How To Create a Mirror Frame

How do you make a wooden mirror frame?

Building your own mirror frame is a genuine woodworking project — routing a rebate, cutting mitres, gluing up under a strap clamp — but each step is manageable and the result is a piece you will look at every day. Two Selleys products do the work: Selleys Aquadhere Interior holds the timber frame together, and Selleys All Clear beds the mirror into the rebate.

The critical measurement in the whole project comes late: you size the mirror from the finished frame, not the other way round. Glue the frame first, measure rebate wall to rebate wall, subtract 1 mm from each dimension, then order the glass. Ordering the mirror first and building to it leaves you with no tolerance at all.

What you need

• 2 × 1.5 m × 90 mm × 19 mm clear pine
• 1 × 500 mL Selleys Aquadhere Interior
• 1 × cartridge of Selleys All Clear
• Mirror, cut to size once the frame is built
• 1 × 900 mm × 400 mm × 3 mm MDF for the backing
• A router, mitre box, tenon saw, staple gun and staples
• 2 × 8 × 30 mm screws, and 1 m of wire or cord to hang it
• A tie-down strap, a 45° set square, a Phillips head screwdriver and a caulking gun
• Safety glasses, ear protection and a disposable dust mask for the routing

Building the frame

1. Rout the rebate. Using a router, cut a groove 12 mm wide from one edge on each piece of clear pine, as deep as the thickness of the mirror you intend to use — 4 mm in the project pictured. Wear safety glasses, ear muffs or plugs and a disposable dust mask.
2. Mark the first mitre. Draw a 45° line with a set square or combination square at one end of each piece of timber.
3. Cut it. Place the timber in a mitre box and cut to the line with a tenon saw. Once through, clean the ends up with sandpaper, being careful not to change the shape of the joint on the sides.
4. Measure the length. Hook a measuring tape on the base of the angled cut and measure to the length you need. The frame stiles in this project were cut at 800 mm.
5. Mark the second mitre. Carefully draw another 45° angle from the mark, with the slope of the set square running back towards the end the tape is on. Double check that the points of the angles are on the same edge of the timber and pointing away from each other.
6. Cut it. Using the mitre box again, repeat the cut.
7. Repeat for the rails. Do the same for the shorter sides — 500 mm in this project.
8. Dry fit a corner. Place the angles of a long side and a short side so they meet, with the rebated faces downwards. Check for squareness with the set square. If there is a gap along the joint, use a small hand plane to make a couple of fine cuts and retry.
9. Dry fit the whole frame. Place the tie-down strap around the entire frame and check all the angles again.
10. Glue it up. Once satisfied, release the strap and place a generous amount of Selleys Aquadhere Interior on the angles of the two shorter sides. Put all the pieces into position, apply the tie-down strap and tighten. Wipe off excess glue squeeze-out with a damp rag. Allow it to sit for 30 minutes.

Fitting the mirror

1. Measure for the glass. Measure from the inside wall of the rebate to the inside wall of the rebate on the opposite side — rail to rail and stile to stile. Subtract 1 mm from each measurement. That is the size of mirror to order.
2. Sand the frame. Use a cork sanding block over the whole frame, feathering in the joints and rough spots. Soften the harshness of the inside edge with fine grit paper (180 or 240).
3. Dry fit the mirror. There should be about half a millimetre of gap around the mirror to the frame.
4. Bed it in. Remove the mirror. Using a caulking gun, apply a thin bead of Selleys All Clear around the entire frame, keeping the bead mostly in the corner where the wall and floor of the rebate meet.
5. Set the mirror. Reposition the mirror into the frame and press down gently with your hand on the mirror back to settle it into place. Clean off any sealant squeezed out from the back.
6. Fit the backing. Place a bead of Selleys Aquadhere Interior around the back of the frame, about 30 mm from the mirror edge. Lay a pre-cut piece of 3 mm MDF or thin ply over the back, about 40 mm smaller than the overall size of the frame. For added security, staple pins into place with the staple gun.
7. Add the hanging hardware. Insert two 8 × 30 mm screws about a quarter of the length down from the top, then connect framing wire or strong cord between them.

Why All Clear rather than wood glue behind the mirror

Technology	Co-polymer sealant
Colour	Clear
Skin time	15 minutes (weather dependent)
Shore A hardness	35
Elongation at break	500% (ASTM D412)
Service temperature	-10°C to +80°C
Packaging	80 g tube, 250 g cartridge

Indicative data only, not intended for the preparation of specifications.

All Clear is a flexible sealant rather than a rigid glue, and that is the point. Its elongation at break is 500% and its Shore A hardness is 35 — in plain terms, it stays rubbery. A mirror bedded on a rubbery line can move very slightly as the timber frame expands and contracts with humidity; a mirror bedded on something rigid cannot, and glass under point loading is unforgiving. All Clear is also listed as suitable for glass and glazing, and it dries crystal clear, which matters when you can see the bead line through the edge of the glass.

The 15-minute skin time governs your working pace. Selleys notes that All Clear skins immediately and reaches maximum toughness over several days, so bed the mirror promptly after running the bead, and smooth any excess with a tool dipped in turps straight away.

