Hold down for planing slabs

[cradke0419]

I am trying to make a hold down for planing slabs. I bought some unistrut to act as a t track. Planning on bolting that down on the bed and using wedges to keep the slab tight. Also thought of maybe flipping the strut over and using a horizontal clamp.
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[phil_o]

I have used screws from the underside of the table, along with wedges strategically placed to keep the slabs as parallel as possible.

Phil

[coryatjohn]

I've planed plenty of slabs on my SB and I've found that very little hold down support is required. As long as you don't try and take off 1/4" at a time, all you need do is keep the slab from sliding. What I do is load the slab with the bow up, then shim the rock out of the slab on both sides with business cards (a good use of those old fashioned things). I typically use some boards to lock it into place but generally, the bigger the slab, the less hold down required. Once I flip it over to the flat side, the slab needs almost nothing to hold it in place.