Sealing MDF - Worth it? If so, how?

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Forum topic by James Richardson posted 01-07-2009 09:01 AM 31925 views 1 time favorited 14 replies Add to Favorites Watch
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James Richardson

13 posts in 4919 days

01-07-2009 09:01 AM

Topic tags/keywords: mdf sealing help table workshop bench workbench wood timber

Hi all!

I’m 15 years old and am considering building a workshop in the garage.

I have looked around and decided that an MDF topped workbench would be the way to go as it is a cheaper alternative. My only concern is that I would have to seal it to stop it crumbling.

I am wondering how I would go about this and whether I should explore other options for a benchtop?


-- JR.

14 replies so far

View Vince's profile


1334 posts in 4920 days

#1 posted 01-07-2009 12:24 PM

Hey JR,
I have a Ridgid offsite box that I put MDF on. I brushed on some Urthane varnesh about a year ago and still looks pretty good. But I only use it for bench tools like a sander, scrollsaw and a mini lathe. So it doesn’t get much abuse. My workbench has a layer of 1/4” masonite which takes alot of abuse.


-- Vince

View motthunter's profile


2141 posts in 5290 days

#2 posted 01-07-2009 01:20 PM

Mdf becomes dust if it gets wet. Seal away and it will last longer

-- making sawdust....

View Sawdust2's profile


1466 posts in 5579 days

#3 posted 01-07-2009 02:11 PM

If you are going to have a span more than a few feet you will need support in the middle.
As you will need support the most likely support will be 2×4’s or 2×6’s.
Neither are much more expensive than MDF. Use the solid wood.

If you already have a bench (can’t really tell from your post) then a reasonable cover for the top of your bench would just be 1/4” hardboard. It’s less expensive than MDF and easy to replace if it gets too marked up.

My $.03


-- No piece is cut too short. It was meant for a smaller project.

View Kinzua's profile


11 posts in 4918 days

#4 posted 01-07-2009 08:20 PM

Hi JR- Welcome. I’ve been looking at doing the same thing for my first workbench which would also be my first attempt at ww project. I found this design for a “rock solid plywood bench” on I will add link for you to view and if for some reason it doesn’t work I can send you pdf of full plans in email. New to this site as of yesterday and assume there’s a way to contact me here in comment/or private msg?

First workbench needs to do a couple of things for me- let me learn in making it-so mistake forgiving plywood and mdf are cost appropriate :). I do a lot of finishing/staining right now so I decided to add an additional removable top to this design with a flat laminate surface adhered. That way I can fit the alternative top to workbench as needed with ‘no worries’ on spills and messes. I also read several articles and “show-how’s” on adding strips of veneer to workbench in places I know will get a lot of abuse-including the legs. I realize we can substitute other ideas for legs, but I want to learn more about veneer so opting for this route. Veneer will also reduce wear-n-tear and splintering (according to my novice research thus far.) I also like this bench as many have commented on it’s sturdiness and durability in another blog and it can serve as a future outfeed table, assembly table and/or place to store/work with benchtop tools. (I recently added a drill press, bench grinder, band saw to the novice ‘tool stash.’)

As far as sealing and keeping it inexpensive—Z-shellac cut with 2x denatured alcohol is a great layering sealant. You’ll always have more projects to use both products repeatedly so it’s a good “shop” investment. I’ve also used Thompson’s water seal -though it’s marketed for decks-it does a great job protecting wood-based products that I know will endure a lot of work-out. And it can be placed over shellac finish as a treatment repeatedly to maintain your top. There’s also the Kilz and enamel paint route with mdf and hardboard for that matter.

“WOOD” with BHG just published 2009 “Best-Ever Home Shop Ideas.” You could flip through it at your local bookstore mag rack. There are numerous designs and ideas for mdf/plywood in that edition also-with my favorite helping tool: photo’s.

Link podcast on “Working With Plywood” (great instructions):

Link: pdf file on “Rock Solid Plywood Bench”

Finally, here is a link that will take you to a list of video podcast’s on finishing. Peter Gedrys is by far my favorite online “show how” podcast instructor—I’ve utilized several of his technique suggestions very successfully.

Look forward to seeing your project JR.

View PurpLev's profile


8654 posts in 5140 days

#5 posted 01-07-2009 09:00 PM


since you are a new woodworker you might want to be aware of the fact that when working with MDF, it creates a VERY VERY VERY fine dust that is REALLY REALLY hard to control/suck/vacuum/clean and is among the most dangerous dust in woodworking! make sure that you use any means available to you to suck that dust as soon as possible, wear a GOOD dust mask with a good filter on it.

