# 2 1/4" thick butcher block bowing...



## ARTTdylan (Jan 6, 2010)

I made a 8'x7' 2 1/4" thick edge up butcher block with maple and dark walnut. 6 months after delivery it bowed up in the middle more than 1". I did not warranty such a block but told the customer I would do what I could to fix it. We planed it and cut it into three pieces and glued it back together. When we took off the clamps it was bowed the opposite way.

Is there a remedy?


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## GaryC (Dec 31, 2008)

Build a new one and watch the grain direction


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## TopamaxSurvivor (May 2, 2008)

That is what I would do. I never leave a disatisfied customer to complain about my work.


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## pmayer (Jan 3, 2010)

I am having a hard time visualizing this, and I am not quick to say start over from scratch because if you don't get to the bottom of understanding the problem, it could happen again. Some things that I would be considering:

- is it fastened to something that can help hold it stable? Can it be fastened in the middle to help to maintain flatness?

- is it finished evenly on top and bottom? Could it be that the greater amount of moisture on the top is causing it to bow?

- can source of the bow be isolated to a single board or small number of boards that can be replaced? One or two boards with stress or moisture imbalance can cause dramatic problems in a panel that size.

- If this is mounted on a table or stand, could you possible bolt an iron bracket to the bottom, drilling elongated holes into the bracket which allow the wood panel to expand and contract? A thick angle iron could stabilize this panel if the bow is gentle. 1" is a lot, but over a span of 8' it might be manageable with some heavy duty hardware.


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## Timbo (Aug 21, 2008)

Can you post pictures? That may help in understanding from this end.


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## a1Jim (Aug 9, 2008)

Depending on how much bow you could send it through a drum sanders


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## Broglea (Dec 9, 2009)

How is the customer maintaining the board? Are they letting it soak in water or running it through the dishwasher? Boards should stay relatively dry.


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## childress (Sep 14, 2008)

Do people even read posts….it's a counter and it's 8 FEET BY 7 FEET. nothing you can "soak" or throw in the "dishwasher".

Sorry, had to say something. but my suggestion is to run some sort of stringers underneath to help keep flat. But also doing so in a way to allow for movement. tricky when working with such large pieces. I like tha angle iron suggestions by pmayer.


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## 33706 (Mar 5, 2008)

Who builds a butcher block counter-top that's 8 feet by 7 feet? That's just crazy.


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## roman (Sep 28, 2007)

newtons law of physics

for every action there is an equall and opposite reaction and when applied to a counter/butcher block of that size you can do a few things, but not limited to the following

: make sure the wood is dry from the get go
: watch grain direction albeit experience has shown me that it makes little difference
: allow the top to "float" in the that the underside shouldnt be covered by another surface, elevate it
: whatever finish is applied to the exposed top surface must be applied to the bottom surface in equall amounts to the top…........that is critical, because the top will absorb moisture, the covered bottom woint and thus….....severe warping.

NO BUTCHER BLOCK manufacturer warrenties a counter that size, and that should be thoroughly expalined to the client before they purchase it.

Good Luck


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## roman (Sep 28, 2007)

poopie cat…................lots of places make butcher blocks that size, even bigger including me.


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## 33706 (Mar 5, 2008)

OK roman, but this whole thread doesn't make sense. We're expected to believe that someone wants an 8' x 7' counter. It just sounds like an incredibly inefficient waste of space to have a horizontal surface that big, whether commercial or home use…unless it's a floor. Possibly, a conference table but, come on! Awesome too, to think how they magically shrunk it down to fit through a doorway. Architecturally, it strains credibility. And on top of that, it's 'edge-up butcher block'? I'd want it to be 8" to 10" thick, in order to assure structural integrity for that size, but then it would weigh a ton! Man, I really think someone is trying to pull our chain! Or maybe the dimensions were typo'd in the OP.


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## cliffton (Dec 18, 2009)

what i have seen with counters that size, "L" shaped, is that they dont glue them at all. you mount all your pieces in a tight fitting frame to allow the wood to move and shift. the counter still looks like a single piece but its not. when your dealing with sizes like that you have really take into account the minute shifts in each piece of wood. .001 on each individual piece has a neglible affect at ~12 inches but multiply that by eight and add in the fact that every shift is going to multiply, your going to have a huge problem keeping it straight.

and ditto, pics would help allot.


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## cabinetmaster (Aug 28, 2008)

poopikat, evidently you have not seen some of the Kitchen and Bath magazines lately. It is amazing how many people have huge kitchens now with an Island that big or larger. Bit I have to agree that a top that big would be hard to Warranty.


