How to Care for Your Mold and Get 500+ Presses

A steel fingerboard mold is a long-term tool. With proper maintenance it should last hundreds of presses without any drift in geometry. Here's how to get the most out of yours.

After Every Press

Once you've opened the mold and removed the deck, wipe down both plates with a dry cloth to remove any glue squeeze-out. Even water-based PVA will leave a residue that builds up over time and can alter the effective geometry at the contact surfaces.

If glue has hardened on the mold plates, use a wooden or plastic scraper rather than metal to remove it. Steel on steel can leave micro-scratches that trap glue in subsequent presses.

Light Oil Every 50 Presses

Apply a very light coat of food-grade mineral oil or 3-in-1 machine oil to the mating surfaces using a clean cloth. Wipe away any excess. This prevents surface oxidation, reduces friction between plates when opening and closing, and helps the deck release cleanly without sticking.

Do not over-oil — excess oil can penetrate the glue line of your deck and cause delamination.

Check Your Fasteners

If your mold uses bolt closure (like the BD26), check that fasteners are tight and that the torque is consistent across the plate. Uneven clamping pressure produces inconsistent concave — one side of the deck will be deeper than the other.

Use a consistent torque sequence: tighten fasteners from the center outward in a cross pattern, and apply the same torque each time. A small torque wrench takes the guesswork out.

Inspect for Drift Every 100 Presses

Press a blank test deck and measure the concave depth at three points along the width: left edge, center, right edge. These should be symmetric. If they're not, check for:

Debris or dried glue on the contact surfaces
Uneven fastener torque
Warped veneer that wasn't properly soaked before pressing

Our steel molds are machined to ±0.1mm tolerance and should hold that across their lifespan with basic care.

Storage

Store molds closed, in a dry location away from humidity. If you're in a humid climate (which is most of Australia in summer), place a silica gel sachet inside the storage bag or box. Oxidation on steel surfaces is cosmetic at low severity, but heavy rust can alter contact surface geometry and contaminate your glue bonds.

If you're storing long-term, apply a heavier coat of oil before closing and wrap in a cloth to prevent dust accumulation.

When to Clean Thoroughly

Every 200 presses, or whenever you notice glue transfer to your decks, do a full clean: disassemble the mold, soak the plates briefly in warm soapy water to loosen any built-up glue, scrub with a soft brush, dry immediately and thoroughly, then re-oil before reassembly.

Signs Your Mold Needs Attention

Deck is sticking to the mold: Insufficient mold release (oil) or excessive glue squeeze-out. Clean and re-oil.
Inconsistent concave side-to-side: Uneven clamping or surface debris. Check fasteners and clean plates.
Deck popping up from the center after press: Veneer springback — try longer press time or slower glue. Not a mold issue.
Visible rust: Light surface rust is cosmetic — clean with fine steel wool, oil immediately. Deep pitting affects geometry and should be addressed before the next press.

All Concave Craft steel molds are manufactured from 45# carbon steel and are designed for high-volume production. Follow these guidelines and your mold should outlast hundreds of deck builds.