Epoxy hardboard repair


Hardboard SUPs with classic epoxy construction have a very high life expectancy with proper care, because you can repair them very well yourself, but should ever come to a hole:

A hole is in the hardboard!

Unfortunately, it happened to our Ambassador Andy at an event: a participant hit a stone with the Lite Venture Cruzer Touring 12'6". The result: a hole in the nose area - the board has to be patched!

You can see very well here that the hard shell of the board is thin: the layers of fiberglass and carbon are hardened and sanded with epoxy resin in this construction method. The carbon weave results in high stiffness with low weight. And to keep the weight down on such a long board, expoxy boards have a hard but thin shell that can flex when hit or impacted by sharp objects.

The white material inside the board is the foam core. It should be avoided that this absorbs a large amount of water in case of damage. It is best to take the board directly out of the water and let it dry. If this is not possible and you have to go home with the board, the area should be taped if possible.

Material needed

Epoxy resin and hardener, a cup, a brush and sandpaper, and a respiratory mask (FFP2) are required for the repair. Since the resin hardens and is not water-soluble, the brush and cup can unfortunately only be used once.

We recommend purchasing the following material:

- epoxy resin

- the appropriate hardener from the same manufacturer

- Microballoons filler to stir into the resin

- disposable cup and disposable brush

- spatula

- coarse (200) and fine (800) sandpaper

- FFP2 or FFP3 respiratory masks

- disposable gloves

- Paint in matching color, if necessary

For greater damage, some additional fiberglass fabric can be useful. A piece of fiberglass fabric provides the necessary hardening of the outer shell. The fabric feels like cloth and hardens only through processing with the epoxy resin:


The board must be completely dry. If the foam core has become damp, leave it open to dry for a few days in a dry, warm room as a precaution. To repair the board, it is best to place it outdoors or in a garage on wooden trestles. Subsequent sanding will create fine dust and the resin may "spill", so the repair should not be done indoors. The ideal temperature range for processing the material is at 18° to 28° degrees Celsius.


Mix the resin with the hardener in the mixing ratio specified by the manufacturer. Depending on the size of the damage, add filler material (microballoons), which makes the mixture more viscous and thus easier to process. The mixture should now be applied quickly - within 15 to 20 minutes, as it then begins to harden. It is advisable to mask the area around the damage. Fill in the filler with the spatula / brush. Remove excess material again and smooth. Then allow to cure.

In the event of major damage, a piece of fiberglass fabric should also be incorporated. To do this, first fill the hole and then place a suitably cut piece of fabric on top. Then brush this in place with epoxy resin + hardener without microballoons and allow to dry.


Once the material has hardened, it can be sanded. First use the coarse sandpaper, then rework with the fine paper until everything is smooth. It is essential to wear a respiratory mask during this process!


The cured and cleanly sanded area is now repaired, but it is still visible. Varnish provides additional protection and also makes the damage invisible, so varnishing is part of the clean finish. Either you achieve a color mixture that is as similar as possible or - like Andy in this example - you choose a deliberate accent:

For this purpose, the. The board must be clean and precisely masked so that the contours do not become blurred.