Bar Top help

[jrmvt]

OK, the cabinet base is almost complete and I need to make a decision on the bar top, but dealing with wood movement has me worried.  The top will be 7 feet long and the main part will be about 20 inches deep.  There is a wing on each side that is about 1 foot wide and adds about another 16" to the depth.  There is about 3-1/2 to 4 inches of bar rail around the outside which is included in those measurements.  The top will have a 3/4" plywood subsurface and then 3/4" x 3-1/2" cherry boards on top.  1/2" trim on all of the sides that don't have bar rail.  I'm planning to use GF High Performance Poly for topcoat if that makes a difference.  I've attached some sketches.

My first thought was to just lay all of the boards lengthwise, even on the wings, for uniformity.  But then I got to worrying about how much the trim on the back edge of the wings could move and how to deal with the bar rail.  (See Bar Top B )

I also considered turning the wings the other way (Bar Top C) or maybe staggering the boards (Bar Top D).  I don't think a miter would look right with those narrow wings.

The Bar Rail manufacturer recommends gluing the rail to the subsurface and the top board.  That shouldn't be a problem along the front, but I'm concerned about gluing it to the top board down the sides unless I go with Bar Top D.

So I'd appreciate any insights anyone may have on how to lay this out and connect it all.  I'm sure the back trim on the main section will have to be connected only to the top boards and not to the ply.  What about the trim on the side and back of the wings?  And what about the bar rail on the sides, am I OK with gluing it or should I glue it to the plywood subsurface only and maybe just put some silicone under the lip that overlaps the bar top on the sides?

I know I'll need to use some oversize holes or slots and washers when screwing the top boards to the plywood from underneath, but right now that's the only thing I'm sure about.  Any recommendations on layout and dealing with the trim would be greatly appreciated!  Thank you!

 

[wtnhighlander]

IMO, use Bar top A design. Glue the front edge and trim to both the board and the ply. Use screws up through the ply, with elongated holes, so the cherry can expand toward the back. The trim on the 'wings' could be pocket-screwed through the plywood. I would rigidly attach it to the cherry top, but perhaps use a floating spline to keep it all in alignment.

Any reason, aside from cost, that you need the plywood, as opposed to solid?

[jrmvt]

First, the original post didn't keep my file names.  So instead of "B", "C" and "D" like I referenced in the original post, let's change them to "A", "B" and "C" like you referenced them.

Thank you for the reply!  When you mention the trim on the "wings", do you mean the bar rail, the inside and rear 1/2" trim, or both?  I can probably do a spline for the 1/2" trim, but not sure if I can for the bar rail.  Though I suppose maybe the top lip on the bar rail would help with the alignment.  I'm attaching a shot of the bar rail for reference.  If I go with Bar Top A layout, any suggestions on how to handle where the 1/2" trim pieces meet on the 2 inside corners and 2 outside corners to best handle the movement?  (One butting up against the other the way I show them, butting up the other way, or mitered?)

In response to your last question, three factors.  Most of the plans I looked at when designing the bar used 3/4" hardwood over 3/4" ply.  The bar rail I purchased is designed for that layout.  And, of course, cost.

Thank you!

[wtnhighlander]

Yes, I see the bar rail is designed to work over 2 layers of differing dimensions. You should be able to simply run screws up through the ply for that.

The inside trim could be miters on the 2 inside corners, but I wouldn't miter the outside corners. Butt joint or miter, I would fasten the inside corners tightly to the bartop, but allow the outside ends to float. Is the trim meant to cover the full thickness, or just the plywood edge?

[jrmvt]

The trim pieces will cover the full thickness.

OK, let me be sure I understand:

1. Attach the long trim piece in the middle to the hardwood top but not the ply.
2. Miter or butt joint at the 2 inside corners.
3. Inside trim pieces should be attached to hardwood top near the inside corner, but should "float" near the outside corner.
4. Butt joint at the 2 outside corners
5. The short trim pieces at the back of the wings should be attached to the hardwood top but not the ply.

