making some end tables. Advice needed

[DanWalker]

Hey guys, I'm building some slab end tables and need some advice from some of you more experienced woodworkers. I have some beautiful slabs that I am going to sand and finish with a bar top epoxy, and then mount on hairpin legs. as you can see in the pics, the slabs have a really cool void in the center of them. I plan on filling this void with epoxy and black pigment. My question is, how should I go about reinforcing the table so it doesn't crack in half? I was thinking about using fiberglass matting and resin on the underside, but don't know if that will be strong enough. What are your suggestions?

[rancher1913]

get a metal shop to cut a sheet of steel just a little smaller than the top, painted black it will match your epoxy filler.

[OnHoPr]

Get a 3' piece of 1/2" square stock steel. Cut it in three 1' pieces. On the underside layout a symetrical or supporting pattern to go across the gap. Put two pieces of wood or steel together paralell on each side of the pattern for a drill guide. Drill down a 1/2" deep the whole length of the patterns and clean the 1/2" channels with a chisel. Or make the same 1/2" inlets with a plunge router. Drop the steel 1/2" square stock in and screw them down with 1.5" no. 12 or 14 wood screws. Oh, drill holes in the 1/2" steel stock for the screws. You might want to make the 1/2" steel longer or what you might think would work for you. Looks like a pretty thick piece of wood and those wood piece grains like that can be very tough. It definitely looks dry. But, I can see point to whereas you wouldn't want it season more and crack more and possibly break in five or ten years.

[bdicki]

Butterflies
http://images.rockler.com/images/articles/01_Planing_Key_lg.jpg
http://images.rockler.com/images/articles/10A_Hammer_med.jpg

[bangerjim]

Whatever you do......FINISH the bottoms! Unfinished wood will let moisture in the bottom grain, allowing it to expand at a different rate than the top and swell and shrink and crack the whole thing in no time. Your epoxy would seal both tops and bottoms nicely. Just no need to stain/finish the bottoms.

I assume you have either kiln dried these or they have air dried for at least 2 years?????? That is what it takes for long-lasting furniture. Looking dry and BEING DRY are two totally different things when it comes to working successfully with thick large pieces of wood like you have.

I have been doing this for over 40 years.

banger

[DanWalker]

Whatever you do......FINISH the bottoms! Unfinished wood will let moisture in the bottom grain, allowing it to expand at a different rate than the top and swell and shrink and crack the whole thing in no time. Your epoxy would seal both tops and bottoms nicely. Just no need to stain/finish the bottoms.

I assume you have either kiln dried these or they have air dried for at least 2 years?????? That is what it takes for long-lasting furniture. Looking dry and BEING DRY are two totally different things when it comes to working successfully with thick large pieces of wood like you have.

I have been doing this for over 40 years.

banger
Thanks for the tips. Yes sir, these were cut from a stump that has been sitting dead for around 5 years. EVERYTHING in this part of Wyoming dries quickly, thanks to our semi arid climate. Now that the oilfield appears to be shutting down for the forseeable future, I am looking at making and selling this stuff to supplement my income. Been having a blast so far.

[BigEyeBob]

Butterflies
http://images.rockler.com/images/articles/01_Planing_Key_lg.jpg
http://images.rockler.com/images/articles/10A_Hammer_med.jpg

Ive always known these as dutchmen

Kev

[Preacher Jim]

Save all your sanding dust mix with a good epoxy and fill the void you will be surprised if you have enough dust how good the void will look. Put your Dutchmen in the bottom for additional strength .

[bedbugbilly]

And one thing to be aware of . . . if placed near an air duct, they will dry out . .. if placed near a humidifier, they will take on moisture and swell. How thick are your slabs and how long have them been "air drying"? You are going about ti correctly but if they haven't been dried out for several years - you are going to get more "checking" and "cracking". I normally purchased kiln dried lumber (hardwoods) for use when I had my custom woodworking/millwork shop. At times, I had lumber sawn or purchased "green" when I could get it at a really good price. It instantly went into a "stickers" pile in an open side shed whee it was covered to dry out at least 1 year per inch thickness - from there - it went in to a barn where it was again "stickers" and allow to dry for a couple more years. You are working with "end grain slabs" so that is going to "pull" when drying ending up with the weakest point splitting or checking as the cells loose their moisture content.

Where we have our home in AZ, there is a sawmill about twenty miles away that deals strictly with "mesquite". They do a lot with "slabs" cut lengthwise of the tree and oftentimes, thee are internal splits/voids. They use epoxy mixed with turquoise "powder" and fill the voids and then sand off. It gives a beautiful contrast with he dark heartwood of the mesquite. All sorts of possibilities and only limited by the imagination. Those should be some beautiful end tables you are making. Good luck with you project and I hope you'll post some photos of them when you are done! :-)

[bdicki]

Ive always known these as dutchmen

Kev
Dutchman
http://1abxf1rh6g01lhm2riyrt55k.wpengine.netdna-cdn.com/wp-content/uploads/make-images/hKfqtG1HuwBPpblP.jpg

[True.grit]

Use coffee grounds as a filler with your clear epoxy. It will look like wood and will take a finish. Cool looking wood what is it?

[upnorthwis]

I fill cracks like that with clear epoxy. To me, any added filler looks fake. I use the West System #105 with #207 hardener. Same stuff I use on cedar strip canoes. It's so clear, you can see the bottom of the crack like looking thru glass. I like the effect.

