[davidpm]

I have come into possession of a 20-year-old used dacron sail. No rips or tears but no crinkle either.

I have just started learning on how to use my SailRite machine and thought I could get some good experience making bags and covers etc from the old sail. Would only cost me thread.

I would like the cloth to be clean, however.

I'm pretty sure it is possible to clean the sailcloth if you don't care about the strength or shape.
The reason I'm of that opinion is that a couple of years ago I traded another sail I had with a guy who makes bags. The bag I got was bright white. I'm sure it was made from an old sail also.

So what is the trick? Just soak it in bleach?

 

[Minnewaska]

Couple of guesses. First, soaking in a highly diluted bleach is probably step one. It's very caustic, so dilution is important, I'm sure. Oxalic acid works better on some stains (barkeepers friend). I also highly suspect the commercial bag makers re-dye the cloth white.

 

[RegisteredUser]

Id try sodium percarboate...oxyclean in warm water

 

[pdqaltair]

Id try sodium percarboate...oxyclean in warm water

^^^ THIS!

All of the professional sail cleaning solutions are percarbonate. Soak for 2-6 hours.

 

[pdqaltair]

Oh, and if there are rust or black corrosion stains from hardware, assuming the sail in polyester, a weak acid like citric, lactic, or oxalic (all found in rust stain removers) is best for that. Oxiclean won't touch those. Never acid on nylon, though.

Borax is good for a first wash. It will kill any mildew and help remove dirt. Always wash off the surface dirt before soaking.

 

[danvon]

I make bags out of old sails & just toss them in the washing machine. They come out fine. Oxyclean would help.