5% Luff stretch?

[2copplane]

How much does a luff stretch by. I’m looking at 2nd hand laminate genoa and it should fit the foil okay with about 6 inches to spare (on a 50’ luff) which seems ideal to me.
I’ve previously looked at another that was about 3’ short and the vendor advised that was ideal as I needed to allow 5% for stretch.

5% stretch sounds like sales-patter bollox to me especially with laminate?

 

[youen]

i think that stretch is less than 5% on new laminates.If you have the exact type of laminate you can ask to a sailmaker

 

[Clive]

Luff bolt rope tend to shrink from new, many makers leave a tail by the tack so that the stitching can be unpicked, the bolt rope released and then re stitched.
AS to the actual sail cloth, this tends to have very little stretch. you can see this when applying the cunningham. on my 12.5m luff it is less than 50mm. about 0.5%. (based on North Sails paneled Kevlar)

3Di (the black sails stretch even less)

The thing to really check is the leech, the laminate and strands can have a tendency to crack along the leech, having a "wavey" leech tape re-enforcement) helps spread the load and reduces this problem.