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New to forum and have a question. I have been doing hobby woodworking for 20 years or so and can cobble together some decent projects on occasion but this one has me wondering.

A friend wants me to repair this dining room table they had custom built a number of years ago. As you can see by the pictures, the "builder" used blocks of walnut about 4" square glued into the field of the table. All the glue joints have now failed due to expansion and contraction. Ant ideas on how to approach making this table look presentable again? Any and all suggestions welcomed.
 

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I don't have any idea how you would go about repairing it. Maybe "masking" by routing out the glue joints (using a router with downcut spiral bit along a straightedge; you'll need a vacuum attached to remove the dust being forced into the groove) and then refilling with a anything from fine grout, to died epoxy, and then sealing it with a 2 part epoxy flood coat. You could use one of many techniques discussed on this forum to change the natural high gloss sheen of the epoxy to something satin so it doesn't look so plastic-y.

The problem may have developed for a number of reasons. Do you have any idea what kind of environment the table saw? If it was left outside or saw high humidity somehow and then exposed to low humidity the end grain cookies had no chance of doing anything but what they did.

That design is rooted from cordwood construction and could even be called a faux cordwood look. My wife and I experimented with making indoor cordwood paneling a few years ago and we actually both like it. We used eastern red cedar but we used the natural round end grain slices - IOW didn't square them as the builder of that table did. We filled the gaps with cream-colored epoxy.

As far as actually doing a foundational type repair to that top I don't see how. End grain like that will crack very easily so there's goong to be no way to remove them IMO. I'll be interested to see the replies though.







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I might add that if you do attempt any repair, you do have to seal the top with a flood coat because end grain like that acts just like a sponge. Water will pass right through thin end grain like that almost instantly, as in a spilled drink every now and then and especially if it's a patio table that will get rained on. Once that happens the end grain wood fibers bonded to the glue base will eventually rip themselves loose from the glue, which does not expand and contract at all compared to the amount the end grain slices do when they see lots of moisture and then very arid conditions.

I think that was an important point for me to add in case you attempt a repair. HTH.








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If we can assume that the joints were once tight when the piece was constructed, I’d say the glue line failures were a result of the blocks shrinking as they dried out. It looks like the builder took a walnut 4 x4 with the pith in and cross cut off strips to make the blocking. Unless they were perfectly seasoned, the trouble might have started there. Since wood moves forever, the problem won’t go away even after you repair it, and the table is especially vulnerable if it was outside or if drinks were spilled as Texas Timbers suggested.

I’ve never done this, but the only thing I can think of would be a marine caulking that will expand and contract as the wood moves. It’ll give the table a tiled floor look, but these caulking are designed to allow the wooden planks of a boat to expand and contract. I don’t know any specific names, but an internet search might help. Routing the joints first as TT suggested would even up the joint lines and give you space for the caulking.
 

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Flooding with epoxy?

I had thought of some sort of "plastic" top coat as well, when you folks say flood with epoxy...if you look at the edges you will see that they are sort of bullnosed and the field blocks are at the same level as the border. I wouldn't know how to go about flooding the entire table. In addition to that problem, the bottom of the table is covered with plywood which I'm sure the individual blocks have been glued to in the initial construction.

I suppose I could rig up a jig to route out the entire field and fill the resulting area with epoxy but the finish would not be perfectly smooth unless I tried to sand it out which would be a pain to do.
 

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You may get lucky and find a solution that may work...how permanent it will stay that way is up to Mom Nature.

I might do the routing thing. Using a straightedge and a router with a straight faced cutter (mortising bit). The cut width would have to be wider than the worst crack, probably 1/4". My first thought was to rout 3/16" deep. Then cut strips of face grain Walnut and use a small bead of glue at the center of the groove. Fit in the strips and leave them slightly high. Then using a ROS, sand the entire table top. Finish with lacquer, oil base varnish or polyurethane or waterbase polyurethane, with enough build to seal the entire top.

My second thought included the routing, but fill with a dark grain filler, and then do the same finishing regimen. There are grain fillers available with a choice of colors that would fit well with that top. Or they can be tinted to fit the application.

