Replies

1. 
   saschafer | Dec 16, 2007 03:44am | #1

   A clear epoxy is probably the simplest to use. Unfortunately, you need only a tiny bit, and I don't think you can get less than a pint or so.

   Something like this one from Woodcraft would be suitable. If you don't want to buy that much, you can try this one from Rockler. The West System epoxy is more viscous, though, so it might take a little more effort to smoothly fill the void without bubbles.

   Whatever you use, practice on a test piece first. Epoxy doesn't give you much of a second chance....

   -Steve

    

2. 
   woodshaves | Dec 16, 2007 03:44am | #2

   Epoxy.

1. 
   JMorris | Dec 16, 2007 05:47pm | #6

   Will epoxy show the knot, because I want to be able to see it, just have it smooth with the rest of the surface.

   Edited 12/16/2007 9:47 am ET by JMorris

1. 
   saschafer | Dec 16, 2007 07:10pm | #7

   Epoxies vary from water-clear to completely opaque. They also vary in viscosity from thin liquid to solid putty. If you want a clear filling for your knot, your epoxy needs to be both transparent (obviously) and have a reasonably low viscosity, so that it flows into the knot hole without leaving air bubbles. That's why I recommended the specific products that I did, because I know that they have the necessary characteristics. You may be able to find an appropriate product at a hardware or big-box store, but I've never seen such a thing, except for fiberglass repair. You'd have much better luck at a crafts store. You can also find appropriate stuff at a marine supply store (again, for fiberglass work), but you'll probably have to buy it in large quantities there.

   -Steve

    

2. 
   woodshaves | Dec 16, 2007 07:33pm | #9

   That is exactly what it does, it is a favorite method of mine to show knots. The clear epoxy let me see the knot while at the same time it fills the gap and makes any unstable knot solid. The dark reflection of the wood inside the knot (into the epoxy) makes it look like it is part of the wood and not a filled space. Place the side horizontal and pour enough mix to protrude above the level of the surrounding wood, let dry and sand. If there is not enogh epoxy to fill the gap when it is dry, do not sand, prepare more epoxy and pour more, let dry and sand. As mentioned, use epoxy with a long set time, not because there is no time to do it in 5 minutes, but because you want any air bubble to be able to come to the surface. Final sanding is the same sandpaper grade as the rest of the surrounding wood. The opacity of the sanding over the epoxy disappears when the finish is done.

3. 
   PCM | Dec 16, 2007 04:34am | #3

   If you want to use epoxy, which I have used to fill similar problems, get the 2 tube variety, snip off the cap and push out enough onto wax paper (this gadget looks like a double syringe).

   Spread and mix the two parts with a small dowel until you are confident it is mixed. Use a tooth pick to fill the holes. The cap can be put back on, the tubes are ready for the next use-shelf life does not seem to be a problem.

   Do not:                                                                                                                          Buy the 5 minute type!! You will not have enough time to mix and fill. 30 min works fine.                                                                                                                    Squeeze a thick puddle-It will set up too quickly. Once I mixed an entire syringe into a styrofoam cup, thinking 30 mins is more than enough time to use it. Very soon the cup got hot, the glue was set up, I threw the cup out onto the lawn!

   Pete  

    

1. 
   pzaxtl | Dec 16, 2007 08:03am | #4

   Wow! that was kinda hard to read.  It appears that your tab key/space bar was having an epileptic fit.

4. 
   knuts | Dec 16, 2007 04:46pm | #5

   I mix a tablespoon of the most powdery walnut dust with a little yellow glue to form a thick paste. Press that mix in /around the knot. Next day; sand it flat.

5. 
   | Dec 16, 2007 07:18pm | #8

   Hello JMorris,

   You did not say how large the cavity was, however, on smaller knot cavities and cracks I have had great success with supper glue. I put some fine sanding dust in the cavity, add some supper glue and allow it to cure. If the cavity is deep or the first application did not fill completely, repeat. It is better to do this in stages. level and finish. The photo attached shows a box top that had some cavities, can you tell where?

   
   

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   Edited 12/18/2007 10:24 pm ET by salamfam