[DanWalker]

Use coffee grounds as a filler with your clear epoxy. It will look like wood and will take a finish. Cool looking wood what is it?
I think it is elm, but not entirely sure.

[True.grit]

Very nice , I hope you can post pics of the finished product. Wood working is a very close second to casting for me. thanks for sharing.

[DanWalker]

Butterflies
http://images.rockler.com/images/articles/01_Planing_Key_lg.jpg
http://images.rockler.com/images/articles/10A_Hammer_med.jpg

What do you cut the butterflies with?

[sparky45]

Most folks cut them with a router.

[garandsrus]

And use a template!


http://www.woodcraft.com/Product/146903/JASPER-BUTTERFLY-INLAYTEMPLATE.aspx?gclid=Cj0KEQjwtaexBRCohZOAoOPL8 8oBEiQAr96eSDH4LMRkaRxeHomGXTYz_S9soVvNUA84ioPJyd0 dC4UaAt_d8P8HAQ

[DanWalker]

Sanding is done. Trying some hairpin legs on this one. I also reinforced the bottom across the crack, with a 1/8" aluminum plate. Epoxy will go on tomorrow.

[bdicki]

What do you cut the butterflies with?

http://makezine.com/2011/02/28/skill-set-making-a-butterfly-spline-or-arikata/

[Just Duke]

Poly Ethylene Glycol...............................
Goggle PEG

[Ballistics in Scotland]

Hey guys, I'm building some slab end tables and need some advice from some of you more experienced woodworkers. I have some beautiful slabs that I am going to sand and finish with a bar top epoxy, and then mount on hairpin legs. as you can see in the pics, the slabs have a really cool void in the center of them. I plan on filling this void with epoxy and black pigment. My question is, how should I go about reinforcing the table so it doesn't crack in half? I was thinking about using fiberglass matting and resin on the underside, but don't know if that will be strong enough. What are your suggestions?

I think if that fiberglass was strong enough, it is only on the bottom and would therefore allow expansion or contraction of the top, producing noticeable concavity or convexity even if it doesn't crack. If you are selling them, remember that some may not stay in your climate.

I can see two ways of preventing cracking. One is to drill two or three holes from side to side and epoxy in some threaded steel rods to hold it together. The idea of the threads isn't for screwing (though if the hole is tight enough to cut a slot in the end and screw them in, it should be even better), but to act as a key for the epoxy.

The other way is to pre-empt any such cracking. Saw them in two, passing as much as possible through that central void, finish the sawcut as smooth as possible, and fix them tightly together, either by glue and screws or the abovementioned epoxied rods. The cut could be straight, or curved for less conspicuousness if you have a bandsaw. If you feel people will see the join and consider it poor work, you could say "Rude noises to you, then" by inserting a thin intervening strip of some contrasting, straight-grained wood.

What you shouldn't do is rely on the strength of glued wooden dowels to hold it together. I once considered buying a East German yacht of pine on bent oak ribs, and they did beautifully work, the way Stradivarius would build a boat. But the pine expanded when damp, and had literally torn some of the ribs apart in tension. It wasn't the end of the world, but she would have required some expenditure before hard service. Don't underestimate what it takes to overcome the expansion of wood.

[Just Duke]

Actually there really is no way of fixing the crack permanently.
You have two substrates that change dimension continually due to air temperature and humidity level. Dissimilar substrates will never bond on a substrate that changes shape 360 degrees. The only time in wood working history, the grain of the wood was run in the wrong direction, was when they made round maple butcher blocks which were wrapped in steel banding. The block was also three feet tall and a 18 inch radius. But of course the block had continual rehydration from cutting meat and oils from the fat.
What you can do is replace every water molecule in the cells with a polymer. PEG
The best you can get wood down to as far as moisture content is possibly 5 percent. But then again, per relocation of the product to another environment the wood will try and absorb any ambient moisture or loose wood moisture.

[Ballistics in Scotland]

I think, though, the chances of cracking (which is likely to be radial aimed at the heart of the tree) is much reduced by the void in the middle. So it would be better to fill it with something resilient, which would never go completely hard.

[Just Duke]

I think, though, the chances of cracking (which is likely to be radial aimed at the heart of the tree) is much reduced by the void in the middle. So it would be better to fill it with something resilient, which would never go completely hard.

What he said............

[Ballistics in Scotland]

Yes, radial cracks happen because the outside won't fit around the inside any more. I'd use the powder I have from cutting cork composition discs with holesaw, to make a fishing-rod handle. With the minimum of epoxy that should remain quite resilient.

[DanWalker]

I plan on pouring the void full with the same bar top epoxy I am using to finish the table with. The bottom of the crack is now sealed with a 1/8" thick aluminum plate that spans the gap and runs the width of the table. It is secured with 6 1 5/8" long stainless screws.

[DanWalker]

Here it is after the second coat of epoxy. Will put the third coat on tomorrow, just to even up some low spots in the finish.

[Boolit_Head]

I've seen some cool stuff where they grind up jade or turquoise beads and the like and put in the voids with epoxy. I think you could do the same with gold or silver foil. I've got a piece of walnut I was going to try that for a knife handle.

[MaryB]

Get a bunch of very dry walnuts and fill the void then add epoxy... squirrel hoard!