New to framing
Industrial framing production ā factory setup guide
Your Framing Workflow in 4 Steps
Cut the Moulding
Use a Double Miter Saw to cut your frame moulding at precise 45Ā° angles. Accuracy here determines the quality of every corner. Even 0.1Ā° of error multiplies across 8 cuts.
Apply Glue
Apply PVA glue (Type II, moisture-resistant) to the miter face. End-grain absorbs glue like a sponge ā this is called a Starved Joint. A thin pre-coat layer prevents this.
Join the Corners
The Underpinner (V-Nailer) drives V-shaped nails upward through the miter joint while the frame is clamped. This holds the corner while the glue cures.
Fit & Finish
Insert glass, mat board, artwork and backing into the frame's Rabbet (Rebate) ā the internal groove. Secure with glazier points or a point driver and seal the back.
The 3 Machines Every Framer Needs
Double Miter Saw
Cuts both ends of moulding simultaneously at 45Ā°. The foundation of accuracy ā everything downstream depends on a clean, precise cut.
Underpinner / V-Nailer
Pneumatically drives V-shaped nails up through the miter joint. Provides clamping force while glue cures. Requires compressed air (6ā7 bar for hardwood).
Mat Cutter / Point Driver
Cuts mat board at precise beveled angles and drives glazier points to secure artwork inside the finished frame. Essential for the final assembly stage.
Common Mistakes & How to Avoid Them
90% of pneumatic failures come from moisture in the air line. Before you run any machine, install a Filter-Regulator-Lubricator (FRL) unit on your compressor. This single step eliminates the majority of V-nailer problems.
Different brands use different glue formulas with different melting points. Mixing brands causes jams in the Distributor Block. Stick to one brand and one size per machine setup to avoid costly blockages.
Never use WD-40 or machine oil on pneumatic parts. Oil-based lubricants attract sawdust and form sludge that clogs the Driver Blade channel. Use dry PTFE spray for all moving parts.
To calibrate your underpinner clamp pressure: slide a business card between the frame and clamp pad. It should require effort to pull out but not tear. Too easy = not enough pressure. Immovable = too much.
Hardwoods (Oak, Maple) need 6ā7 bar. Softwoods (Pine, Cedar) need 4ā5 bar. MDF sits in the middle at 5ā6 bar. Always adjust your regulator when switching material types.
A gap at the front face (Top Open) = insufficient clamping pressure. A gap at the back (Bottom Open) = cutting angle over 45Ā°. Knowing which type of gap you have points directly to the right fix.
New Framer FAQs
You need a compressor with a minimum 50-litre tank capable of delivering 6ā7 bar (85ā100 PSI) sustained pressure. A small 24L tank will work for light use but will cause the compressor to cycle constantly during production work. Ensure your air line is at least 6mm diameter to avoid pressure drops. Always fit an FRL unit (Filter-Regulator-Lubricator) between the compressor and the machine.
This is called a Step or Offset at the corner. The most common cause is Molding Warp ā the moulding itself is slightly twisted. Check by laying the moulding on a flat surface. Second most common: the underpinner clamp pad is too hard (rigid rubber) and can't conform to a slightly curved moulding profile. Switch to a triangular felt pad or soft silicone pad to compensate for surface irregularities.
Start with the Distributor Block (åéåØ) ā remove and clean it with isopropyl alcohol (IPA). Glue residue mixed with sawdust is the #1 cause of jams (over 60% of cases). Next, inspect the Driver Blade (ęé) tip for burrs or bending ā even 0.5mm deformation causes drag. Check you're using the correct V-nail size for your machine setting, and confirm you haven't mixed nail brands. Clean every 5,000 nails as a preventive measure.
Hardwood (HW) V-nails are made from harder steel with a sharper tip geometry to penetrate dense wood fibers in Oak, Maple, and Walnut. Softwood (SW) nails are slightly softer and wider to spread in less dense materials like Pine and Cedar without splitting the grain. Using HW nails in softwood risks crushing the moulding; using SW nails in hardwood risks them bending or not seating fully. Always match nail type to material. MDF has its own dedicated nail type.
Chipping (Chip-out / Tear-out) is usually caused by two things: a missing Zero Clearance Insert (ZCI) under the blade, and the wrong blade tooth geometry. Replace the factory plastic insert with a custom ZCI that supports the wood fiber right up to the blade ā this alone reduces chip-out by 80%. For blade choice, use a Hi-ATB negative hook angle blade (80ā100 teeth) for fine crosscuts. Negative hook creates downward pressure instead of pulling fibers upward. Also ensure your blade is sharp ā a dull carbide tip tears rather than cuts.
Essential Framing Terms
| Term | What it means |
|---|---|
| Rabbet / Rebate | The inner groove of a frame that holds glass, mat, artwork and backing. British English: Rebate. American English: Rabbet. |
| Miter Joint | A 45Ā° end-to-end joint. This is the weakest glue joint in woodworking because end grain absorbs glue before it can bond ā always reinforce with V-nails. |
| V-Nail / Wedge | A V-shaped metal fastener driven upward through the miter joint. Available in soft (SW) and hard (HW) wood variants in sizes from 5mm to 15mm. |
| Driver Blade | The striking pin inside a V-nailer that pushes the nail into the wood. A high-wear consumable ā inspect the tip regularly for burrs. |
| FRL Unit | Filter + Regulator + Lubricator. Mandatory accessory for any pneumatic framing machine. Removes moisture, sets pressure, and oils the air line. |
| Starved Joint | A glue joint where end grain has absorbed all the glue before bonding. Prevent by applying a thin sizing coat first, letting it tack, then applying full glue. |
| Runout | Wobble or vibration in a spinning saw blade. Axial runout = front-to-back wobble. Radial runout = off-centre rotation. Both cause poor cut quality. |
| Kerf | The width of material removed by a saw blade. Important when making spline slots ā the spline thickness must match the kerf exactly. |