Fill cracks and gaps in a hardwood floor during sand and refinish with Dr Schutz X-tra Fill. Blends with a wood floor's own sawdust to create a smooth filler to fill dents and scratches before applying stain and finish coat. This is the most popular Schutz product in the 1-877-FloorGuy store. Easy to use, instructions included, extra fill water based formula accepts wood stain just like the rest of the wood flooring. 1 877 Floor Guy is available via telephone or email to answer questions about the use and application of Dr Schutz Xtra Fill.