More questions:

1. On the inside corners, if I choose butt joints, does it matter which one fills the corner and which one butts against it?
2. The inside trim pieces are causing me the most concern.  You say to attach them to the hardwood top near the inside corner which makes sense.  I assume they cannot be attached to the ply anywhere because of movement from the main top pushing/pulling on them.  And I don't think I can attach them to the trim pieces on the back of the wings because of movement along the wings.  You say that outside end should float, but just a spline isn't going to be enough to hold it there, is it?
3. Bar rail on the sides - since I cannot glue the top lip to the hardwood top to help seal it from spills (it is a bar, after all), do you think I should put a bead of silicone where I'd normally put the glue?  Or something else you recommend?

Sorry to hit you with more questions, but I really appreciate your help!

 

[pkinneb]

Or you could use a shop made hardwood veneer and not have to worry about wood movement. Personally I would use two layers of MDF as a substrate then use a shop made veneer top of 3/32s or less for the top. Then the only movement that would have to be considered is that of the rail. Curious where did you find that rail in curved sections or are you making that yourself?

[wtnhighlander]

IMO answers to the questions above:

1. I don't think it matters.

2. You could attach the inside trim to both the ply and the hardwood at the inside corner. You can attach the outside corner to the ply, but not the hardwood. The trim at the end, that aligns with the hardwood grain, can attach to the hardwood. Just accept that this part will grow and shrink as humidity changes, so you need a gap between it and the plywood. And the outside corner where the trim meets will never be a perfect fit.

3. In this case, wood movement and water-tightness will likely be mutually exclusive. To get a good seal @pkinneb's solution is probably the best.

For comparison, I recently built a simple bar top, with an electrical outlet in the top. To minimize the risk of spills running into the outlet, the recess for the outlet box included a 3/8" curb to raise the box above the bar surface. The curb was formed with long grain pieces on the two edges that aligned with the bar top grain, and the other two edges were from end cuts so that they matched the grain pattern and direction of the 'butcher block' style top. Everything moves in unison, so I coukd glue it solidly, and finish it without seams. It appears as of the curb is part of the block, with the rest of the surface carved away in relief.

If you are making the contoured rail, milling it from blocks with grain orientation that matches the hardwood top would let you glue it up solidly. Except for the radiused front corners, that rail profile could be milled on a tablesaw and cleaned up with a block plane and scraper. The corners would probably require a good deal more hand-carving.

[G Ragatz]

4 hours ago, pkinneb said:

Curious where did you find that rail in curved sections or are you making that yourself?

I think radius sections of bar rail are pretty readily available.  Here's one example:

https://www.hardwoodsincorporated.com/product-category/hardwoods-bar-rail/

 

[jrmvt]

Good eye on that bar rail radius corner.  Hardwoods Incorporated is where I got the rail and the radius.  They're fairly close and making my own on the table saw wasn't a project I wanted to tackle right now (time is an issue).  Plus, my wife requested the radius corners and I wasn't about to try and make those myself with my limited equipment.  She agreed we could splurge on those.  There's no chance I could get any rail pattern I made on the table saw to match theirs to use their radius corners.

wtnhighlander - Thank you for the answers!  I don't see how I can attach the inside corner of the inside trim to the ply.  Won't it be affected by movement of the main top back and forth (north-south in the sketch above) and need to be free to move?  I think that would prevent me from attaching it to the ply at the outside corner too.

That bar top sounds awesome!  Would love to see a picture of it sometime.  I see what you are saying about everything moving in unison.

At this point, I'm thinking about switching to design B and narrowing the wings so that there is only about 5 or 6 inches of cherry hardwood on top in order to limit movement issues.  I'll still have to worry about north-south movement, but hopefully I can be less concerned about east-west movement.  Still drill oversize holes/slots and attach the 1/2" trim to the hardwood only.

 

Edited December 5, 2019 by jrmvt
Clarification

[Coop]

6 hours ago, pkinneb said:

Or you could use a shop made hardwood veneer and not have to worry about wood movement. Personally I would use two layers of MDF as a substrate then use a shop made veneer top of 3/32s or less for the top. Then the only movement that would have to be considered is that of the rail. Curious where did you find that rail in curved sections or are you making that yourself?

