Category Archives: woodwork

Finishing Wood: Counters & Food Safety?

So, as I mentioned in a previous post, I put two nice oak planks together to make our counter.  While I had hit the counter with a Minwax stain, I had held off on finishing it for two reasons.  First, I was hoping to get the sink placed, and second, I wasn’t sure which finish to use. 

There had been some condensation (I think) drips from the roof in the corner all the way back by the fridge and the window, and that had discolored the stain a little, so I wasn’t really worried about using the counter for our trips as it was.  After our Allegany trip last October though, condensation from a hot pot boiling water for tea and the cold closed window produced a couple of dark rings and spots on the oak that I wasn’t happy with.  I was able to take care of them with the orbital sander and some new stain, which proves that the stain did help keep the water from penetrating deeply, but I wanted to make sure it didn’t happen again, so I needed to finish the counter, sink or not.

That meant that it was time for research.  If you do a quick google search for ‘foodsafe wooden counter finish’ (or something similar) you will find that there are a myriad of options, and it really seemed that each woodworker would only use ‘this’ or ‘that’ and that all their customers were happy with the work.  However, in looking for the product and trying to pin down the ‘foodsafe’ stuff, there’s a problem. in that none of the information sheets seemed to indicate that it had been rated as such.

There were some very common answers in looking at food safety and woodworking, mostly the oils like tung oil, raw linseed oil (not boiled), walnut oil, and mineral oil.  These are soaked into the wood, and all but the tung oil need frequent reapplication to maintain the protective ability, but leave the wood oily to the touch, and need periods of air-drying after.  Great for a butcher-block or cutting board surface that you’ll be putting your food directly on, but kind of inconvenient for a counter in a place where all your space counts, and you have to wait for the oil to soak in or dry to a point where you can set things back on it.

Waxes were another answer, with beeswax coming up quickly.  A soft, nice smelling wax, beeswax is often sold to woodturners as a finish for things coming off the lathe, but can be used as a finish on non-turned woods as well.  While it is water resistant, it can be mixed with oils to be easier to apply and somewhat more water repellent.  Carnauba wax (which I only knew was good on cars) is another option, being a more durable (hard) wax than beeswax and as more resistant to water as well.  It is often used on wooden utensils and as a topcoat over other finishes on wood.

Shellac is another that came up at the top of my searches.  Made from the secretions (lac) of any one of a number of species of  lac insects. Harvested mostly in India, but also a number of Southeast Asian countries, China & Mexico, these resinous secretions are crushed, sieved, and either heat-treated or chemically dissolved to create the solid shellac which is later dissolved in denatured alcohol to produce the finish used on wood. Super blond (clear) shellac is the most water resistant variety, though the amber variety was more used on furniture in the past.

And while most of these pages of information decried polyurethane as a sort of dangerous evil for food safe finishes, some sites said it was their preferred choice, so I did some more research.  Polyurethane is an organic polymer bonded together with a urethane to produce a thicker, tougher, abrasion and water resistant finish than shellac.  While it is often used on floors for its durability, many furniture makers don’t like to use it as it covers fine details and can look overly thick.  It also has a problem in that repeated knocks or flexing can cause the finish to break lose from the wood beneath it (though not from the surrounding finish) causing opaque or milky pockets within the finish.

But people know that polyurethanes give off VOCs as they cure, and thus they must be evil.  Likewise, two-part epoxies can make an awesome covering for a bar, being both thick and amazingly water resistant, but their self-leveling properties mean that they can only really be used on horizontal surfaces as they will drip and run off a vertical or angled surface.

The thing with the food safety of any of these finishes is that they are a smooth, unbroken surface.  Any of the above finishes are food-safe once fully cured, so long as flakes of the finish won’t come up in your food as you take it off.  Cracks and shatters would make the finish unsafe for food.

So, in a way, all my research came down to that – all the finishes on the market would be food safe (baring spar varnish, which never fully cures, though spar urethane is probably okay) so long as they are intact and fully cured.  And, that said, I set on shellac for our wood, and I’ll explain why in my next post …

The Master Bed/Back Benches (Final!)

So, finally, after several planning attempts to get a workable means of getting a master bed out of two benches in the far aft of the bus, I did it.  While I set up detailed plans for the back benches in a couple of previous posts (Parts One and Two), I ended up making some variations based on our assessments of our stays in the bus over this last summer.

The bench in profile, showing the `pocket` for the platform.
The bench in profile, showing the `pocket` for the platform.

While I had planned to have pallet sections span between the two benches before, I had designed for only two pallet sections of ~29″ width each to be the ‘back’ of the bench.  What we decided to do was to make the span into three sections of 19 1/2″ width, to be stowed under just one of the benches.  While this loses a little more storage area overall, the sections are much easier to unstow, and there’s more accessibility to the storage area.

Oak & 2x3 frame, starboard side.
Oak & 2×3 frame, starboard side.

So, I started with a simple frame made of 2x3s and 1 3/8 x 1 3/8″ and 1 3/8 x 5″ oak that I planed down.  This gave a stable, and in places, visually appealing structure for the bench. Along the outside wall of the bus, I ran another 2×3 which I screwed into the structural ribs of the bus body for the wider planks to rest on.  In working on the counter in the galley area, I found that the pocket screws were a pain to put into the ribs.

Port-side bench, showing storage area for the pallets.
Port-side bench, showing storage area for the pallets.

