Filling voids

[Porter Bassett]

I want to fill in some cracks/voids that showed up in the middle of a piece of walnut.

I know that I've read of mixing something with a bunch of sawdust and slathering it in there, but I don't know what would work well for that. Wood glue? Epoxy? Something else?

[Michael Faurot]

You can do wood glue and saw dust. Another thing to do that can come out nice is do something like the 5 minute epoxy and then dye it black.

[Porter Bassett]

Dye what black? The epoxy? What would I dye it with?

[Stephen Edwards]

Crazy Glue works well. If the void is ragged, clean it up a bit with sandpaper. To keep the color uniform, put a coat of whatever stain and/or finish that you're going to use on the finished piece, in the void. You may need to do the CG in several applications to bring it up proud of the surface.

When it's completely cured, sand it down flush. I learned this trick here on SMC and it has worked well for me.

[Denny Rice]

There are different types of cyanoacrylate glues that will work for small holes, cracks and voids in woods. For larger voids I will use epoxy mixed with sawdust from the wood I am working with. Make sure the dust is very fine and mix it with the epoxy fill the void and sand after it has set. I keep both on hand in the shop. If you decide to go the cyanoacrylate style glue be aware they come in in different thickness from very thick to almost as thin as water. I have purchased both from my local Woodcraft and they have worked very well. Hope this helps:D

[Gene Howe]

For real small voids, the glue and sanding method works well. For larger ones, 5 min. epoxy mixed with sawdust works. Tape the void and cut the shape away with an Exacto. Saves a lot of finish sanding grief.
I've also read that artist's acrylics can be mixed with epoxy for some interesting results.

BTW, while shopping in my local health food store, I spotted a bin of loose, finely ground (powder) walnut shells. I bought 1/2 lb. on spec. I put a t.sp. in a pint glass container and added boiling water. Works great as a dye/stain. I've used it on white oak and black walnut. On oak, one application darkens the oak to a lightly fumed hue. On walnut, coloring sap wood to match has been somewhat successful. It really darkens the rest.
1/2lb. will probably last my lifetime.:o

[Jim Becker]

Small and slightly larger voids are best filled with slivers of wood that are made with the same grain direction and from scrap of the same material. Really small slivers can just be inserted and will be held in by the finish or a tiny amount of glue. Larger voids can be filled using an inlay; either to match or to contrast, depending on the style of the piece and the preference of the builder. Using sawdust and glue, while workable, will very often be a lot more visible than patching with actual wood slivers, especially when finishes are applied.

That said, for "natural" edge piece, burls and material with bark inclusions, materials like coffee and nut shells glued in and then sanded flush will often be a very good choice. Just be careful with where the glue goes so that it's not staining or otherwise marring the surrounding area.

[Sonny Edmonds]

I've used CA glue, and with the spray that makes it set fast, you can really get a void done nice and quick.
In oak, I've filled small voids and it comes out invisable to all but my eye. Just looked like a dark vain in the wood when done.
I keep CA in thin and medium, and the spray hardener, in my shop all the time. ;)
One of the "Tricks of the trade".

[Michael Faurot]

Dye what black? The epoxy?


Yes. When you're mixing the parts of the epoxy together add a drop or two of black dye. Now instead of the epoxy being clear or amber--it's black.

Another trick, if the void is big enough, stuff it with coffee grinds and then put the black epoxy over it.



What would I dye it with?Transtint black (http://www.woodcraft.com/product.aspx?ProductID=128490&FamilyID=1718) is one option. Mixol (http://www.woodcraft.com/product.aspx?ProductID=832386&FamilyID=5522) is another that works, and is a bit less expensive.

[Lee Schierer]

I agree with Jim, try to use a thin piece of wood to fille the void if it is a crack type opening. Tapping a wedge shaped sliver into a crack and sanding it flush makes a nearly invisible patch.

The problem with sawdust mixed with glue is that the finish may not color that area the same as the wood surrounding it and it becomes more obvious when the finish is applied.

[Chris Padilla]

If you go the epoxy/sawdust route, be sure to try it out ahead of time because the color may shock you. Maple dust mixed with epoxy comes out chocolate colored. Pine dust tends to be a little less chocolately. With walnut dust, it will be black, which might be fine. Using sawdust and glue/epoxy will help a little bit in finishing since you will have actual wood exposed after sanding but there will be glue/epoxy around it. You may wish to practice on some scrap to see what you think.

Can you post any pics of the voids you are trying to fill? We might have other ideas for you as well. Do you think the voids are done moving around? Might they get bigger?

[Joe Chritz]

Sounds like a perfect spot for a fancy inlay of some tiger maple or something similar. The other methods mentioned work great and you really aren't out if you don't like the results since you can always go for an inlay after and remove the patch.

Sometimes it is best to hide stuff in plain sight.

Joe