I have made a few MFT slabs using the PARF GUIDE SYSTEM. I had 3 sheets of 4 x 10 MDF, so I cut the first one in half and made my own design for the holes, clamp slots etc., then commenced to the drilling. I found the first one to be an excellent size which allowed me to work on cabinets, cabinet sides, face frames, big glue-ups. 4x5 tops seem to work for me.
Most of the time I'm working in a conditioned area so the humidity is low. Nevertheless, I do notice sag when I used the plastic horses. It helps to use the 2 x4's in the slot provided in these horses. Having the 2 x 4 support also gives you a way to temporarily clamp your top down. Just pick 2 really straight ones. Good luck. [emoji38]I use two Bessey clamps and it makes the setup pretty solid.
I'm thinking that the next batch of tops I do will have the handhold in the middle, that's a great idea. I might even urethane the tops.
At this time I'm using the several pair Store Horse metal horses, of which I have now purchased every grade they make. Be aware that the lower number grades hold less weight and do not have adjustable height. I've bought them at home depot and online, when a deal came up.
BTW I use Harbor Freight movers quilts to put over my mdf tops to make a nice soft, scratch free zone for finishing parts and such. It's proven to be a great work area for my intermediate sanding between coats of finish. Just don't try to wash the quilts, they'll just fall apart, and they will deform horribly in the dryer [emoji33] I got several sizes, about 15 of them for 100 bucks.
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