OPEN JOINTS IN WOOD TABLE TOP

 Dear Uncle Lar; I cane and refinish small items. Mostly chairs, rockers, small tables etc.,nothing very large.  I am not a professional - this is just a hobby. Learned the caning and refinishing at  adult night school classes. Most of the items I have worked on have been acquired at auctions, garage sales, etc. and even off the street. I do not consider myself an antiquer (?) but more a recycler of old used furniture. I do not know antiques well enough and would be afraid of ruining something. I prefer to do the hand caning rather than the pre-woven because I feel that I can control the quality of the finished product.  Now to my question... I am currently refinishing a hexagonal shaped tabletop that will have a mosaic in the center (mosaics being my other beginner hobby). The refinishing is going fine except that the six joints of the tabletop frame do not meet cleanly. There is a gap of roughly 1/16" or so that I am trying to fill between each section .I cannot take the top apart and reconstruct it. I am looking for recommendations for stainable wood filler that will harden and stay in these small cracks between each section. Previously I had used a wood putty that looked great initially but cracked and crumbled over the winter maybe due to expansion and contraction. Joan in PA.  

Hi Joan,First I'd check to see why you have the gaps.  Is it a poor fit?  Are the joints failing? 

From your description, I'd guess it is  due to wood shrinkage.   Wood doesn't shrink much with the grain, but since it is an open center top, the frame would be attached to the sides, which would shrink and pull the frame with them, accounting for your open joints.  Since you've used wood filler, and was satisfied with the look, it sounds like you are only looking for a stable product.  I'd guess you used one of the wood fillers in a can.  These have no strength and always crumble very easily, as you've
experienced.   As for a stable wood filler, go with an epoxy based filler.  It won't crumble and fall out and is tougher than the wood.  There are several brands available that are two component putties which you work together with your fingers to activate.  Some are colored.  Even though they are sandable, I'd make every effort to make the application as smooth as possible.   Mix in a
little alcohol (denatured alcohol, not medical or rubbing) with a spatula or spreader if it is too thick to spread.   You can find these epoxies at Lee Valley, Wood Craft, Van Dyke, almost any wood working company or home center.
I prefer to use the liquid epoxy and mix in  oil paint from tubes to get the right color match, but the putty is easier to use, not as messy and can be readily carved.

1. Clean the area where you are going to apply the filler.  Be sure to clean out all the old filler from the joints.  Folded sandpaper should fit into the crack.  Place masking tape over the wood on each side of the open joint.  This will protect the existing finish while you are putting epoxy in it.Mix the epoxy thoroughly.  Inadequate mixing results in epoxy not curing.  This is the biggest problem people have with epoxy. 
   Mix the putty epoxy until it is a uniform color.  If you are using a liquid epoxy and wish to color it, add a small amount of the desired artist oil paint to your epoxy as you mix it.  Only use enough to color the epoxy. Too much coloring will affect the strength and curing time.Use a toothpick, spatula or similar item to place the epoxy into the open joints.  About now, you're glad you put the masking tape on the sides.  Only fill until it is level with the top.  Now is the time to remove
   the masking tape.  Don't wait until the epoxy cures as it may not come off then.If it looks ok, you are done. If it is too high, allow the curing time stated on the container.  Test to see if it has cured by sanding very lightly with 220 or finer sandpaper.  If you get a fine powder, it is cured.  If it is
   gummy, wait longer and test again the same way.When sanding to level, be very careful of the existing finish.  Placing a small amount of petroleum jelly like Vaseline on the finish will help
   protect it from the sandpaper.  Be sure to remove all the Vaseline with naphtha or mineral spirits before staining or finishing.
2. Before finishing, if required, you can color the new fill.  I prefer artist acrylics as they dry very quickly.  If the color is now right, put a coat of matching latex finish on the repair. By matching, I mean matching the gloss of the finish. 

 Now you're ready to install your mosaic top. Enjoy the experience.

NOTE:

Any information provided here is primarily based on my experience. While I can't guarantee you will obtain the same results, the various procedures should work for you if you follow the precautions before attempting them. For example, determine the type of finish that currently exists before starting any procedure. Always determine the stability the existing finish. If is flaking, it is unstable and either needs to be left alone on a valuable item, or amalgamated or removed if it is a piece that will have a greater value if restored and refinished.

This brings up a very important issue. TV programs such as the Antiques Road Show increase people's awareness that not everything should be restored, and that in cases of valuable items, it will decrease the value considerably. Now, the hard question to answer-what should you leave "as is"? If you are in doubt, contact an expert, knowing that he may charge you several hundred dollars to evaluate the piece. If you buy regularly from a knowledgeable antiques dealer, he may give you an opinion for little or no cost. If the item is one you see at most antique shows and shops, you can bet it is safe to restore it yourself. If it is something you've never seen, and you don't want to hire an appraiser, look for it on the internet and at the public library.

I can tell you some things I don't think you should strip and refinish. These would be furniture with its original paint, even if it is almost half missing. Usually these will be primitive items such as pie safes, cupboards,tables and chairs. Also, the wood beneath the paint will most often be pine, poplar or a mixture of woods.