HB42 Ultimate 2-Part Woodfiller

B42 Ultimate Wood Filler is a professional-grade, two-part high strength polyester wood filler for all professional wood repairs, inside and out. Its easy mix application sets hard to a strong, weatherproof finish in just 30 minutes. Once cured, it can be drilled, screwed, carved, sanded or planed, and is both paintable and stainable to blend seamlessly with the surrounding timber.

It's the ideal solution for repairing wood damaged by wet rot on furniture, window sills, frames, doors and banisters, as well as grain filling and repairs to shakes, cracks, splits and knot holes up to 50mm deep. Supplied with a separate hardener, HB42 Ultimate Wood Filler is non-slump, making it well suited to vertical and corner work, and accepts all known paint systems and varnishes. It can even be used to repair wooden constructions, including some marine applications.

• Styrene free - low odour formula, easier to breathe around during use
• Interior and exterior use - weatherproof once cured
• Fast setting - sets to full strength in just 30 minutes
• Fully workable once cured - can be drilled, screwed, sanded and planed
• Paintable and stainable - accepts all known paint systems and varnishes
• Ultra smooth, easy sanding - finishes to perfection
• Non-slump - stays in place for corner work and vertical repairs
• Easy mix application - simple base-to-hardener ratio

• Ensure the surface is clean, dry, sound and free from oil or grease.
• On old timber, cut back any rotten or weak areas to solid, sound wood.
• Lightly abrade smooth areas to ensure a good key for the filler to bond to.

• Add the hardener to the base paste on a suitable mixing board, using the ratio of 50 parts base to 1 part hardener (roughly a golf-ball volume of base to a pea, or 1.5" strip, of hardener).
• Mix thoroughly with a spatula or stiff knife until you achieve a smooth, even-coloured mix.
• Scrape the filler clear of the mixing board at least once during mixing, to ensure all material is combined with the hardener and no uncured filler is used.
• Only mix small quantities at a time, enough to apply within 5 minutes.
• Apply using a putty knife, spatula or similar tool directly to the area of timber being repaired.
• Shape as required with a spreader or flat former, leaving enough excess proud of the surface to allow for sanding.
• For deep filling, build up the product in layers.
• Plastic shuttering can be used to create a smooth, straight edge - only remove once the filler has fully cured.
• Allow the repair to cure fully before finishing.

Tip: Sand the entire surface of the repair thoroughly before staining or finishing, so the stain or paint can fully penetrate and blend evenly.

• Allow the filler to cure to full strength (around 30 minutes, longer in cooler conditions) before drilling, screwing, sanding or planing.
• Sand the full repair area evenly to ensure a smooth, consistent surface ready for finishing.
• Once cured, the repair is weatherproof and suitable for both interior and exterior exposure.
• Apply your chosen paint, varnish or stain once sanding is complete, following the finish manufacturer's guidance.

Clean Up

• Clean mixing boards, spatulas and knives promptly, before the filler cures, using a scraper followed by a suitable solvent if needed.
• Once cured, the filler can only be removed mechanically, such as by sanding or scraping.
• Replace the dish lid on the tin after use to keep the remaining product clean and ready for the next mix.

Storage

Store between +5°C and +25°C. Shelf life is 12 months from the date of manufacture.

Q. Can HB42 Ultimate Wood Filler be used on wood exposed to the weather outside?

A. Yes. Once cured, HB42 Ultimate Wood Filler is weatherproof and suitable for both interior and exterior repairs, including window sills, frames and doors exposed to the elements.

Q. How long do I have to work with the filler once it's mixed?

A. It's a fast-curing filler with a typical gel time of around 10 minutes at 15°C, so it's best to mix only small quantities and apply within 5 minutes of mixing to ensure a smooth, workable finish.

Delivery - All orders placed on a working day before 3pm will be dispatched on the same day for next working day delivery. Orders placed before 3pm on Friday will be delivered on Monday (excluding bank holidays). Orders placed after 3pm on Friday, weekends and Bank Holidays will be dispatched on the next working day. 

Delivery of Tinted Products - Tinted paints are dispatched in line with our express order process, shown below. However, due to their bespoke nature, please allow up to an additional 5 working days to accommodate any potential courier delays or delivery issues before receiving a refund or replacement.

We strongly suggest customers avoid booking tradespeople until they receive their order. Next Day Paint will not be held liable for any costs incurred due to order processing errors, delivery delays, or other issues that may result in financial loss.

Delivery Options

Express Shipping - £3.99

Order by: 3pm, Monday - Sunday

Expected delivery: Next working day, 8am - 9pm

AM Delivery - £12.99

Order by: 4pm, Monday - Sunday

Expected delivery: Next working day by 4pm

Late Cut-Off - £5.99

Order between: 3-4pm, Monday - Friday 

Expected delivery: Next working day, 8am - 9pm

Extended Late Cut-Off - £7.99

Order between: 4-5pm, Monday - Thursday

Expected delivery: Next working day, 8am - 9pm

Saturday Delivery - £9.95

Order by: 4pm, Friday 

Expected delivery: Saturday, 8am - 9pm

Standard Delivery (Out of Zone Postcodes Only) - £8.99

Order by: 3pm, Monday - Sunday 

Expected delivery:  3-5  working days, 8am - 9pm

Note: Orders placed on weekends or bank holidays will be dispatched on the next working day for delivery on the following day

We do not deliver to the Channel Islands or the Republic of Ireland

Certain postcodes delivery times and charges may vary please head to the cart to see your available delivery options.

Returns

We offer a 14 day money back guarantee for all goods shipped correctly that are not required. If the item is not required, please send the item back for a full refund in its original condition, unused with its original packaging. Please note return for unwanted item is at your own expense.

Contact us as soon as possible to inform us you will be returning the product either by a contact form or by calling our team on 0161 960 0217.

All tinted paint purchases are final and non-refundable. If you're unsure about your selection, please refer to the product listing or contact us for guidance before ordering. Once mixed, tinted paints cannot be returned or refunded, regardless of delivery delays or changes in circumstances.

While we aim to meet delivery timelines, we are not responsible for delays caused by couriers, weather, or other external factors.

We recommend ordering samples or colour charts before purchasing. While we strive to represent colours accurately, screen settings and surface types can affect appearance. Opened tins cannot be returned due to dissatisfaction with colour.

For non-tinted products, we offer a 14-day money-back guarantee. Items must be returned unused, in original condition and packaging, at your own expense.

Damaged Paint

Please visit our damages page, where we can help resolve the issue for you. 

Incorrect Item

If we have sent you a different item from what you ordered, we will be happy to organise an exchange for the correct goods at no extra charge to yourself, please get in touch to organise this.

Faulty Items

Faulty items can be refunded or exchanged within 30 days. All returns are tested, and if no fault is found, no refund will be issued you'll have the option to have the item returned. For faults discovered after 30 days, please contact the manufacturer for further support.