I need help with finding a permanent crack filler that will not pop out with seasonal changes/movement in the flooring. I installed 3/4" tongue&groove pre-finished Bolivian Cherry flooring. It has factory baked ceramic finish. During the install I did not have the interior temp. high enough to stabilize the wood, and so now I have gaps at the joints. Questions: What product is recommended? I have read on this website about a product called Timbermate. Anybody have any practical experience with it?
After using any crack filler I need to seal it to keep it from wearing different from the surrounding surfaces. Any advice on what to use and how to apply a sealer to cracks ranging from 1 to 3mm in width??
I found stain in a felt pen applicator , but I have not found any sealers in such an applicator. Can anyone out there help??

9 days and no replies?? Can anybody out there help?

No experience here, but many on this site seem to favor the Timbermate or Woodwise product. I have a small thin crack to fill and a local store carries Woodwise for pre-finished floors, so I'll give it a shot. Hope that helps.

Thanks for the input. Since my original post, I have actually received a sample of Timbermate from the manufacturer, but I'm open to trying the Woodwise as well. I'm really stuck trying to find a sealer like a poly, or other varnish that is compatible with a factory applied ceramic finish and comes in some sort of dispenser suitable for applying to thin cracks. I could really, really use some help with this...

If the floor is swelling and shinking that much, my advise is to get your ambient conditions under control, or you will never find that magic wood filler, that will withstand the pressure of swelling and shrinking wood. If you must, fill it during the summer, and live with cracks during the winter.

Thanks, FloorGuy! I didn't mean to imply that I still have great amounts of movement from season to season still at this point. The year I originally installed it, it was November, and I only had temp heat from my heatpump going with a temp thermostat. BIG MISTAKE!! I've learned the hard way. Now I have a finished home with wood heat from a free standing stove using the heatpump only as backup. so it is exceptionally dey inside in the winter. Here in central Kentucky, we go almost immediately into cooling season with central A/C system. The movement I see now is minor compared to that first few months. Being a professional hardwood installer, do you have any advice on sealing the filler once it is applied and stained to match the floor??