: I am currently working on an SOF (almost ready to put in the ribs),however I
: already have the strips milled for my first strip boat.

: Do most folks use Titebond or an Epoxy to glue scarfs? I would prefer to use
: Titebond due to the ease of use. However, am I giving up needed strength
: in the scarf joint by not using epoxy? If in fact the strip infrastructure
: is essentially an internal framework for the glass and epoxy
: sandwich(where the real strength is), is there really a need for epoxy
: scarfed joints?

Well, you are talking about two different types of boat construction, so I may as well give you the answers in both applications.

Scarf joints for stringers, or chines on an SOF: The angle of the joint affects the amount of bonding area. With a stronger glue you can use a shorter scarf joint. If you have doubts about the strength of your glue, use a longer scarf.

The "traditional" length or ratio of a ascarf joint is sometimes mentioned as being a 12 to 1 ratio. If your wood is 1 inch thick and you use this ratio, you measure back 12 inches from the end of the board and cut the end of the board at an angle starting from that point. When you do the same on the board you will be mating to this you will be spreading your glue on the hypotenuse of a triangle which has a base of 12 inches and a height of 1 inch. I'll let you do the math, if you wish, but you can take my word for it (and Pythagoras's) that the glue line will be slightly longer than 12 inches. The width of the board will affect the actual area which your glue is bonding.

With a shorter scarf joint, say one which is a 6:1 ratio, the base of the triangle will be 6 inches long for a 1 inch thick board. Assuming the width of the board is the same, the glue line will be nearly (but not exactly) half the length of a 12:1 scarf. It is close enough, though, so I can say that the strength of the shorter joint will be about half the strength of the longer one. Assuming you use the same glue. With the right glues either of these scarf ratios will give you a joint which is nearly as strong as the original board, and in any case they should be stong enough for your needs.

There are lots of ways to do scarf joints, including inserting nails, wood pegs, or screws into the joint area to keep the wood pieces together. A little bit of carving can give you a scarf joint where there is an added notch on one piece which mates with a "tab" or prjection from the other piece. Of course making this symmetical would give you two mating notches and tabs. such joints were common with kayaks that were assembled by lashing the pieces together (no glue at all on the scarfs!)

Scarf joints for the stringers and chines can also be reinforced by putting another layer of wood behind them. If this was a butt joint, the wood behind would be called a butt block. Placing a block behind a scarf joint is sometimes called "sistering". You do this after bending the part into shape

Scarf joints for strips? Mostly unnecessary. In some cases totally unnecessary.

Here is the exception: You may find it easier to align the forms and to start your first row if you have a few strips which are longer than the full length of the boat. I like to have 5 on hand for this. One for the keel line and two for each sides. If I'm not using a pair of those as starters, then I'd want 2 more nice strips, for at most, 7 strips.

I usually get these by scarfing my boards into long lengths before cutting my strips from it, as opposed to scarfing strips after they are ripped. by doing the scarfing first I lose a bit of length from the lumber, but I do one joint for many strips, and when I rip the strips the joint area is as perfect in thickness as anywhere else along the length of the strip.

The amount of time saved in fiddling around (or more precisely, in NOT fiddling around) is dramatic. Cutting the scarf joint in the lumber is a simpler technique, too.

I stack the ends of the boards and make a single diagonal pass through both of them with my circular saw, which is guided along a straight board clamped on at an angle matching the line of my scarf. Once the wood is cut I flip the pieces to mate, and look along the glue line for any areas which might need to be touched up with plane, sander, rasp, etc. Glue and three clamps usually complete the job. Doing just one pair of boards gives me all the full-length strips I need to get started.

After that all my joints are made by simply butting the end of one strip against the end of the next. The strips on each side of this joint hold the strips in place just fine.

A few refinements you mhgt consider:

If the ends of the boards have discolored -- which is rather common -- cut an inch off of the ends of each strip just before using it so the joints match better.

A butt joint which has a mere 1/64th of an inch gap will be perfectly strong, but when you have the boat over your head to put it on the roof of your car you will be able to see light through those skinny cracks. If this bothers you, the cut the ends of your strips at 45 degree angles. not only will this remove the discolored areas, but the overlap will keep you from seeing those light leaks. the increase in glue area is negligible. This is not enough of an angle to properly be called a scarf joint, it is just a butt joint with the ends cut at an angle. You can do a consistent 45 degree angle cut with a cheap miter box. Stand 4-5 strips on end and cut the stack of strips all at once.

Some people believe that matching the bead and cove edges of the strips helps with aligning the butt joints between strips. I'm sure that is true.

On the other hand, I've had no problems aligning the ends with stips that had square edges. A scrap of waxpaper over the joint to keep the glue from gluing the worng things together, and pinch the ends of the two strips between two small scarps from strips held on with a clamp. a spring clamp works fine. When the glue hardens the strips will be in place forever.

One book suggested holding the ends of strips together with staples at butt joints. I tried it and I do not recommend it. I held the strips close, fired in a staple, and cursed loudly as the 9/16th staple went through the 1/4 inch strips and penetrated 5/16ths of an inch into my fingertip, which was right under the joint. No major physical harm, but it stung, and I felt like an idiot for holding the strips there. You won't have this problem if you go with staple-less stripping.

: I am totally new to building, and have NO engineering experience. What do you
: pros think?

I don't think you need any engineering experience. Everyone has had to go through the same problems on their first boat, and oh! do we remember them!. We know where you are coming form. You can do this.

Hope this helps

PGJ