How much Paulownia do you need for a hollow wooden surfboard?
The question we hear most from people building their first hollow wooden surfboard is simple: how much timber do I actually need? This post walks through the parts of a typical rib-and-spine board, what each one is made from, and how to put together a shopping list before you order.
Every build is a little different, so treat this as a starting point. If you send us your board's length, width, and build method, we'll check the list for you.
The parts of a hollow wooden board
Most hollow wooden boards are built around an internal frame, then closed in with skins. The main parts are:
- Spine: the centre stringer that sets the rocker.
- Ribs: cross-pieces along the spine that set the deck and bottom shape.
- Rails: solid timber around the outline, which takes most of the knocks.
- Blocks: solid timber at the nose and tail, and wherever a fin box, leash plug, or vent will go.
- Deck and bottom skins: thin boards glued over the frame to close it in.
Skins: use sheet
For the deck and bottom, we recommend our 4mm edge-glued Paulownia sheet. Each sheet is 600 x 2400mm, already edge-glued with waterproof polyurethane adhesive, so one sheet covers a whole skin in one piece. There are no strips to resaw, match, join, and clamp, so you need far fewer tools to get from timber to a finished skin, and you start with a clean, even surface.
4mm works great for rib-and-spine boards. If you're vacuum bagging skins over a foam core instead, use our 2mm sheet.
At 600mm wide, a sheet covers the outline of most shortboards, fishes, and mid-lengths. At 2400mm long, it suits boards up to about 7'10". You'll need one sheet for the deck and one for the bottom.
Spine and ribs
The spine and ribs can come from the same sheet. One 4mm or 6mm sheet is usually enough for the spine and ribs of a shortboard, and the 2400mm length covers the full spine of most boards in one piece. The offcuts are handy for small blocks.
If you've drawn your frame in CAD, we can CNC cut the spine and ribs from your files, which saves a lot of time with a jigsaw.
Rails
Rails need solid Paulownia. Some builders bend thin strips around the frame and laminate them together. Others cut the rails from thicker stock. We can resaw and dress strips to suit either method, from 4mm up, in lengths up to 3000mm. Tell us how you're building the rails and how long the outline is, and we'll cut what you need.
Blocks
Fin boxes, leash plugs, and vents all need solid timber around them, with plenty of material on every side. Nose and tail blocks finish off the shape. A short length of rough sawn Paulownia, about 0.5m of our 58 x 250mm plank, covers these, and sheet offcuts can often handle the smaller ones.
Glue
For gluing up the frame and skins, we use and recommend FixTech Fixit Mate FMP200. It's the best glue we've found for building wooden surfboards. It's a one-part, waterproof polyurethane adhesive that bonds well to Paulownia, with about 30 minutes of working time and a 3-hour clamping time. It foams as it cures, expanding to three or four times the amount applied, so use less than you think you need.
An example list for a 6'0" shortboard
- Two 600 x 2400mm sheets, 4mm thick, for the deck and bottom skins.
- One 600 x 2400mm sheet, 4mm or 6mm thick, for the spine and ribs.
- Rail strips cut to suit your method and outline length.
- About 0.5m of rough sawn Paulownia for the blocks.
- A pack of FMP200 glue.
- Hardware: a vented leash plug and fin boxes to suit your fin setup.
Delivered sheet orders are a minimum of five sheets, in any mix of thicknesses. A spare sheet is worth having on your first board anyway, and a 2mm sheet is handy for test pieces. There's no minimum if you collect from Sydney.
Ordering and delivery
Current sizes and prices are on our Paulownia timber page. We supply Paulownia Australia-wide. Timber over 1m goes with whichever courier is most economical for your address, and you can collect from Sydney for free if you arrange a time with us first.
To order, or to have your list checked, send us your board's length, width, and build method through our contact page.