Net attachments

[strontiumdog]

Hi,
I am looking into molded in net attachments a la ORMA/BnQ

Has anyone any experience of these eg what size conduit to use, stainless rod or fibreglass rod, what diameter etc?

many thanks
andyf

[s v ugly sister]

Hi - my son & I are re-building an ORMA-60 for cruising - we have removed most of the net attachments for the re-build - the boat was built in 1994 - the attachments consisted of 2 types - 1.) stainless tracks which ran along the main hull & the amas - nylon slugs ran inside the tracks & the net was secured by line to the stainless part of each slug - 2.) along the fore & aft connectives a 3/8" plastic pipe was glassed to the X-arm - the pipe was covered by a layer of fairing material - sanded or ground to shape - glassed or carboned-over with epoxy - then the re-inforced shape was ground in a VEE every 4 inches exposing the plastic pipe - a 3/16" stainless rod was threaded thru the pipe & the rod was secured by glass lay-up at each end - the net was attached every 4" to the stainless rod - - very strong & very simple - - - - the seriously strong net used was about 2" x 2" mesh & seems to be kevlar - - - HOPE THIS HELPS Dale - Miami , Fla.

[tspeer]

I just had similar net attachments added to my tri. The nets had been secured with eyestraps that had self-tapping screws into the fiberglass fairing on the beam and the carbon tube built into the cockpit sides. As you might expect, with the load being resisted by the screw threads, they started pulling out when I put on more robust nets.

The flanges used a fiberglass rod (batten material) with carbon cloth wrapped around it and molded to the shape of the beam. Then holes drilled between the rod and the flare of the flange to accept the laces.

Here's a cross section of the flanges I had added:
http://farm4.static.flickr.com/3207/2686256931_b44aed2152.jpg

Here is a flange being glued to the beam:

http://farm4.static.flickr.com/3181/2686257327_211af10bd0.jpg

I probably should have specified larger holes, but those were adequate for the lacing material I am using (24 strand UHMW twine).

[strontiumdog]

Thanks Dale and Tom,
that's very helpful.

Dale: any idea what the lay up is over your plastic pipe?

cheers
andrew

[tspeer]

Sigi Steimer used tube-and-rod net attachments on his F-33 Hi-5. (http://www.sigi.ca/hi5/hi5/index_02.htm)
You can contact him through his website to find out more about the details of layup and construction of the attachments.

Here's a picture of it at the earliest stage of construction.

http://www.sigi.ca/hi5/pictures_f33_construction_2004/Im001657.JPG

There's a stand-off between the tube and the hull. I'm not 100% sure what the purpose is, other than to act as a filler and fillet. It would also give you some room behind the rod to help pass the lacing around it.

http://www.sigi.ca/hi5/pictures_f33_construction_2005/Img_0041.JPG

http://www.sigi.ca/hi5/pictures_f33_construction_2005/IMG_0215.JPG

[s v ugly sister]

Hi Andrew - - the fairing material that forms the shape & gives body to the net attachment looks to be microballoons & epoxy - probably had a bit of cabosil mixed-in as it was harder than regular microballoon / epoxy fairing. - - fairing material was probably screeded-on with a shaped screed - then sanded & glassed or carboned with epoxy - when we get to the net replacement stage of our project we will be using this same tube/rod net attachment system. Hope This Helps Dale Miami