Poke Test FAQ

Sails of Dacron: Pass a sail needle or similar sharp object thru one layer of cloth (on mains at the leach near the head or clew). If you feel little or no resistance and or hear several popping sounds the fabric is “dead.” If you have a tough time passing the needle thru and do not hear the popping sound the sail is good and we will be happy to handle it for you. Dacron sails deteriorate due to ultra violet exposure (the sun). Prolonged exposure weakens the fibers. When the fiber becomes so weak that you hear the popping sound it means the sail is on its’ last leg and is subject to “blowing out” any time. Dacron cloth with a hard resin finish may test well, but check for stress cracks and crazing of the resin finish. Crazing sometimes looks like long snags. Patching is difficult at best; therefore, these sails may have no resale value.

Sails of Mylar: Most racing headsails and some mains are now built of the plastic film known as Mylar. Early mylar sails have a very limited life (1 season). Today’s Mylar sails are more durable. Examine mylar sails for extreme stress lines. You will usually find delamination started along the stress lines. Now check the stress area near head and clew. If the stitch holes are elongated, the sail is over-stressed. Next look for delamination. A few (2-3) small flakes can be patched. Sails showing these faults have no resale value.

Sails of Kevlar: This very expensive material makes ultra fast racing sails. Cruisers usually do not want Kevlar or composite Mylar Kevlar sails. The racer wants the used Kevlar sail in exceptional condition, used less than a season. Use the same check points as above under Mylar sails.

Sails of Nylon: Ripstop Nylon is usually used for drifters, spinnaker staysails (Dazy), bloopers and spinnakers. Since these sails are only used in good conditions, they last quite a while. If your sail has a resin finish, the resin may break down or peel-off making the sail no good as air will pass thru the cloth. Also, a stiff resin finish reduces the tear strength of the fabric. A sail that tears easily is no good.

Other fabrics: Few cotton sails have been made in the last 25 years. If you have one call for details as age and mildew can hurt a cotton sail. Orlon sails must now be in the old sail grave yard, but if you find one check as under Dacron.

Sails in poor condition, torn, very dirty or in need of rebuilding are rarely of any value. Donate such sails to your local scouts or theater group for making back drops, tents, teepees.