Just a quick update on adding the gunnels to the boat, the last one was applied yesterday and i will be going out after coffee to start the cleanup and fitting thwarts and decks.
This post will cover adding in the first gunnel (inner) and the next will cover the completion and cleanup.
First, this is the shape of the gunnels I made at the start of this thread, they are 5/16" x 5/8" and the inners have a 45 chamfer cut. The chamfered ones are for the inners and the slope allows water to easily flow out when the boat is inverted.
The top 1.5" or so is sanded with 120 grit and any glass with air underneath is cleaned up and removed.
I dry fit the gunnel and drop it a bit lower than the sheer, in this case I am dropping it 1/4". As it approaches the ends, I will lessen the drop as the strip starts to roll it will get trimmed quite a bit in this area to accommodate the decks. Once I like the dry fit, I run a pencil along the top and bottom to give a guide for preparing the area to apply the gunnel. If you look at the dry fit, you can see the lines i have scribed.
and the end area
Why drop it a 1/4" ... I usually plan to do this as the edges of the sheer always manage to a) get thinner b) there always seems to be "imperfections in the glass at the edges c) trimming the sheer is usually a very rough cut
Planning to lose a 1/4" cleans all of those issues away.
The issues always seem to be in that first quarter inch
Apply painters tape (or whatever you use) just below the lower guide line and add a drip skirt ... I always seem to lose a drip or blob of epoxy, so I use one, it is easier than cleaning up.
Mix up a batch of epoxy (I use a 4 shot batch) and apply unthickened epoxy above the painters tape and onto the selected side of your gunnel
I am using cherry gunnels and it is a white cedar hull, I like to use the epoxy to create an accent, so when I do the epoxy thickening, I go quite dark. This batch is using cherry and black walnut dust , with cabosil to thicken to peanut butter. (also in this pic is the foam brush and paste brush I use to apply the epoxy)
There are imperfections in that sheer edge area, so i butter the gunnel quite generously with the thickened mixture ... you could also butter the sheer area if that is your preference, but only one needs to be done. The idea here is that the thickened epoxy won't run, it will stay in place. So as it gets clamped, it will squeeze out filling any voids and leaving behind a solid, filled area with no weak spots.
The clamping does not need to be anything other than moderate, I am using spring clamps this time and they are adequate, if you use C clamps, a good gauge would be to tighten to not leave any marks in the gunnel wood.
I use a 1" foam brush (JEN) to apply the unthickened epoxy and a small stiff glue brush to apply the thickened epoxy.
Start by clamping/aligning at each form location or every foot or so ... then go in between adding clamps and "tweaking" the gunnel to fall on the guideline. I like to have a clamp about every 3".
A few comments on the epoxy work, the only real time worry is to get the unthickened epoxy on the gunnel and the sheer area before it kicks, if the epoxy starts to kick while you are buttering, you will still have ample time to complete the task as it will stay soft and "flowable" for quite some time. In practice, you will be done long before the epoxy even kicks, as it is a relatively fast and easy operation.
VERY IMPORTANT ... once you have finished clamping, go around the bottom edge and cleanup the squeeze out. Use a putty knife, your finger , a stick, whatever you have or are used to using. Get the bulk of the squeeze out removed, then go around with a folded paper towel to remove the rest, get as much as you can and leave that bottom as clean as you can ...
you will be happy you did this when the time comes to sand and cleanup the hull for varnish ... soft epoxy is easier to cleanup than hard epoxy.
Remove the guide tape and skirt at this time, it isn't need anymore ... wipe the area of the guide tape for anything that got under the tape.
Now, leave it for the night ... at least that's what i do, just plan the work so it's done near my quitting time.
Next day, off come the clamps and you have a messy looking top like this
I grab a shorter plane and trim off the excess sheer to an angle the same as the gunnel forms ... this just needs to get the 2 at the same height, don't try and make this the finished product, just get it at the right angle and mostly smooth
if it's anything like mine, the accent line will vary a bit in thickness, again, don't worry, it will just blend and disappear when it gets all finished.
Now a bit about the ends (stem/bow) ... the gunnel was allowed to rise a bit and not have the 1/4" sheer stick out the top, there is a reason for this ... you can see the angle formed by the gunnel near the end. that will be getting planed flat when I get ready to install the decks, when that area gets flattened, you can see pretty clearly a 1/4" is coming off the entire area as well. So you need to plan this area with how you will finish it ... deck on top (me), decks between or no decks at all and markup accordingly.
The outer gunnels use pretty much the same treatment, dry run markup, taping etc., one notable exception, the alignment will now be to the top of the sheer, by planing after the inner gunnel is attached, you establish the angle and the outer can be aligned to match, this will make the final cleanup/leveling/sanding a lot easier.
I will do up the last part of the gunnel install in a few days when I am a little further along in the finishing ...
Brian