Tramp lacing points

Guys - I posted a question over in the fiberglass building section, but realize now that you all may have more knowledge on this topic. Please take a look at this thread and comment if you have something to add:

http://www.boatdesign.net/forums/fiberglass-composite-boat-building/trampoline-lacing-points-52005.html

 

My F-32 has 36oz of Biax tape. I put some extra uni directional where everyone steps out of the cockpit onto the tramp and at the ends
3 seasons on and no problems

 

^^^ Sounds ideal, especially the end treatment, be careful with sanding/fairing & maybe an extra layer to bust through & maybe catch some extra substrate with some wider tape.
Jeff

 

Thanks - that is very useful !!!

 

I would recommend double bias - plus and minus 45 degrees and not normal cloth or biax. Two layers of 400gm would be sufficient. Stagger the edges. If you want to locally reinforce areas consider getting some uni tow - long strands of glass and stitching these through the gunwale and over the tube at stress points. Then you fill the rest of the holes and it is very strong and light. I have stitched on PVC tubes as genoa tracks as well as my motor pod attachment points. It makes the bond much stronger as you are not relying on the peel strength of the core.

cheers

Phil

 

Project Update

Thanks for all your input, Guys. Here is where this project stands.

My recent purchase was very well built according to the detailed architect's plans. The architect called out specific build processes and materials for 98% of the boat. But there were a couple of items that were not specified in detail in the plans, and the builder had to improvise. 10 years later, two areas of concern reared their head - the engine pod and the seats. Both were built using exterior ply and the edges were sealed with resin only. That is bad juju, because plywood checks when there is no glass on it, and allows water to ingress etc, etc.

So I have two projects - the engine pod and the seats.

This is the central engine pod from the boat. My son and I removed the 9.9 hp motor and brought the pod back to the house for some refurbishment. Because of the way the trampoline lacing points were mounted, and some improperly built edges, there was some rot on the core plywood pieces. The pod holds the motor, the fuel tank and the anchor+rode. Maybe 200 pounds of stuff spanning 8 feet. Plus your weight if you stand on it. So it has to be strong!

I replaced the bad wood on the surface, removed the heavy Trex stuff that was mounted on it and added PVC around the perimeter to which the trampoline will be laced. It is covered in 6 layers of 6oz cloth and resin. 4 of those layers go under the new framing cedar that I mounted to the top. If I've engineered it properly, this is 30 pounds lighter, rot proof and stronger. All that remains is cutting the notches for the lacing, painting and priming. I am sewing a topgun cover for the top.

Notches will be cut in the PVC using a router, and a fiberglass rod will be inserted to the end of the rod. The trampoline line will lace around that.

How it looked before:



How it looks now:

 

Engine Pod ready to remount:

 

Nice job. A question; did you get the build plans with the boat?

 

Yes I did. Or 75% of them anyway. Most of the drawings, I think, but few of the build instructions, B.O.M. etc. The architect apparently specified Bolt Rope Track be used for tramp lacing, but for some reason the builder deviated on that. It would also have some vulnerability to water intrusion, because it requires thru-bolted fasteners.

As you know, those can be made impervious by overdrilling, filling, re-drilling etc, but I'm hoping my no-fastener approach removes any doubt.

The nacelle must be strong as it spans about 7 feet, and holds 110 pounds of outboard, 35 pounds of fuel, 50 pounds of battery and maybe 20 pounds of ground tackle. Plus your weight should you need to stand on it! It weighs about 75 pounds I suppose.

 

I was never able to locate the track myself. It is available in various proximate forms in awning extrusion stores, but at the time nothing I wanted or could afford.

I eventually just drilled holes into the shears of my tri, and potted bits of wire rope. Has worked fine for years.

 

Just an update fellers. A picture tells a thousand words:

 

Just a thought.......... if one piece of string [I know its d12] breaks, you whole crew goes into the drink.
Put a d12 loop around every 3rd lashing point for piece of mind

Smart job by the way!

 

That 4mm D12 used there could lift the whole boat

 

@paxfish,

Excellent work. Can you explain how the engine pod is fixed to the beams/boat?

A couple of pictures would be great.

thanks

 

Correct, I should have said chaffs