There may be some flexible marine caulk that moves with the wood, but I'm not aware of any that I would recommend. I'm thinking that it still will separate from the edges.

As for coating the entire table top, here is a short tutorial I've posted in the past on how to do a pour on finish with a two part epoxy:

Have the top in an easy to work and move around area. Cover the floor with drop cloths. Visqueen (brand or other brands of clear plastic sheeting) the area completely.

Mixing:
When ready, do not stir either container per se, but rather use a stir stick and slowly pass the bottom of the can for any settling that may have occurred. Slowly mix equal parts so as not to create any bubbles.

For tops that will have an edge with overflow from the top pour:
Use a brush and coat the edges with the mix so when the top is poured it will have a clear run on the edges. Pour from the center of the top near the end and slowly work your way to the other end. For long tops, pour from the center to the outer ends. Allow the mix to run off the edges until you get coverage all the way around.

When the consistency gets to a gelled state, take a knife and cut off the excess from under the top.

For tops with a captive edge:
Depending on the height of the pour desired, you may want to do two pours. If you get ¼" to ⅜" minimum per pour that is fine.

Right after the pour:
Use a propane torch passed over the top, keeping the flame off the epoxy. This will heat up the material so any bubbles will rise and dissipate. Using a heat gun or a hair dryer may cause a gelling or areas that kick too soon, due to the hot forced air. Block or belt sand the cured epoxy off the bottom and ease the sharp edge where it ran off, and it was cut off.

Here is a good site that covers most questions you may have. There...see how easy it is.





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. . . . and fill the resulting area with epoxy but the finish would not be perfectly smooth unless I tried to sand it out which would be a pain to do.
The epoxy is self-leveling, no sanding will be required unless you use that method to change the sheen. Routing it wouldn't be a difficult thing to do. You could use virtually anything in the routed grooves you wanted to if you cover with epoxy. I'm not sure how the idea to use long grain strips would look but it might look great. Whatever you use build a mockup using end grain walnut cookies so you can test several things.

As far as the movement, since it's glue to plywood and the top and sides would be covered with the epoxy, the moisture transfer is going to be almost nonexistent. Movement won't be a big issue unless it's used outside and not under cover.

The link C'man provided is the same product I used and not only is it a great product, the last time I bought some which has been a while, it was like $33 for a kit which was about half the price of others.



I suppose I could rig up a jig to route out the entire field . . .
You don't need to build a jig to rout with, just clamp a straightedge across the table. To determine the proper distance the edge needs to be from each old glueline, clamp a straightedge across a piece of scrap plywood or something and rout a rabbet using the same bit you'll use to rout the table's glue lines. Measure how far it is from the inside of straightedge to the inside of the rabbet. This is mush more accurate than holding a tape against the bit and trying to eye the distance to the outside of the router base. That's your offset and that's how far you'll clamp your edge away from the inside of each glue line.

Make sure you don't just do it willy nilly. You have some intersections that aren't lined up . . . . .

Cimg3145.jpg


..... so you'll have to stop there, readjust your edge, and continue. This isn't necessarily beginner stuff but it isn't advanced by any means. This isn't a hard "fix". Use C'mans tutorial for the flood coat and there's also YT videos to watch it done. That's my bag - I got to see something usually.


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Well guys.....

I must say I REALLY appreciate all the good advice! Often when you are a newby and ask a question on the internet forums you encounter somewhat of a "holier than thou" attitude. Happy to say this forum isn't like that and I hope to be able to contribute in the future.

Now my problem will be convincing the folks that the only viable option for the table will be totally sealing it. The table resides in a very upscale 1930's mansion kitchen with black walnut cabinets and even a large built in walnut hutch all of which is lacquer finished. To finish the table in plastic that will look like your local fish house is gonna be tough to sell. The original builder didn't make wise choices in design and finish. We'll see what happens.

Regardless of the outcome, thanks again for the advice and warm welcome!

John
 

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. . . Now my problem will be convincing the folks that the only viable option for the table will be totally sealing it. . . . To finish the table in plastic that will look like your local fish house is gonna be tough to sell.
Glad you like the place here John. Not trying to cram info down your throat, but you're missing some of the things we've said (I know it's a lot of reading).

