Sanding Sealer v Grain Filler

[Steve Mellott]

I need to finish a multicolor segmented bowl that has a lot of open grain. Can someone please explain the difference between sanding sealer and grain filler? Any thoughts as to which one might be better on a segmented vessel to help prevent (or minimize) bleed from one wood to the next? Thanks.

[Stew Hagerty]

Grain filler is just that. On open grained wood, it will fill in the big open pores so that you end up with a smoother glassier finish.
Sanding sealer, on the other hand, seals the wood. you can buy actual "sanding sealer" or you can use a 1/2 to 1lb cut of shellac. Either will seal the wood to prevent bleed, or any interaction between an oil and a topcoat.

[David Walser]

Grain filler is generally a paste that you trowel onto the wood, forcing the paste into the pore's of the wood. You then sand the excess paste off, leaving behind the wood and filled grain. Often the grain filler is dyed to match the wood, or it can be dyed a contrasting color to accent the wood's grain.

[John K Jordan]

I use grain filler when I want the final surface to be smooth like glass. Grain filler is often colored to match the wood. Seems like it would be hard to apply to segments without getting it on adjacent segments.

As others mentioned, sanding sealer will not fill the pores but will sink into the grain and harden it a bit. I generally mix shellac 1:1 with alcohol, paint on liberally, let dry, then repeat. You can watch it soak into the wood. Then final sand and apply my finish of choice. This method seals the wood somewhat but still allows the pores and grain to show in the final finish if the smooth-as-glass look is not desired.

You can also fill grain with multiple applications of clear finish, but it is slow. I've used TruOil for this.

JKJ

[David C. Roseman]

Steve, all good comments. If you decide to try grain filler, suggest you experiment on scraps of the same material you've used in your finished piece. It can be tricky to use.

[Prashun Patel]

Steve,
These are good explanations of the diffs between sanding sealer and grain filler. I don't believe either is what you need for your issue though.

Are you trying to dye or stain the segments different colors? I think that's a difficult proposition. Sanding sealer or shellac will help in theory, but applying it neatly to - but not over - the seams is tricky. SS is intended to speed production since it dries fast and sands easy. You can use your topcoat as a sanding sealer (dry time notwithstanding). Grain filler is a thick syrup that is intended to be slathered and squeegied in order to achieve a flat surface so gloss top coats will go on and level without divoting into the grain. So, it would be really tricky to apply properly and neatly to preferential segments.

If you are trying to minimize sanding dust contamination then I suggest you just sand it as if it were a solid piece, and then use compressed air to blow out all of the dust prior to finishing. If you can spray aerosol shellac or lacquer as a sealer, you can also minimize wiping dust from one segment to the next.

If you are using oily wood as some of your segments, then you can additionally cleanse the piece with acetone before and after sanding. You have to test that any drying of the wood and dulling of the color imparted by acetone is not permanent once you put the topcoat on.

[Bill Boehme]

I need to finish a multicolor segmented bowl that has a lot of open grain. Can someone please explain the difference between sanding sealer and grain filler? Any thoughts as to which one might be better on a segmented vessel to help prevent (or minimize) bleed from one wood to the next? Thanks.

This article from Woodworkers Journal should clarify things. Their editors didn't catch the homophone in the title that calls it "pour" fillers instead of "pore". I suppose a poor excuse is that you pour the pore filler onto the ring porous wood.

Sanding sealers bond to wood better than paint (especially latex) and sanding sealers are generally softer than the top coats so that they can be easily sanded smooth. Sanding sealers also are effective in sealing pores on diffuse porous wood where the pore size isn't visible without magnification. They also contain sterates which keeps the sandpaper from clogging. Sometimes bare wood will draw the solvents or water out of the topcoat too quickly leading to visible brush strokes. I don't use sanding sealers very often because the sterates reduce clarity slightly. I also don't use house paint or a roller on turned wood pieces except for an occasional architectural item.

Pore fillers fill large visible pores in the grain, generally on ring porous wood.

[Steve Mellott]

Thank you very much for this information. I was wondering if the sanding sealer would fill the pores and it seems like it won't. (I'm not sure that is a bad thing.) I think I will clean the surface with compressed air and then spray light coats of the sanding sealer. Hopefully, that will minimize the bleed from one wood to the next and will give me the surface that I want. Then I can decide what type of topcoat to use. Thanks again.

[robert baccus]

I strongly disagree with the above concerning SS filling pores. It should be applied(straight on open pore woods) and sanded until the surface is perfectly flat and smooth. 220 if fine for SS as the lacquer will melt far coarser scratch marks then that. The lacquer or finish coat should be only applied after the piece is level and smooth. The only wood fillers I have seen come out a light pine color and must be dyed to match the wood used. Most woodturners seldom use dyes except for special effects. SS can be thinned and sprayed on tight grain woods--usually 2 coats if desired.

[Prashun Patel]

I think I may be misconstruing what you are trying to do. Can you post a picture and explain whether you are trying to avoid bleed from some kind of stain or colorant or bleed from sanding dust. Confused.

[John K Jordan]

The only wood fillers I have seen come out a light pine color

I use a dark walnut-colored filler on walnut. I bought it at least 20 years ago. I also use it to fill texturing for contrast on a light wood.

A few handles I made for some small Hunter tools:
textured_handles_hunterIMG_.jpg

How sealers and fillers are used on any project depends on the effect desired.

JKJ

[Bill Boehme]

... The only wood fillers I have seen come out a light pine color and must be dyed to match the wood used....

ColorTone Professional Clear Grain Filler is used by guitar makers. There are several other clear grain fillers in addition to a few colored fillers.

[Thom Sturgill]

My mentor down here in Florida uses thinned lacquer (1 part lacquer to 4 parts thinner) and soaks it until the wood stops taking it in. Then sand until smooth looking for shiny spots that did not sand . Repeat as needed sanding up to at least 340 and then apply several coats of rattle can (Deft) lacquer. This definitely will foll pores and give a glass like finish.

Whether it would prevent color bleed is another issue. Bloodwood is famous for bleeding over into other woods and Holly is very hard to keep clean, accepting color from whatever it is next to. I suspect his regimen would actually INCREASE the bleed.

[Steve Mellott]

I am trying to avoid bleed from sanding dust. Unfortunately, I do not know how to post a photo on this forum. The bowl I am making is commonly called a vortex bowl and was created by Hal Metlitzky several years ago. (You can see one of these bowls on his web site if you want.) The problem I am referencing is a problem which I think is common to most segmented turners. I've already sprayed 2 light coats of sanding sealer on the bowl and there was no bleeding between the woods. I wiped and used compressed air to clean the surface beforehand. All seems to be well. Thanks for all your help.

[James Combs]

I am trying to avoid bleed from sanding dust. Unfortunately, I do not know how to post a photo on this forum. The bowl I am making is commonly called a vortex bowl and was created by Hal Metlitzky several years ago. (You can see one of these bowls on his web site if you want.) The problem I am referencing is a problem which I think is common to most segmented turners. I've already sprayed 2 light coats of sanding sealer on the bowl and there was no bleeding between the woods. I wiped and used compressed air to clean the surface beforehand. All seems to be well. Thanks for all your help.

If you want to learn how go to this sticky thread.