Table Top Assistance

[JackLeg]

We are going to build an oak dining table for a friend. The boards are approximately 5 1/2" wide. We/he wants the table top to be close to 5' in diameter.

SO, having never glued up anything that big before, and knowing that getting a flat surface is imperative, I'm open to and soliciting any and all advice on glueing up, joining, sanding to finish etc. I am contantly in awe of some of you guys and your expertise, so I'm reaching out.
Thanx. :eusa_pray:eusa_pray:eusa_thin:eusa_thin

 

[Jon]

Subscribe thats all

 

[JackLeg]

What'd I miss Jon? Subscribe?

 

[DaveO]

Start with well dried and acclimated stock. Face joint and plane to desired thickness or a little thicker if you think you might want to run it through a wide belt sander (if you can find one that wide). Lay out your boards, looking for the best grain match. Don't worry about the growth ring orientation. If you think that you might use a hand plane to flatten the top, make sure that the grain all runs the same way. Once you've found the best board orientation, mark the boards so you will now how they go together (I like to use a big triangle mark). Edge joint the boards, putting the opposite face against the fence for each group of two. That will counter act any slight discrepancy in the jointer fence's 90º setting. Glue the boards together in groups of two or three using homemade cauls or Bowclamps to help keep the surfaces flush and the glue-up flat. Once you have your groups of two or three glue-ups done, start gluing them together, again in small groups. Once the whole top is done, hopefully all you will have to do is a little sanding or hand planing to get a uniform surface. During this process, if you have to stop for a while, make sure that there is even air flow around both sides of the glue up, and once the whole glue up and flattening is completed get the top attached to the aprons or base as soon as possible to help keep it flat.
I have never done that wide of a glue up, but taking it slowly, and step by step you should have really good success.
Dave

 

[Jon]

What'd I miss Jon? Subscribe?

I was just keeping up with this thread so I could learn also. sorry to confuse you.

 

[JackLeg]

Biscuit joints?

 

[nelsone]

Biscuits aren't going to help that much with alignment. I think you'd do best with a couple cauls to keep the boards in alignment and just glue up your edges.

 

[JackLeg]

Gotcha. This one is going to be a real challenge for a couple of outdoor furniture builders, but I'm looking forward to getting started. That's why this site is so great.

 

[skysharks]

I have done items this big, and my suggestion would be to follow closely to what Dave said. But in addition I would use biscuits or dowels. At times I have used double stacked biscuits with great success.
:icon_thum

 

[JackLeg]

Thanx, John. I'm gonna experiment with some scrap first using my biscuit joiner.

 

[toolferone]

I would error on the side of thicker boards to give you room to plane/sand down any unevenness after the glue up. Mixed feelings about biscuits. They are not needed for strength at all. Only for alignment. The problem being if you put the slot in out of alignment then you can't work th board in line. With out the biscuits then you can work each board as you clamp to get the best possible seam. My .02 cents worth.

 

[JimmyC]

I agree with Mac about the use of biscuits, I have had good luck with them in the past. But I have one warning, make sure the biscuits are going to be clear of your final cut, it's pretty ugly when they show. I know this from experience.

Jimmy

 

[JackLeg]

Good thought! Nothing like experience! That's why I started this thread!

 

[adowden]

Dave offerered some great advise. One thing I would add is to scribble all over the final top before sanding (with a pencil). This way as you sand, you can see where the high spots are and concentrate your sanding efforts there. When I started out in woodworking, I would sand on the areas near the glued surfaces (to make sure there was no glue to mess up the finish), and it was not a flat surface. You can also put a ruler or level on the top to sight how level the top is. Once all your pencil marks disappear, you should be in pretty good shape. Good luck, it sounds like a fun project!

Amy

 

[walnutjerry]

With a top that big I like to do the glue up in halves. Next I run the halves through the wide drum sander to flatten and rid the top of any glue that may be at the joints. That only leaves one joint to deal with for alignment.