TexasTimbers said:
. . . You could use one of many techniques discussed on this forum to change the natural high gloss sheen of the epoxy to something satin so it doesn't look so plastic-y.
Now that I know what kind of environment the table is in I think your options have dovetailed a little. You can probably get away without the thick epoxy. When I said that you had to seal it with epoxy I had assumed the table was a patio table with the kind of damage that it has. I often remind members not to assume as we all know it makes an "ass" out "u" & me". Nice to get a dose of my own medicine - happens all the time.

Waterlox makes a great varnish that you could shoot enough layers with to seal it in that "kinder" environment. It's durable, looks like a professional finish (it is) and would create a thick enough film to hold back any temporary moisture like spills and grandkid activity. However if you ever do ever need to consider the epoxy whether for this project or another in the future, epoxy can be applied without having to look like plastic. I should've given you a link earlier when I mentioned it.

Here's one thread with some good links.



. . . Often when you are a newby and ask a question on the internet forums you encounter somewhat of a "holier than thou" attitude. Happy to say this forum isn't like that. . .
No we don't turn people off with Ivory Tower Syndrome, we run them off by inundating them with massive amounts of information, beaucoup options, and endless possibilities. :icon_cheesygrin:









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for best looks i would remove the squares and instal new . second choi8ce, i would scrape out the cracks and fill then top coat. might be a good look.
 

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I have a idea you might want to try

As everybody has stated the problem is that the 4 x4 blocks are too thick and that causes movement over time. I suggest you remove all of the blocks. I would then slice the blocks into 1/8" thick veneer on the band saw. The 1/8" veneer would have a lot less expansion problems. After slicing the veneer I would use the table saw to square up the edges and make all a uniform size. Of course you would not have to slice all of the 4 x 4 blocks into veneer, just choose the best and most interesting blocks.
Before you reassemble the veneered blocks you would have to build up the inside of the table so the 1/8" veneer will be flush with the top. You could build a torsion box to fill the void. Then apply the 1/8" veneer. I assume that you do not have a vacuum bag large enough for the table top so I would build a press and clamp the heck out of it. You could build a second torsion box for the press. I know that is a lot of work but quote it high and then pad it some more. Also you would have a whole lot of the 4x4 blocks left over. You could suggest to the owner that you could build them a matching piece of furniture.
 

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As everybody has stated the problem is that the 4 x4 blocks are too thick . . . The 1/8" veneer would have a lot less expansion problems.
Those are end grain blocks. Radial movement isn't affected by thickness. Make them too thin though, and they won't be able to handle the stress as well and could crack worse, though the movement would be the same as a thicker section.





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Just a suggestion but if you do decide to replace the large 4x4 squares you could eliminate this by moving down to a smaller end grain square like a 2x2 or at most a 3x3 block. I do realize it will be a lot of work but like texastimber said the problem is the radial movement thus meaning the larger block the more movement that will occur. Like I said just a sugestion.
 

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I must say I REALLY appreciate all the good advice! Often when you are a newby and ask a question on the internet forums you encounter somewhat of a "holier than thou" attitude. Happy to say this forum isn't like that and I hope to be able to contribute in the future.

Now my problem will be convincing the folks that the only viable option for the table will be totally sealing it. The table resides in a very upscale 1930's mansion kitchen with black walnut cabinets and even a large built in walnut hutch all of which is lacquer finished. To finish the table in plastic that will look like your local fish house is gonna be tough to sell. The original builder didn't make wise choices in design and finish. We'll see what happens.

Regardless of the outcome, thanks again for the advice and warm welcome!

John
Yeah, some real nice cats on this forum.
 

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Wow thats a tough one, you don't want to spend more time repairing the old top than building a new one from scratch. I think you could clean up the glue joints using a router and strait edge in a reasonable amount of time. Then fill the joints with wood filler, maybe a filler you mix your self with sawdust and glue or epoxy. Then sand and refinish a good choice for finish might be varnish it adheres to most everything and it doesn't have that hard shiny look you don't like.
 
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