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## 33706 (Mar 5, 2008)

cabinetmaster,
It's hard not to jump to conclusions, once you follow his link. This question was not posed by an amateur, but someone who is in the business of fabricating large butcher-blocks, yep, specifically up to 8' by 7'. This is what they do professionally, but cannot anticipate wood movement? A custom project requiring a strong engineering background. The fact that their website specifically mentions 8' by 7' butcherblock tells me that they're churning up exposure for their business, in a round-about way, by posting a query here. It's the top hit in Google now, with the LJ post #4. Mission accomplished.


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## ARTTdylan (Jan 6, 2010)

PoopieKat, it was built for an island. The top actually pulled the cabinet it was sitting on apart.

Roman: Customer did not finish the bottom as instructed. They used the pour on urethane on top. As I read on I see that the culprit must be that they did not finish the bottom.

"whatever finish is applied to the exposed top surface must be applied to the bottom surface in equall amounts to the top…" - Is mineral oil enough of a barrier? I thought about recommending to future customers finishing the bottom with urethane even if they are using mineral oil on the top. Since mineral oil is supposed to be applied around once a month it is not likely that someone will every apply a second coat to the bottom of their installed counter top.

I appreciate the feedback.

I didn't take a picture of it after it crooked but here is a picture just before we sent it out.


__
https://flic.kr/p/4254261002


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## pmayer (Jan 3, 2010)

" did not finish the bottom as instructed. They used the pour on urethane on top".

that seems to be the smoking gun to me. At minimum, I would address this before doing any other troubleshooting. Also, I sure hope they are not planning to do any cutting on this surface if they covered it with pour-on poly. That will look lousy in no time. If they wanted to cut on it, then mineral oil or an oil/wax mixture would have been the way to go.


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## roman (Sep 28, 2007)

I rarely photograph my work, but I've done island tops bigger then that, much bigger and they looked awesome and were very functional. Some folks have money, some dont. Some folks dont have enough and try and "save money" by choosing an inferior product, and or "doing it themself" only to find out that in the end….............it would have been worth hiring an expert and spending the extra dime. Some butcher block companies will not sell their product "retail" for good reasons, like the reason above…......warped, cabinets ripped apart.

If you had the customer "sign off on the warrenty" and the warrenty/guarentee is "crystal clear" on who's liable…..................then whats your problem? You cannot turn a pigs ear into a silk scarf and some things cannot be fixed without starting over.

There are many things that I WILL NOT warrenty and if the client is clear after hearing my objections…...sure, I'll build it and install it. Sometimes and much to my surpise it works, and sometimes it doesnt but my two rule theory on business applies

Always make more money then you spend

Always do a good job.


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## ARTTdylan (Jan 6, 2010)

I did have them sign off on the warranty - clearly on their bill. No problem as far as this client goes.

But is mineral oil enough of a barrier? It is not likely that someone will ever apply a second coat to the bottom of their installed counter top. I would like to recommend to future customers finishing the bottom with urethane even if they are using mineral oil on the top. Thoughts on if that would work or not?


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## JAGWAH (Dec 15, 2009)

It sounds to me as if the perimiter was locked in place, not allowing seasonal movement. As the top expands and the sides fixed it can only bow up or down, direction of least resistance.

Everyone who's used biscuits to make a top knows the biscuits can telegraph through the surface due to moisture expanding the wood. Natural tendency is to sand the bump thus smoothing the top. Problem with that is the glue and biscuit finally dries and the former bump shrinks back to normal except you sanded that wood away and now you have a divot.

Is it possible the rise revealed excess moisture and by planing it down the resulting divot is due to that moisture being now gone.

The size of the top is fine and you can get away with a lot of misdirection of the grain but if you don't build or attach the top in such a way to allow for seasonal movement your going to have issues.

I would not seal the bottom any more than you did the top, you want that beast to breath.


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## tbone (Apr 24, 2008)

The John Boos website addresses how they deal with warping. Maybe there's some info in there that will help.
http://www.johnboos.com/support/countertop.cfm


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## 33706 (Mar 5, 2008)

Still waiting for pictures… a link…anything..anyone? I mean, pics of an 8' X 7' counter, which I've yet to see.


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## Ger21 (Oct 29, 2009)

Pic is 6 posts up.


