Making a New Helm Seat

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And here's what I ended up with.

The new propane locker tucks under it very nicely,
and there's a very handy
stash spot
right under the seat.


February 2007 --

I dropped my camera and lost the first few pictures for this project.

Here's a picture of the helm seat, taken back in 2001 when I bought the boat. There's nothing wrong with it, although the gelcoat
was chipped down to laminate in a few places.

However, I'm converting from CNG to Propane, and am putting a locker
under the seat. I bought a nice propane locker that holds two 10 pound tanks, and that fits in the space kinda sorta nearly almost perfect. (Big Grin.)
The only problem was that the propane tank is just a bit too tall.
Okay, in truth, I knew it was going to be too tall before I bought it.
This project has actually been on my mind for years, but didn't make "the list."

I have always wanted to change the seat,
because it really doesn't work for me when close hauled.
Moving the outboard sides a bit more -- well -- outboard,
would really help me to see better.

To make sure the seat stays high enough
to clear the propane locker,
as well as to provide support,
these prefab FRP angle irons are
epoxied to the old seat frame.
I spent a few months
thinking and measuring, and
dragged the "hacked up" seat
down to the boat to verify.

This puts some serious tension on the edges, which have to be fastened securely to the edges of the seat frame.

Since the existing seat fits,
I used it as a frame for the new seat so that I don't have to work too hard.

I cut away the existing seat so the propane locker can extend through it, but left the very top section, as well as back side.

This makes it possible
to maintain the basic shape.

The new seat is made from 1/8" prefab vinylester FRP from McMaster-Carr.

To help it bend, I scored the bottom side with little grooves, using a carbide blade
on a Skil saw. Zoom zoom.

To keep everything aligned properly, I bolted two steel angle irons to the sides of the seat, and clamped them down to the bench.

This keeps the whole seat from getting twisted out of shape.

That vinylester FRP is pretty stiff, and until it's secure it acts like a huge spring.

Then I dipped bolts into some mineral oil, so that epoxy won't stick to them, and cranked down hard on the edges.

The idea is to put a bit of a concave curve into the seat edges, so it will look nicer. It didn't bend as much
as I would have liked, but I'll live with it.
I broke a couple of bolts trying to make it bend more.

After tacking the edges down with a single screw, I injected a super thick putty of West System epoxy and colloidal silica into the edges.

The edges have been scuffed up well with 36 grit on a grinder.

The next day, the whole thing was fiberglassed together.

Huge fillets of thick epoxy thickened up with colloidal silica fill the corners, and also smooth out the transition for
the center support brace
(part of the old seat top.)

I used Knytex, also known as
X cloth with Mat.
This stuff is easy to use, and really strong. It has two layers of unidirectional fibers,
sewn together on top of
a layer of mat.

The next step was to glue the back on. This is structurally important.

Leaving the back piece
of the old seat in place
made it really easy.
I epoxied the back piece to the old seat frame, which positioned it perfectly without having to work hard.

After about six hours,
when the epoxy had
kicked but not cured,
I glassed in a lateral brace.
This makes a chemical bond between the new work and the stuff done earlier. Really strong.

This is also a shelf,
and will give me a
really handy storage spot right at the helm.


The propane locker is going to tuck under the seat very nicely.

At this point, it was ready for a trial fit.

It's really too late to make any significant adjustments, but I needed to know if it was going to work.

It's a rainy day.

That little storage stash is going to be really handy.



Time to put the front on.

To make the front arch,
I traced it onto some paper
and then cut it off.

This turned out to be a wasted step, because after looking at it I want the arch smaller.

No big deal. It's easy to make it smaller, but really tough
to make it bigger.

The front panel was clamped into place, with the edges tacked down with huge globs of super thick epoxy putty.

Here you can see the front corner.

I just packed the spaces with epoxy putty,
and will grind it into shape once it's cured.

Here's a close up view of the joint between the new front panel and the corner of the old seat.

That extra bit of old fiberglass will be
ground off, now that I'm sure it's not needed.

Once the area was packed with super thick epoxy putty, I brushed over it with thin stuff. That smoothed everything out.

Then a strong, thick fillet of epoxy putty was laid across the corner, and fiberglass
tabbed over it.

After looking at it for a while, the front panel was
just too massive.
It was ugly.

So I cut it down some more.
By the way, these expensive carbide saw blades, made for cutting ceramics and tile, work well on fiberglass.

All the little nooks and crannies
that were packed with epoxy putty will be invisible once it's painted.