On the port side, however, I put the storage for the pallets, so instead of a large open box, I ended up with a box-within-a-box sort of system.  This still left some shallow storage space above the pallet area and a deeper section all the way to the back.

The angled supports for the pallet sections.
The angled supports for the pallet sections.

One of my reasons for designing the original set-up for having the wider pallets being the bench backs was that they wouldn’t be able to slide around, as the back of the bus gets the brunt of bounces and tail-swing forces.  In storing the pallets under the bench-seat, though,  I designed the storage area to have angled supports, only dipping down about 3/4″ over 21″ of width.  I’ll have to decide after a few drives if I’ll need extra stops to keep the pallets from sliding out.

Rail & stile router bits and my handy pocket jig.
Rail & stile router bits and my handy pocket jig.

With the bench frames in place, I needed to build the outer shell of the benches, still using the flat panel wainscoting that I used elsewhere in the bus.   For this, I pulled out a set of rail & stile router bits and my Kreg pocket jig, which together make some really nice, secure wainscoting.

All the panel pieces, and some of the oak plywood ...
All the panel pieces cut and routed, and some of the oak plywood …

There were three pieces of panel to make up, as the fore part of the starboard bench opens into open space, it needed a section that the port bench (coming up to the bunk wall) didn’t.

Almost set, just needs plywood panels and the top rail.
Almost set, just needs plywood panels and the top rail.

Assembly was easy, just drilling for the pocket screws, evening up ends, and measuring for spacing of stiles.  Once these were set, I cut 1/4″ oak plywood for the panels, and set those in place with a single brass wood screw.  I don’t like to use glue for these, as the wood tends to expand and contract with heat and humidity, and I wanted to give it that flexibility.  On the other hand, I don’t want the panels (very literally) rattling around while the bus is rolling.

Panels installed, notches in top rail visible.
Panels installed, notches in top rail visible.

The last detail to work out was in the long top rails, so that the 1 3/8 x 1 3/8″ supports on the edges of the pallets would rest securely in place.  This is one of the places where having the oak frame was important, as it would be visible behind the notches.  But it all worked out nicely.

The port side bench with wainscoting installed.
The port side bench with wainscoting installed.

The port panel was more tricky, and involved some chisel-work to get the rail above the pallet storage to sit nicely and give a robust, non-routed opening for the pallets.  The bench tops were made of 3/4″ oak plywood for the hinged bench top, faced with a 1″ strip of oak as an edging, then the rest was oak boards that lapped over the supports.

Look the benches are gone, and now it's a bed!
Look the benches are gone, and now it’s a bed!

With the pallets in place, it makes a 58 1/2″ x 92″ bed-space.  One of the nice things about it is that the space under the bed is still accessible, either by reaching underneath from the front, opening the rear door, or opening up the bench tops.  I’m planning on getting some nice recessed handles that will make opening the lids easier.

The bench goes all the way around the back.
The bench goes all the way around the back.

But the modular design of the pallets makes them interchangable in all the notches, and allows for a U-shaped bench in the ‘observation area’ of the back of the bus.

So this new design fits better with our uses of the back area of the back, and makes it really versatile, as we could have the center pallet in as a table, and have several folks around it.

Changing designs (for the master bed) (Part II)

So I set about designing benches whose backs would be able to be lifted away from the bench, turned and rotated so that they would each become half of the bed across the gap between the two benches.  Each of the benches will be 24″ wide (from the wall) and 58-59″ long (I’ll figure this out more exactly when I empty out the back of the bus and get to the actual building), with a height of 20″.

The overall design of the platform sections.
The overall design of the platform sections.

This would leave a space of roughly 58″ by 42″ that would need to be filled in to make a flat bed surface between the benches. A single platform that big would be very hard to hide away, so I set up the design to make this into two parts (one for the back of each bench seat), each roughly 29″ by 43 1/2″.  The extra 1 1/2″ for this length is for an overlap with the bench of 3/4″ on either side.

The paneled bench front with notches to fit the platforms.
The paneled bench front with notches to fit the platforms.

In order to make these really stable, I designed each of the sections to have three 1 1/2″ x 1 1/2″ supports that would rest in notches in the benches. The tops of the benches and the platforms is going to be 3/4″ oak faced plywood (and the panels in the bench will be 1/4″ plywood).

The bench in profile, showing the `pocket` for the platform.
The bench in profile, showing the `pocket` for the platform.

Given that the windows start at 29″ from the floor and the bench seat would be at 20″, making these 29″ wide platforms into the back of the bench posed a small problem, since we wanted to keep as much of our window view as possible.  Toward this end, I decided to cover not more than 6″ of the window with the bench seat (which would be about the same height as the back of the sideways seat in the cabin area), which necessitated deep pockets in the back of the bench.

The top-view of the bench.
The top-view of the bench.

This would still allow for the area in front of the pocket to be used for storage.  In order to access this, I worked out a hinged panel in the seat top that could still be opened when the bed platforms were in place. In arranging this in the design, it occurred to me that the ‘pocket’ where the platform would rest while it was a bench would be a big empty area when it was made into a bed, so the design needed another hinged panel that would fold down and close when the platform was in place to be a bed.

The side and fronts of the bench would be the same oak paneling that I’ve put up for the wall between the bathroom and galley area. knowing that, I came out with a whole materials list and cutting diagrams.  I’ll post the building of this when I get there, but this seems the best way to compromise our wants and our needs.

The materials list for the benches.
The materials list for the benches.

 

The cutting diagrams for the plywood.
The cutting diagrams for the plywood.