Repair, Reinforce, Waterproof.  Wood, Fiberglas, Plastic Boats, Plumbing, Metal. 


  • 6 OZ ARK Epoxy Resin.  See RESINS for larger quantities
  • 4’ Fiberglas Tape
  • Gloves, Sandpaper Brushes, mixing containers & sticks


MIXING: Mix 2 parts Ark Epoxy Resin with 1 part Ark Epoxy Hardener. Measure using graduated containers, don’t guess, too much or too little hardener will affect proper cure. Mix thoroughly, scraping sides of the container, spread with solvent resistant Brush, Roller, or Squeegee.

WORKING TIMES: Pot life at 20C about 20 min, sandable in 8 hours. These times will roughly double for every 8C drop and ½ for every 8C rise in temperature. Overcoat without sanding as soon as the first coat is tacky, 1 to 2 hrs., after 6 hours sand with 80 grit before recoating.

WOOD: Should be clean, dry, free of oil and paint.

WATERPROOF COATING: Roll or brush a thin coat of mixed epoxy, apply a second coat after the first has begun to tack up, about 1 hour. If epoxy is allowed to cure hard (6 to 10 hr) it must be sanded or the next coat will not stick.

GLUE: Spread a thin coat of mixed epoxy on both surfaces, clamp until glue just starts to squeeze out, do not over clamp. Thickening to a paste with Colloidal Silica will make a good gap filler for uneven surfaces.

BODY FILLER: Add Wood Flour, 3M Bubbles or Micro Balloon to make a sandable fairing compound or gap filler.

STRUCTURAL FILLER: Add Cotton Fibre with about 25% Colloidal Silica.

FIBERGLASSING: For light weight (6oz) cloth on Canoes/Kayaks etc. Lay the cloth on dry spread carefully with your hands, do not pull. Starting from the center and working to the ends, roll or brush enough epoxy to saturate the cloth, working out wrinkles with a brush, spreader or gloved hands as you go. Use a plastic spreader to remove excess resin or you will get runs. Apply a second and third coat as soon as the previous coat has gelled (1 to 2 hr). Sand the next day or when hard, allow 7 days for full cure before Paint or Varnish. For heavier fiberglass see below.

PREP FIBERGLASS: Use Acetone and a clean cotton cloth to remove wax or oil. For light weight fiberglass such on small boats, ATV,s etc use a sander with course (40 grit) paper to remove gelcoat or paint for at least 2” around damaged area. Continue sanding until all damaged fiberglass has been removed, delimitation shows up as white patches, remove this too. A mini grinder with a course resin fibre disk will work faster on heavier glass but is more aggressive.

PREP METAL: Use Acetone and a clean cotton cloth to remove wax or oil. Sand to remove paint, rust and other coatings. Surfaces should be clean and dry for Epoxy to adhere properly.

PREP PLASTICS: Epoxy will adhere well to most hard plastics such as PVC and ABS plumbing pipe, just sand with course paper to remove shiny surface. Most Kayaks are made with Polyethylene, for this and other waxy plastics “flaming” will improve adhesion. Use a Propane torch with a flame spreader to heat the plastic surface just to the point where it starts to go shiny. Keep the tip of the flame 2” or 3” off the surface waving it slowly back and forth, don’t rush it. Overheating will cause severe damage. Apply Ark Epoxy immediately after flaming.


Fiberglass will not cover open gaps, so holes will have to be backstopped. If you can get at the backside of the damaged area cover the gap with 3 or 4 layers of masking tape. If you can’t get at the inside cut a piece of heavy cardboard or plastic (Yogurt container tops work well) so it will just fit through the widest part of the hole. Put a piece of string or wire through the center of this piece, tie a knot on the back. Push the backstop through the gap, tie off the string or use double sided tape or 5 minute epoxy to hold in place.

Use scissors to cut the first piece of fiberglass so it is just covers the sanded area, cut subsequent pieces slightly smaller so you can avoid a bump around the outside edge. Fiberglass bodies on most ATV’s and PWC’s are about 1/8”/3mm thick, 3 layers of glass will fill back to the original thickness. For thicker fiberglass just add more layers.

You can mask the area around the repair to avoid drips and runs on the surrounding area but the masking should be removed as soon as the resin gel’s.

Brush a thin layer of the catalyzed resin on the sanded area. Place the largest piece of fiberglass over the wet resin, use a brush to work the glass into the resin, add just enough resin to wet out the first piece of fiberglass, apply the next piece over the first, add more resin as necessary and repeat until you have used all the cut material. A plastic spreader or over the limit credit card can be used to smooth the wet glass and remove excess resin.


Do not use any more resin than is necessary to make the fiberglass go transparent, excess resin will just run out.

The resin will take a minute or so to saturate the glass so be patient. The catalyzed resin should last in the mixing pot for 20 minutes, pour mixed resin into a pain tray or other flat surface to extend pot life. If it starts to get warm chuck it and mix a fresh batch.

Avoid working in rain or direct sunlight

Cured Epoxy will chalk over time if exposed to sun, cover with Spar Varnish or paint.


The patch should cure hard in about 8 hours. Sand smooth and flush to the surrounding area with 80 grit paper. Low areas can be filled by adding micro balloons to a small amount of mixed Epoxy until you get thick putty, apply with a spreader. For small amounts of filler almost any dry powder can be added to the resin, such as fiberglass or wood sanding dust, baking flower, etc.

Gelcoat does not adhere well to Epoxy and may pop off if the subsurface flexes, but is usually OK for small areas. Sand with 80 grit paper for mechanical grip, wipe with Acetone before applying Gelcoat.

Two part polyurethane pant works best over Epoxy, but Alkyd Enamel or Aerosol Sprays are good alternatives. Allow epoxy to cure for at least 7 days, sand the repair area with fine paper and wipe with acetone before over coating.