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joining boards on a 14 foot countertop

wvjack's picture

I need to glue up a 14 foot x 25 inch zebra wood counter top. My supplier doesn't have lengths over 10 feet.  My question is, what is the best way to join end grains over the length of the counter top?  My first thought  was to join them as two units over the under mounted sink by cutting a 45 degree and epoxy and pocket screw at that point.  What do you think?

MikeHennessy's picture

(post #85128, reply #1 of 20)

You're a braver man than I am to use a wood countertop with a sink, especially an undermount sink. Still, I've heard it CAN be done -- although I love wood countertops, I'd never trust the finish to hold up at a sink, especially on end grain. YMMV.

That said, with regard to joining the top, I've had success simply staggering the cuts over the length and using biscuits and poly at the joints. I just carefully cut them square, so the joint is tight. Never bothered scarfing. The adjacent boards hold the whole thing together just fine. Whether or not this would look OK on your top kind of depends on how wide your boards are in the finished piece. The narrower they are, the better this looks, IMO.

Mike Hennessy
Pittsburgh, PA

Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.

ring's picture

(post #85128, reply #2 of 20)

If you're making up the 25" width from some 5-6 boards, stagger the end-to-end joints like a random laid plank floor. Don't make joints on the bridging pieces in front of and in back of the sink cutout. Use splines or biscuits in the end grain joints.

If the sink is anywhere near the center you can plan the board layout so you only need the end-to-end glue up on the front and rear boards. All the others can fall at the sink cutout.

wvjack's picture

(post #85128, reply #3 of 20)

Thanks for the advice.  You have to understand, I'm not the supervisor on this job--the dear wife is. As such, if she likes zebrawood, she gets zebrawood.  May be I'll get a tool or two out of this.  Using the splines and staying away from the 45 cuts sounds right.

rjones69's picture

(post #85128, reply #4 of 20)

Smart man!

Just remember Rule #1

If she aint happy you aint happy and if she aint happy long enough your gonna be unhappy with half your

Jeff Foxworthy


ring's picture

(post #85128, reply #5 of 20)

Tell the superviser that we will not be responsible for the results of using an undermounted sink with a wooden countertop.  Much better to use a flush mounted sink with some kind of lip on the top.   But if she insists, get her to sign a waiver and then seal the endgrain on that cutout with something serious like 50 coats of marine varnish, regardless of how you finish the top.

sapwood's picture

(post #85128, reply #6 of 20)

I think that your idea of joining two lengths at the sink is best. The staggered end look is sort of rustic or old fashioned in my opinion. Having a lot of butt ends will draw attention to them as opposed to having a butt in one location. Concrete counter tops are typically joined at the sink cutout and their join is not obnoxious in the least. You might consider doing two perpendicular butts that are offset a bit from another. Maybe one at one corner of the sink and the other at an opposite corner. Draw a few plans and see what's most pleasing. The front cut is really the only one that will be noticed, with the rear one most likely obscurred by a sponge or something. The butts could be "fastened" by using a butterfly if you're so inclined...... or even a valentine shape. That may garner you a bonus from the client!

An epoxy sealer will be your friend on this project.

ring's picture

(post #85128, reply #8 of 20)


The 2 areas you mention (in front of and in back of the sink) are the places that are CONSTANTLY WET in any working kitchen. Your esthetic preference for placing joints there will pale and be forgotten beside the "esthetics" of those joints starting to mildew and rot. This is a case where the practicalities have to outweigh anything else. You can't compare the situation with a concrete or stone countertop. Wood has its beauties but also its limitations.

sapwood's picture

(post #85128, reply #9 of 20)

I agree that there are hazards aplenty for any kind of wooden kitchen counter top, let alone one that has end grain joints spanning an undermount sink. Nevertheless, numerous individuals have successfully made and maintained such countertops. Indeed, there are many examples of working actual wooden sinks and baths. Those who have chosen these for themselves have undoubtedly made that choice based on personal preference and aesthetics, and not on practicality. There are ways to construct the contertop in question that will prove successful. In the event there is a breech in the defense, the man is a woodworker, he'll figure out how to fix it.

