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On the dinghy that my son and I are building we ran into a problem that is probably common to all boats. This little boat has both chine logs and a rub rail that obviously meet at the point of the bow. The problem is that this point is actually a compound angle; the angle due to the point, but also the angle due to the top of the boat being wider than the bottom. I guess I'm stupid but I just can't figure out how to cut these angles. I keep ending up with either one or the other being waaaaayyyy off, and then my board ends up too short and has to be scrapped. I've looked at countless pictures of boats that have what look like nicely mitered ends at the bow but I can't find any explanations of how this is done. Maybe it's so simple that it doesn't deserve an explanation? Well, simple or not I can't get it.

Can someone please either explain this proceedure or point me in the direction of someone who can? Thanks

The way I did the rubrails was to practice on a short piece of wood that was the same as the rails.  I used a miter saw and cut the angle close then I did a trial and error thing to cut a second cut that mated the end of the rail to the stem.  It was a lot easier to position a 4 inch long piece of rub rail then the 12 foot ones that boat required.  After getting a cut that matched up I used a short piece of 2x4 to hold the rubrail in the position I needed for the compound cut.  Once I got the 2x4 cut to hold the piece I just swapped out the short 4" piece of rail for the 12' one and cut it.  Picture your miter saw with a 6" long piece of 2x4 (with a diagonal cut to hold the rail at the second angle) clamped against the short raised back splash of the miter saw deck.  The blade on the miter is set to the first angle.  Use some of that rubrail you are tossing because it is to short.  Make sure you reverse the angle on the miter saw for the rail on the opposite side of the boat or you will end up with two rails cut for the same side of the boat.

I was pretty picky about getting the cut just right so it would look nice but remember you can use epoxy with wood filler to fill in almost any gaps.  I have used epoxy and wood flour to rebuild edges on door frames, patch holes where knots came out of wood (on the house not my boat), and epoxy with silica to fill the gap in the trash compactor handle where it cracked and a chunk busted out.  A little sanding and black paint and you can't tell the hande was ever broken.

Terry's explanation is a good one.  Use an angle keeper to "read" both angles.  If you have access to a compound miter saw, it's a piece of cake.  If not, you can cut it by hand.  Practice on short lengths as Terry describes.  I have a compound miter saw with laser cutting guides (the most used tool in my shop!).  If you capture an angle with the angle keeper, then align the laser with the angle, you can read the angle in degrees right off the saw!  I used this method a hundred times on the boat.

Dave

I know that somewhere in here I have seen a "Post" and pictures of a home made jig using a block plane for jointing the rub rails.  Made sence at the time, I just don't merember right now.

                                  Alan

Being lazy and not a very good carpenter I do it the easy ways ...  :

Method 1 - cut them off square to the stem and don't try to joint them.
Method 2 - Let 1 run long past the stem and have the other meet to it - it's not symetrical but after a coat of paint, who will know.
Method 3 - the Norm Abrams method - have them come up close to each other and then use a hand saw to saw down the joint - it doesn't matter what the angle is, since it will match on both sides.

You have to "pick up" the bevels on the work. This is easiest with a small miter or bevel gauge, but you can make one from a couple pieces of anything. The last one I made was from a broken piece of hacksaw blade and a bit of pine. I used a #6 machine screw to hold the blade to the pine and "ta da" a bevel gauge.

Wood butcher's friend can help a lot here too. If the parts are visible, then a bit of effort to get the angles to match looks nice.

Thanks guys. I'm really having a brain block on this thing. I think Terry's idea is what I will have to do; I'm just going to have to experiment on short pieces until I get it.

Thanks again.

A bevel guage is an esential tool for boat building.  Here is what it is.  This is what Paul was talking about.

http://www.bobvila.com/HowTo_Library/The...A2043.html

My method for getting two oposing pieces to fit together is to start on the hardest ( Typically bow joints coming together at accute angles)  once they are perfect, then cut to length the balance of the strip and fasten.

How to get a bow joint perfect, get the pieces as close as you can using saws etc.  There almost always will be a gap that you can throw a cat through.  Clamp them in as close to final position as possible with the points meeting or where ever else they meet.

Take a piece of 1" or 2" 80 grit or so sanding belt about 2' long and fold it in half and now you have grit on both sides.  Slide this between the two pieces of wood and pull up and down and very very quickly, you will feel the two pieces begin to fit perfectly.  When you are close, loosen one and move it closer and continue until you have a perfect joint.  Now fasten those in place and work you way to the stern fastening all as you go.

Here is what the end result can look like using the sand paper technique.



Tom...

Tom, WOW this is a great tip and I am sure I'll be using it quite a bit.

Awsome looking work on the boat in the picture too. I only hope I can do work like this some day.

Thanks again,

David

I've always called a bevel gauge an "angle keeper".  Learned the term from my Dad.  Must be a midwest thing!

Dave