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Fishman38

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There is quite an optical illusion going on in this photo.  Check out the upper right hand corner of this photo, where the chine is.  Normal view, then the enlarged view.  Weird wild stuff.  Can you see it?  In the post above.  It would appear there is no chine on what would be the port side.  But it is there.

 

Not a lot got done today, mostly clean-up.  Did however get a flat spot for the motor mount glued up.

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Fishman,

 

You can't us a router on those angles. You need to dust off your trusty plane and plane a facet all of the way along the chine on both sides. The facet is tangent to the radius and the facet should take off the same amount off of both surfaces. The reason why you should do it this way is that you can seepost-127-0-86104500-1394289516_thumb.jpg the width of the flat if it is even and fair along it's entire length and on both sides of the boat.

 

You then plane off the corners of the flat and only then do you break out the coarse sand paper which wraps around the radius and do a few laps fore and aft and it will look like it was done by a router.

 

In the drawing you will see the red line which is the final radius that you want. The blue line represents the flat that you will plane. You will note that the blue line in the enlarged view is tangent (or kissing) to the red radius line.

 

You can just round off the chine in segments but it will not be as even or fair.

 

While it is important to round over sharp corners before you glass or it will bubble, remember that after the boat is glassed you will have to build it back up to a sharp corner on both the chines and transom.

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Got it this time Graham thanks.  The picture helps.    Just had a little uncertainty about the process and was concerned about doing some serious damage. 

 

For other newbies reading this, with the angle of the planks being what it is, it behooves one to become ambidextrous and plane fore to aft on both sides so as to be cutting with the grain for a smoother surface. 

 

Quoting Graham here:  "remember that after the boat is glassed you will have to build it back up to a sharp corner on both the chines and transom."

 

Thanks for adding that Graham.  It would not have occurred to me to do that.  And use the same mixture for the build-up as is used for fillets I assume?

 

Jerry

 

Note to Frank if you're reading this: I'm unable to make the "quote" function work.  Have used it before so don't think it's operator error but may well be my W7.

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Yes, you need a high strength fillet mix. Cabosil based, if you have any milled fibers, it would be even better. Because high strength fillets do not sand well, I tape the sides with the top of the tape level with the chine flats and fill the cavity just above level. After it kicks I pull the tape and trim it while the epoxy is still green. I have even used continuous rovings pre-wetout or teased out some glass strands from glass cloth.

 

I always worry about the sharp edge chipping. Marissa's chine was done this way and she is about 5 years old now and the chine edges are still perfect.

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It seems the tape used for this would need to be heavier (stiffer?) than any masking tape I'm familiar with.  Otherwise it would seem that some sort of backing would be needed, that is maybe held in place by an assistant, while the void is being filled? 

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Dale most if not all of what's being cut here is the end grain if I understood Graham's instructions correctly.  I may have used the wrong terminology.  Given that with the boat upside down and the planks sloping toward the bow, you are planing the bottom end grains at roughly a 45 deg angle if you work fore to aft instead of roughly 135 deg by planing toward the bow.  The latter makes a rougher cut though not a big deal since a few strokes with coarse sandpaper smooths it out.

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Fishman,

 

I believe I mis-spoke.  I was thinking of the solid wood planing such as the inwale or gunwale.  I was not thinking you were speaking of the ply edges.  After looking back at the previous posts I realize it now.

 

On planning ply edges, I am not sure it makes much difference which way you plane.

 

Sorry,

 

Dale

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Dale, if you're planing directly cross grain (90 deg) you're right, of course.  But otherwise, that is, more than say 15-20 deg from 90, for me it made a significant difference.  In the particular situation I was in, maybe not, as it's going to be sanded, then glassed, sanded again, painted etc,etc.  But if it's for bright work I'm sure it would make a difference.

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I was beginning to get a little smug, thinking I didn't have as much sanding/fairing to do as I had expected...................then the sun got real low in the west and OMG...........

 

even though in direct light I cannot see the bumps where I filled the screw holes , and can feel them only if I know they're there, nor see them when I lay a fairing stick against the surface,

they are definitely there.  So it looks like I need to spread fairing compound over the entire surface then knock it back down with the long board.  Is that about right?

 

These were taken before the sun got low. 

post-2179-0-30358700-1395103305_thumb.jpg

post-2179-0-07081600-1395104177_thumb.jpg

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I think on my next boat I will (1) wait 'til I'm done fairing and sanding the wood to fill the screw holes and (2) use fairing compound to fill the screw holes.  (I used regular thickened epoxy on the first pass at filling screw holes and switched to fairing compound for the second and final pass)

 

Because (1) otherwise the area around the screw hole is very hard to sand making it difficult to avoid removing more wood than epoxy and (2)the goo seems to continue hardening for a couple of weeks, so the sooner the  sanding of it can be completed, the better.

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Ah, then bungs may not be the answer.  You would have to drill the holes out larger to use them.  Though maybe with a depth stop on the drill bit that isn't necessarily a terrible idea.  Having the grain of the plug on the same plane as the plywood would make sanding fair a lot easier.  And there would be no shrinking to require a second step.   Just thinking out loud here.

 

Toothpicks, golf tees, dowels are really all the same thing, just acquired in a different way.  The closer the density and hardness of the parts of the surface, the easier to sand them all equally.

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Looks really good from here!  I haven't been posting much because sanding pics aren't too much fun, hopefully will be glassing in a couple weeks. I rounded with a plane and sander, been putting resin thickened with 407 as a fairing compound and long boarding. I filled my holes with thickened resin first, then sanded, then fairing compound. My goal is to get it as good as possible in wood, then use peel ply with the glass, hopefully then I can go to the Alexcoat system without too much major fairing. 

 

I was under the impression that only the transom angle at the bottom needed to be built back up to a sharp angle, do the chines need to be built back up as well?

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Regarding building the chine back up to a sharp angle, that was my understanding in talking with Graham.*  Matter of fact, that was the first I knew that it should be done on either the chine or the transom.  And I'm still not sure I understand the method of doing that. 

Guess I'll figure it out when I get there.  Graham said to use tape to construct a wall to contain the epoxy.  What kind of tape would be rigid enough to work for that?  Masking tape maybe if doubled or tripled?

 

I'm at the same stage as you, sanding and fairing and you're right, it's a rather tedious process, although as I get further into it and learn some of the tricks, it gets a little less so.  A friend of mine stopped by yesterday who has some experience with auto body work and gave me a tip on fairing a concave compound curved surface: build a longboard that has a convex sanding surface.  May be old stuff to some but not to me.  Helped me a lot. 

 

I'm trying the method suggested by someone, Paul at PAR or maybe Charlie Jones down on Matagorda Bay in Texas, of lightly spraying the surface to be faired with primer, then sand with the longboard to help highlight the highs and lows.  With a little practice I think it will be very helpful.  (actually I think it was Charlie in the "Epoxy Tricks" thread).................scratch that, I don't know who it was....sorry.

 

*See Graham's March 8 post above.

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