Your statement: "The 2 areas you mention (in front of and in back of the sink) are the places that are CONSTANTLY WET in any working kitchen." You paint a nervous scenario, but not reality. There are some times when any area surrounding a sink will be wet, but they are not constantly wet unless it's a scullery in a 24 hour restaurant. In my own kitchen those areas may be wet for one hour in twenty-four. But we are just a couple (who both cook) without children who may up the ante. Thoughtful use by the owner/user of this countertop can ameliorate the water damage.

The entire proposal of wooden countertops is not for the faint-hearted and neither are my suggestions . There are maintenance issues and the initial construction/finishing is not standard. Nevertheless it's possible. And if one is choosing to have wood countertops that individual ought to think twice about compromising his aesthetic by incorporating a lot of butt joints over the entire wooden surface as was suggested by others. Successful design means full attention to all the details. If a thoughful join can be done elsewhere on this countertop, then the poster might better consider that.

ring's picture

(post #85128, reply #11 of 20)

No need to convince me of the possibility of wooden countertops.  I do kitchens for a living, and from time to time I do wooden countertops on the condition that the client fully understands what it entails.  And yes, I've also made a wooden tub that's still in use after 10 years.  However, under no circumstance would I put a joint on the sections bridging the sink, no matter what the client says.  It's not just asking for trouble, it's begging for it.

The scenario he brought actually requires only 2 joints - one in the front board and one in rear.  It's not a question of "a lot of butt joints all over" as you say.  Why choose to put them in the worst possible place?

Finally, the fallback rationale that he's a woodworker and can deal with it down the road...well, let's just say I thought we were pursuing a higher standard here.


sapwood's picture

(post #85128, reply #12 of 20)

Well I'm not going to belabor this point. Obviously we are seeing this situation differently. I cannot fathom what the big difference is between having exposed end grain at the undermount sink and an endgrain butt joint adjacent to it. Oh, I suppose one could argue that a joint can trap moisture whereas the sink opening will simply drain water away. But a deft application of silicone or a permanent glue-up with epoxy will solve that. Anyway, I'm arguing this point with considerable reserve since I don't really like wood countertops in a kitchen.

As far as my reference to "he's a woodworker ..... so he can fix it..." I did not say this with the idea of lowering our community standards. Rather, as a custom fabricator, I often take a chance with things I'm making for myself, and sometimes with those of willing clients. It's the best way I know of to add real knowledge to my store of information. By not taking chances once in a while, all one is doing is practicing what one already knows. And I, for one, wish to explore.

Midnight's picture

(post #85128, reply #7 of 20)

where's Sarge when ya need him...?? He resolved this very issue when building the top for his shop bench...

Finger joints... that's the key to it.. you need to kid your end grain joints into behaving like they're long grain.

With any luck he'll (Sarge that is) see this and explain better than I can... his pictures were pretty kewl too...

Mike Wallace

Stay safe....Have fun

Mike Wallace

Stay safe....Have fun

Hal J's picture

(post #85128, reply #10 of 20)

I often do this same thing.  In fact, I did it just last week.

I have found that it works really well to first cut the joints and join them with splines, clamping the lengths with long pipe clamps.  If the wood is thick enough, two splines are much better than one.  5/4 lumber can easily take two 1/4" x 1" splines.  Make sure the splines grain runs the same direction as the lumber.

Once the lengths are made, the boards can then be edge jointed to match each other and glued edge to edge.

The double spline is really strong.


I have also done scarf joints.  They are hard to do, but the strongest joint, but need to be glued with epoxy.  Think angles of 1:8 or as much as 1:12.  Longer is stronger.

