Kevlar

is there a non destructive way to determine if kevlar has been bonded to a fibreglass panel?

I've been trying to think of a way to tell, but if you can't see it then no. If it's hidden inside the layup you can't tell. If you can abrade an edge, Kevlar doesn't grind easy, it fuzzes. That doesn't help unless the kevlar is right at the edge, obviously.

Brian

Bend or twist the panel. If you hear any popping or crinkling sounds, there may be an internal delamination. If you see an area bulge out while you are flexing the panel, it's definitely delaminated there.

Another way is a tap test. Use the edge of a quarter or big washer and tap all over the panel a zillion times. Listen for differences in the sound it makes depending on where you tap. An area that sounds different than the rest could be delaminated.

The only way I can think of would be to drill a hole in it. If there's kevlar in there, it would MOST LIKELY show up in a drilled hole (as "feathers"). Might be a good place to put an extra fastener :D. You would, however, need to know what kevlar "looks like" to spot it.

Steve, FV80

What color is the interior of the panel? Kevlar is usually yellow....

Mine came out golden yellow with clear resin. I guess if someone pigmented their resin then it could hide the fabric color. If the inside is painted, then sand or strip through a spot on the paint and look for the telltale golden yellow Kevlar layup (assuming clear resin was used), where there is an existing hole look for fuzzies and if in doubt, file the hole a bit bigger with a medium or coarse file and fuzz should become evident if there is Kevlar in there

thanks to all for their replies. The piece I have has been painted black so an immediate visual is not possible, but their was a hole drilled previously and it does have some "furring" around the hole. I will try and remove some of the paint and see what colour is underneath.

Keith