Card scrapers work real good blending that final joint. I use a ROS for the final sanding.

Jerry

 

[Nativespec]

I like using a glue joint bit for added strength. I use a jig that my pipe clamps rest in and lay down was paper on the clamps. After gluing all the boards, I put wax paper on the top of the glue up where my cawls (mine are straight 2x4"s) and use smaller clamps to flatten the table onto the pipe clamps. I never get a perfeclty flat surface and have learned not to use the drum sander because I will wind up with a table a 1/2 inch thick. Next I use my jointer plane accross the grain (maybe at 45 degrees) the plane it flat and will finish up with scrapers and ROS sander. I now have an 8" sander that will help avoid creating peaks and valleys in my table top.

I would never use a biscuit jointer (got rid of mine) due to telegraphing the biscuits into the finished piece. If you insist on a biscuit jointer, allow plenty of time for the glue to dry around the biscuits befor any sanding takes place.

Thanks,

David

 

[jlwest]

I have made several table tops and agree with Dave. I use biscuits for alignment and stay away from the edges (ends). Proper jointing is imperative for tight joints and a true flat work bench for glueing.
Jeff

 

[cpowell]

I like DaveO's approach.

Biscuits or not is a personal choice. I get better joints edge jointing and gluing than I did using biscuits. My joint lines have improved a lot since I stopped trying to apply too much clamp force. :icon_thum

As Nativespec pointed out, if you use biscuits then the joints around every biscuit will swell slightly due to the concentrated moisture gain and swelling of the biscuits in those areas. If you sand during that time, you will likely end up with depressions around every biscuit joint once the biscuit loses moisture and equilibrates with the surrounding stock.

I would recommend rough dimensioning the stock (S4S) oversized and laying the boards on stickers for a couple days afterwards to make sure they don't warp/twist/cup, etc. Easier to deal with problem stock before you've glued up since you can discard outliers.


Chuck

 

[skysharks]

You know this has been an interesting read about the different views on using biscuits.
I guess that all the panels that I have glued up and edge joined using biscuits to align the surfaces, I have never run into the problems that some of you have.
I am scratching my head wondering why.:eusa_thin
Whether it's gluing up panels for cabinet doors or gluing up table tops for customs desks I have always used biscuits.
Is it cause I allow suffcient time for drying/curing of the glue, clamping pressure, etc? I'm not sure.
I used to not use them, but would run into problems with the joining surfaces flexing just enough that it took alot more finishing work to work them out.
I do have set of router bits that are designed for edge joining glue ups. However I personally wasn't really impressed with them over a large surface.
Facing out the ends/sides of plywood with solid wood they worked decently.

I too have learned about clamping pressure. A while back someone posted the clamping pressure required for wood working glue.:icon_thum
Man I was putting way too much pressure prior to that read.:BangHead:
Now I watch the joint, when it closes up and I wipe the glue off. I look for no gap then I back off. Wait for just a bit then reapply pressure just til it's tight again without over doing it, as to cause it to bow.

As far as line up: set out your boards however the grain and your preferance is. put all the edges together, then using a straight edge, mark a straight line across every joint (indexing line).
As other have said if it is a larger surface do your panels in sections.
Align the indexing lines with the indexing line on your bisuit jointer. Make your cuts.
Apply your glue as normal, don't forget about the pockets for the biscuits.
alignment then is easy. If the bisuit jointers is set for the specific thickness of your lumber and you are right on the indexing line, then I don't see the problem with alignment.
We used to use basically the same procedure for aligning trouble some counter tops pieces (inside the miters). So that the edges once clamped where virtually non existant.

like I said this has been an interesting read. I am always learning and very open minded. I would be interested in hearing the problems others have had and why.

 

[JackLeg]

Many thanks to everyone who has responded. Biscuits or glue joint bit, seems like either will work if the proper prep work is done. I'll definitely let you know how this progresses and also shoot some pics. Thanks again to all.