sanding after waterlox

[Rob Diz]

I am in the process of wiping on some Waterlox. I have opted to sand with 320 between coats to knock down high points. I have put down two coats on cherry, and the second coat generated far fewer high points thant he first.

I was wondering if I could use 1000 grit sandpaper after the final coat to knock down the high points, or if I should wait a week to let everything really harden and then rub with a paper bag.

What do you all do to get rid of those final nibs?

[Joe Chritz]

60 grit should knock them right off. Preferably with a 4" belt sander but a ROS works in a pinch.

If you are going to sand you will likely change the sheen by doing so and you will in essence be rubbing the finish out. It all depends on how you want it to look.

I use a fine sanding sponge for most things. I think it is 320 grit.

Joe

[Steve Schoene]

There are two things going on. Between coats you are leveling, and at the same time giving some tooth for the next coat to adhere. 320 grit is about ideal.

After the last coat--ie after 6 or 8 coats of the original sealer, then you would be rubbing out. Depending on how you applied the coats, waterlox doesn't give you much thickness to really sand without cutting through and creating witness lines. In general if the coats have been spaced overnight between each, I would wait and use the brown paper approach to eliminating dust nubs.

However, there is a way that will usually let you actually rub out the final finish. You can apply coats in "sets" much closer together than overnight. You can apply another wipe on coat after the proceeding one has just dried enough to not come off on your finger when touched. (You won't be able to sand this you would just amost immediately clog the paper.) One one day, you could apply about 3 coats in this manner, as long as you then let it dry more fully over night, and then sand to level and scuff before you apply the next set of three. Coats applied this close together generally crosslink enough that they won't show witness lines.

Then you could rub out starting with the finest paper that will remove the dust nibs and other defects--oven about 600 grit, and then proceed to about 1200 grit. From that point it matters whether you are going to a gloss finish or more satin. If satin, you can rub with pumice on felt, lubricated with paraffin oil, or use 0000 steel wool lubricated with wax, or you can use a rubbing compound. If you are going to gloss the next step would be either a finer polishing compound, or rottenstone lubricated with paraffin oil. If you want really high gloss you can use "swirl remover" after the the polishing compound. But all these steps of abrasives would cut through a single wiped on coat, but most likely won't cut through a "set".