Trimming up the Trim

     In my last post I talked about how I lucked into the material used to build the ceiling in the sleeping cabin, and how this bit of serendipity resulted in that part of the build being virtually free.  This post is going to be something entirely different.  Pictured below are the three sapele boards I will need to build the trims that will frame the exterior sides of the camper.  At $6.55 bd/ft, they were far from free.  I have mentioned in previous posts that I am using a set of plans that I bought from "Big Woody Campers".  I have departed from the text quite often, but this is one case when I did so not due to some stylistic consideration or as a result of preferred methodology, but because I really feel this way is better.  Their trims are cut from two sheets of plywood, sanded smooth, and finished.  This is much quicker, easier and cheaper than what I decided to do.  It feel that solid wood will make a much better trim.  For one thing, seeing that plywood core every time I looked at the camper (trust me, I wouldn't be able to help it), would really bother me; aside from aesthetic concerns, having the plywood core exposed to the elements, albeit protected by a thick finish, would make me a bit nervous.  More importantly,  the trim is the most likely thing to get dings and nicks in it, and solid wood will be much better to repair than a veneer covered plywood.  So, now that I have revealed something of my somewhat fastidious and worrying nature, we might as well get into how I went about accommodating it.

     The first step was to make a template for the continuous curved trim that will run along the edge of the roofline.  To do this I flush trimmed a piece of 3/8" mdf to the camper side template, then scribing a line 2" in from that to make the inside shape. I also added a bit of a curving taper at the bottom of the forward part to reinforce the movement of the circular line.  The next phase is what I like to call the "head scratching, staring at stuff on the table, muttering, grumbling, and bitching" phase of this particular task.  This is the part where I have to figure out how to get my curvy trims out of my straight boards.  Using strips of cardboard cut to the widths of the boards I have to work with, it was a lengthy process of trial and error to work out the sizes of the blanks and at what angles they would have to join each other so that the curvature of the trim would fall within them once they were all joined together.  In the end I came up with a set of six cardboard templates which would overlap 2" at each joint to account for the 2" half lap joinery.  Now that the figuring was done it was time to mill up the boards and make the blanks.

Curved trim template on top of the cardboard blank templates.

Templates on the left, rough-cut blanks on the right.

Here the blanks have been flattened, milled to 3/4", and cut to match the templates.  You can see the cardboard template sandwiched between a pair (left and right) of blanks.

     Now that the pieces are all cut, it's time to make the joints.  I will be using a 2" half lap joint.  This basically means that I will remove 1/2 of the thickness of the board on opposite sides of the joint, 2" in from the end of each board.  Then they will be overlapped and glued.  This gives you a good surface to  face glue  and thus makes a very strong joint.  If my explanation is confusing, it's okay; I have pictures.

First, most of the waste is removed with a dado stack on the table saw.  It takes a few cuts, but the pieces are cut by simply running the butt end of the boards against the fence.

Here you can see that the dado stack makes a scored surface on the face of the cut and a burnt edge.

To clean up the joint and to fine tune the fit I use a wide flat router bit in the table.  Here you can see the difference in the quality of the surface produced by the dado stack compared to the router bit.

Once all the joints are cut they are dry-fitted and screwed together from the back side.  This allows me to assemble the whole trim blank for a final check before gluing.  The screws will also act as my clamps during the gluing process.

Here the blank has been dry-fit and is being checked to make sure that the template falls nicely within its edges.

         Now that all of my parts have been made, assembled, and checked against the trim template, it's  time to take it all apart and glue it back together.  I simply remove the screws, paint up the joint with glue, and screw it back together.  Because the screws go back into the same holes, the joints register themselves, more or less, automatically.  I allow the glue to dry overnight before moving on to the final shaping process.  The next day I start by sanding the assembled blank, front and back to the point that the entire surface  is evenly sanded and I can't feel any of the joints as I run my hand across them.  Next, I lay the template on top of the blank, trace it, and cut outside the line with a jig saw.  The final trimming is done with a flush trim router bit.  Due to the linear nature of wood grain, it is always tricky to rout curves.  There is always somewhere along that curve that the wood just wants to tear out and throw a big chunk of your workpiece across the room.  You can mitigate the tendency of the wood to tear out by carefully nibbling away at the material, running the router away from the cutting direction.  I say carefully because if you allow too much pressure the bit will grab and take off on you.  It just requires a little patience.

Rough trim blank glued up.

Sanded and ready to be cut out.

Template traced onto the blank.

In the process of cutting away the waste.

The next step is trimming.  Here you can see the trim on top, the template screwed to the bottom, and the half lap joint.

Trimming process.

The sad truth is that when all is said and done, there is as much wood on the floor of the shop as there is in the finished product.

           All of the grunt work is pretty much done.  I have neglected to mention the lower horizontal trims because they are  fairly basic; 2" wide boards, cut and fit, that's it.  I mention them now because they are integral to the next part of the trimming process; the fitting process.

Here you can see the trim clamped into place flush with the edge of the camper sides.

The bottom edge of the blue tape represents the top edge of the lower trim.  I use it as a reference to mark my trim piece for cutting.

It's a bit unwieldy, but this is how I trimmed the ends of the upper trim.

     Fine tuning the fit of the trim took a bit of back and forth; cutting a hair off the bottom, adjusting the angle a bit more or less.  After going to all that expense and spending all that time to make the trims, the last thing you want to do is cut it a little too short.  When all of the pieces are sitting just as they should, there are the finishing touches to attend to.  The bottom of the lower trim and the inside edge of the upper trim will get an 1/8" round to make the edge less susceptible to dents and dings while the outside edge of the upper trim will get a 1/16" round; just enough to break the sharp edge.  The top of the lower trim will be beveled away from the trailer to more easily shed water.

Junction of the forward section of the curved trim and lower trim

Rear and lower trim

     It may seem strange to deal with the trim before there is a proper roof on the thing and there are still so many parts of the camper, as yet unresolved,  but there is a reason for doing it now.  I don't want to put any fasteners through the trim once it's finished.  At this point I can still screw the trim to the camper from the inside where the screws will be hidden.  There will be more about that when I get to installing the trim, but before I can do that one more chore remains.... finishing...did I mention how much I love finishing?