The entire seat was hacked into shape with a grinder, then sanded with a palm sander. Finally, I spent an hour wet sanding it with 180 grit, so that it's nice and smooth.

Then it went to the paint shop.

Normal people call this
the dining room.

I got really lucky, and found a perfect 1-5/8" thick plank of teak. To find perfect wood at a reasonable price, one must frequent hardwood stores. You have to plan ahead, and when you see the right piece of wood for a future project, you have to buy it.
You can't buy perfect wood over the internet.

The grain is straight and true. It was a gift from the wood gods.
This tree died for me. I must respect that.

I don't know how much I paid, because when I saw this hunk of wood, I knew I had to have it. It was perfect.

The edges were rounded over on the router table, using a 3/8" round over bit.

It was ripped into 3/8" thick battens, so all the teak on the seat will match.

Well, it's about time to say something nice about this drill press.

It's crap.

I bought it for $40
on eBay, and got
what I paid for.
It's barely able
to drill a hole
through wood,
and totally worthless on steel.

However, it finally gave me my $40 worth on this project.
After clamping a carpenter's square to the press, I used it to drill clean holes for the bungs. The holes only extend half way through the batten.
Precision is important for this job, because all the bungs have to line up when it is done.

The seat is curved, so I used a router to put a very shallow depression on the bottom of the battens. This will keep the batten from rocking back and forth, which might split it over time.

Each batten is a little different. For some, the little groove is much wider, and for some it was moved over to an edge.

Then they were pulled off and numbered, and the back edge
sanded flush
with a bench
belt sander.

Fitting the end pieces presented a challenge.

They're cut at a 45 degree angle, and will get sanded smoother after they're installed.

I want a smooth transition from wood the the fiberglass on either side of the seat.
Doing it without messing up the bung
is going to be tricky.

On the back edge,
which will be up
against the cockpit, they'll be cut flush.

As the battens were fastened down for a trial fit, they were separated by a small space
to allow expansion and contraction of the different materials.
This might not be necessary,
but there's no point risking cracked wood.

They hang over the front edge about 1/8".

The bottom side of the battens were wiped well with Acetone, to remove surface oil that would interfere with a good bond.

I'm using
Teak Brown Lifecaulk underneath
the battens.

The main reason for the caulk is to make a nice gasket under the battens, so they're fully supported underneath.

It'll also seal the screw holes, and keep water and dirt from collecting
under the battens.

I tried masking off the battens before setting them in the caulk,
but it was too much of a hassle.

The whole thing is going to be sanded down in a big way, so what the heck, let the mess happen.

Lifecaulk is a polysulfide, and cleans up well with mineral spirits.

After waiting two days
for the wood to dry out from the mineral spirits,
it was time to set the bungs over the screws.

Because this might need to be worked on in the future,
I went the traditional route and set the bungs with varnish. Hopefully, the holes are deep enough so the bungs won't fail over time. Varnish will allow the bungs to be
popped back out if a batten needs to be removed.

The whole thing was washed down again with mineral spirits to remove drips,
then left to sit for a few days
so that the varnish would dry out
and glue the bungs in.

The bungs were tapped in with a rubber mallet, taking care to align the grain with the grain in the battens. That was harder than one might think.

One has to be careful when knocking the bungs down, so I sharpened a chisel and nudged them up near the top. This is because they might split at an angle, and it's important to figure out which side to work from.

Bummer. Three of the bungs fell out, so I had to clean up the holes and varnish in a new bung.

This one split okay, so I knew to cut it off from the right side to avoid having it split down below the surface of the batten.

Then it was time to spend about
four hours sanding it.

I started by cleaning out the slots between the battens, by folding sandpaper down in half and sanding the caulk down.

This made the width and depth of
every gap consistent.

After letting it sit in the sun
for a few hours to dry out,
I oiled it.

For this application, it seemed to me that oil would be better.
Varnish would be slippery, and
I don't want a slippery seat.
Besides, I don't want
to maintain more brightwork.

I think a swipe of oil every six months or so will be really easy to do.
If it eventually turns gray
that'll be okay, too.

Dry sanding the whole thing into shape
with a palm sander was fast and easy.

This smoothed out little mismatches on the front edge, and got it ready for wet sanding.

Then it was wet sanded with 220 grit to get it exactly right, and finally with 600 grit
to make it perfectly smooth.

This turned out
just fine.

The propane locker fits very nicely underneath.

The outboard sides are about four inches further than they used to be, and I think that will make it easier to see while close hauled.

On San Francisco Bay
you spend a lot of time close hauled.