by Sherwood Heggen
In the latest Gadgets and Kinks, we discussed the making of a new stem. In the process we found out the chines had also gone south on our project and there was nothing else to do but replace them.
One of the issues that haunts the novice restorer is where to find replacement wood for the chines. The chines were typically made of clear straight-grained white oak or mahogany and were steam bent to obtain the relatively tight curve aft of the stem. If you have spoken to any one about getting a length of such oak that is 18 feet long, you hear that though it might be available, it is a process to get it. Also steaming, though not difficult, requires equipment and some know-how. Why not just work the easy angle and do what many restorers do – laminate the chines from strips of oak or mahogany in more readily available and manageable lengths. Here is how.
Start by removing the old chine. Presumably, you have removed the bottom planking already to accomplish this. You will find a number of large screws and carriage bolts securing the chines to the frames. Remove them, taking written note of what size screws and bolts go where. Order new ones in silicon bronze. Measure the width, depth, and length of the old chine and make written note of that. Measure the width and depth of the chine at forward and aft locations and take note of the greatest dimension. That will be the minimum size of the new chine blank. Obtain lumber with which to make the chines. Mahogany is easier to cut and work and oak is harder and stronger, so make your choice. Honduras mahogany or white oak both are satisfactory materials. With the dimensions available, determine the thickness of the strips to make up the chine. Three strips work well but four strips allows thinner strips making the wood easier to bend, especially if you use oak. Simply divide the width of the chine by the number of strips you intend to use and that would be the thickness of the strip. A table saw with a feather board is a necessity here. The feather board will hold the lumber tight against the fence leaving a smooth surface on the sawed strip. You will want to use lengths of at least 12 feet so a helper on the other end of the lumber going through the saw is important unless you have a long out-feed table to hold up the other end.
With the right amount of lineal feet of strips sawed, it is time to glue things together. West System or similar product is the glue to use along with a filler to give the epoxy body to fill any minor voids. Be prepared with plenty of screw clamps, about one every foot of length. Also, unless you have lumber that is long enough for the entire chine, you will need to cut a second piece for each thickness of lamination to make the proper length. Allow about an extra foot of length past the transom to assure enough length to work with.
Now you are ready to start gluing. Start by gluing the first two inner strips together and then one at a time to build it up to the correct thickness. Gluing all of the strips together at one time becomes a slippery, sloppy mess that is difficult to handle. Mix a batch of epoxy in a clean plastic container and add the filler. Paint the epoxy on with a 2 inch disposable bristle brush. Coat both the outside surface of the first inner strip and the inside surface of the second strip. Temporarily clamp the two strips together on the workbench with a few clamps and place the new chine blank in the chine notches on the hull. Clamp the strips to the stem first and then attach clamps at one foot intervals all the way back to the transom. Always attach a clamp at each frame, drawing it down tight. If the chine is not fitting snugly in the notches, or not assuming any twist that should be there particularly towards the transom, use clamps like a wrench to induce the twist and secure them to hold that position until the glue is cured. The clamps should provide enough pressure to squeeze epoxy out all along the joint to assure a consistent bond. Let this mess cure and then repeat the process to install another strip. Be sure to stagger the butt joints.
If you are in a hurry, you can laminate all of the strips at once. It becomes a bit more cumbersome to work with is all, so take your pick.
When all of the strips are in place, the chine blank is ready to be trimmed on the forward end. This is the most difficult part of making a new chine and will require a little thought on you part. Remove all of the clamps and remove the chine from the frame. Clean up epoxy drippings on the underside of the chine with a plane or belt sander. Refer to the old chine and transfer dimensions and angles with a ruler, a bevel gauge, and pencil on the forward end of the new chine blank. Use a sharp back saw to cut the lumber. Make the first cut length-wise with the chine blank and the angled cut second. The cut will be angled, deeper at the top than the bottom according to the angles you transferred from the old chine. Trim the end of the chine to lay snugly in the stem rabbet. Dont be discouraged of you have to make a second attempt at a good fit. It is confusing to a degree, and besides, you allowed for extra foot of length just for the occasion of adjusting the first cut, didnt you? The chine, ready to fit to the stem, should look like this.
Considering the frames are ready to accept the chine, it is time for installation with those new bolts and screws you ordered. Drill the bolt holes with a foot long one-quarter inch bit. If the original bolt hole is the existing frame, let that be the drill guide to drill through the chine in the correct place. If you have new frames and knees, refer to the old chine for the hole location and angle the drill to come through the center of the bottom frame. You might want to clamp a stick at the correct angle of the intended hole on the frame to act as a guide for the drill. Install your bolts and screws and you are done. If you are so inclined, you might bed the chines in 3M 5200 before final assembly. The original lasted for 50+ years without the bedding, but it isnt a bad idea to do so. Do not cut the aft ends flush to the transom frame. Leave them at least couple inches beyond the frame. After the bottom transom plank is in place, cut it flush to that plank.
The next step is to cut the rabbet in the chine, if it is rabbet chine. That actual process is described in a previous Gadgets and Kinks article in the August 2000 Boathouse. It can be read on the BSLOL web site www.acbs-bslol.com if you have misplaced that copy.
The above method is takes some time to do over a few days, but the end result is a perfectly shaped chine blank that is very strong. Coat the chine with a couple of coats of penetrating epoxy, including the screw/bolt holes and you will have a chine that will be there for many, many years to come.
As always, if you have any questions regarding this or any other process of restoring your boat, feel free to call me at 715-294-2415 or e-mail me at Heggensj@Centurytel.net.
As ever, dont destroy it; restore it!