Q: My house has wide pine floors and several of them have partially split along the long side, right next to the gap from an adjacent board. I am afraid of one of these splits breaking off completely. I am unsure how best to repair this.
I would be happy to send you a photo.
A: Do you have any way to inject some adhesive under this cracked piece?
Follow-up Q: I think I could get something under there. Maybe some clear epoxy. Can you suggest something?
A: I’d like to suggest Gorilla type adhesive except in this case it worries me. It expands as it cures. I’m afraid if this split edge is just hanging on, the adhesive will actually push it up and we will have made the matter worse. If the gap is wide and deep between the boards, you may have to pack something in the gap to prevent the glue from running away. Cyano acrylate (from Lee Valley Tools) sets up in seconds. It would be ideal if the adhesive bottle also came with a long nozzle allowing you to direct the adhesive sideways into the groove on the board. (assuming it is the groove side that has the split). Fast setting with a nozzle, and best to stay away from expanding foam urethane. Some wood glues set in about half an hour. That might work too.
Follow-up: Thanks again. I’ve attached a photo but its a bit difficult to take a picture of. I had read about the gorilla glue and I thought that the expansion might help as the splits go downwards when stepped on but maybe the expansion can’t be reliably predicted or controlled. I have previously tried inserting some wood matchsticks (not the striking end) and some wood glue but I was hoping there might be something better. I’ll look into the the cyano too as you suggested.