LSL cabinet

Published 2016 July 20

Overview

I’m considering for my cabin an exterior insulation wall system. Among other benefits, putting insulation outside means that stud bays can be left open to the interior and used as in-wall storage. Replacing standard 2x4 or 2x6 studs with deeper 2x12s essentially turns walls into “structural bookcases”.

As a first step in testing the visual aesthetic and material workability of such an approach, @wootbeep and I decided to build a freestanding cabinet out of LSL studs.

Design

LSL is an engineered lumber made out of wood flakes pressed and glued together. Unlike solid sawn lumber, which can warp as it changes moisture content, LSL is perfectly straight and stays that way. (Not to mention the environmental benefit of using young, fast-growing softwood trees instead of old-growth timbers.)

We ordered three 8’ long LSL studs which were 1 ¾" thick and 11 7/8" deep (slightly thicker and longer than 2x12s). The studs cost $5.56 / linear foot from Parr Lumber in NE PDX.

The LSL face is similar to oriented strand board:

LSL face

and the side has a wavy grain pattern from the individual wood flakes:

LSL side

We designed the cabinet to be 24" wide (the same spacing as studs in a wall) and 6’ tall:

Cabinet CAD

Our cabinet will only have one side exposed, but we didn’t want it to have the “unfinished construction site” aesthetic of the LSL face. Instead, we decided to expose interior grain patterns by cutting into the face at shallow angles.

We tested on a scrap piece:

Angle cuts test Top row ramps parallel to the board, bottom row perpendicular; columns left-to-right are at 7°, 10°, and 12° ramps into the face.

We then designed a cut pattern for the full cabinet side:

Cabinet side CAD

Fabrication

The boards were cut to length via circular saw.

The angle cuts on the visually exposed side were CNC milled:

side

and then orbital sanded with 60 grit paper to remove tooling marks:

finished side

We tested a variety of stain colors and finishes:

stain stain

However, none of the stains came out well (LSL’s flakes seem to absorb unevenly, which leads to blotches).

For a protective finish, we first tried polyurathane (left), but it yellowed the light-colored lumber too much, so we went with two coats of Minwax’s Polycrylic (middle).

The four sections were joined with generic knock-down hardware. A ¼" MDF panel was screwed into the back for lateral stability. The stainless legs are Ikea’s Bjorli.

Doors are ¾" plywood painted with Behr Ultra “Saga Blue”:

final cabinet

Will do real handles at some point, but for now we’re just using ribbon = )