Fine Woodworking Getting Started Workbench top quandry...

I like melamine it works great plus cleans up well

-- Jim from Heirloom Woodshop, custom furniture ,maker, woodworking school, heirloomwoodshop.com

Again the concern is swelling due to humidity.

This summer average has been 97 degrees F and 70+% RH.

My Grizzly Melamine Drill Press table has some obvious swelling to it now…

I’m not sure Melamine, MDF, or particleboard are appropriate for my environment… Can the stuff be sealed?

-- Trying to follow the example of the master.

I’d have to go against Jim’s suggestion on this one – melamine is great when you need a SMOOTH surface – for things like router-table, outfeed-table, and the likes. but for a workbench you want anything but a smooth surface – since you want the workpieces to be held properly to the table top without sliding around.

I’d go with whatever is cheaper/accessible. both will give you a good surface. however- plywood would have a bit less issues with humidity changes then MDF, although from my experience MDF’s sensitivity to humidity is minor at best- it is however very sensitive to (direct) moisture – so don’t get it wet! (that’s how I lost my router table) also the plywood might be easier to screw things to (such as your trim, and also the lamination would hold better, and does not require special (confirmat) screws like MDF does).

good luck on your workbench – it is a very good design/choice as my previous bench was based on the same design. looking forward to see some progress on it.

-- When in doubt - There is no doubt - Go the safer route.

The edge banding I am planning on will be dowelled in place. Not sure if this is my best idea, but I have seen it done here with MDF tops and it looks GREAT… Banding material will be SYP, and pegs are from walnut dowels.

Right now the progress is limited to my stupidity… I started by trying to recycle Hurricane Ike damage 4×4s, but figured out pretty quickly they were pressure treated, and I do NOT want that…

The kiln dried stuff I came up with is FAR less than perfect, but it is as good as I can find locally… (Insert long string of laments here on lumber quality close to me). I will just have to work with what I have going.

One of the reasons for asking, is this will impact the length of the legs, and I want to get them cut, and sealed up so they don’t pick up moisture and twist before I can move to the next parts… With MDF / Hardboard I am dealing with 1-3/4” top thickness, with plywood, I am dealing with just shy of 1-1/2”...

I am leaning VERY heavily toward the Plywood top for a lot of different reasons, the most notable, MDF makes me nervous due to humidity… Not to mention I can finish plywood and make it look a lot nicer…

-- Trying to follow the example of the master.

What about a solid core exterior door? Im not that familiar with the plans you are using….but I have a bench with the door as a topper and it seems to weather everything that gets thrown at it…..and I didn’t have to laminate any pieces….it already came primed… so you can either put some varnish or use as is….The great thing was that I hit the box stores for their seconds and damaged items….they get a lot of dinged doors that will sell as a steep discount….

-- Woodworking.....My small slice of heaven!

Solid door is the way to go, I work in a hospital and just scored a couple of 2 1/2inch thick and 4ft wide doors. They even say fireproof for 90 minutes…time to cut’em down and make a few benches.

-- ericandcandi, Louisiana- Home of the "LSU Tigers"

In my experience it has been not so much the humidity or lack of it, as it is the change of it that causes problems. If it is always 70% humidity then once the wood reaches equilibrium you’re good to go. It is when it swings from say 45% to 75% (seasonally, or when bringing a project indoors from the garage) that you get movement after the fact. Modern HVAC systems keep indoor humidity at around 45% (when in operation) and well, . . .nevermind

Whatever you choose to use, I would avoid “picture framing” the top. Which is to say using a different material, mitered at the corners. It will likely fail or open up over time. Breadboarded ends would be one option but would still leave the long edges of parent material exposed. It might be worth investigating a sort of “Greene & Green” style bridle joint type of affair allowing the top to move in both directions but still affording coverage of the top/parent material.

Instead of trying to hide the joint, celebrate it. This is certainly not my idea, as any ardent student of joinery will tell you <bg>

Good luck with your endeavor.

