Polyester Resin Unwaxed Drum
This item is a reserve. We will contact you with the total weight and price of the drum.
Going through resin fast? If you run a repair yard or build boats, a drum of unwaxed polyester resin keeps the shop supplied for layup work. It's the same marine laminating resin as our gallon sizes. The top layer stays tacky (uncured) while the resin under it cures, so every new layer bonds well to the one before it.
This product is sold by the kilogram in a drum
Who it's for
- Boat builders and production fiberglass shops
- Marine repair yards doing hull, deck, transom and stringer work
- Fabricators making shower pans, bathware or exterior wood decking
Why shops use it
- Strong layer-to-layer bonds for big, multi-layer laminates, thanks to its air-inhibited (unwaxed) surface
- Predictable working time: a 20-minute gel at 25 °C with 1.5% MEKP
- Prepromoted and thixotropic, so it's ready to catalyze straight from the drum
- Tough, crack-resistant laminates with the proper glass content
Spec sheet summary
| Spec | Value |
|---|---|
| Type | Unwaxed (air-inhibited) polyester laminating resin |
| Gel time | 20 min at 25 °C with 1.5% MEKP |
| Peak exotherm | 208 °F / 98 °C |
| Viscosity at 25 °C | 550 cps |
| Thixotropic index | 3.5+ |
| Styrene content | 45.1% |
| MEKP catalyst level | 1.0–2.0% of resin weight |
| Shop conditions | 18–32 °C (65–90 °F), 40–90% relative humidity |
| Cured casting (no glass) | |
| Tensile strength | 12,000 psi / 84 MPa (ASTM D638) |
| Tensile modulus | 560,000 psi / 3.9 GPa (ASTM D638) |
| Tensile elongation | 3.6% (ASTM D638) |
| Flexural strength | 20,800 psi / 143 MPa (ASTM D790) |
| Flexural modulus | 580,000 psi / 4.0 GPa (ASTM D790) |
| Heat distortion temperature | 153 °F / 67 °C at 264 psi (ASTM D648) |
| Packaging | Drum, sold by the kg |
Typical values for unreinforced, post-cured resin castings tested at 25 °C (77 °F) and 50% RH; not specifications.
Running it in the shop
- Keep MEKP between 1% and 2% of the resin weight, and test a small batch whenever conditions or catalyst lots change.
- Hold the shop at 18–32 °C and 40–90% humidity for consistent gel times from batch to batch.
- Layups left in sun, heat or dust lose some of their secondary bond, so scuff them before carrying on. Sand any laminate made with waxed resin before bonding to it.
- Over gelcoat, wet it out with a thin coat of catalyzed resin before laying in glass.
Finishing the last layer
Unwaxed resin won't cure tack-free on its own. Top off with waxed polyester resin by the drum, or blend Styrene Wax Solution (Air Dry) into the final coat for a hard, sandable finish.
Know the limits
- For better osmotic blister resistance, lay down a vinyl ester skin coat first.
- Don't build fuel tanks with it: resins like this have very poor resistance to hydrocarbons.
Questions from shops
How do I order a drum?
Place the order and we'll contact you with the total weight and price. The drum is sold by the kilogram.
Is it different from the 1 and 5 gallon resin?
No. It's the same unwaxed polyester laminating resin, just in bulk.
How do I keep gel times consistent?
Keep MEKP at 1–2%, keep the shop between 18 and 32 °C at 40–90% humidity, and test a small batch under real conditions.
Data sheets
- Technical Data Sheet (TDS) – PDF
- Safety Data Sheet (SDS) – PDF
- Fiberglass polyester resin instructions (PDF)
- Ark fiberglass repair instructions (PDF)
Related
- Unwaxed polyester resin – 1 and 5 gallon
- Acetone for clean-up