Round over on chine lines and panel joints?

So I have the majority of the hull and deck of my Shearwater Sport sanded in prep for fiberglassing the outside.  I'm looking for some advice on how to know if I have rounded over the joints between panels enough so the glass will lay down nicely.

In many places, like in the middle of the boat this seems easy, especially on the chines and shear panel areas -- these panels meet at fairly low angles, but in the bow and stern the panels meet at very sharp angles.  This is especially true where the deck meets the hull and  where the left and right side of the hull come togther and sweep down to become the keel line.

I know the manual calls for a 1/4" R round over -- however I don't want to sand through the first layer of ply and cause some issue that is only repairable with paint.

Any suggestions on how to judge what is enough round over?  -- Seems like a silly question, but this is one of those times when it would be great to have someone who has built a kayak -- looking over my shoulder, saying "that's plently" or "a bit more there..."

Skill will take me so far -- I need experience!

Thanks again.

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RE: Round over on chine lines and panel joints?

   Hi Dave, Sounds like you're making good progress.  I'm pretty sure I made the bow and stern on my SWS 1/4" radii.  I don't think I would go less than that.  The shear and chine joints are a bit harder to describe just because of how the meet one another.  Just try to keep that rdius in mind as your rounding over.  Go slow and frequently run your hand over the joint.  If your gut is like mine you'll reach that point where it just "feels" right.  Remember, its your kayak, and right and wroung are somewhat subjective.
I think I've mentioned it before responding to one of your questions, there were many times I wished I could have had someone standing over my shoulder too.  Now I feel confident enough to give out some advice from time to time from what my gut and I learned while building two kayaks.
Keep plugging away!



RE: Round over on chine lines and panel joints?

BTW, where are you located?  Wouldn't it be a kick in the head if we lived in the same town?



RE: Round over on chine lines and panel joints?

Thanks for the advice -- I really appreciate it.

I have decided to take a break from the boat and sleep on my sanding till tomorrow.  Sometimes it is better to walk away than sand too far -- I can always round over a bit more tomorrow.

I do have one other question -- I found getting the glass tapes into the comartments to be quite a chore.  It was quite difficult to be able to "see" what I was doing in the front compartment with the small hatch, even the back hatch was hard to do.   In light of that, my fiberglassing was not the neatest. I know that's not a big deal, (no one will really ever see it...) but there were some sharp points and edges in the tapes when it cured.  It's rough enough in places I decided to sand it to make it less likely to poke anyone when reaching in the compartments.  This wasn't a huge sanding job, but enough to take the edge and points off.  

-- My question is should I now go back and re-coat that with a light layer of epoxy to seal up anything I may have exposed?  My thinking was to go back over it, as it will fill in any spots and smooth it all out.  But maybe this is overkill?  

Thanks again for the advice --  I'm actually located in Ottawa, Canada.


RE: Round over on chine lines and panel joints?

Since you were sanding off sharp points and edges you probably didn't even get near to bare wood.  If you suspect that you did expose bare wood you would really need to get that covered with some unthickend epoxy.  One coat should be adequate since wear and tear aren't really an issue in the fore and aft compartments.

I did forget to mention one key tip in my previous post.  When you are cutting your glass for the bow and stern where those roundovers are so sharp it really helps to cut it on the bias where the weave runs at 45 degrees.  I'm pretty sure it mentions that in the manual.  The bias really helps the material to conform better.  It still requires a good bit of patience mind you, but it definitely helps.



RE: Round over on chine lines and panel joints?

   If you're putting a 1/4" radius on ply you're guaranteed to sand through layers. The trick is to sand evenly so the ply lines are nice straight lines (or following the desired curve). As long as it looks to the eye like it was on purpose, it'll look fine with a bright finish.

RE: Round over on chine lines and panel joints?

i was looking at my shearwater 17

and my sense is i executed it with less than 1/4 round and i was able to get the cloth to work with me to do that. 

like you, i was doing a bright finish and i wanted to have a clean look that i think is a bit more difficult to do with a larger rounding.  that said i also was pretty careful to bevel my panels as part of the assembly process.  becuase i did the bevels, the consequences of how much ply was shown when i rounded it was minimized and it looked very clean.

on what to do after you sand off internal burrs, i agree with Dave.   ou probably aren't coming anywhere close to sanding back into the wood.  but, of course, a quick swipe of epoxy never hurts and if it makes you more confident that nothing will go wrong, just go ahead and do it.

like you i reached in pretty far to make sure i was not leaving a sharp edge anywhere i was likely to ever put my hand in normal that is a really smart move.   i learned about the need to do that the hard way when using my first boat.  not a lot of fun to have a bloody hand when using your boat....especially when it's not your hand. :)



RE: Round over on chine lines and panel joints?

Thank you for everyone's advice -- very helpful!

I think I have gotten to the place where the roundovers "feel right" -- well maybe I should say that I have gotten to the point where I don't really want to go any further.  Sometimes it's better to stop....?  

If I was building this boat again, I think I would stop a bit earlier in fact -- but I won't really know that until it lay the glass down and see how it conforms.  -- I guess that's why people don't stop at building one boat.  I do have my eye on that Petrel Play SG.  Such a good looking boat.  -- But I dirgress.

In any even with my SWS - I have decided that if I don't like the way edges look afer glass and some varnish, thnen I will add some stripes to hide them and then still have the majority of the boat a bright finish.

Now to see if I can become a jedi with fiberglass...


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