Wide Slab Conundrum

[Steve Wurster]

All,

I've got this nice piece of walnut that I having some issues with. It's about 10/4 thick, nearly 7' long, and about 13.75" wide. That's too wide for me to joint, plane, or resaw using any of my machinery (12" max on all). It was originally flattened by a local shop sometime last year, but it's moved a little bit since then so it has a slight rock to it. I jointed the edges on my machinery sometime back.

This piece is destined to be part of a table top, with the targeted thickness closer to 6/4. I'm wondering which course of action I should take to bring the piece down to that thickness. My options as I see them are:

1. Cut it down to 12" wide, joint one face and one edge, resaw to closer to desired thickness, etc. Definitely not my preferred option, since I do not want to change the width any more than I have to, and we're talking close to 2" loss with this method.
2. Use a router sled. That's not only going to take a very long time and generate lots of debris, but it's also going to waste a lot of material. Again, not the best option.
3. Take it back to the local shop and have them flatten it again and bring it down to very close to final thickness. I don't know if they have the ability to resaw something this wide or not, so we still might be talking about a lot of material loss. This is an inconvenient option due to the size of piece (tight fit in car or borrow a truck) and the cost for them to process the material.
4. Cut it in half width-wise using my bandsaw and then just treat each piece as a regular old ~6.75" wide piece that I can joint, plane, resaw, etc. That should only cost me a few fractions of an inch in overall width, I would think.

I'm leaning heavily toward option 4 since that lets me process the material in my shop and has the least amount of wasted material. Just wondering what the Creekers think about this one.

Thanks,
Steve

[Doug Bowman]

I know this is the power tool forum, but if I only had a little bit of rock (I assume it twisted) i would use a hand plane to remove the high spots - but that does not solve your resaw problem - and I am NOT recommending a hand saw for that!

[Steve Wurster]

Yeah, it's got a little twist to it, which in theory I could remove with a hand plane. But of course my skills in that realm are very lacking, so I would most likely use a router sled to just take care of that.

But as you noted that doesn't solve my resaw issue. And, no, I'm not going to hit this with a hand saw or even a bow saw!

[Prashun Patel]

Can you post a picture of the slab? Is the width of the table going to be 13.75" wide? Are the two live edges or only one?

I've made slab tables keeping the whole thing in tact, and also by resawing and bookmatching, and sometimes by sawing into slats and leaving a gap in the middle. It all depends on the aesthetics.

[Ted Reischl]

Well, if it only has a "slight" rock to it then you will not have to remove much from the offending corners. So a router running on a bridge would do the trick.

From your description it sounds like you want to resaw it into thinner boards for the table top? If that is the case I would do as you mentioned and go ahead and cut it up in planks that you can handle in your shop.

[Tom Bain]

I'm not sure I understand the need to resaw as you aren't likely to get two boards that are 6/4 or ~1.5" thick from a board that starts at 10/4. It's highly possible I'm misunderstanding what you are attempting to accomplish.

[John Lanciani]

Something else to consider is that when resawing a slab like this it is very likely that both pieces will move a fair bit after you cut them if you just try and cut a 3/4 or so piece off of the 10/4. What I would do if it were mine (and I'm very fortunate to have all the machines to work with a piece this size) is the following;

1. Joint one side flat
2. Plane as little as possible to have both sides parallel.
3. Saw 1/16" veneers off of each side
4. Verify plank is still acceptably flat
5. repeat step 3 and 4 until plank is 1/8" over final thickness
6. Joint and plane to final thickness and flatness

Doing this will keep the plank in balance and give the greatest likelihood of success.

[Steve Wurster]

There's a picture of the slab below, although it doesn't show the thickness.

The table is going to be about 45-48" wide, and this piece will be the middle piece (or pieces if I rip it). Neither edge is live anymore as a result. I have 2 other pieces that will be the outer live edges, and another 2 pieces that go between this wide slab and the outer pieces. Those other 4 pieces are nearly ready for glue-up.

