LumberJocks

Plywood or MDF?

  • Advertise with us

« back to Woodworking Skill Share forum

Forum topic by MrRon posted 04-27-2014 09:37 PM 1565 views 0 times favorited 14 replies Add to Favorites Watch
View MrRon's profile

MrRon

3927 posts in 2710 days


04-27-2014 09:37 PM

Topic tags/keywords: question

I will be 80 in a few months. I have been designing an adjustable height workbench for a couple of years and have it down to where I’m ready to build it. my son wants my old bench for his shop, so now is the time to get going. The bench will be 96” wide x 42” deep. the height will go from 30” to 42”. I designed the bench as a base for the top of choice. That can be solid wood, plywood or MDF, or torsion box, whichever is your preference. I have designed this bench to use sheet goods for the base, either hardwood plywood (Lowes 3/4” oak or birch). I have been thinking about using MDF, but I’m concerned about it’s habit of absorbing moisture, especially at the cut edges. The reason for thinking MDF is the hardwood plywood, big box stores carry is not very good quality. It has the habit of warping and delaminating that MDF doesn’t have. Obviously furniture grade plywood would be prohibitive in cost. Now that I know the pros and cons of the two materials, which material would you use? Can MDF be effectively protected from moisture infiltration? So far, I have priced the total cost out to $200. That includes the parts needed for the adjustable feature. Attached is a preliminary sketch of the bench. https://s3.amazonaws.com/vs-lumberjocks.com/n4plhtb.jpg!


14 replies so far

View endgrainy's profile

endgrainy

240 posts in 1355 days


#1 posted 04-27-2014 10:05 PM

Cool bench design! I have a rudimentary bench I made when I first started woodworking about a year and a half ago. The top is two 3/4 MDF sheets laminated together. I like that’s it’s very stable and was relatively cheap (but very heavy to work with initially.) I don’t like that is relatively soft and scars easily. I haven’t found the moisture issue to be a problem, but you could try a coat of shellac or other finish if you went with MDF.

Have you considered Baltic birch from a plywood dealer? It’s often sold in 5’x5’ sheets, but I believe they have it 4’x8’. I just got some for a project, it’s much higher quality than the big box plywood I’ve used previously. It wasn’t too expensive, about $60 for 5’x5’ (3/4”).

If I were to build another bench, I’d probably go with a solid hardwood top (ala the Roubo crowd), but that would likely exceed the $200 budget you set. Good luck!

-- Follow me on Instagram @endgrainy

View thetinman's profile

thetinman

294 posts in 1005 days


#2 posted 04-27-2014 10:16 PM

That’s going to be a fine bench!!

MDF is a favorite of many and will do fine. The concern about moisture may be valid if your shop is damp, etc. I don’t like the dust when I work with it or the fuzz if you don’t get the industrial harness. I personally prefer plywood. I know what you mean about the poor quality at the big box stores. Where I live they ran the local lumber stores out of business. I gave up on Home Depot because they cater more to the contractors who seem to accept less (or have to due to time). I went to the Lowes near us many times waiting for the “right” shipment of ¾”. It never came. I talked to the manager (fortunately I know him) and got a call 2 days later that some “good stuff” was in. I still had to go through the top 4 sheets to get at a good one. It is the classic standard ¾ – 5-ply and works well. Try talking to the manager and have the workers sort through it for you. I also like the ply for dog holes. Just never had any luck with MDF for this. Solid lumber is better but ply works well enough.

Best of luck.

-- Life is what happens to you while you are planning better things -Mark Twain

View ,'s profile

,

2387 posts in 3014 days


#3 posted 04-28-2014 02:27 AM

That is a really cool design you have there for your adjustable bench.

I personally use Melamine for shop table tops. That stuff is great for the shop. Very durable.

A 4 by * sheet of baltic as mentioned would be good quality ply.

And with MDF, I am not a fan. But maybe if the edges were primed and painted that would seal it up good. Also you might consider laminating the MDF with an inexpensive sheet of laminate from HD. But by the time you get into laminating a sheet of MDF, you could get a sheet of melamine and be further ahead.

-- .

View Loren's profile

Loren

8314 posts in 3115 days


#4 posted 04-28-2014 03:22 AM

Torsion box will stay flattest and you can use 3/8” construction
grade ply for the faces, screwing down a top layer of something tough
like baltic birch. The face veneers are the same thickness
as the internal plys. Those thin veneers on something like
oak play will likely get damaged at some point. Same will
happen with the baltic birch but the damage won’t have
veneer peeling off and you can fill it or leave the scar.