I’ve never made veneer but have had pretty good success with resawing. For 3/32, would you re-saw down to about 1/4” or less and then final dimension on the drum sander? 

[wtnhighlander]

Here is the build thread for that bar. Not fancy, but there is some info on the electrical box arrangement.

 

[pkinneb]

11 hours ago, K Cooper said:

I’ve never made veneer but have had pretty good success with resawing. For 3/32, would you re-saw down to about 1/4” or less and then final dimension on the drum sander? 

Yep

[jrmvt]

pkinneb - Sorry I missed replying to you.  Thanks for the shop made veneer suggestion.  I'm not sure I will try it on this project, but will definitely keep it in mind in the future.  This thing is going to be running with the floor joists instead of across them and I'm already a bit worried about the weight.  I know MDF is pretty heavy.  I'm not a big fan of working with MDF, but that does seem like the perfect application for it.  I'm going to echo K Cooper's question - What thickness would you resaw to start?  And I guess a drum sander would be essential for getting it to the desired thickness?  Maybe for Christmas...

wtnhighlander - great looking set of projects!  I do like the way that electrical box turned out.  Thanks!

[pkinneb]

13 hours ago, G Ragatz said:

I think radius sections of bar rail are pretty readily available.  Here's one example:

https://www.hardwoodsincorporated.com/product-category/hardwoods-bar-rail/

 

Thanks! Man they don't give it away do they LOL

[BillyJack]

That top will have to expand and contract. Why I didn't use solid wood on my bar. Used tile instead...

[jrmvt]

That's a great looking bar BillyJack!

One more question - screwing down the boards.  The panels have been glued up and just need to be glued together into one top and I was trying to figure out a screw pattern so I could go ahead and drill the holes and slots in the subtop.  I read somewhere to be sure and stagger the screws, but I wasn't sure if that meant stagger in each board or not.  Here is the pattern I came up with, but that is about 50 screws.  Is that overkill?

I couldn't figure out how to draw ovals, so just imagine that the holes get larger and more oval as you come back towards the wings.  Bar is about 7' wide, so the horizontal spacing ranges from 7-12".  The individual boards are about 3-1/2 " wide.

Any suggestions on a better pattern?  Thanks!

 

[BillyJack]

You'll have a problem if moisture gets between the boards. My concern is the expansion and contraction.

[Coop]

@jrmvt. You say the panels have been glued up, does that mean there are three of them? If so, are you just butting the right and left panels to the top panel or are you using tongue and groove, dowels, etc.? And I say top, meaning the panel on the top of you pic/drawing? Me, I would use some sort of unglued floating tenon or biscuit to allow the side panels to expand and contract against the top main panel. One, yes I think 50 screws are a bit of an over kill. Two, keep in mind that wood does not grow longer with change in humidity, only wider and narrower. Having said that, orient your oval holes accordingly. I think you’ll do fine. 

[jrmvt]

I just meant the top panel was glued up, I haven't attached the wings yet.  The wings are only 7" wide so I'm thinking about doing something along the lines of your suggestion.  I'll attach each wing to the main bar top with 2 biscuits.  The biscuit on the inside will be glued so that the wing can move up and down with the main top.  The other biscuit closer to the bar rail will have it's slot cut slightly wider and not be glued in to allow it to move.  I'll leave 1/8" - 1/4" of space under the lip of the bar rail to allow for the wing to expand out.  Would that work?  I'm wondering if I should also glue about 3" of that butt joint around the glued biscuit, just to be sure the 2 tops move together.  I'd have to size the endgrain first.

Yeah, the more I thought about it, the more it seemed like 50 screws would probably keep movement from happening, even with slots.  Here's the revised plan.  I'm under 25 now!

Thanks for the help!

 

[BillyJack]

I just think it will be compressed and expand. My bar is in my basement where the concrete is. Heated but it doesn't keep the concrete from getting  cold under the cabinet under the bar top. This was the reason for a tile top. Hope the best to ya. 

Had plenty of bar rail just chose not to use it...