How to use a biscuit jointer
Updated: 2026-10-21
The first joint is usually a cupboard side and a shelf, and the biscuit either steps the face or rattles in the slot. This is how to use a biscuit jointer on that board: one reference face, a depth that matches the plate, a scrap slot that grips a 4 mm biscuit, then glue and a clamp. Which of the six listings to buy stays on the [biscuit joiner comparison](/hub/workshop/biscuit-joiner). Products Compared followed DIY Doctor's UK sequence, Ray Girling's notes on fence lean, and the faults reviewers describe, not a lab, on 19 October 2026. A qualifying purchase can earn a commission at no extra cost to you.
The first joint is usually a cupboard side and a shelf, and the biscuit either steps the face or rattles in the slot.
The first joint is usually a cupboard side and a shelf, and the biscuit either steps the face or rattles in the slot. This is how to use a biscuit jointer on that board: one reference face, a depth that matches the plate, a scrap slot that grips a 4 mm biscuit, then glue and a clamp. Which of the six listings to buy stays on the biscuit joiner comparison. Products Compared followed DIY Doctor's UK sequence, Ray Girling's notes on fence lean, and the faults reviewers describe, not a lab, on 19 October 2026. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Stated depth | Depth stops | Dust | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Einhell Einhell TC-BJ 900 biscuit jointer | 14 mm | 3-stage | Bag and adapter | 8.4 | about £65.00 | View offer |
| Alternative |  Einhell Einhell TE-BJ 18 Li biscuit jointer | 20 mm | 6-stage | Dust bag | 6.7 | about £86.99 | View offer |
| Best value |  Draper Draper Storm Force 900W biscuit jointer | 20 mm | Not listed as presets | Dust bag | 8.1 | about £61.32 | View offer |
On this page
Set the size and the face
Standard plates are 4 mm thick. Size 0 is about 47 × 15 mm, size 10 about 53 × 19 mm, and size 20 about 56 × 23 mm. Set the stop to the biscuit in your hand. A size 20 in thin stock breaks the face. The Einhell TC-BJ 900 states a 14 mm maximum. The Draper states 20 mm. If the fine adjust will not move, which one Draper buyer found on arrival, stop and return it.
Mark the centres while the pieces are held in the finished position, then take them apart. Put the same face against the fence on both halves. If you flip one board, the slots no longer share a plane. Girling shows that a fence only slightly off upright puts the biscuit out of parallel. Cut one slot in a scrap of the same material and adjust until that scrap is flush.
Cut, dry-fit, then glue
Plunge square and hold the tool until the cutter has left the slot. The slot is slightly deeper than the biscuit and slightly longer along the edge, so the plate can slide as you line the ends up. A tight fit in the 4 mm thickness is the other point.
Dry-fit every biscuit before glue is open. Water-based PVA, a thin coat, and clamps across the joint are the usual indoor method. The beech swells a little as it takes up moisture. That is workshop practice, not a measured swell. Spacing along a long edge is a workshop rule of thumb, often every 150 to 200 mm, and it is not a cited standard. Fence and stops as a purchase question are on the buying guide.
When the slot is wrong
A slot wider than the biscuit is a setup fault or a bad cutter. Draper reviewers describe slots cut too wide or too deep, and a blade that arrived out of line. On the corded Einhell, one buyer found the base was not flush, and another had a blade that smoked in plywood. A second pass widens the slot. Unplug or remove the battery and sight the blade. A bent blade, or a listed case that never arrived, sits under the Consumer Rights Act 2015. One Draper buyer had a replacement blade within two days. That is one report, not a service promise.
The cordless Einhell's chamber blocked after about 8 to 10 slots in a UK review. Empty it, or use the extractor port with a class M vacuum. HSE says extract wood dust and do not sweep or blow it.
Worktops, only as far as biscuits go
On a kitchen worktop the biscuit is only the alignment. B&Q's guide dry-fits the biscuits, then uses the worktop adhesive, then clamps. Bolts belong in that joint when the top needs them. If you cannot clamp the run, especially beside a sink, a fitter takes over. Practise the plunge on an offcut.
Before the next slot, match the size, keep the same face on the fence, and have the clamps ready before the glue is open. Chairs, bed rails and anything that carries a person are on the biscuit joiner vs dowels page.
Common questions
How do I cut matching biscuit slots?
Mark both pieces together, then reference the same face against the fence for every plunge. Set the depth to the biscuit in your hand and prove it on a scrap of the same board. Plunge with two hands, let the cutter leave the slot, and dry-fit before glue. If you turn one board over, the faces step even when the pencil marks meet.
Which face do I put against the fence?
The face that has to end up flush, and the same one on both halves. On a carcass that is usually the outside, so the show face lands in line. Pick it before the first cut and do not swap halfway along a shelf. A fence that leans puts the biscuit out of parallel, so the scrap check is part of choosing the face.
How tight should the biscuit be before glue?
Snug in the 4 mm thickness, and free to slide a little along the joint. The extra length and a slightly deeper crescent let the plate align the ends and give the glue a place to sit. A biscuit that rattles up and down is a wide slot. A biscuit that will not push in is a short depth or a slot full of chips.
Why is my slot wider than the biscuit?
The fence and the blade are out of line, or the cutter is bent, blunt or smoking. Draper reviewers describe wide slots. An Einhell buyer had a base that was not flush. Do not take a second pass to clean it up, because that widens the kerf. Unplug, check the blade, and return a bent one. A blocked dust bag produces a rough slot that looks like the same fault.
What glue should I use?
Water-based PVA on a normal indoor carcass, with a thin coat and clamps until the joint closes. The biscuit swells slightly as it takes up moisture. That is the usual workshop account, not a lab figure, and it does not transfer to polyurethane. Worktop adhesive is the glue B&Q describes for a worktop, used with clamps or bolts. Glue does not rescue a slot that is already too wide.
When should a fitter take over?
When you cannot pull a worktop joint closed and clamp it, especially near a sink, or when the job is a chair, a bed rail or a fire door. Also stop if employees are using the tool without the extraction their employer owes them, or if you are about to put a 230 V jointer on a 110 V site lead. The biscuit method does not fix a voltage mismatch.
Related pages
Sources
Public UK sources and the amazon.co.uk listings in this comparison, read on 19 October 2026.
- HSE: Wood dust (retrieved 19 October 2026)
- HSE: WIS23 Wood dust – controlling the risks (retrieved 19 October 2026)
- HSE: Electrical equipment (retrieved 19 October 2026)
- Consumer Rights Act 2015 (retrieved 19 October 2026)
- Provision and Use of Work Equipment Regulations 1998 (retrieved 19 October 2026)
- Ray Girling: Plate joiner sizes and fence (retrieved 19 October 2026)
- B&Q: How to fit a kitchen worktop (retrieved 19 October 2026)
- Screwfix: Makita PJ7000/2 240 V biscuit jointer (retrieved 19 October 2026)