Installing NFM Ports on the Tartan 37c

With the old ports torn out it was now time to prepare the installation.

A template was made out of plexiglass so it could be used on either side and I could view details under the template.

Well the Tartan 37 has to be one of the worse case boats to install the New Found Metal Ports in a simple way. Here's a couple of the problems I found and how I worked through them.

  1. The cabin trunk on the 37c is approximately 1/4" glass layup with 1/8" teak plywood on the inside. This requires a 5/8" teak spacer with the NFM ports so the outside flange only extends 1/2" outside the frame. One of the beautiful things about the NFM ports is that there is no outside bolt. The outside frame has cast into it 1/2" female hubs which are about 1/2" long. This means they will extend all the way through the cabin trunk. For the T37 I used a 5/8" pointed cutting bit from Sears. First I drilled a 1/4" hole using the template and then bored the hole to 5/8" first starting on the inside until through the teak ply and then finishing from the outside making a clean cut. As I look back, I remember seriously considering having the flanges milled down but this would not leave a proper mate between the outer frame and the drains which are tapered.
    Note: Normal designed installation into a cabin trunk 1" thick would only require you to drill a 5/8" hole 1/2" deep to securely insert these hubs.

  2. The oversized teak spacers are too wide for certain internal areas of the cabin trunk of the Tartan 37 with the original trim. Careful thought was given to the placement of the ports in comparison to the original location both to fit the ports around obstructions and create minimum cutting. I did not want to do glass work to move the holes to a better location. The locations in the V-berth took careful centering between the top interior curvature of the head liner and the exterior radius between the cabintrunk and deck.

  3. All the bolts supplied were 6mm 1 pitch threads almost 2" long. The actual bolt length required with the spacers is only about 1" long. So all 64 bolts had to be cut to the proper length. I cut some to a slightly longer length to be used as "puller bolts". More on this later, just leave some long. I found some metric nuts to help with this project. I tried both a die grinder and dremmel tool with cutting disc to cut the bolts. First I placed the nut on the bolt and made a template to determine the length and hold the bolt while cutting. I found with the die grinder the cut was fast but the threads were damaged just enough that I had to used a wire grinding wheel to smooth the threads and get the bolt off. The dremmel cut much finer and did little damage and I could remove the nut with a little force by hand. But, I was lucky to get 4 bolts cut with one disc and went through most of a $20 20-pack of cutting discs (don't buy the 2 packs).


OK, now I have over thought this project seemingly way to much (for 3 years). But wait, I have held back on the starboard port by the hanging locker and the port in the head because I know there will be more modifications to consider with these in those confined areas.

All teak spacers are varnished with 5 coats of Interlux Schooner and taken to Nicknack.

All port holes were enlarged for the new ports. I found the fastest way to cut or grind out the hole was a 1/2" sanding drum on a Dremmel tool. I also tried various raspers on a drill which didn't work as well for general removal but worked well in certain areas. Remember, we're only removing about 1/4" of material around 2 sides of the hole plus the drain area.

Click on for larger picture. Click on for larger picture.

A port and spacer were picked for each hole to make sure they fit, including the outside frame aligned in its holes. After a few adjustments with the dremmel tool and a sanding drum, the frame and inside teak which was in less than perfect condition was coated with epoxy to help solidify and water proof things. The spacers actually extend about an inch over the teak ply.


Now, it's time to install a port and see what I'm really in for. Make sure you have some good clamps. I tried and like the wide jaw plastic grip clamps and had an ample supply of plastic spring clamps in various sizes. First, the galley port because it seems like it will be the easiest. I decided to go with the butyl rope recommended by NFM and I think it was a good decision. It can be messy if you let it get out of control, but that's your fault. First, I applied a strip of rope around the inside of the port. With the Butyl roping you can control the "bead size" by stretching the roping as you push it into place. It was in the 70s in April in Cleveland while I did this, maybe warmer under the boat cover and I found the Butyl too soft so I kept it chilled in the icebox.


Click on for larger picture.

The first inside bead I made big enough to make sure there would be a good seal between the port and the teak spacer. Then I added a second bead stretched a little smaller so the spacer would fit over. I then took the grip clamps and squeezed the port and the spacer together slowly. I used an ample supply of spring clamps to hold this all together as I moved the grip clamps around squeezing the port and spacer. I have dozens of the spring clamps in various sizes as they find many uses with boat projects.


Click on for larger picture. Click on for larger picture.

Once all this was together I filled in the spacer to port gap with more roping as necessary to the lip plus a little more to seal between the spacer and the interior wall.


Click on for larger picture.

I then removed all the clamps and placed this in the hole, BUT, before applying too much pressure I tested the outside frame to make sure it fit and aligned with the holes. THIS WAS VERY IMPORTANT!

I then removed the outside frame and used 2 grip clamps to hold the port in place. At this time I added another strip of Butyl roping (more if necessary) from the outide to any gaps and to make sure there would be an overlap to make the seal.

Click on for larger picture. Click on for larger picture.
Click on for larger picture.

With all this in clamped in place I applied a bead of 3M 4200 to the frame rim and then removed the clamps, placed the frame in place and held everything together again with the clamps.

Click on for larger picture.

Next from the inside I started inserting bolts trying to get a bite on the frame hubs. Not long enough? A little more pressure on the clamps. Remember those longer bolts? Get the first bolt started and then try an opposite side. Carefully, screw them in until they bottom out and then try some adjacent holes with the shorter bolts. Work your way around the frame pulling things together like you would hub nuts on a wheel. Remove the longer bolts and insert the shorter bolts. Not too tight for now.


Check the outside frame for any gapping. The caulking bead should fill the frame gap on the outside and the Butyl should slightly ooze out between the port flange and the outside frame. Re-adjust the inside bolts as necessary but not too tight. You maybe compressing a lot of Butyl roping depending on all the spaces. Tighten the bolts the next day.


The first port didn't go quite this easy but by the third port this system was going quite smoothly.


Installling ports in the head and over the hanging locker required other considerations. The teak spacer frame had to be cut to fit in the narrower space of the cabin trunk in the head. The hanging locker trim had to be modified to allow for the locking arm to turn and to make room for the port to open. I also notched out a corner of the spacer to allow proper vertical spacing of the port.

Click on for larger picture. Click on for larger picture.


Here are some finished shots of the port installation. I'll update some of the shots when the winter cover comes off, any day now!



Click on for larger picture. Click on for larger picture.
Click on for larger picture. Click on for larger picture.
Click on for larger picture. Click on for larger picture.
Click on for larger picture.




Tearing out the old ports

New Port Home page