Hi all,
I’m pretty new to the forum here. I’ve got some wood working experience but not a seasoned vet, especially when it comes to finishes.
I’m building a table (Spruce slab, 10′ x 18″ x 1.75″) that will be used in a coffee shop. I decided to use Vermont Natural Coatings Satin (http://www.vermontnaturalcoatings.com/VNCFurniture.html) as the finish. There are a couple of knots with decent sized cracks. The biggest is about 1/4″ running about 2″. None appear to go all the way through. So here are my questions:
Can I just leave the cracks open and drizzle some of the finish coat down into them? Does this mean I risk the cracks affecting the rest of the piece? We’re going for rustic look (the table has a live edge) so I like the visual effect of the open cracks.
If it is recommended to fill, is a crystal clear epoxy better than a wood colored epoxy. Seems to me the wood colored fill is an eyesore because there’e really no way to make it look natural.
Should I finish the entire surface of the table or can I get away with just the top? My assumption is that it’s better to do the whole thing, but just want to clarify.
Thanks in advance for all the sage wisdom. I’d like a good book on finishes. How is the Tuanton press “Complete Guide to Finishing woodworking”? Any other recommendations?
Justin
Replies
One technique is to fill the voids with artists acrylic casting resin. It's the stuff they encapsulate bugs, shells, etc. in. Crystal clear, looks like you used molten glass. You probably don't want any nooks and crannies which can trap nasty stuff. I haven't used epoxy for large fissures and holes and don't know how it would work.
I would finish all around just to reduce moisture absorbsion. Can't comment on the book.
The book you mention is by Jeff Jewitt and is an excellent choice. The other book you need to help understand finishing is Bob Flexner's Understanding Wood Finishing.
For cracks that wide, I would use black epoxy. Yes, black. You cannot color match well enough to make it look good, but the black, somehow, looks very good on a rustic table.
Brent
Black Epoxy would work the best. A crack will show as shadow or negative space. The black epoxy best approximates that effect. Since it is used in a Coffee Shop, you need a sanitary surface so filling it makes the most sense. Post a pic will you?
AZMO
I'll get a pic up tomorrow. I like the idea of seeing the crack and the clear epoxy (or acrylic resin) would allow it to be visible. The black would of course not do that. I'd have to see it with black first. Do you have an examples?
I don't have any with epoxy, but I have used dark shellac as a burn in stick and filled knot holes with that. It takes a lot more work... but the result is the same. You might check some woodturners sites where they do use black mixed with turqouise and other stones.
Problem with clear epoxy is getting the material to flow into the crack without leaving an air gap along the contact points. I have seen several examples of this where you see the sides of the epoxy fill, but not the wood it is bonded next to it.
I spoke with a gentleman at a show who makes boxes with stones, sliced geodes mixed with wood. He uses a vacumn chamber to eliminat the void between the objects and the epoxy.
If you buy the expoxy, you can get a tube of color to go with it. Do a test piece on a scrap or such and see what you like. The color is cheap at $2 and kit is $20 or so.
AZMO
AZMO
I have made a coffee table for a customer that had a top with quite a few large knots missing. He wanted them filled somehow and the way we achieved it was to use the potting resin with samples of flowers and insects encased in them. Made quite a talking point
wot
wot/azmo,
the bookmatched voids in the crotch walnut door panels that i'm currently working on have been filled with ground granite and epoxy. looks good. i think i will try the resin you both mentioned.
eef
Norm Abrams made a book case out of mesquite. The wood had some large holes that were filled in with a black epoxy. He used West's #423 graphite powder to color the epoxy.
I am currently experimenting with fill in some large voids on some spalt maple with Elmer's steel epoxy. Comes in the 2 part syringes and is already black. It is very thick and despite my attempts to thoroughly and carefully work it into the void, once sanded there were some bubbles, so another light coat is required. The epoxy bonded tightly to the sides and other than the bubble holes, the surface sanded beautifully.
Epoxy resins are reported to be harder and stronger than polyester resin.
Don
Don01,
you might try heating the epoxy. It will set faster however, but it will also flow better.
Brownell's sells Acuraglas epoxy for use with rifle stocks. It comes "normal" as a fairly thin 2-part mix that will flow fairly well. It also comes as a gel that is much thicker in instances where that is useful. They also sell coloring agents (brown and black) to pigment it. The pigments come with the "kits" and are also sold separately.
I have heard of using india ink to color epoxy but have not tried it myself
Brent.
As other posters have stated, i have used epoxy with black shoe dye added for fairly large cracks in Pine Harvest tables, levelled with a chisel or block plane, finished with several coats of pre-catalyzed sprayed lacquer. Really blends in well. I have a large, live edge Pine slab to eventually become a coffee table or bench & plan on using the same technique to replace some bad spots, fill large crecks in the heart wood & through some huge knots.
Here area some pics of the test piece. Today I'll chisel away the humps and sand to see which one looks better. But I'm leaning towards the black.
I used Envirotex Lite: http://www.eti-usa.com/consum/envtex/envlite.htm and mixed in some black acrylic paint.
I need to work on getting the air bubbles out on the actual piece.
Another question. I taped the bottom of the knots and was surprised by how much material the knots took on. And as one commenter said, it did go all the way to the underside. So on the final product is it better to pour from the bottom? I would think that would all the air bubbles to float to the top (which is really the bottom) and makes for a cleaner top side.
Justin
just cut some wood wedges of the appropriate size put some glue on them and tap them in. levet off when dry and finish. will not crack out as bad as the epoxy will and it will. any solid filler will eventually crack
ron
That's a good thought, but I've already poured it. I ended up going with clear and I'm really happy with it. I also switched to a 5 minute epoxy, folded rather than mixed and it came out really nice with almost no air holes. You can also see into the cracks which was the effect I wanted. I'll post pics after I do some more sanding today.
Justin
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