Dry Carbon, Wet Carbon, FRP and ABS: What You Are Actually Buying

Four materials get used for aftermarket 4WD panels, and three of them get called "carbon" by someone trying to sell you something. The differences are large and measurable.

Dry carbon (pre-preg)

Carbon fabric arrives already impregnated with a precise, controlled amount of resin — pre-impregnated, hence pre-preg. It is stored cold, laid into a mould by hand, then cured under heat and pressure, usually in an autoclave.

Because the resin ratio is set at the factory and excess is drawn out under pressure, the finished part is close to the theoretical minimum resin content. Resin is the heavy, weak part of a composite. Less resin means a lighter, stiffer part.

What it costs you: money and lead time. Autoclave cycles are slow, moulds are expensive, and the material has a shelf life and must be refrigerated.

What it buys you: the numbers below.

Wet carbon (hand lay-up)

Dry carbon fabric is laid in the mould and resin is applied by hand with a brush or roller. It cures at room temperature.

The result looks identical from three metres away — same weave, same gloss under clear coat. It is substantially heavier, because the operator cannot control resin content precisely and there is no pressure to draw out the excess. Resin content is often double that of a pre-preg part.

Wet carbon is not a scam. It is a cost-appropriate process for cosmetic parts. It becomes a problem when it is sold as though it performs like pre-preg.

How to tell: weigh it. A wet-laid part is typically 30 to 50 percent heavier than the pre-preg equivalent. If a seller cannot give you a weight, that is your answer.

FRP (fibreglass reinforced plastic)

Glass fibre instead of carbon fibre, otherwise a similar hand lay-up process. Cheaper than both carbon options, heavier than both, and more flexible.

FRP is genuinely good for large panels that need to absorb impact and be repairable. A fibreglass flare that cracks can be repaired by any panel shop in a country town. A carbon one usually cannot.

ROHMY's 79 Dual Cab FRP rear wider flares weigh 2.3kg per side. The dry carbon equivalent is 1kg per pair.

ABS

Injection-moulded thermoplastic. This is what most factory trim is made from, and what most quality aftermarket flares and grilles are made from.

ABS is dimensionally consistent between parts, holds paint well, tolerates UV and impact, and is cheap at volume. It is heavier than carbon and lighter than steel.

For a flare that is going to be painted body colour anyway, ABS is frequently the correct engineering answer, not a compromise. ROHMY's LandCruiser 71/78 rear wider flares are ABS at 2.7kg per pair.

The numbers that actually matter

Weight, on the parts where it counts:

The bonnet is the one worth thinking about. 17.5kg removed from the highest, most forward point on the vehicle. That is mass off the front axle and off the top of the centre of gravity simultaneously. It changes how the vehicle behaves on corrugations in a way that a 17.5kg saving from somewhere low and central would not.

The sunvisor is the same argument in miniature: 3.6kg removed from above the windscreen line.

What dry carbon is not good at

Point impact. Carbon composite is exceptionally strong in tension along the fibre direction and comparatively weak against a concentrated impact perpendicular to it. A rock that would dent a steel bonnet can crack a carbon one.

Repair. A cracked structural carbon panel is generally replaced, not repaired. Fibreglass is repairable. Steel is very repairable. ABS can often be plastic-welded.

UV. Bare epoxy yellows in sunlight. Every raw carbon part needs clear coat with UV inhibitor, and that clear coat needs maintaining. Parts shipped in raw finish — which is common, and is how ROHMY ships dry carbon flares and sunvisors — must be clear coated before they see permanent sun.

This is why ROHMY's dry carbon bonnet uses 12K reinforcement on the underside and is load tested to 100kg. The reinforcement exists because the base laminate on its own would not tolerate someone standing on it.

Choosing

Dry carbon — when weight matters and the part is high or forward on the vehicle. Bonnets, roof visors, panels above the beltline.

Wet carbon — cosmetic interior trim where the look matters and the weight does not. Be told which one you are buying.

FRP — large panels in impact zones where repairability beats weight. Rear flares on a working vehicle.

ABS — anything being painted body colour, anything needing consistent fit across a production run, anything where cost per part matters. Most flares. Most grilles.

The short version

• Dry carbon is pre-preg cured under heat and pressure. Wet carbon is hand-laid at room temperature and 30–50% heavier.
• Weight is the honest test. Ask for it in kilograms.
• A dry carbon LC70 bonnet saves 17.5kg from the highest, most forward point on the vehicle. That is the strongest case in the whole catalogue.
• Carbon resists tension, not point impact. It cracks where steel dents.
• Raw carbon needs clear coat before it lives outside.
• ABS is often the right answer, not the cheap answer.

Before you buy

Dry carbon and FRP panels are supplied in raw finish and must be clear coated or painted before permanent sun exposure. Wider flare panels that extend beyond factory bodywork are off-road use only. Professional installation required. Weights quoted are per the item stated — confirm pair versus per-side before ordering.

ROHMY Australia manufactures dry carbon panels for the Land Rover Defender and Toyota LandCruiser 70 Series. Richmond, Melbourne. Off-road use only.