I'm laying 3/8" thick hardwood and it's time to reverse directions. I made some splines from scrap boards, but they are slightly too wide so the pieces don't join nice and tight.
So, my question is can I make splines from plywood? I have some 1/8" thick baltic birch and it fits perfectly into the groove. So, I could rip strips to the correct width and be on my way.
Has anyone used plywood for splines?? Does it split? I started in the center of the room, so I obviously don't want any problems with boards raising up, etc. Please help, because I am at a stand still..... Thanks.

I'll let the pros respond to the plywood question. I am installing 1/2" engineered and found 1/8" x 3/8" hardwood (not balsa) strips at the local Michael's craft store that I am going to use for my splines. This seemed to be the best alternative for me since I do not have a table saw to rip 1/8" plywood to size.

If you are using a solid flooring product, I would say you would be better off with a solid spline, over a plywood one. If your flooring is engineered, you could use both. The plywood should be of good quality. Glue it into the grooves of the boards, making sure not to get too much glue all over the place. Use yellow carpenter's glue. Promptly nail into the spline to anchor the backside of those boards and lay the new boards right away as well. If the glue from the splines oozes out and dries on the spline, it will be difficult to get the new, reverse direction course tight.

Thanks for the prompt replies. I'm going to try plywood splines because I can't seem to find anything else. It's good quality baltic birch... Wish me luck!

The plywood splines worked great! I guess time will tell if they continue to work... Thanks again for the advice.

I also rip mine out of plywood or even paneling. You can make alot of cheap splines that way. I got bookoo's of splines