Surfing Waves

I went surfing recently with a board that I haven’t used in awhile. It had almost no wax on it, so I waxed it, but when I used the board I got scrapes on my knees. I am pretty sure that the scrapes are from the wax since it felt more rough to the touch than it usually does, and I also go on my knees when I bail on waves.

Is my assumption right, or could the scrapes be from something else? Does anyone have advice for avoiding this?

Also, the place I surf at has no rocks or other obvious causes for scrapes.

The only time something like that happened to me was because there was sand in the wax. However seeing as there was no old wax that seems unlikely

Maybe you got very hard wax? Or you probably got large sand pebbles fused into the wax. That’s most likely why your knees are getting hurt. Probably rewax the board.

Happens to me this time of year when the water gets colder and the wax I use gets harder and more abrasive because I reckon the water is too cold for the wax. Only happens on morning surfs in June, July and August - once the sun comes out and warms things up the issue melts away. I changed wax on a board a few years ago because if it; used a colder water wax and it was ok until the sun came out. And since the cold water period is about 8-10 weeks, I was stripping the board and changing wax back seemingly just after I’d begun so I said I’d never do that again.

I put duct tape in my knees a few years back and that helped. The best solution and the one I stuck with was to hit the gym and build more muscle as well as to break down and improve my pop up. Issue is gone now regardless of the wax because in cold water mornings I have it in my head I need to give a little more ooompf and pop up as clean as I can to avoid the sandpaper wax.

Per your question I’d guess you used the wrong wax for the water temps you were in.

Are you wearing a long leg wetsuit, short leg wetsuit or board shorts ?

I usually wear a bikini with a rash guard, but I recently got some board shorts that I hope to surf in soon.
Also, thanks for the input everyone!