If you are having a hard time getting the final finish to lay down just right, these tips can help finish your project and make it the envy of your friends and neighbors.
There are a myriad reasons for poor appearance ranging from dust, wood fibers, rushed application, bugs, bubbles, streaks, climatic change during drying, etc., but the solution is almost always the same.
Sanding, scuffing or buffing between coats is not required for adhesion (other than H2OLOX and URETHANE products); however, it can sometimes help achieve a pristine final finish. This guide will detail how to fix problems with WATERLOX Film forming finishes (ORIGINAL, URETHANE, MARINE and H2OLOX).
The key is to save this procedure for the end and before the final coat (or even after your final coat in some instances, but we’ll get to that later). Doing this after your initial coats may reopen that wood surface we are trying to seal and cause the problem to re-emerge (i.e. wood fibers, “micro bubbles”, shiny spots). Once a few coats are applied, the sanding/buffing/polishing process will be done on the Waterlox film layer and not on the wood underneath.
Ensure you have enough product on the surface.
This process should be completed when a WATERLOX film is achieved versus the wood substrate. The project should have a nice even gloss over the entire surface, and no dry or “starved” areas in the wood. This indicates a good continuous film. In general terms, “enough product on the surface” would be at least 2 healthy, brushed on coats on anything red oak or harder, or 3 healthy, brushed on coats on softer woods like pine, fir, walnut, etc. See Number of Coats for your Project for more information.
Gather the proper materials.
Small project (e.g.: countertop, table top, vanity, etc.):
- Sanding block – Used to hold sandpaper flat. Can be done by hand, but the block makes it easier to just glide over the surface. We do not recommend the use of power sanders as these would be too aggressive.
- 320-400 grit sand paper – Used on the block to knock down the major bumps, blemishes and imperfections. Coarser paper may leave scratches in the film that are visible to the eye, finer paper may cause too much heat and may gum up the paper making it less effective.
- 0000 steel wool or a maroon scotch-brite pad – To lightly polish out the scratches from the sandpaper and help to ensure a good, even surface.
- Regular mineral spirits (or paint thinner) – Lubrication for the sanding process will help reduce the aggressiveness of the abrasives to minimize noticeable scratches and keep dust to a minimum. You can also use some lightly soapy water, but you’ll need to immediately rinse the surface off with some clean water and wipe dry when you are done buffing.
Large project (e.g.: floor):
- You can use the same materials as listed in “Small project”, but more common would be to use a maroon scotch-brite pad (a.k.a. SPP or Surface Preparation Pad) or other lightly abrasive pad on a floor buffer (round or square). This step would replace the paper and steel wool steps. You can also do this by hand and just do spot treatments if necessary. See below floor buffer tips.
Fix the major imperfections.
After allowing at least 24 hours for drying, lightly sand the surface using sandpaper on a block, along with some regular mineral spirits (or paint thinner). This step should be done by hand, requiring only 8–10 gentle passes with minimal pressure. For best results, always sand in the direction of the wood grain whenever possible. Once you’ve finished, you may notice small dull spots where you’ve smoothed out any bumps, but the majority of the surface should still retain its glossy finish.
Buff the surface and eliminate any scratches.
After completing the sanding, proceed by hand-buffing the entire surface with 0000 steel wool, using regular mineral spirits (or paint thinner) as a lubricant. This should be done with minimal pressure and across the entire surface. The steel wool will leave a very fine scratch pattern that is not visible to the naked eye, so there’s no need to worry about sanding along the grain.
For larger projects, you can use a floor buffer with a slightly abrasive pad to lightly buff the surface. This step should be quick and gentle, as you’re not trying to remove a lot of material—just addressing any noticeable imperfections. After buffing, make sure to vacuum or sweep away any dust left behind.
Clean Up
Wipe the surface clean with a lint-free cloth lightly dampened with regular mineral spirits (or paint thinner). Let it dry for 30–45 minutes. This will help remove any remaining slurry and/or debris from the buffing process, restoring clarity to the finish.
At this point, you should have a smooth, even surface. You’re now ready to apply your final coat, starting from a great foundation. As mentioned earlier, this step can also be done after your final coat. It will result in a beautiful satin luster. If you’re planning to finish your project at this stage, it’s a good idea to apply an extra coat, as the buffing process may remove some material. It’s best to perform this after your third or fourth brushed-on coat of finish to ensure you don’t compromise the protection with too thin a layer.
Tips:
This procedure can be applied with any of our ORIGINAL or URETHANE products. If you’re dealing with a streaky satin finish, following this process should help even it out, leaving a smooth, consistent satin sheen. For smaller projects, continue polishing with finer abrasives to enhance the clarity—pumice stone and rotten stone work particularly well for this.
If you already have multiple coats and are concerned about building up too thick of a film, you can apply your final coat as a thin wiped-on layer. The goal is simply to fill in the fine scratches left by the abrasives, so it won’t require much product.
Before applying your final coat, run your hand over the surface to check for imperfections. It should feel very smooth, with no dust sticking to your hand. If needed, you can always do a bit more buffing to perfect the finish.
