How To Fix Splits in Wood
What can you use to fill splits and holes in a slab of wood — and can you use Araldite?
Yes, an Araldite epoxy is a sound choice for this. Selleys Araldite Super Strong Epoxy Adhesive is a crystal clear epoxy that leaves an invisible bond line, which is exactly what you want in a feature timber slab where the split is part of the look rather than something to hide.
The practical constraint is volume. Araldite Super Strong is most commonly sold in 8mL and 24mL dual syringe packs, with a 35mL tube also listed on its technical data sheet. Those sizes are sized for repairs, not for pouring into a long split across a benchtop slab.
For larger fills, Selleys points to a 200mL kit of the Araldite Super Strength version (100mL part A plus 100mL part B). Super Strength Araldite dries virtually clear and is often used for filling holes or splits in timber slabs used for benchtops and tables. Not many retailers keep that size in stock, but most will order it in — call ahead rather than driving around.
What the epoxy figures mean for a slab fill
The published cure schedule for Araldite Super Strong is short, and that is the thing to plan around:
| Set time | 5 minutes |
| Usable time once mixed | 2 to 3 minutes at 20°C |
| Initial bond time | 30 minutes — do not apply undue strain |
| Maximum bond time | 16 hours |
| Bond strength | Up to 150 kg/cm² on clean, abraded surfaces |
| Packaging | 8mL syringe, 24mL syringe, 35mL tube |
Indicative data only, not intended for the preparation of specifications.
A 2 to 3 minute usable time is very short for filling a split. Mix small batches and work along the split in sections rather than trying to do the whole thing at once — a batch that goes off in the pot is wasted, and epoxy that is already gelling will not flow into the fine end of a crack.
If you want longer working time for a big pour, Araldite Extra Time has a 60 minute set time, 6 to 8 hours initial bond and 24 to 72 hours to full cure, and is supplied in a 200mL tube. That is a very different working experience from a 5 minute epoxy, and much easier to control on a large fill.
How to fill a split in a timber slab
- Clean the split out. Blow or vacuum the dust from inside it — epoxy bonds to timber, not to sawdust packed in the crack.
- Abrade the bond surfaces where you can reach them. The 150 kg/cm² figure is quoted on clean, abraded surfaces, and abrasion makes a real difference.
- If the split runs through the slab, tape or dam the underside so the epoxy does not simply run out. Work on a level surface.
- Dispense equal parts of both liquids onto a clean disposable surface and mix them thoroughly with a spatula.
- Work the mixed epoxy into the split within the 2 to 3 minute usable window. Small batches, repeated, beat one large batch.
- Leave the fill undisturbed for at least 30 minutes for initial bond, and 16 hours for maximum strength.
- Sand or machine the surface flush once fully cured.
Clean up uncured adhesive with acetone. Store the product in a cool, dry place.
Limitations
- Araldite will not bond PTFE, polyethylene or polypropylene plastics. Not usually a problem on a timber slab, but relevant if you are using plastic dams or tape — test that the tape you use releases from cured epoxy.
- The product information does not specify a gap-filling capability, and the standard method is to apply the mixed adhesive to both surfaces being joined. On a wide void, work in layers rather than one deep pour.
- Pretest on leather and rubber.
Where a filler would be a better answer
If the split does not need to be transparent, and you are going to paint or stain over it, a rigid filler is easier and cheaper. Plasti-Bond Heavy Duty is a two-pack bog that can be sanded and drilled once cured, and Knead It Multipurpose can be moulded to reform or reshape damaged timber. The case for epoxy is specifically the clear, glass-like fill in a slab where the crack is meant to be seen.
Common questions
Will Araldite dry clear?
Araldite Super Strong is a crystal clear epoxy that leaves an invisible bond line, and the Super Strength version dries virtually clear.
What is the largest Araldite pack?
Selleys states that the largest quantity made is a 200mL kit — 100mL part A and 100mL part B — of the Super Strength version. The Super Strong technical data sheet lists 8mL and 24mL syringes and a 35mL tube.
Where can I buy the 200mL kit?
Not many retailers stock that size, but most will be happy to order it in. Call ahead.
How long do I have to work with it?
The mixed adhesive stays usable for 2 to 3 minutes at 20°C on Araldite Super Strong. Araldite Extra Time gives a 60 minute set time if you need longer.
How strong is the fill?
Up to 150 kg/cm² when fully cured on clean, abraded surfaces.
How do I mix it?
Dispense equal parts of both liquids onto a clean disposable surface and mix thoroughly with a spatula.
When can I sand it?
After full cure. Initial bond is at 30 minutes and maximum bond at 16 hours; do not machine it before it is hard.
How do I clean up?
Uncured adhesive comes off with acetone.
Will it bond to plastic dams or tape?
It will not bond PTFE, polyethylene or polypropylene, which is useful — those make good release surfaces. Test first.
Is there a guide to working with timber slabs?
Yes — filling dents in timber furniture and maintaining outdoor timber and decks.
What product can I use to fill splits and holes in a slab of wood?
According to the Selleys page title, the question addressed is whether Selleys Araldite Super Strong Epoxy Adhesive can be used to fill splits and holes in a slab of wood.
What is Selleys No More Cracks Exterior Wood Filler used for?
Selleys No More Cracks Exterior Wood Filler is a rigid filler product specifically designed for exterior wood repair applications, including fixing splits in wood.
What preparation is required before filling a split in wood with Selleys No More Cracks Exterior Wood Filler?
Before applying Selleys No More Cracks Exterior Wood Filler to split wood, you must first remove any rotten wood from the affected area, and split fixing is a critical preparation step required to ensure proper adhesion of the filler to the wood surface.
What are the physical characteristics of Selleys No More Cracks Exterior Wood Filler?
Selleys No More Cracks Exterior Wood Filler is formulated as a pine-colored paste filler designed specifically for exterior timber repair applications, and it is available in a 450g tub container.
Can Selleys No More Cracks Exterior Wood Filler be used in permanently wet areas or joints subject to movement?
No, Selleys No More Cracks Exterior Wood Filler should not be used in permanently wet areas or in joints subject to structural or environmental movement, as it is a rigid filler.
What product should be used instead if the wood area is subject to movement?
If the application involves areas where movement occurs, Selleys No More Gaps should be used instead, as it is a flexible filler specifically engineered to accommodate building movement and settlement.
Why shouldn't rigid fillers like Spakfilla Rapid be used on exterior timber?
Rigid fillers like Spakfilla Rapid are not suitable for exterior timber that is likely to swell or shrink upon water absorption, because the rigid nature of the filler will crack and fail under the stress caused by the wood's dimensional changes due to moisture.