How To Apply Thunderbird Finish
Epoxy Bow Finishing Tips
Using Thunderbird Epoxy 'Endurance Bow Finish'


Thunderbird Epoxy is a two-part finish that must be mixed, allowed to stand, then thinned prior to use. The components are marked ‘Part A’ and ‘Part B’.. Combine equal parts of Parts A and B by volume (such as two ounces each). Mix, and wait a minimum of one half hour to allow the chemical curing action to start and activate the mixture (a process called induction). After induction, thin the mixture approximately 25 to 30% by volume. [For example: 25% of the combined volume ( 2 oz. A plus 2 oz. B =4 oz) would require one (1) ounce of Thunderbird Epoxy Thinner]

IMPORTANT: You MUST let the mixture of parts A and B stand for 30 minutes minimum BEFORE you add the Thinner.


Before spraying the finish coats, properly prepare the surface of the bow so it is ready to accept the finish. This preparation is no different than using most other finishes, and should consist of adequately sanding the entire bow and wiping it clean from dust and fingerprints with denatured alcohol or acetone. Do NOT use lacquer thinner, mineral spirits, paint thinner or any other product except denatured alcohol or acetone to clean the bow.


Start the finish process by filling the wood in the handle section, edges, and tip overlays, if open grained hard woods are used. We have a high solids vinyl filler and sealer for sale that works with our epoxy. However, the epoxy itself also makes an excellent sealer. Either product fills the grain and provides a barrier to the oil in the rosewood, cocobolo, and other similar hardwood families. There are two ways to apply the sealer (or the finish as its own sealer):

(1) Spray or brush on two heavy coats, about 3 hours apart, and allow to dry at least twelve hours. Sand this prep coat down smooth with #220 grit sandpaper. Repeat this process, if more is needed to fill any remaining grain. Usually two coats of sealer are sufficient.

(2) The second way is to mix a small amount of epoxy as directed and brush or rub this into the wood with your fingers or a cloth dipped in the mix. Wait a few minutes for the solution to fill the grain; add a little more, wait, etc, until the grain is filled. After the grain is filled, let the wood dry at least three hours. When it's dry enough to sand out, then sand the riser section smooth, and begin the final finish process. At this point only use a clean dry towel or Tack Cloth to remove dust so as not to dissolve the finish which is not totally cured. 

 Do NOT wipe down or "clean" with solvents (acetone, denatured alcohol etc.) after applying, drying and sanding on bow as it will have an undesirable chemical reaction.

Actual application is like most other finishes. The epoxy goes on evenly and lies down nicely. Depending on temperature and humidity conditions, it will be touchable in one to two hours, and recoatable in three. In preparing the bow before spraying, sand with #220 grit sandpaper, and wipe down with a solvent to remove fingerprints and dust. You need not sand between coats, but if you do, then allow more time, up to 12 hours, between coats. We recommend three coats of finish to provide lasting protection for a bow. You can achieve a hand-rubbed, extra smooth finish by sanding the bow after two days, with #400/600 wet sandpaper, and then buffing with #0000 steel wool. For cleanup and spray gun cleaning, use Thunderbird Epoxy Thinner, lacquer thinner, acetone, or a mix of the two.


Extra tips:
For a smooth Gloss finish use a prayer with a .08 to 1.0 Valve. Satin and flat can be sprayed with up to a 1.4 valve in your HVLP sprayer


Be sure that all flattening agent in the Satin and Flat is mixed though and that none has settled in the bottom of can. I like to store the can upside down so when done shaking none is left on the lid.


Spray 3 or 4 light coats about 5 minutes apart to achieve on good coat. This give a more even and smoother finish


We also sell:

Pen Kit: The black or white ink will not fade or run with this finish. Dropper the ink into the "reservoir" on the underside of the pen tip. Write smoothly; clean up using plain water before ink dries waterproof.