planing a slab

[xlogger]

Question for live edge planning. If you had a live edge slab and wanted to run it threw a planner would you worry about it being flat and square like you would a board without being able to use a jointer first?  Also on filling the rot holes on cedar with some kind of clear what would you use? Ricky

[beenthere]

Can't very well plane a slab that is not flat as the planer blades are straight. And any bark on the live edge will often cause the knives to be knicked. However planing a little at a time can eventually get you a flat slab, up to a point.
Epoxy will fill the voids.

[mesquite buckeye]

You could do a quick and dirty hand jointing with twist sticks, a power hand planer and just knock off all the high and twist on one side. The big planer would then clean up the other side pretty well. ;D

[Ianab]

If you are just using a planer, the board needs to be relatively straight before you start  If you put a banana in, you get a banana out.
Uneven thickness and a bit of cupping the planer can handle , but a twist will just feed though twisted.

Like the guys have suggested, you can "knock of the lumps" with hand tools. If you get one surface at least looking straight, you will be able to feed it through the planer.

Another way is to surface with a router bridge. This will let you plane and joint any size board, just need to make the "bridge" big enough. 

Ian

[Larry]

You might think about a planer sled.  I have one made out of MDF.  I lay the slab on top of the MDF and block it up with shims so it won't rock.  Sometimes I put a drop of hot melt glue on the shims to hold them in place.  Run the whole mess through the planer.  It works great. 

My sled is only 3 or 4' long as I mostly use it for crotch wood.  For longer slabs it would still work but might require two people.  I've never did it with long slabs so just a guess.

[hackberry jake]

Maybe you just need a bigger jointer  ;D


 

[WDH]

Larry, I would like to see a pic of your planer sled. 

[Larry]

Pretty simple.  Just an MDF board with a lip on the end that goes into the planer first.

This was the only picture I had, but you can see a scrap of walnut holding up one corner and another hidden shim on the opposite corner to keep the slab from rocking.  The white oak crotch had twisted a lot during drying but I had enough thickness to flatten one face.  It ended up as a door raised panel.

If Jake would ever take his jointer off the trailer so I could use it, I wouldn't have to go to all this trouble. ;D

[Leigh Family Farm]

Funny thing that this comes up. I'm currently helping my friend plane slabs for table tops. These slabs are about 28" wide and a good 8/4 - 10/4 thick. I'll get you a picture of how he does it but I'll explain as best as I can.

He built a sturdy ladder with 5" high sides, flat rungs, and is 34" wide. Squared the whole thing up and its perfectly flat and level. This gets laid down on the work surface and the slab gets laid on top of the rungs. He uses shims to level out the slab as best as possible. Next, he built a sliding trestle that fits snugly over the sides but can still slide easily. The trestle holds a standard router that can slide in the trestle across the width of the slab. A straight bit is used to plane off the uneven portions. He got the idea and design from an old Fine Woodworking Magazine article. 

Basically, after you set the slab and level it as best as possible, your depth on the router is for the lowest portion of the slab. Then you run the router back & forth across the width of the slab and slowly make your way down the length of the slab pushing the trestle after each pass. It takes about 45 minutes to do one side of a 4 1/2 foot slab.

Yes, I know it doesn't make it perfectly level but it comes pretty darn close. If you want both sides level, then after one side is done, just flip the slab and the back side. A good sanding will take out most of the uneven spots. I hope this helps and I'll get pictures the next time I'm there but its gonna be a few weeks.

[John S]

Fine Woodworking #222, December 2011, actor-woodworker Nick Offerman.

[tule peak timber]

 

  

 

[Leigh Family Farm]

That's the one John! It works great. Tule, that's a good set up too.

[tule peak timber]

on july 2 2014 , under the title "big crotch desk", I listed a bunch of other ways to flatten a slab. Hope it helps.  Rob

[21incher]

I have been thinking about making a sled with wheels to hold my 4 inch Bosch hand planer that will ride on my sawmill tracks to flatten slabs. The planer would be spring loaded like a plunge router so you could take a little off at a time and back over high spots until the slab was flat. Plus the planer has a dust port that works well with my dust collector.

[hackberry jake]

If it's wider than 16" , this is the method I use.
http://youtu.be/kb8H4qBqrZo

[POSTON WIDEHEAD]

You gots some toys Hack! I likes it!!

[John S]

HJ,
What CNC machine is that in the video?

[hackberry jake]

HJ,
What CNC machine is that in the video?

homemade.

[redprospector]

I've got all of my shop equipment in storage, so no pics. But I used to use an old stroke sander for leveling slabs. The one I've got will take about a 7' long slab up to about 40" wide. When I was making table tops, I didn't do much to them before they were glued up to the finished width.