View MrRon's profile

MrRon

3927 posts in 2710 days


#5 posted 04-28-2014 09:54 PM

I am not going to use a torsion box top, nor do I want to. This bench will be for general purpose. A perfectly flat top is not needed. A machinist vise will be added and the bench needs to stand up to heavy use, like pounding, and hammering. Only material for the base is my concern. I can go with veneer plywood, OSB, particle board or MDF. MDO would work well, but it is expensive at about $100 per sheet; I need 2 sheets. My consideration for the topis 2 layers of 3/4” MDF and 1/8” of Masonite. The construction will be mostly dado and rabbet joints, glued and nailed, but I want the glue to be the principal source for strength; nails will only be for clamping and alignment.

View MrRon's profile

MrRon

3927 posts in 2710 days


#6 posted 04-28-2014 10:20 PM

Here is my progress: The top is a torsion box. https://s3.amazonaws.com/vs-lumberjocks.com/n4ri21v.jpg!

View Loren's profile

Loren

8314 posts in 3115 days


#7 posted 04-28-2014 10:47 PM

Sounds like a good plan. Better grades of particle board can
be got as well. I’ve found lightweight MDF to be less
flat than the 90lb/sheet stuff.

View MrRon's profile

MrRon

3927 posts in 2710 days


#8 posted 04-29-2014 10:03 PM

The types of plywood available is limited where I live. I have to rely on the big box stores. Even the independent lumber dealers have to sell the same junk in order to compete with big box. Better material is available, but not without greater cost. Sure it can be special ordered, but you know what that costs. I think I will have to go with big box, maple or birch plywood. Appleply used to be available from HD and I will check that out.

I’m hoping to get this project finished and tested. There have been requests for adjustable height workbenches in past posts and 1 or 2 have come forward with their design. I think mine is a superior design, but I want it to work flawlessly before I release information on it. If it works out like I think(hope) it will, I will make plans available with complete instructions for it’s construction for a nominal cost to assist my meager SS retirement.

View Jackietreehorn's profile

Jackietreehorn

150 posts in 1405 days


#9 posted 05-01-2014 04:23 PM

My old shop was complete mdf carcass and mdf top with Formica. Lasted 7 years daily use, without any moisture problems. I’m starting to rebuild my bench and am thinking of 3/4 mdf and 3/4 melamine for top. This comes out less expensive than using Formica. That way if something gets thrashed I can replace easily, only downside I can think of is how sheet goods aren’t always true, so if I damage top I could replace one sheet at a time, but if new sheet is thicker or skinnier than that could be problem.

Nice design by the way!

-- www.nobleprojects.blogspot.com

View Underdog's profile

Underdog

907 posts in 1502 days


#10 posted 05-01-2014 05:37 PM

Whoa! Whoa! Whoa!

That’s not your bench MrRon. That’s a picture of your CNC router build. Or are you planning on using it for a bench now?

-- "woodworker with an asterisk"

View oldnovice's profile

oldnovice

5733 posts in 2835 days


#11 posted 05-01-2014 07:26 PM

MrRon, I would either use double sides MDO as is has a very good surface for finishing, whatever you chose, and it is very stable. It is what the California highway department, and I suppose other highway departments, use for the large highway/freeway signs.

Or you could do what I saw Norm Abrams do, cover the working area with 1/4” tempered hardboard that can be replaced when it get too worn. With that approach you could use either plywood or MDF with a waterproofing finish under the Masonite.

-- "I never met a board I didn't like!"

View jinkyjock's profile

jinkyjock

487 posts in 1041 days


#12 posted 05-01-2014 08:14 PM

Mr. Ron, I don’t know about suppliers in your area but generally you can get Moisture Resistant MDF with a green central core.
I also sometimes glue a pine (or scrap/offcut hardwood) fore-edge on to the MDF.
I have also mixed a 3/1 water/PVA solution and applied this to the edge as a sealant and find this reduces the de-lamination of boards.
Good luck Sir.

View MrRon's profile

MrRon

3927 posts in 2710 days


#13 posted 05-02-2014 12:45 AM

Sorry about that. I posted a picture of my CNC router project on the wrong forum.
My only concern with MDF is the raw edges where they are exposed to moisture laden air. I’ve seen things made from MDF where the raw edges would turn to mush after a few years. I don’t want that to happen; not on a project that will stand the ravages of time. I’ve read up on the pros and cons of engineered materials like MDF. OSB and particle board. I’m thinking veneer plywood or MDO may be the only way to go, at least for piece-of-mind.

View MrRon's profile

MrRon

3927 posts in 2710 days


#14 posted 05-02-2014 05:07 PM

Thank you all for your replies. So many choices, so little time.

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com