Pilot House Floor

Teak Strip Floor... a slightly different take on the West System.
(edited my text, rushed the post so re-read) Thanks!

African Teak ready to mill

First it's not teak, it is Iroko or African Teak, not the traditional and extremely expensive stuff that is from SE Asia. As a matter of fact, there are several species that are used as a substitute. In quite a few boats out there, and on a lot of what is sold as "teak" in outdoor furniture and in quite a few European Yachts (as I understand it) the real teak used is of the African variety.  The secret in its longevity is the oiliness of the wood that creates some issues when gluing, but, in general is a heavy and rot resistant material.
The African variety has a bad reputation among the purists (as long as its not their wallets they have to dip into) and it is a little hard on tools due to its high silica content and interlocking grain that can actually be felt as it is machined into strips by the resistance felt when pushing it through the blade.
I had purchased two 8/4 boards around nine feet long and wearing a respirator with a 36" fan behind me, I ripped the strips slightly oversize, then planed them down to 1/4" final.
One thing for those folks out there running this through a planer.  Take extremely shallow passes and go slow if you have two speeds to choose from.  A few times I attempted to push the cut and speed and the result was a lot of tearout.  The strips seems very stable and sat for almost three weeks before assembly.  I noted no wild movement or twisting.

Strips milled and what's left of the second board

Talking about strips...
I have made a decision to use the Teak Decking Systems or West epoxy approach to laying this floor with a few modifications of my own.  The general procedure is to mill the Teak into 1/4" thick x 1-1/2" to 2" strips, edge-sawn, and glue this using a bed of epoxy as we set a 1/4" gap between the strips.  This would be traditionally filled with a poly-sulfide rubber caulk to prevent water from entering the gap.  In the West System approach the gap would be filed with graphite colored epoxy to simulate the rubber caulk.  I had little faith in the epoxy having enough flexibility to compensate for the natural expansion and contraction of the material.  In my experience epoxy was a fairly brittle material over the long haul.  Instead, I had decided to use the Teak Decking Systems (TDS) SIS 440 caulk.  It is a rubber caulk that is extremely flexible and, so far, is fairly easy to use if you follow directions.
Our "different approach" is to use a backer board to create a solid panel and build this on the bench to be installed as one piece.  Brainstorming ended with my Dad suggested using left over 1/4" Marine AB Fir.  It was perfect and would stiffen the floor even more.  The weight is down low and that can't do anything but help.  TDS  uses this concept on one of their products that they sell and manufacture for the boat building industry.  They are pre-assembled panels that are ready to glue down.  We took this approach for the convenience of construction and to add an even more stable platform for the teak strips.

Pattern Complete

So, to start, we needed to get our pattern off of the floor on what we would need to cover.  We opted to go ahead and teak under the galley cabinet and steps.  We don't think its a waste and will help prevent creating a low spot for water to pool under the batteries and galley if ever there was a flood.  The Settee will occupy the port side of the house so the line was continued straight off of the head's wall.  We used a cheap poster board which is less likely to stretch and distort like brown paper might.
















Once complete, 1/4" marine ply was pulled out and the pattern transferred and cut.





















Off to the wood shop!

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Here we will build the panel on the outfeed table of the table saw.  The problems with adhesion, as mentioned earlier, is the oiliness of the teak. The answer is a liberal wipe down with acetone prior to starting the process.
So here is the procedure and I'll let a few pictures follow until we caulk:
1. Roll the panel with a thickened mixture of epoxy, silica and milled fiber for strength.
2. While I rolled the panel, Dad rolled the back of the strip with the same mix and handed them across to me.
3. We stapled the edge strips and ends where molding will cover.
I also discovered that the pneumatic stapler can toenail the strips edge if placed just right so that the strip is held tight against 1/4" tile spacers.  Please use a firm plastic spacer.  The tombstone rubber ones I used are too flexible and I resorted to 1/4" strips of UHMW material as the tile spacers crushed under the tension of the strips.
4. Once the entire panel was glued and stapled, We used packing tape covered cauls and clamps to hold all snug.





Pictures of this follow...

A little of everything holding the strips in place.  Note the spacers
and weight added where needed.  It doesn't take too much for epoxy.

Panel, final trimmed, and ready to fill the seams.  Note the roll of
3M fineline tape that needs to go at the bottom of the seam with
a paint stick to help it along.

Filled seams

Now, (I always start the recommencement of instructions with the word "now" for some reason), we are ready to caulk the seams and this starts with the application of a bond breaker in the bottom of the groove.  This is not easy.  As a matter of fact it is tedious and I found the best method to start the tape at one edge and apply a lot of tension to the tape held close to the groove while using the opposite hand to poke the tape down into the bottom with a paint stick.  

Why a bond breaker?  The idea is that the caulk typically fails when it is adhered to 3 sides. During normal expansion cycles, the caulk will tend to crack along the third edge.  This is typically one strip edge.  If its is bonded to two edges only and floats along the bottom, the caulk can perform as designed.  This is one aspect that the TDS folks attribute to the success of the system over all others.  They assert it is absolutely critical to the caulks success. 

Next time I will try a screen spline wheel to "pizza cutter" roll it in. Regardless, it worked and got faster at the end.  The SIS 440 was the standard 10 oz. caulking tube variety and we used the pneumatic gun to push it in.  There was nothing special about the application... push it in till it is just proud of the teak surface and then follow with a flexible putty knife to push out entrapped air.

This has to set for 48 hours before sanding...

Partially done, look closely at the
ends of the grooves and you can see the
tails of the bond breaker tape.

"Easy to sand" the directions said, yea right...

I started the sanding process with an RO sander.  I quickly put it down and walked to the boat shop for my belt sander and a new belt.
Folks, two things here:
1. scrape as much of this stuff off as you can before the cure, and
2. don't bother with anything other than a belt sander.
You can follow up with the RO and I did, but belt sand the panel like a table top and make long figure eights with the belt sander always pointed  in the direction of the grain.  Avoid the temptation to turn it cross grain or you'll have scratches that will be tough to remove.

For this application since I did not scrape off the excess, I used a razor scraper to slice the cured excess off of the surface which helped immensely in the removal.  Wear a respirator and vac often so your aren't sanding over dust and fighting the process.

Up Next:  Installation!

The finished panel, ready to be glued and perimeter nailed in place.

July 4th Update... Happy Independence Day!

I wanted to end this with final installed photos and a brief description.
What we did was to bring the panel in for a test fit.  It was tight but "shook" it place.  We were satisfied.
To install the panel we stood it up and put a chunk of four inch PVC under it to keep it off the floor.  Twelve ounces of un-thickened epoxy was rolled on the back of the raw panel to wet it out and then thirty six more ounces of thickened epoxy was rolled on the floor and panel back.
It was simply "dropped" in place and perimeter nailed with hot dipped, ring shanked duo-fast nails.
That's it!  It's in, and the galley cabinet was set back in place and fastened permanent.
Thanks for watching!
-M