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Item Price Qty
Quart w/ White BPO hardener
Gallon w/ White BPO hardener
Quart (2.75 lbs)
Gallon (11 lbs)
Polyester Fairing Compound

Durable and Highly Adhesive with Low Shrinkage

Polyester Fairing Compound is a fibrous filler for structural repairs, bonding, and part fabrication. This structural putty is great for rebuilding broken, void, or damaged areas in composites and other materials. Unlike other body fillers, #4100 Polyester Fairing Compound exhibits low shrinkage, high impact strength, and excellent temperature and chemical resistance. It also has great temperature resistance and does not bleed out. It is easy to mix, has excellent adhesive qualities, low moisture absorption, and can be applied in varying degrees of thickness. Use this versatile Polyester Fairing Compound to permanently repair damage on a boat or to smooth and shape the external surface of a part.

Using this fairing compound is simple. After prepping the surface, mix #4100 with a BPO Hardener. Our kits ship with white BPO hardener, however you may want to purchase either Red or Black as an off-color mix indicator. When mixing is finished, the fiber-filled putty can be applied and smoothed with a squeegee or spreader. If your application requires a perfectly smooth cosmetic surface, after using #4100 Polyester Fairing Compound, we recommend using our #4116 Lightweight Polyester Cosmetic Filler.

To get the best mechanical bond, it is recommended to use #4100 Polyester Fairing Compound on rough or fibrous surfaces. Bonding applications include: composite repair, marine fabrication, FRP composites to FRP, metal inserts to fiberglass, metal to concrete, detail blocks to FRP, wood to wood bonding, and metal to metal bonding.

  • Working Time (100 gram mass) – 8-10 minutes
  • Finish Schedule (100 gram mass) – 15-30 minutes

#4100 is compatible with all the resins on our website, including epoxy, polyester, and vinyl ester.

Requires BPO Hardener - 100R:2H (parts by weight).

#4100/264-A Kit contains (1) Quart Polyester Fairing Compound, (1) 1 oz. tube of White BPO Hardener.

Polyester Fairing Compound quart (#4100-A) and gallon (#4100-B) units and kits can be shipped via standard ground service without hazard charges within the 48 contiguous United States. All sizes of #4100 (quart and gallon) will be subject to a hazard charge if shipped by air. Please see our Hazardous Shipping Chart for more information about hazard fees. We will consolidate items whenever possible to minimize these fees.
Polyester Fairing Compound This fairing compound is available in two sizes: One quart (#4100-A) One gallon (#4100-B) This fairing compound can be purchased as part of a kit that includes BPO Hardener. You should purchase the kit unless you already have hardener in your workshop. Kits include: One quart of compound, with one 1 oz. tube of White BPO Hardener (#4100/264-A) One gallon of compound, with one 4 oz. tube of White BPO Hardener (#4100/264-B)