Please visit our other sites at and for plans, background and focused discussion.

15 March 2015

Navigating Foamy Seas of Fabric

That's some chalkboard, "Einstein"!

Every point on the mollusc is treated as a space-point, and every material point which is at rest relatively to it as at rest, so long as the mollusc is considered as reference-body.
From Relativity by Albert Einstein

Navigating Foamy Seas of Fabric

To those of us used to the Newtonian absolutes of 'rigid' plywood, turning to fabric is to enter the undulating reaches of Einstein's relativistic universe.

Fabric is visibly flexible. Roll out a strip of it, and it may lay straight. Or it may curve like a banana, one way or the other. Or snake both ways. It can fold, hump and pucker, too, leaving its two dimensional plane. Hang an end over an edge, and it has the tendency to siphon itself to gravitational equilibrium. Fortunately, in the era of synthetic threads, we don't have to worry about shrinkage in the temporal dimensions!

Foam - at least the cushy sort - isn't much better.

To tame the mollusc, we need an external reference... in our case, the straight edge of a long-ish table in the caretaker's cabin. Line up one edge of foam or fabric with that (and keep it aligned) and smooth it flat, and we've imposed a reference edge and a planar surface. After that, it's just a matter of layout, cut, fold, and sew to the lines.

Of course, folding is something we seldom do to plywood.

Spatial visualization of flat stuff folding into shape tries the imagination. Some folks have developed it more than others. But really, unless you're a genetic sport, it starts out hard. Practice makes perfect. Like learning a new dance, the first attempts tread on toes. First one is a mind-bender; second is not half-bad; third a piece of cake.


As in all things, we looked for the KISS approach. No piping, fancy shapes, zippers (velcro, instead), etc.. We sewed a single join around the perimeters. At the corners, where excess gathers, we fold under as one would wrap a package in paper. Here and there we tack any floppy excess with thread and needle, or dart it out, as seems indicated.

A confused sea

Tips n' Tricks (from the Ignorant):
  • Bobby pins can be used to secure hems for sewing... not as prickly as pins.
  • Hot Melt Glue can often be used to tack things together... be sure to press the 'dots' flat before they cool!
  • Woof and Warp (the long and cross threads in fabric) are freebie square and parallel... follow them and it's hard to go wrong.
  • An Electric Knife cuts foam cleanly... the double bladed, turkey carvin' kind.

Dinette, cushions, left
Settee cushions behind
Folded Bunk (upside in), with ice blanket showing
Loose fit will snug up when finished with Hook n Loop

Salon Seats and Backrests:

These were all variations on a theme. Simple boxes in simple wrappers.

The only complication was that we wanted to use a second type of fabric for inboard faces. It was from SLACKTIDE's bunk, and we like to carry a bit forward from each boat. Also, we under ordered the blue nylon seconds by about a yard.  8/


Pretty simple in retrospect, but we burned a lot of braincells on this one.

First, our 60in cloth has to be joined to cover the 72in x 78in bunk. A longitudinal join, we figure, runs up where our sensitive upper bodies lie, like a miniscule bolster. A transverse join runs across our shins/calves, and seems much less intrusive. So that was our choice.

Our foam is open cell. Moisture travels downward and condenses at the first cool surface (the plywood bunk deck, in this case) and soaks the mattress from the bottom up. One semi-fix is to raise the mattress on a low lattice for airflow under, which evaporates and transports moisture. But also, we laminate a layer of close cell foam on the upper surface. This keeps moisture to the upper surface where it can harmlessly evaporate. Plus it firms the total foam, which we like for sleeping.

Next problem is that, to access the under-bunk storage, the bedding has to fold in half around the long axis. If the foam is a single block, this is AWKwaaaaard! But if we cut the foam into two blocks, then, if not compressed equally, we get a cliffy rift along the centerline.

Our solution was to cut the foam in two along the long centerline, then glue the close cell foam in a contiguous sheet to both surfaces, crossing the divide. We left the first foot to either side of the divide unglued.

Our cover unfolds to resemble a couple of bicycle panniers; two pockets topped by a flap that tucks between open and closed cell foam into that first, unglued foot.

The entire cover is made from a single strip 'scrolled' from one flap, down the divide face, across one bottom face, up the side face, all across the top face, down the other side face, across that bottom side, up the divide face and tucked between foams. End faces sewn together pillow-case style along the mid, end face (not shown). Whew!


The fabric and closed cell foam form a longitudinal hinge for folding the mattress over. Meanwhile, since it spans the divide, it eliminates that cliffy ridge. Result... works like a charm and comfortable!

Looks like we made harbor.

No comments:

Post a Comment

About Me

My photo
Anke and I live aboard WAYWARD, our T32x8 ketch. We sail by wind, tide and muscle in the waters of mid- to northern Southeast Alaska. We try to maximize the joys of life, and minimize the chores. ........ We live between the communities of SE Alaska, but drop in to visit with friends. Lately, we've worked, every other winter, care-taking Baranof Wilderness Lodge in Warmsprings Bay. This has given us a window on Web. ........ We're working toward a subsistence lifestyle, somewhat impeded by addictions to coffee, chocolate and cheese. ........ We think TEOTWAWKI is looming, and while we won't be ready, we'd at least like comfortable seats.