how much sanding is necessary for a shellac sealcoat?

  • Advertise with us

« back to Finishing forum

Forum topic by marc_rosen posted 09-27-2015 02:25 PM 1236 views 0 times favorited 8 replies Add to Favorites Watch
View marc_rosen's profile


143 posts in 3356 days

09-27-2015 02:25 PM

Topic tags/keywords: question finishing

Hello All,
This is the first time I am using shellac; it will be as an undercoat or sealcoat beneath General Finishes Arm-R-Seal or Waterlox. I am preparing 4 test pieces of Paduok for my friends to decide what finish they want on their table.
Each test piece is sanded to 240 and one half is coated with the shellac. After sanding, the entire piece will be coated with the final finish.
I want to know if I should sand the shellac coat to the point that its “sheen” disappears or should I allow it to remain visible? Last night I sanded the shellac coat until it was not discernible and then applied a second coat. Before I sand this off I wanted to know how far should I go. I will be using a random orbit sander and 240 paper.
Thanks in advance for any suggestions. Marc

-- Windsurfing, Woodworking, Weaving, and Woodducks. "Most woodworkers are usually boring holes"

8 replies so far

View johnstoneb's profile


3036 posts in 2347 days

#1 posted 09-27-2015 03:31 PM

I just sand lightly to remove any dust or fibers that the shellac might have raised. Once I start finishing I hand sand you have much more control over how much you take off.

-- Bruce, Boise, ID

View jdmaher's profile


437 posts in 2754 days

#2 posted 09-27-2015 04:20 PM

I often use shellac as a sealcoat on bare wood before Waterlox or Arm R Seal. I just do a very light sanding – just to smooth any roughness and yet provide just a bit of “tooth”. For me, that means hand sanding. An ROS would be way too aggressive.

Let me qualify that advice, a little. First, I use a 1 lb. or 1.5 lb. cut. When well-dried, I feel with my bare hand. There’s usually just an occasional bit of “grit”, here and there on the surface. That’s what I’m trying to smooth.

The first coat on bare wood usually has only an occasional area of sheen (often, just over tight little knots). Second coat has larger areas of sheen, wherever the wood is less porous. Those sheen areas are where I want to provide a bit of “tooth”.

I use a folded 1/4 sheet of 220, and just the weight of my hand as pressure. I just pass over the whole surface, long strokes with the grain, one or two strokes per pass. I try to knock down the sheen to a consistent level, but I have to resist the temptation to over-sand the shinier areas.

Key for me is to clean up after sanding. I always vacuum the surface. Normally, I then wipe it off with a dry wiping cloth. If I want a very smooth finish, or if I applied the shellac unevenly, I’ll use a wiping cloth dampened with denatured alcohol. If I used a colored shellac (orange or garnet), I may even out the darker areas with this alcohol wipe down. (Note that an alcohol wipe removes most of the “tooth”, but its never been an issue for me.)

Do note that most folks believe I’m way too OCD about finishing. Many people just hand wipe with brown kraft paper (grocery bags), just to smooth it off.

-- Jim Maher, Illinois

View MrRon's profile


5139 posts in 3418 days

#3 posted 09-27-2015 04:34 PM

I lightly hand sand the shellac until it is smooth; 400 or finer grit. I use a “micro fiber” cloth to dust off the surface. The cloth tells me when it is smooth enough because if it is not smooth, the cloth snags. By sanding, a quick “swipe” with a piece of sandpaper is all that is needed to take the sheen off the surface. Do NOT use a power sander. You can also use some very fine steel wool or bronze wool. Do this for ALL parts of the table. Also make sure you apply the shellac in an even coat so sanding will not remove too much coating in some places.

View marc_rosen's profile


143 posts in 3356 days

#4 posted 09-27-2015 04:37 PM

Hi Bruce and Jim,
I’m was still deciding on hand sanding vs an ROS since I will be doing an 8 foot by 42 inch top. I thought I’d get more consistency with the sander than by hand and that’s why I was making the samples the same way. Aside from that, based on both of your comments I over sanded my first coat so I will go lighter when I sand the second.
And here’s a second question; Would you go through using a seal coat on the base (legs, apron, stretcher) when that area is not the focal point of the table? Some of the test pieces I did B.S. (Before Shellac) using the same finishes look very good but I thought I’d try the shellac technique on the top since it is a porous wood.
Thanks again, read you all later, Marc

-- Windsurfing, Woodworking, Weaving, and Woodducks. "Most woodworkers are usually boring holes"

View marc_rosen's profile


143 posts in 3356 days

#5 posted 09-27-2015 04:41 PM

Hey Ron,
Thanks too for your input. As I typed to Bruce and Jim I over sanded coat one so coat two ill get a light smoothing. Still not certain if I’ll try it by hand or go with the sander. Marc

-- Windsurfing, Woodworking, Weaving, and Woodducks. "Most woodworkers are usually boring holes"

View jdmaher's profile


437 posts in 2754 days

#6 posted 09-27-2015 05:36 PM


I finish all components the same.

-- Jim Maher, Illinois

View Jim Finn's profile

Jim Finn

2684 posts in 3097 days

#7 posted 09-27-2015 08:52 PM

400 grit with my slow speed Festool sander on shellac works to make the surface very smooth. Ready for the final finish. I put lacquer or poly. over this.

-- No PHD just a DD214 Website>

View Fred Hargis's profile

Fred Hargis

5142 posts in 2668 days

#8 posted 09-28-2015 11:11 AM

There is actually no reason to sand the shellac at all other then to remove any nibs and whatnot. That can be done with a light hand sanding of a fine grit. Should you choose to use an ROS, look carefully with an angled light to determine if it has left “pigtails” (swirl marks). if you have them, they may be visible in the final finish.

-- Our village hasn't lost it's idiot, he was elected to congress.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics