Making a mega-slab out of two large slabs is not for the faint of heart. You don't necessarily need biscuits. They are not really accurate enough to guarantee perfect alignment at the seam, and can actually work against your efforts to get the halves matched perfectly.

Unless the joint is perfectly executed, you will have to dress it level somehow.

Not a project for a first-timer.

Casey

It seems if it is 1/2" thick you should use something under it to make it more solid. Plywood is a good choice as it should have good dimensional stability. However it will probably have a different shrink/swell coefficient than teak. It might be best to finish the plywood with varnish or whatever you use on the top to minimize differential shrinking and swelling as the humidity changes.

You might ask the store if they can order any different width or thickness. And check other vendors (online) as well.

Thanks guys! 1/2" thickness of the teak is a typo- it is 1-1/2" . I think that is standard thickness for wood countertops.

I agree this sounds a little scary for a first timer. My husband is very handy and we have done almost the entire remodel DIY... but if we messed it up it would be a costly mistake!

Do some research(You Tube will have videos) before you start. For example, making the joint a butt joint is asking for a failure. The better alternative is a half lap butt joint. That joint can be a good DIY project, requiring just a circular saw and some sharp chisels.

Very brief example of the joint.

It almost certainly will, resulting in giant warp or a giant split.
>However it will probably have a different shrink/swell coefficient than teak.

I do agree with this:

>Not a project for a first-timer.

"Handy" isn't going to cut it, when you consider the risk/reward.

This isn't a simple task and useing plywood backing isn't the answer. Contact a custom cabinet shop about building one. I believe they will build one to your diamensions for $1,500 or less. If you attempt joining two pieces,haveing a sturdy flat surface to lay them face down while gluing and clamping is key to getting an even seam. If you must do it without a perfect support surface,use dowels to alighn two parts eventhough dowels aren't required for strength.

Am I misunderstanding something here? It sounds as if the OP wants to edge join two 21 x 108 x 1-1/2" boards together, a task that is not exactly rocket science.

It does take a bunch of long clamps (I'd use ~8), but that's about it. Find a big flat surface, lay down four clamps, lay down your two hunks of butcher block, put another four clamps alternating with the ones underneath on top (to help counteract bowing), make sure that you have all the sacrificial blocks you need to keep the clamps from damaging the wood edges, practice putting it together a time or two, then do it with glue. Tightbond 3 is a reasonable choice, you may want to wipe the edges with acetone right before gluing to get rid or oils in the surface of the teak that may inhibit the glue bond.

Once the glue is set plane or sand the surface flat, assuming your alignment wasn't perfect and you're done.

I did exactly this with my curly maple island top, I just did it right on top of the cabinets so I wouldn't have to move the assembly-- boards that size are heavy! I used my Stanley #7 jointer plane to flatten the final assembly, a rare chance to use that big boy to real advantage. You don't need to get the whole surface perfectly flat (it won't stay that way anyhow) just the region across the join, assuming you've kept it within a sixteenth of an inch. Unlike others, I do find biscuits to be useful for alignment, and employed them in making my countertop.

That is correct, I want to edge join to separate slabs. This video demonstrates the method that I was thinking might work (minus the plywood base) on a very small scale.

The video is about edge joining. You, in your original post, said you want to join end to end. Two different sets of issues. End grain does not glue like edge grain.

You can glue end to end, but I'd be wary of a joint failure later in use. And, getting the ends straight and even(exactly the same when butted together), is not easy.

Actually, now that I think about my original recommendation, I think it is not a good DIY project. Because of the alignment issues.

Sorry for the confusion. I want to make a 108x42x1.5" top for my island out of 2 120x25x1.5 pieces. I said counter depth which I think made it confusing. So I want to EDGE joint the slabs. I was hoping we could just glue them together and have them sit on a plywood base. I would finish the edges with some 1 inch wide, 2" thick pieces as a border to hide the plywood and give the butcher block a thicker appearance.

I am rethinking the whole thing though... I have contacted a local wood working shop to get an estimate. I am not trying to be cheap... I am willing to spend up to $1800 on it...

Why do you need the plywood base? 1-1/2" thick solid wood is plenty strong as is.

Teak is hard to glue because of the high oil content. Some sort of a biscuit or dowel, or even those countertop connector bolts would make the joint less likely to split.

then do the sanding and finishing.

I have teak countertops in my kitchen. Done out of 8/4 planks, edge glued.

I used biscuits and West System epoxy. I wiped the plank edges down with acetone just prior to assembly.

The run of countertop as a whole is 30" deep by roughly 18' long, it's two separate pieces that overlap on the ends, one about 12' long, the other about 6' long. The overlap is because one countertop is a couple inches lower than the other one.

I have an under mount kitchen sink, so the end grain of the planks is exposed to water at the sink. Zero damage.

Been in for almost 20 years. No warping, lifting, curling, no separation at all on the glue lines.

Finished with mineral oil. The oil holds up well, I try to renew the oil once or maybe twice a year, though I have gone several years without renewing it.

I have another teak end-grain butcher block cutting surface as a kitchen island end cap. Roughly 4' square with one corner clipped on a 45, and 5" or so thick. The individual blocks are about 3-1/2" by 2" and assembled in a running bond pattern.

Same assembly; I wiped the blocks down with acetone, then epoxied. No biscuits on that one. We do cut on it some, not a lot, but the cutting surface has held up perfectly. On the side or edge of the block, there's one break on a glue line, where the grain orientation of the two blocks don't remotely match up due to one of the blocks having wild running grain. The break isn't noticeable to the eye, but you can feel it when you run your fingertip along the edge. There's maybe a 1/32" lippage at that joint. Just enough to catch a fingernail on if you run it along the side of the slab. I've never bothered to sand it flush.

Great material for a countertop. Been used and abused in a heavily used kitchen, and they still look pretty darn bueno.

Yes, lots of glue and clamps. I prefer titebond 2

Did you ever complete this project for your island? I am wondering about this same project. I was going to custom order one - with COVID, the wait is long and it’s pretty expensive. Like you, I will purchase the custom one if that is the best option. I am not going to build this myself - I will probably have my cabinet maker do it for me.

I can purchase prefab walnut counters quickly - and joining them together - at the edges - would work for my island (F&D actually makes these in a 36” width vs 26” - and I need a 66” x 60” surface in order to cut a unique shaped 5 sided island). If you did, would you please post some photos - and let me know how it was accomplished? If you ordered a custom made one, will you let me know where you purchased it? Thank you so much!

MongoCt - if you happen to see this, would you mind sending some more photos of your perimeter countertop? I tried to do the “@MongoCt in order to notify you of my comment - but for some reason, the app isn’t pulling your name up for me to select.

I like the color/grain of black walnut - actually face grain is what I would like vs. typical butcher block end grain - but I’m trying to compromise in order to get this accomplished. The color of your perimeter countertop looks pretty from what I can see in the photos you posted. I’m wondering if maybe using teak is a good idea. Thanks!

This kind of stuff is intertaining to discuss but sdvice and photos aren't enough to alow a diyer to accomplish what you want. And for what it's worth,if you asked me to build it using techniques you picked up online,I'd tell you to have your interweb buddies build it. The best advice I have is draw what you want and search for a shop to build it. You can ask shops what they think but I'd use veneer over compostit base if you want face grain. Edge joining a 5'x5' top will risk warping but joining 2 of those pefabs should work well.

@shill I know this thread is a bit old, but do you still remember the name of the company that would make a custom walnut counter top based in Ohio?

Thanks!