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## 33706 (Mar 5, 2008)

Gerry,
Oh, I was looking for a 8' X 7' pic. of a BB top, preferably installed, because I have never seen or visualized such a mammoth monolithic structure in a home. My guess is that the one pictured is about 50" X 96" based on wheel diameter of the forklift. Even a link to an aforementioned Kitchen and Bath magazine, as Cabinetmaster pointed out. I scanned two magazines at the supermarket the other day, but didn't see anything in the neighborhood of those dimensions. I will keep looking, just to satisfy my curiosity.


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## Karson (May 9, 2006)

I had a bowling Alley for a countertop. It was 26" wide by 8' long and 2.5" thick. On the bowling Alley the botton is covered by a tar like substance. I left it there. The top was covered by an oil (Pennofin) and I never had any problem with it.

Hope that everything works out OK.


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## 33706 (Mar 5, 2008)

Karson,
I've only used that tar-like stuff one time, when working for an architectural fixtures manufacturer. We called it "Bedding Compound" and it was probably some sort of mixture of tar, tile adhesive, and asbestos. It was used to set massive 2" X 8" maple in a wall, horizontally, it was hand-rail height and indeed there was handrail attached to it. It was attached directly to 3/4 plywood sheathing, set in under the sheetrock. I think it may have also been used behind some commercial alcove mirrors for an upscale Lady's fashions boutique.
Have you ever seen a butcher block top as big as 8' X 7' ?


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## papadan (Mar 6, 2009)

ARTTdylan, You actually built a top that size, but didn't finish it at all. I wouldn't give it a second thought if I were you. BUT, I wouldn't build and install something like that without finishing it anyway.


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## ARTTdylan (Jan 6, 2010)

papadan, we don't finish or install. Our products are raw and we cater to new home builders. It is their responsibility to finish all raw edges and install properly.

I appreciate all the input everyone. I have updated my butcher block maintenance/tips sheet and will be watching the grain direction more carefully. Hopefully I won't see this problem again.


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## bill1352 (Nov 8, 2009)

i know this is woodworking 101 stuff, not trying to insult with such a simple thought but did you rotate the wood crown?. the growth rings aim 1 way then the other with the next board.


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## SawdustWrangler (Feb 4, 2009)

I saw the picture and it appeared to just be a dinosaur sized cutting board. Its too late now but I would have sectioned it in 2'x3.5' pieces that fit flush in between cross-sections of a matching color. Seems less risky and easier to fix a section than the entire top. As stated above though, I sell nothing that I didn't apply the finish to myself. Its much easier to work out the kinks in my shop the first go around. In conclusion, that's one hell of a butchers block my friend.


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## miles125 (Jun 8, 2007)

May be an issue of dishwasher steam….big cooking pots hanging over stove top….Water sitting too long on the top…..Watch that its not bowed when in the clamps then figure you out a screw system to hold it down yet allow to move widthways.


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## teenagewoodworker (Jan 31, 2008)

yeah sounds to me like the finish was the problem. Epoxy pretty much shuts down all of the absorbtion of moisture. I've even heard of bowl turners who turn bowls out of green stock all the way down to a 1/16" wall and then use epoxy finish to stabalize it and its done. its pretty strong stuff so you NEED to coat both sides on something like that. Honestly i would 100 percent blame the finish. Its crazy how just finishing one side can make such a difference. I've learned that while stripping pieces that you must strip both sides and if you don't and leave finish on one side it will go everywhere. its pretty cool to see though. since you didn't finish it i wouldn't think you would be held liable but just for future use i would tell your customers to finish both sides. even the growth rings isn't that big of a deal. its the finish that killed it in this situation.


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## Deathwabble (Feb 9, 2010)

Am I missing something, or is this not truely a butchers block. (i.e. end grain up)


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## mtnwild (Sep 28, 2008)

Probably not doable, but what if you could drill through the sides and insert dowels? Just a thought from a rookie.


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## Jim Jakosh (Nov 24, 2009)

Wow, that is one heck of a big cutting board. The expansion is going to happen with moisture and I would guess that the top got more exposed to moisture than the bottom and they expanded at different rates. With something that wide, the difference has to go somewhere and it probably popped upwards in the center. Uniform sealing of both sides is about the best you can do to guard against this problem. You have balanced construction with the same wood on both sides and if you flipped the boards with the grain going opposite directions on every other board that is the best you can do. Down in N Carolina they called that confusing the wood so it would not warp the layup.
Try drying it out to see if it levels out and then seal both sides and give it a go again. If you cut off the high area with it full of moisture and it dries out, it may rise up on the ends when it dries naturally.


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