If I resaw the pieces, I don't expect to use both parts for the table. I only need ~6/4 for the table. The remainder from the resaw would be potentially used on future projects. Yeah, it would be around 1/2" thick if I'm lucky, but small boxes or veneer-style things for a decorative project could come out of that.

slab.jpg

[Prashun Patel]

Nice. So if it were me I would rip the pith out and grain match the straighter edges. I like the effect better and the result will be more stable than using the enter board in contiguous form.

Also while it's definitely nicer to the environment beware of saving the resawn 1/2" board. I end up with a lot of future project boards that I end up discarding because they are not perfect.

Besides you may end up with more stable boards for your table if you take equal parts off the top and bottom of the slab.

[Steve Wurster]

If I rip out the pith then I'm losing I would say at least 3 inches of width. That might make the table too narrow overall. Of course I could find some more pieces at my local mill to make up that difference, or try to get something out of a remaining board. That remaining board was very close to the outside of the log though so it's probably less stable.

Good point about taking equal parts of both faces, although I'm not sure how much was removed from one side vs. the other when it was originally flattened at my local shop. Plus I still have to flatten whatever I do end up working with. That extra material can be used for box tops and bottoms, decorative room things, etc. There's no telling what my wife might want to do with it!

[Andrew Pitonyak]

Disclaimer: I have limited experience in some of what I am about to say, so please engage your brain and look for bad advice...

The thought of resawing this scares me because I expect wood movement if you do this. Then, when you are done, you will have this very wide board that you still need to flatten; again. I would also not be inclined to remove more than 1/2" of wood using a hand plane. To minimize movement, I would want to remove equal amounts from each side, but I probably would not if I was using a hand plane.

If possible, I would probably just make it flat and let the table top be thicker than originally planned.

So, is one side flat and the other is not? I expect that both sides are out a bit.

if it were me, I would consider the following:

1. I would first hit the high spots with a hand plane to remove the main offenders. If things seem to be working well, I might finish the entire thing this way.
2. I would investigate having a shop handle the final bit (if possible).
3. If I needed to thickness it myself, I would use a track saw to cut the board to an appropriate width so that I could use my own equipment and then then flatten and thickness using my equipment. I could then glue the boards back together. The problem, of course, is that if you do not register the track saw on a flat surface, than you probably need to joint that edge before you glue them back (after you have tacking care of the twist and such).

Be interested in what you decide to do.

[John C Cox]

So... If you already flattened it once - why would it all of a sudden become stable once you have it flattened again? Now... It its still about where it ended up last time and you just need it a little flatter - go for it..

If its destined to be a table and is going to be used indoors... How does it behave when you take the slab inside and let it live in climate/humidity control for a month or 3? Will it twist more or flatten back out?

Where you are at now... I wouldn't do much to it till you are near final thickness... It could well move again after resaw...

[Sam Murdoch]

I vote for your # 4 option. Saw to width that you can process. Then glue the two rips back together AFTER you have processed each piece to be flat and straight etc. As for the 1/2" +/- fall off from the resawn stock you can make nice stuff out of it even if those piece require more resawing or other work to suit your needs.

In a perfect situation you could resaw off each face to maintain some semblance of equilibrium but as long as you allow for some extra jointing/flattening after you get it to your near working thickness you will be fine.

[Steve Wurster]

Obviously I'm not going to resaw this right down to final thickness. I know I have to joint it and plane it afterwards. I already did that with the other pieces for the top, which are all pretty close to final thickness already.

All of the pieces have been in my basement shop, which isn't much different climate-wise than my kitchen where the table will reside. I do have a humidity monitor though so I should compare the two locations. The original flattening from the local shop was done about a year ago. I did the edge jointing probably a couple months after that (limited shop time last year, unfortunately). The piece has only twisted a little since then.

I am heavily leaning toward option 4.

[Steve Wurster]

Okay... I went with option 4. I went down to my shop a little bit ago, stared at the piece, and said the heck with it and ripped it in half using the bandsaw. Aside from the trouble of hauling this big piece up to the bandsaw table, it went very smooth. So now I have two ~6.875" wide pieces that I can process in my shop. And if I'm really lucky I'll be able to work on that before the week is out.

Thanks all.