover.
Click to expand...

What diameter of OSMA pipe would you recommend and how far apart were the supports (fore and aft, I mean)?

I have bought a roll of 40mm o/d MDPE pipe to use for the hoops but I think I may need a ridge pole and I wonder if the OSMA pipe would do for that.
 
No ridgepole needed.

parsifal said:
What diameter of OSMA pipe would you recommend and how far apart were the supports (fore and aft, I mean)?

I have bought a roll of 40mm o/d MDPE pipe to use for the hoops but I think I may need a ridge pole and I wonder if the OSMA pipe would do for that.
Click to expand...

No ridge pole was used on mine and it withstood a 70mph gale with no probs and as you can see, the tubing was just cable tied to the stanchions. (The shrinkwrap was secured by cord under the hull at 2m intervals)
 
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