I had considered as you say, “celebrating” the edge if I used plywood. I actually like the stripe pattern plywood makes. (I have routed profiles into plywood projects in the past specifically to GET that pattern). Might be worth doing…

I have seen a few of these benches “picture framed” as it were, and I knew the long edge would be more prone to expansion, I was figuring on some sort of overlap / butt joint at the corners held together with dowels… I am however certainly not allergic to exposed ply….

The solid core door idea is interesting for sure. Might have to consider that too…

-- Trying to follow the example of the master.

I would be careful if you are gonna consider a 12” overhang. You may end up with some sagging over time. I used a couple of sheets of 3/4 mdf glued and screwed together and topped it with a 1/4” sheet of hardboard. the hardboard I chose was a contact paper covered sheet and I would highly recommend against using it. The crap peels and looks like hell, gotta learn somehow. My top is replaceable and I will be getting a new 1/4 hardboard top, the regular stuff, soon. As for your original question I think you will be fine with either the ply or mdf. If I had to do it over I would have used 3 sheets instead of 2.

The door option is also good. You might check with the big box stores and see if they have any shipping damaged doors that you could use. They will sell them really cheap and you might even get it for free if the mgr is in a good mood!!

-- My job is to give my kids things to discuss with their therapist....medic20447@gmail.com

i use solid core doors for my benches but if i had to do something else i would definetly use MDF. 3 layers of 3/4” mdf would make an awesome bench top and as far as the 12” overhang i really dont think it would sag that much overtime. you could always brace it underneath with some channel iron or something if you were worried about it.

seal the mdf with some shellac on both sides and you wont have any trouble with humidity as the mdf is stable to begin with and the shellac will seal it from moisture

I really like my birch solid core door assembly/outfeed table top coated with three coats of poly (on all sides). glue and other spills clean up easily and if damaged can be repaired.

Its beauty can be a drawback, LOL. I can’t bring myself to pounding anything on it without a sacrificiial surface to keep from marring the surface. Similar thing when finishing or painting on it – I cover it with a plastic tarp.

I special ordered it so it wouldn’t have any door knob or lock holes – cost about $70.00.

-- Joe

I’d use MDF, sealed with any water based poly finish. In Chicago, we get 90 degree days and 90% humidity most summers. I have 2 router table tops that interchange with my base that were sealed with MDF-no swelling problems. Same for a lot of table saw fixtures built with MDF.

-- Gerry

Here in South Africa we have weather proof or ‘wet’ mdf, chip board and exterior ply.
My friend has a place at the coast where humidity exceeeds 80% at times and rains non stop for days. He uses all 3 with no swelling or deviation. Do you have similar in the States?

-- "Even small steps makes a distance." (Shawn Phillips, musician)

I have 4 workbenches in my shop- 2 with solid-core doors that are 36×80, and one that is 32×70. No problems with them at all, as long as you have good support all the way around them. I put about 3 coats of quick-dry poly on them, and it holds the scratches down pretty good, if you don’t go overboard!!
My newest bench(about4 mos old), is 40”x101”, and is 4 sheets of MDF glued and screwed, and edged with 1 and 1/2×3” spruce. I put 2 coats of Danish oil rubbed in good, and after drying for a couple of days, put 4 coats of the quic-dry poly on, letting each coat dry for 24 hrs. Here where I live in Arkansas, we also have very high humidity, but it won’t get to that table. That sucker is BIG and DEAD FLAT!!! I can work on a flat-bed trailer on that dude. If you got the room—go for it!

-- Remember--- one good turn-- gets most of the blanket!!!!

I don’t know what your budget is, but I suggest something like these maple blocks. http://www.grizzly.com/products/category.aspx?key=360100

They are dead flat and won’t move much with changes in humidity.

-- "At its best, life is completely unpredictable." - Christopher Walken

I did my two benches with solid core doors and think they are fine. You can get good deals on the doors at builders surplus stores. Good luck/Steve

-- Big Steve

I am going with BB Sanded Ply. The pieces are cut, the lines are marked, and the drilling, screwing and gluing will commence tomorrow as I just got home from Woodcraft with the glue. (I ran out of Titebond, and Woodcraft has a sale going on…)

-- Trying to follow the example of the master.