Question About Gluing Panels

[flatheadfisher]

For my next project, I need to make a long panel that will be our kitchen counter top. I am using 8/4 hard maple. I finished the small top and it looks like this:

It is face grain and will be finished on both sides with Waterlox. The rest of the counter top will be 18' long. The boards will be oriented short ways instead of long ways per my wife's instructions. That will prevent me from having to join ends and will keep the pieces small enough to handle. Here is what the kitchen looks like (in complete disarray from moving stuff around):

I haven't figured out how to glue panels together while keeping the boards smooth. In the past, I have used a hand plane to smooth the boards down or I have made them small enough that I could run them through the planer. It took two hours to smooth the panel above. I have used blocks to try to keep the boards even but there are always some that are off by a millimeter or two. Am I doing something wrong or is this to be expected? I can smooth this counter top with the hand plane but I want to get it as smooth as possible to eliminate extra work. What advice can you give me?

I will have to bring the top in in several pieces. What advice can you give me about how to glue the pieces together and keep them flat? The existing counter is level and framed out with 2 x 4s that the top will sit on. I will leave a space around the edges for expansion and hide it with the back splash which will be a piece of maple. I will propaply just stick the top down with a little bit of glue - I think the weight will keep it in place?

Finally, I haven't figured out what to do with the sink. Should I make the panel and then cut out the hole? Or, should I build the hole into the panel? The current sink is stainless put we may get a new one. But, I don't expect to get one that is cast iron or anything very heavy. Of course, when it is full of water, it will have some mass to support. The final thickness should be around 1.75 inches. I know moisture will be an issue. But, the coats of Waterlox should take care of that problem. I will seal it on both side.

What have I not considered? What pieces of wisdom can you share to help?

Thanks!

 

[Travis Porter]

First off, lets be straight. You are going to have variances. I have been doing this for 20 years, and it is a VERY rare thing to get edges aligned perfectly.

You can get them close by using biscuits, splines, dowels, a glue line bit, etc. Normally, I just try to get it close

Flattening them will be several choices. Hand planes (not a bad solution, I flattened my 7 foot long bench top this way), belt sander (very easy to screw up), or the ultimate method, a wide belt sander.:gar-Bi

If you don't have a wide belt sander, you should be able to find a cabinet shop nearby that does that will rent time on it. $20 for 20 minutes and a $1 a minute is a good price.

Hand planes will work, and with your recent acquisitions is actually very realistic.

Oh, and lastly, I would make the panel then cut out the sink. That way, you get it right, and have a cutting board left over. ;-)

 

[DaveO]

For the glue up I would work in sections of 5-6 boards each. Use cauls to help keep them flat. Once you've got the 5-6 board sections glued up them you can glue however many sections together to the size that you can handle getting into the house. That should give you only a few glue joints to be concerned with that can't be handled by the cauls. For joining the longer sections together in the kitchen I would use countertop bolts-

They should give enough pull power to bring the sections together and give you a good glue line if you are going to glue.

I would cut out the sink hole after installing the counter top, and after a practice cut on a piece of scrap to make sure your template is correct.

Glue-up strategies -
http://www.taunton.com/finewoodworking/pdf/FWW141-044.pdf

Making curved cauls -
http://www.taunton.com/finewoodworking/Community/QADetail.aspx?id=26546


HTH,
Dave

 

[DaveO]

Get ya some Bowclamps - http://www.bowclamp.com/

http://www.ncwoodworker.net/forums/f35/bow-clamp-clamping-cauls-7110/?highlight=Bowclamps

Two sets of one size used on the ends of the glue-up will keep things pretty dang flat, and they are handy for a lot of other uses too.

Dave

 

[flatheadfisher]

Thanks for the comments, gentlemen. Travis, it is good to know that they usually don't come out perfectly! It looks like I will be getting a workout using the ole hand planes. Dave, thanks for mentioning those counter bolts. I forgot about those things and they will help me out a ton. I will check into those clamps - they look really neat.

What would you cut the hole out for the sink with?

 

[Mrfixit71]

By orienting the boards the short way (front to back), you will get more movement in the length of the top with moisture changes. I see it as an 18' wide tabletop. I would be concerned about gluing the top in place without some allowance for the movement. FWIW.

Rich

 

[sediener]

By orienting the boards the short way (front to back), you will get more movement in the length of the top with moisture changes. I see it as an 18' wide tabletop. I would be concerned about gluing the top in place without some allowance for the movement. FWIW.

Rich

Yeah, if you get 1/16 movement per foot you are looking at over an inch movement the ends. I think something is going to have to give...

Maybe attaching to the cabinets with screws in a keyhole slot?

 

[flatheadfisher]

I am planning to leave an inch for movement on the end that meets the wall. This will be covered by the back splash. There is nothing at the other end so it should be ok. What if I just let it sit on the top without attaching it except in the center? Would the weight be enough to hold it in place? That section is 18' x 25' x 1.75". I guess it would weigh around 250 pounds or so.

 

[Travis Porter]

What would you cut the hole out for the sink with?

Assuming you are mounting the sink above the counter I would use a paddle bit to drill out each corner and a jig saw for the remainder.

 

[sediener]

I am planning to leave an inch for movement on the end that meets the wall. This will be covered by the back splash. There is nothing at the other end so it should be ok. What if I just let it sit on the top without attaching it except in the center? Would the weight be enough to hold it in place? That section is 18' x 25' x 1.75". I guess it would weigh around 250 pounds or so.

I doubt it would move much unless you do some heavy butchering or handplane on your counters. I would probably attach at one or two points close to the sink to keep it stable in the middle and force the movement to go away from the sink. The plumbing will thank you.

- Steve

 

[Travis Porter]

I thought you were running the boards long wise.

It is going to be VERY fragile to get it in the house and in place without breaking if you glue it up as 1 or 2 pieces and as suggested, it is going to move a LOT.

 

[JimD]

I would not be overly concerned about fragility given the thickness but it needs sealed well on both sides or it will move from humidity changes. Wood around a sink is a particular concern for moisture.

The granite slab on our island weighed around 200 lbs too but would move when we leaned against it. I used a few dabs of construction adhesive but silicone would also work to keep it in place without absolutely preventing movement. Screwing solid in the center and in slotted holes at the end would also work. I would tend to think of screws because even if it is flat when you put it in, with humidity changes it may not stay flat (unlike granite).

Jim

 

[cpowell]

If you seal it well then movement shouldn't be an issue but you could use fixed fastening points in the sink area and use slotted angle brackets or something similar to fasten down the top in the remainder. The slots would be oriented to allow for cross grain expansion and contraction.

Stop the screws around 1/32" from seating to minimize friction and allow movement. I like to use this type of screw since the washer head provides a flat reference and the saw teeth cut their own way. http://www.mcfeelys.com/product/0810-WRK/Black-Oxide-Round-Washer-Head-Screws

MTCW.


Chuck