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Thread: Best material for MFT style outfeed tables -Permanent Table

  1. #1
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    Best material for MFT style outfeed tables -Permanent Table

    I have seen 3/4" ply, 3/4" MDF and even 3/4" particle board with melamine on both sides. I know festool opted for the MDF, obviously not because it is lighter than 3/4" ply, but perhaps because it is less expensive too. The particle board with melamine gets a really, really slick top and would be excellent in glue up (clean ups) but seems it would have a tendency to chip out as well as the plywood. Thoughts or observations? Remember will be drilling plenty of 20 mm PARF holes and have a semblance to the Paulk support underneath it.
    Tim in Hill Country of Texas

  2. #2
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    Tim -- The advantage of MDF is that it is dead flat. It is also durable in this use. The most critical thing for an MDF top is the accuracy of the holes. If the holes become oblong through wear, the accuracy of the top is lost. Particle board will not resist such wear for much use. Plywood is typically made with a core of relatively soft woods, making the holes prone to elongation. MDF is very stable and dog holes in it are surprisingly durable. Baltic birch might be even better, but more expensive.

    If you really want a scuff resistant surface, it's really easy to cover MDF with plastic laminate.
    David Walser
    Mesa, Arizona

  3. #3
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    I'm in general agreement with David. MDF is a really good material for this application because of its flatness, because it's actually the thickness specified rather than thinner like plywood and because the grid machines into it cleanly when done correctly. You can treat the surface to make it "slicker" to help reduce glue adhesion, including waxing it, oiling it or applying a film finish. You can also apply laminate as David noted for a "more durable" surface, but that's going to add substantial time as you may be best served by doing the grid in the MDF, applying the laminate, re-drilling the centers of the grid holes with a .375"/10mm drill bit and then trim routing the laminate back to the 20mm hole circumference. You do NOT want to be drilling the laminate with your nice, expensive Parf system, etc...

    I've used MDF surfaces in my shop for a very long time and they are surprisingly durable. My old miter bench that was in place for almost 20 years still had the original MDF top on it when I ripped it apart about a year ago to do away with it. Other than a few minor abrasions and paint splotches, it was in excellent shape. It only ever had BLO on it.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  4. #4
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    So sounds as it it will be MDF. Thanks all.
    Tim in Hill Country of Texas

  5. #5
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    I'm going to add that while you use the term "permanent" in the title of your inquiry, just because Mr Murphy does exist, as we all know and love, make it so you can replace the top in the future should something terrible befall it without having to rip things apart with violence. As an example, you can incorporate some threaded inserts or blind nuts in your base under the work surface that you can then use bolts countersunk below the surface to hold it down securely. Should you need to change it...remove the bolts, discard the top and replace with a new one configured exactly the same way.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  6. #6
    I chose to use 3/4 softwood plywood for my Paulk inspired outfeed/assembly/track saw cutting station 3'x7' table. The main point I would disagree with the others advising MDF is durability of the holes. Mine has proven to be durable which I think is logical since you will always have end grain all around the hole, just in different layers. I do not believe MDF is nearly as resistant to damage as the end grain of even softwood. MDF is probably more stable but if you fasten the plywood into a structure, like mine is, the plywood stays flat. But to be fair, I strongly resist using MDF for anything due to a dislike for the dust.

    I think the bottom line is plywood is stronger and in my mind at least, more durable. But if it will be unsupported, as it is in the MFT, then the warping tendency of plywood could be an issue and MDF may be the better choice. But with support, I really like plywood.

  7. #7
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    Keep in mind that for a typical "MFT" style grid system, the holes will primarily receive fixed and solid dogs for positioning work but even those with adjustable clamp type setups are well supported so that there is minimal defection to damage the holes. That's unlike using hold-fasts on a more traditional bench where the edge of the dog hole comes into play a bit more when you wack them tight to the workpiece. The advantage that MDF and other composites have over plywood for the "MFT" style grid is simply that plywood produces are built in layers and that thin veneer on the top is very, very easy to chip. Even the softwood plywood that has sometimes has a thicker surface layer still has that layer boundary as a point of failure. You absolutely can "chip" out MDF, but for this application it's very resilient.
    --

    The most expensive tool is the one you buy "cheaply" and often...

  8. #8
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    I'd use Baltic Birch. Yes, it is more expensive than MDF, but with all the work you're going to invest in making it, and all the time you'll spend using it, use the best materials. Besides, it isn't all that more expensive. My hardwood dealer currently sells 3/4" 4'x8' baltic birch for about $60. Yes, this is real baltic birch, from Latvia I think. Okay, it is 18mm, not actually 3/4", but the guys at the counter look blankly at me if I ask for 18mm.

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