We’ve been rolling through Lägler’s “Sanding of Wooden Floors”
manual bit by bit. We’ve talked about how to pull the best work out of your crew and your machines using the big machine, edger and multi-disc. But
the formula for wood floor sanding success isn’t done ’til you nail the final sanding step.
5 Tips for the Final Wood Flooring Sanding Step
1. The grit of the abrasive used for the final sanding step depends on the wood species and how you sanded the floor up to that point, what grit sequence
you used to get there.
2. Wood flooring generally must be sanded with a finer grit when oil or wax is being used. The grit sequence must run accordingly to include finer grits.
3. The deeper the sanding marks, the more oil or wax can penetrate and make these indentations appear dark. Deep sanding marks are much more visible than
with finishing sanding. The usage of colored oils and stains will even reinforce this effect.
4. An even and fine surface structure of the wood flooring is particularly important for colored oil or stain. The deeper the sanding marks, the more
color pigments can deposit in them. The sanding marks therefore appear even darker than with normal oil. A surface treated with colored oil or
stain is therefore generally sanded with one grit number finer than with other treatments.
5. But it is up to the contractor to make the call on whether the surface quality following the final sanding step is suitable for the planned surface
treatment. Make sure to follow the finish manufacturers’ instructions.
6 Points to Consider After Completing Sanding (Before Finishing)
1. No more cracks or joints should be visible. Otherwise they need to be closed by using filler.
2. No more sanding marks from the coarse grits should be visible. With the help of a flash light, existing marks will become clearly visible. Such
faults will stand out after the subsequent surface treatment, due to differences in the brightness of the field. This can result in customer complaints.
3. Differences in the roughness of the wood surface between the field and edge sanding lead to different brightness levels after the following surface
treatment (“picture frame”).
4. No more damage or the other defects should be visible on the surface after the final sanding.
5. The surface should be inspected for foreign particle residues (e.g. iron filings, plaster residue). Small iron particles can lead to brown spots
(rust spots) in the finish coating, especially if the floor is coated with water-based finish.
6. No contaminants such as oils, greases, wax, resin, cleaning agents or substances containing silicone should be present on the surface. These substances
can impair the bonding of the wood surface with the finish, oil or wax and lead to complaints by the customer.
These tips are printed in Lägler’s sanding manual. You can download a digital version of the manual at no charge at laegler.com.
We also cover the how-tos and what-not-to-dos in-person in Denver, during Lägler’s one-day Premium Sanding Technology (PST®) certification training.
Call us if you dare (800-8-HUMMEL / 800-848-6635).