MDF dust is so fine, that it lingers in the air for hours and hours after you’ve finished working. you’ll see it covering everything in your area, and if you blow it up back in the air the process will cycle over and over again causing your work place to be a hazard to your lungs!

not trying to stop you from using that material – just be aware of it’s danger.

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

View James Richardson's profile

James Richardson

13 posts in 4919 days

#6 posted 01-08-2009 09:06 AM

Oh thanks i didnt know that!

:| ill make sure I invest in a mask

-- JR.

View coloradobob's profile


26 posts in 5046 days

#7 posted 01-08-2009 04:59 PM

I have made a number of work bench tops out of MDF. The way I seal and protect them is to get yellow woodworking glue and mix it with water 50/50 mix use a paint roller to apply it. It is also a good idea to sand a little between each coat apply 2 or more coats. Let it dry for a few days and you are ready to go. coloradobob

-- coloradobob

View azor's profile


65 posts in 4934 days

#8 posted 01-08-2009 05:42 PM

Appending to Lee’s comment I would suggest you get a melamine covered hardboard. Then you can do anything with liquids [paint, glue, oil, etc.] on it. When it gets eventually messed up just pull it off and replace it with a fresh one.

-- It isn't as easy as the demos make it seem.

View dennis mitchell's profile

dennis mitchell

3994 posts in 5806 days

#9 posted 01-08-2009 06:17 PM

Mine is a particle board. It might be cheap but it sure has seen some beautiful projects in the past ten years. It is finished with convertion varnish.

View dryhter's profile


74 posts in 5095 days

#10 posted 01-09-2009 04:01 AM

It’s funny how you think of things. I’ve worked off of two saw horses and a hollow core door for years, almost every day. Light and compact,strong enough, break it down and get it out of the way, too small,get a bigger door or piece of ply wood break it get another cheap door. Permanent benches seem to collect things that have to be moved all the time, and they are not always in the right place and if they are up against a wall you don’t have access to all sides. A workbench is a tool just like a saw or drill and it should be able to double duty as some thing else. Like a picnic table or a platform for shooting off fireworks.
Just my $.02

-- Chips and Shavings/ see you at

View trifern's profile


8134 posts in 5258 days

#11 posted 01-09-2009 03:32 PM

My main workbench’s top is 4 layers of 3/4” MDF laminated together. It is a very flat and smooth surface, not to mention heavy. I have sealed mine with blood, sweat, tears and sawdust. I do have all my edges trimmed with wood. MDF is susceptible to crushing on the exposed edges.

-- My favorite piece is my last one, my best piece is my next one.

View PurpLev's profile


8654 posts in 5140 days

#12 posted 01-09-2009 04:21 PM

dryther – it is true that 2 saw horses and a plywood top make a fast-to-stow-away knock down work bench, and I’ve been using that for years, but I found that It is not too stable when it comes down to clamping a board down to joint/plane it’s faces, or when hand cutting joinery – at least for me it was too shaky and unstable. I now have a permanent bench that won’t budge at all even when much force is applied – and that makes all the difference sometimes.

it really depends on what you do, and what you’d like to do with it.

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

View spaids's profile


699 posts in 5185 days

#13 posted 01-09-2009 04:57 PM

HA HA When I first read this I thought you said “STEALING MDF” HA I was thinking um… NO it is not worth stealing.

If you are new to woodworking like me you might check out the wood whisperer video podcasts. He does a show on making what he called an outfeed table from two sheets of 3/4 ply. I copied that design and that table it my workbench. It is surprisingly sturdy.

-- Wipe the blood stains from your blade before coming in.--

View ManOWood's profile


30 posts in 4921 days

#14 posted 01-09-2009 07:55 PM

I have been building my work surfaces from MDF and 1×4 pine for years. It works for me because I change the configuration of my shop alot in order to handle the size of some projects (its pretty small in there). Anyway, with the proper amount of engineering (use lots of triangles) MDF and pine works great. I used 8 1×4s and a sheet of mdf to make my assembly table and it cost me around $30 and is maybe the sturdiest item in my shop (besides the furniture i build) I whacked the sheet of mdf in half and laminated it together and secured it with screws from the underside. I also agree with wrapping the edges because they do crush easily. One coat of a good poly and i was up and running. Paint, putty and stain wipes off easily.

I am a big advocate of MDF especially for painted projects. The dust is terrible but the surface is smooth and even, it takes paint well, and takes a beautiful profile at the router. It is one way I can afford to make my shop furniture look as nice as what I am building on it.

Just heed purplevs warning and keep well ventilated and a mask on :)

-- ManOWoodMan

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