MDF or particle board for saw tables?

[Steven J Corpstein]

I'm getting ready to build both a right extension and an outfeed table for the cabinet saw? Which ever one I use, I plan on putting several coats of poly on the bottom side and a Formica type product on the top.

I've gotten mixed advise at work, some saying the MDF will stay flatter, some saying it is too heavy.

AND... if I go with MDF, what glue have you guys had the best luck with?

[Noel Hegan]

I reckon MDF is flatter (and will stay flatter) than particle board. The slight extra weight is a bonus and regular yellow glue is good for both materials.
But perhaps if I was building an extension / outfeed table myself I'd use birch ply with plenty of bracing on the underside.
Rgds

Noel

[Cliff Rohrabacher]

I've gotten mixed advise at work, some saying the MDF will stay flatter, some saying it is too heavy.
Hmmm sounds like they are mixing apples and oranges.
Stay flat and be heavy are two concepts that don't have much relation to each other. Actually both are good.

As to the heavy who cares unless you plan to pick the tables up and move them around?

I have considered extension tables made with steel legs and frames and 3" thick highly trowelled reinforced concrete working surfaces. It's heavy but it's brutally stable. I'm still thinking about it.

[Walt Pater]

Don't use particle board.

[William OConnell]

I had an Mdf extension with laminate wich swelled and really bit the big one as far as flat goes. I made a new one out of 13 ply birch ply from finland wich has been going strong for years I'm pretty sure it was 1" thick.
33999
Heres a shot of 2 pieces next to each other 1 is 3/4" and the other ids 1". I remember at the time thinking it was pricey but now I think it doesnt it doesnt owe me a nickle.
http://www.woodworkers.us/tempfolderpics/Ply%20profile.JPG

[Barry O'Mahony]

I just used a piece of 3/4" melamine for an outfeed table, with the laminate on both sides. Cheap, and no need to mess with fabricating it. it has a particle board core and stayed flat. No doubt the laminate in tension on both sides helps keep it flat, as does the substrate framework of kiln-dried and jointed 2x4's, spaced 12" O.C.

[Jim DeLaney]

Like Barry, I used 3/4" melamine, but I put a frame of 2 X 2 hard maple under it, and also edge banded it in maple. Only been on there for about a year, but so far it's been solid and stable.

[Jim Becker]

Properly supported, MDF is an excellent substrate for plastic laminate...but do not use water based contact cement...use the "smelly stuff" with proper ventilation.

[Charlie Plesums]

Just don't do what I did. I wanted a thick work table surface, and couldn't decide between plywood and MDF. So I made a sandwich of a sheet of each, glued together (clamped in a vacuum bag). I should have expected it, working with different materials... the bloomin thing is warped!:(

[Kelly C. Hanna]

MDF by far...only thing I will use it for.

[Lee DeRaud]

I have considered extension tables made with steel legs and frames and 3" thick highly trowelled reinforced concrete working surfaces. It's heavy but it's brutally stable. I'm still thinking about it.I've seen kitchen counters done with concrete, but I have no idea if it's possible to get one really really flat unless you use some kind of thin self-leveling stuff for the wear layer.

[Vaughn McMillan]

I've seen kitchen counters done with concrete, but I have no idea if it's possible to get one really really flat unless you use some kind of thin self-leveling stuff for the wear layer.
It could be fine-tuned by grinding it, but it wouldn't be easy. (Then again, a terrazo tabletop would look sweet.) I've heard of warehouse slabs placed to "superflat" specs (.10" variation in 10' IIRC). Not sure if that's quite to the tolerances most guys want their extension tables, and don't know how you'd tool the concrete on a smaller scale. Still seems like it'd be an interesting experiment, and might be easier than it seems. If it worked, it'd indeed be stout. I'd think you'd want some type of reinforcement to prevent cracking (i.e. a steel tension band around the perimeter of the "slab"). Probably want to put the t-tracks in before the concrete sets up. :rolleyes: :D

- Vaughn

[John Hebert]

I use Melemine. Easy to maintain, tough, and nice and brite & can be washed with lacquer thinner to look new again.

[Norman Hitt]

When I finally got around to replacing a temporary extension table, (after several years):rolleyes: , I wanted a good one, soooooo...I laminated two 3/4" sheets of MDF together and even inset "T" nuts in the top to fasten the bottom support frame to it, and used spackling compound to fill and level the holes above the "T" nuts. I banded all four sides with Red Oak and then covered BOTH the top and bottom with formica, to eliminate ANY moisture getting in and causing swelling or distortion. It has worked extremely well, and I do not anticipate ever having to replace it during my lifetime. I made the supporting frame under it from Red Oak. Your outfeed Table is not as critical IMHO, and could be made with a single layer of MDF with a good frame and crossmembers under it for support. I used PVA glue to laminate the two MDF pieces, and the original, "Stinky" kind of Laminate adhesive to apply the formica.

Note: Melamine will also work well, but the surface will not take the beating a good plastic laminate will, but you could cover the raw edges and the top with a plastic liminate (after a light sanding to rough it just enough to give the adhesive something to stick to), and this will also seal the edges from moisture. The melamine coating on the bottom should keep it sealed without having to do anything further there. Rough plans for an extension table with supporting framework can be found on the Biesemeyer site.

[Bill Fields-ny]

Excuse the first post.

I have an extension table made with MDF and it has been in use for four years now. Nice and flat and nice and heavy. Have to remove it for motor clearance on 45 degree cuts. Sears contractor saw. 100 pound drawer slides mounted on the sides of the saw holds it up. Got the idea from Woodsmith Magazine tip.

[Ed Kowaski]

I think the core choice is really 6 of one half a dozen of the other. Neither are particularly stiff however plastic laminate on BOTH sides of either will be stiff and flat. If you can clamp it use plastic resin glue, it will be worth it for stiffness. If you go with plastic resin glue let all the material aclimate before bonding. P-lam contains craft paper and can absorb enough humidity to cause problems. In this case it's not the moisture content but imbalanced moisture that causes problems. I've not had a problem with material that's been in the shop for two weeks or more.

Next choice is solvent based contact cement. It doesn't bond rigid enough to cause warpage problems usually but the panels will not be as stiff. Again do plam on both sides.

[jack duren]

i have more faith in PB over MDF for extension tables. but a better overal product is MDO coat it with wax and glue drops wont stick to it;) ....jack

[Alan Turner]

I recently built two outfeed tables, one for the TS and one for the BS/ I used a traditional leg and apron design, with cleated cross members of 5/4 by 3" chestnut oak at about 16" on center for interior support, and capped it with edge banded melamine. No problems, and the top is replaceable should the need arise. I like the white color. Easy to see if anything is in the way of a rip, etc.

[Jeff Singleton]

I have a 60" x 48" outfeed table on my PM 66. I took 3/4" plywod and made a torsion box, interlock grid, 3 1/2" tall. Took a sheet of 3/4" birch, laminated one side, screwed the laminated side to the torsion box and then laminated the top and sides. It is flat and durable, did it about 10 years ago and it is still used about 5 hours everyday. The first peice of laminate was a stock item at a local distributor and I got it really cheap, the top was Powermatic green or there about. Torsion box is the way to go.

Jeff Singleton;)