One other thing.  I also did a zebrawood countertop a few years ago.  It looked great!



wvjack's picture

(post #85128, reply #13 of 20)

Thanks for the encouragement.  Ttomorrow I order the wood.  It will be planed from 8/4 to 1  7/8.  I will eventually bring it down to approx 1 3/4.  I think my plan will be to hide one splined joint in the back corner.  The other in the front off to the side of the sink, trying to make it disappear.  All other joints will meet in the sink, which I'll cut out and make a cutting board.

Hal J's picture

(post #85128, reply #14 of 20)

That sounds like a good idea.  Do the double splines.  I cut them with a slot cutter in a router, which makes it pretty foolproof.  I don't use poly glue, even though it is supposed to glue end grain better than Titebond.  Titebond III is perfect for this job, and much less painful to use.

I did one last summer that was 1 1/2" thick Jatoba, 19 inches wide, 19' long.  I had no problems handling the end glued boards after doing spline joints, and even the one in the front edge looked pretty good.

Good thing you decided not to do a scarf joint.  At 12 to 1, you would have a cut 22 1/2 inches long!  Good luck making that perfect!



ring's picture

(post #85128, reply #15 of 20)


Your several references to scarf joints just made me wonder  -  in my experience they are so easily done at any angle, why do you make it sound daunting?  BTW, your website is full of great stuff.  You're obviously highly skilled.

Hal J's picture

(post #85128, reply #16 of 20)

That's a good question.

I guess I have probably had issues similar to others doing scarf joints.  One in actually getting the joints at the same angle, especially if the joint is an 8:1 ratio up to a 12:1 ratio, the suggested ratio for work on boats.  I do find that depending on the joint they can be easy.  I have set up ways to cut them accurately on my table saw.  But it is not so easy with a wide, thick board like we are talking about here.

I know that they can be hand planed well, but getting the angles absolutely correct is difficult, I find.  I have scarfed the ends of 4 x 8 sheets of plywood, I have scarfed small ebony moldings, and lots in between.  I usually glue them with epoxy, which makes everything pretty slimy and slippery, and I have figured out how to keep it all from moving upon clamping. 

I don't think that our zebrawood brother should take a chance on trying to learn the tricks of the trade on this precious project though.  It sounds like his 1st mate will be keeping a pretty close eye on things and I would hate to see a mutiny prior to getting the sink back in ship-shape.

It is amazing how strong they can be though.

I personally find that for my clients, the double spline is perfectly fine for these situations.



ring's picture

(post #85128, reply #17 of 20)

I agree that it's irrelevant to the poster's countertop at hand...I was just getting sidetracked wondering about your comments.

I used to have a jig for the TS that worked OK for the scarf joints. But since I've had a slider for 10 years or so it's become completely trivial. I hold the 2 boards together with masking tape, lay them on the saw carriage at what looks like a good angle, and slide. Comes out perfect every time. Next time you're thinking about upgrading to a slider, put another point in the "pro" column.

Hal J's picture

(post #85128, reply #19 of 20)

I do have a slider, although it is just an add-on Excalliber, plus a number of shop made sleds.  I was not thinking about cutting the scarf diagonally across the surface, but diagonally from the top to the bottom of the board.  But if the board is wider than 3", it is pretty hard to do on a 10" tablesaw.

I would love to have a 14" sliding tablesaw like an Altendorf, SCMI, or Martin, but it just doesn't make sense in my little operation.  They are really expensive!

If someone out there has one that they need to give away though, I would be happy to help them out.

Another thing that is a downside to a scarf is that it takes a lot more wood because of the overlap.


ProWoodGuy's picture

(post #85128, reply #18 of 20)

End-to-end dovetails.  You cut two sets of opposing tails (no pins) and glue them together.

Work it out on paper first.


Hal J's picture

(post #85128, reply #20 of 20)

This would look great.  Time consuming, but nice. 

I like your comment about working it out on paper first.