Working with Aquadhere Interior

Aquadhere Interior is a PVA-based wood adhesive for interior woodworking. Selleys' method for this frame is to apply a generous amount to the mitres, strap-clamp the frame and let it sit for 30 minutes before handling — and to wipe squeeze-out off with a damp rag while it is still wet. That last point is worth taking seriously if you plan to stain the frame: dried PVA seals the timber surface and shows up as a pale patch under stain.

Note the product's key limitation. Aquadhere Interior is not water resistant and is for interior use only. It is not suitable for exterior projects, structural applications, or wet or damp areas — which is fine for a bedroom or hallway mirror, but rules it out for a frame destined for a bathroom wall above a basin.

Limitations — what to watch for

Selleys All Clear

• May damage some plastics, for example polystyrene and polycarbonate.
• Not for permanent water immersion, for example fish tanks.
• Not suitable for use over silicones.
• Not suitable for polystyrene foam.
• Porous surfaces must be dry before application.

Selleys Aquadhere Interior

• Interior use only — it is not water resistant.
• Not suitable for exterior projects, wet or damp areas, or structural applications.

If you are mounting a mirror directly onto a wall rather than into a frame, that is a different job with a different product: Selleys makes Liquid Nails Mirror & Metal for it, and Liquid Nails Fast Grab explicitly should not be used on mirrors.

Clean up

Uncured All Clear can be removed with mineral turpentine; cured product has to be cut and scraped away. Aquadhere Interior squeeze-out comes off with a damp cloth while wet. Store All Clear in cool, dry conditions below 30°C and use it within 6 months of opening.

Safety: the sealant behind the mirror is a flammable liquid

The two products here are not comparable on hazard. Selleys Aquadhere Interior, which holds the frame together, is not classified as hazardous under Safe Work Australia GHS 7 — no signal word, no hazard statements. Its safety sheet adds only that it contains isothiazolinone preservatives and repeated contact may cause sensitisation.

Selleys All Clear is classified Danger:

• H225 — highly flammable liquid and vapour (flammable liquids, Category 2)
• H315 — causes skin irritation
• H319 — causes serious eye irritation
• Specific target organ toxicity, single exposure — Category 3, narcotic effects

It is Dangerous Goods Class 3, UN 1133, Packing Group II — the same transport entry and packing group as a solvent-borne contact adhesive. A cartridge of clear sealant does not look like that, and most of the sealants beside it on the shelf are not.

The solvent is the reason the product works here. This page chooses All Clear over wood glue because it skins immediately and stays flexible behind the glass. What gives it that instant skin is solvent flashing off, and that is the same vapour that carries the H225 and the narcotic-effects classification.

What follows for this job. Frame-making happens in a garage or a shed, which is where the gas water heater, the fridge compressor and the bar heater usually are — and H225 vapour is heavier than air, so it travels along the floor to find them. Run the bead with the roller door up, not with the shed shut against the cold. The narcotic-effects category is about accumulated vapour in a small volume, and it is worth taking seriously on a day when you also have a router running and are about to lift a sheet of glass.

The mineral turpentine you smooth the excess with is itself a flammable solvent, so it belongs to the same precaution. The safety glasses this page already specifies for routing should stay on for the bead — a cartridge under gun pressure can spit, and H319 is serious eye irritation.

There is no lower-hazard substitute for this particular bead. Aquadhere Interior is unclassified but, as the page explains, it is the wrong product behind a mirror. If you want the hazard gone, the alternative is a different construction: Liquid Nails Mirror & Metal is the range's mirror-specific adhesive and is classified only Warning — H317 and H319, with no flammability classification. Check it suits your rebate detail before you swap.

Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand.

Common questions about making a mirror frame

How deep should I rout the rebate?

As deep as the thickness of the mirror you intend to use — 4 mm in the project shown — and 12 mm wide from one edge.

What size mirror do I order?

Measure rebate wall to rebate wall in both directions on the finished frame, then subtract 1 mm from each measurement.

How much clearance should there be around the glass?

About half a millimetre between the mirror and the frame when you dry fit it.

How long do I clamp the frame?

Selleys' method for this project is to strap the frame and allow it to sit for 30 minutes.

Where exactly does the All Clear bead go?

A thin bead around the entire frame, kept mostly in the corner where the wall and the floor of the rebate meet.

How long do I have to work with All Clear?

It skins immediately and has a skin time of 15 minutes, which is weather dependent. Maximum toughness develops over several days.

Can I use silicone instead?

All Clear is a co-polymer sealant, not a silicone, and its data sheet notes it is not suitable for use over silicones. If there is existing silicone in the rebate, All Clear is not the product to put over it.

Can I hang this frame in a bathroom?

Aquadhere Interior is not water resistant and is for interior, dry applications. A frame glued with it is not suited to a wet area.

How do I wipe off the glue squeeze-out?

A damp rag, while the glue is still wet. It is far harder to deal with once dry, and dried PVA interferes with staining.

How do I attach the backing board?

A bead of Aquadhere Interior around the back of the frame about 30 mm from the mirror edge, with the MDF cut about 40 mm smaller than the overall frame size, then staple pins for extra security.

Where do the hanging screws go?

About a quarter of the frame's length down from the top, one each side, with wire or cord between them.

Will All Clear damage the mirror backing?

Selleys' published limitations for All Clear cover plastics such as polystyrene and polycarbonate, permanent water immersion, use over silicones, and polystyrene foam — it does not publish specific guidance on mirror backings. If your mirror supplier specifies a particular sealant for the backing, follow their advice.