Commander #155 'Mephisto Cat'

[Rico]

Ok... Now back to our sheduled project documentation program -already in progress:


The Coambings
The Mephisto Cat came to me with what I assume are the original coambings. They appear to be Teak (evidenced by Smell, feel, & grain) and although they were well weathered to the gray patina commomn to weathered teak, and had a bit of mold in the areas not exposed to sunlight. Fortunately, they responded quite to just a bit of cleaning-up and looked relatively good for the next year without any oil or varnish.

They were untreated, but in great shape. I would guess that they had been varnished at some point long, long past, but it seemed that they had received only oil -if anything- in the more recent past, and nothing for at least the last few years.

I do not have specific 'before' shots (I missed these...), but you can see them in some of the previous pictures of the boat on this thread.

After a couple scrubbings with a bit of Ajax cleaner (A bit odd, yes... But it works great on teak!) they came right back to a nice light brown color. This encouraged me to do a bit of work on them and to eventually get them all varnished-up.

Originally, I thought I would not bother removing them, but since I had already taken everything else off of the hull, I thought I might as well...

In hindsight I am glad I did. Taking them off allowed me to be able to get a nice prep on all surfaces while working in comfortable positions, and to do the repair described below.

It was a bit of a bear to get them off as they were quite solidly attached to the boat. There was a bit of well-cured polysulfide against the fiberglass and this held them on quite strongly even with all the fasteners removed.



Reinforcing/Repair of the coambings.

The coambings are positioned with a slight curve to them and this provides a bit of rigidity against bending of the wood plank in the vertical plane, but it still remains a wide piece of wood that is only supported laterally at the cab attachment, and at the winch stands, and at the bottom edge (at the3" or so...) as they are fastened to the fiberglass.

As I mentioned, my coambings were in great shape, but a bit of eager help in removing one of them caused a longitudinal crack along the sharp corner cut into the coambing as it transitions from the deck onto the cockpit's side. (See last picture below) The removal of the polysulfide bond responds much better to warmth from the sun, small wood wedges, and some guitar strings (think cheese-cutting wire) as opposed to brute force...

I did not want to have a weakened coambing as I thought the crack would only get worse over time, but I also did not want to have an obvious repair with wood or metal reinforcements visible.

I thought of using a loooong stainless or bronze wood screw from the bottom edge as this would remain invisible. Failing to find such a beast I used a length of coarse-thread 316 stainless-steel allthread rod and epoxy.

First I glued the cracked surfaces together. Then I took a 5/32" drill bit (9" long, I think it is...) and drilled a hole through the middle of the thin dimension of the coambing. I smothered the sides of the hole with epoxy (using a twig from a natural broom) and then used my drill motor to screw in the length of 3/16" stainless steel all-tread rod into the pilot hole.

This not only pulled the two pieces tightly together, but it should provide solid reinforcement against future side-load stresses that may cause cracks. Especially towards the front where the Commander's coambings are up to 12" tall... and towards the very rear where the stern-most few feet remain unsuported.

After seeing the results, I proceeded to put four more pieces of rod into this coambing. two more as further reinforcement where the crack was and another at the unsupported rear end close to where there is the rear sharp corner cut into the coambing.

...then I put another three pieces of rod into the other coambing. - Just for preventative strengthening...

The holes look large because I drilled a 1/2" hole about 1/2" into the coambing to allow for the jaws of my drill to drive the rod below the edge surface of the coambing and then filled this in with resin.

The driving/screwing of the rod takes quite a bit of torque, as you can imagine. The trick is to keep the pilot hole in the middle of the material - a bit tricky with such a long drill bit / rod.

Out of the six holes I drilled, I only sort of screwed one up. The rod actually came onto the surface but only at the very tip. I ground this down to make smooth and left it. (Somewhat visible in the third picture) - Not too bad for work with a hand drill...

I then cleaned the wood up, did a bit of sanding, and over the course of the next few months sanded and applied some 8 coats of Epifanes clear varnish. The pictures were thaken sometime in the middle of this long process so the coambings do not look their best at this stage.

Epifanes is wonderful stuff. (It is made in Holland - one of my of my most favourite former homes!) I've had good results with it and it is amazingly long-lasting. It really brightened the coambings up nicely... They look pretty amazing and it is one of the first-things that people comment on about the little boat.