GSP stitches?

What if I use a really high modulus fibre like GSP in 0.55mm dia and literally stitch the seams with that using a fine bit on the dremel and a suture type needle? Thats about 130lb average per stitch and a stitch every cm or so. And follow up with epoxy encapsulation. Will this me structuraly close or better then fg tape/resin seam?

 

You're fishing. Drilling holes close enough together to make a seam, epoxy can then saturate and hold, means you don't have any wood left along the seams. The stitches are only intended to hold the panels in alignment until the goo and fabrics cure. In fact, most experienced builders do away with the stitches and use other methods, if only to save the bother of hundreds of holes and wires along each seam, that need to be pulled and filled.

 

PAR is right.
Build your first boat in a manner that has been proven.
Experiment with something radical later (probably been done before anyway, but died)

Or make your self a test piece - 6 foot long, in the shape of a minature outrigger. One with stitches and tape and one with the GSP stitches. Bend them as much as you can and weight them - decide if it is strong enough and worth the effort for the weight.

Nothing beats trying to make a test piece to sort out "new ideas".

You will find the typical stitched and taped method to be good.

I have killed most of my "new, good ideas" by this method and have been very happy I did.

The strength in the joint comes from the separation of the inside and outside layer of fabric. The separation is caused by the epoxy fillet. Nothing that only has the separation of the thickness of the plywood can come close to the strength. Your proposal is even worse since you have one "tow" of fiber every cm where the cloth has ~6-10 per cm - a big loss of strength by its self.

 

Even though GSP has been out since the beginning of the 90s, looks like it hasnt been experimented with in composites :/

I understand about removing too much wood with lots of drilling and making the ply weaker. I will though experiment with staggered height stitch holes and make an outrigger for my boat at some stage soon using the 130lb GSP line. I dont have a closed mind and love to experiment with all sorts of things

 

You do realize the physical properties (here we go again) of GSP (Gel Spun Polymers) don't permit a good bond with the resins systems you'll use right? Most of these are polyethylene, which is exceedingly difficult to bond to. They're also heat sensitive, though the mechanical nature of their fibrous makeup is good and I think it'll tolerate the thermolytic reaction, just not a good choice.

 

An open mind doesn't necessarily equate to good ideas.

You'll have to make a tight, non-slip knot at every stitch otherwise when one stitch breaks the whole seam will open up.

Plus the stitches might eat their way right through the wood.

You have lots of ravenous sharks there, don't you?

 

Open your mind to the fact that boats require plenty of strength, and good joints. One know way to do it is with glass cloth and epoxy.

Its relatively cheap and easy to do.

 

Can a closed mind entertain a wild concept :/

GSP is gelspun polyethylene for those that dont know. Extremely fine diameter woven thread for its strength, in the common packaged form. .45mm is usually more then 100lb test

True it doesnt bond with most adhesives but how is that a limitation?
The amount of heat needed to damage it way more then environmental factors and ambient can dish out. The stuff lasts forever otherwise, not much there that can chemically damage it. What makes it a bad choice exactly?
"I will have to make tight non slip knot"? I dont even try to knot it when fishing with it mate. There are other ways to handle the stuff. A mind that has already decided that its unworkable will hardly recognize the possibilities.

upchurchmr
If its that easy then why am I unable to go ahead and tape the seams on my boat today? I finished the epoxying and fillets last night mate. Something must make it too difficult and expensive for me to move forward with the taping? Is your statement inaccurate? Does one known way make it the only workable way? Why make cars when horses did the job? Apart from the fact how difficult it is to find fg cloth and tape where I am, the damn stuff is heavy, bulky, dangerous to others around where I am working, I dont call $240 australian dollars for 10m and $100 to resin it cheap either mate

You say "Open your mind to the fact that boats require plenty of strength, and good joints". Are you saying it is a closed mind that wants to investigate a very strong fibre such as GSP as an alternative to FG?

 

OK, another of these type threads.

Good luck.

 

If using GSP (yes, I know what it is and there are several grades and formulations) for stitches only, then there's no problem, but there is is you intend to employ it as a substitute for 'glass reinforcements.

 

I can get you 6oz cloth for about $6.35 per yard, 60" wide.
This is what is used on every stitch and glue kayak made.

How much do you want?

I'll check on shipping it folded if that is alright with you.

You can send me a check.

It won't take much to tape the seams.

Or how about I send you a 50 yard roll of 9oz plain weave tape, 3" wide. - $32 per roll + shipping.

I would hate to see a fellow boat builder waste his money on chancy "open minded ideas" that 30 years of engineering convince me will not work.

If you get serious I will check into the total cost.

Give me a shipping point.

There are many guys who have tried to help you who have much more building experience than myself.

How can glass cloth be bulky and dangerous - its one of the most inert things you can put in a boat.

If you are really open minded then collect the husks of coconuts. The fibers are really quite high strength, you could lay them at 45 degree angles across the fillet, stuck down with epoxy since you have it. Seems like a perfect mating of local materials to the need.

 

Hey I have been reading up on the husk, it is even used by some german car makers who use it impregnated with resins and rubbers. It is good stuff and I am seriously considering it

I thought the glass fibres when inhaled were a cancer risk?

I am located in Rakiraki Town Fiji Islands. I do not have a holding point in either of the two major urban centers like Suva or Lautoka. If someone can hold, I can collect. I am a visitor here staying long term so don't really know anyone locally

My boat is 4m long and each panel is 55cm at the widest point. I have posted CAD pics in the other thread. Unsure as to how much tape and sheathing will be required. I am guessing about 55m of tape just to do inside and outside seams and 10m of cloth just to ply a single layer to sheath the hull on the outside

Most boats here are ply on frame and very very heavy. They do not have any sheathing, just marine enamel paint. They are left in the water to sit on the mud at low tide and they last a number of years but look terrible. I have to stay in Fiji for another year I think and pretty much fish off the wharf everyday. I am making the boat to enable me to roam and fish. Budget is tight though as what I have I have to make it last

 

We do have chopped mat here, can this be used?

 

I dont know how this turned towards a debate, my intention in posting was to find help and advice in exploring alternatives. I think the fact that the majority response has been to stick with the tried and true and dismissal of the alternatives without much in the way of technical aspects of the why and how it could be made to work is the very irritating bit and not any help towards answering the question itself

This seems to be a largish forum with the word design in the name. My hope was there be some experimental types who have had the means and have already gone ahead to explore and able to share thots

 

From wiki

Maybe it hasnt been used in boats yet because designers and builders have been sticking with the tried and true?