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Newbie in the process of learning a lesson - MDF workbench.
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=48627		 Page 1 of 1
Author:  Robert Lak [ Fri Dec 02, 2016 8:42 am ]
Post subject:  Newbie in the process of learning a lesson - MDF workbench.
The woes of a woodworking newbie. 6th grade shop did not prepare me adequately. Another example of a public education... :mrgreen:

As you may know, I am gearing up to do some playing with wood and am putting a work area together. The first thing I needed was a workbench and there was this Youtube video on building a "$100" workbench that looked nice enough, albeit a bit wobbly. I made some changes and it's run me about $125 so far. I am actually very happy with it. It even came out square and level... a first for me.

In the video he mentioned that he sealed the top with "A slathering" of tung oil. The top is 4 layers of MDF. I should have guessed that "a slathering" means "near infinite amounts" of finish. Now, i don't know if tung oil is thicker or what, but i let the guy at woodcr*ft sell me a tung oil/linseed oil finish and since i was there, and it was quick, easy and i didn't pay attention to the cost. When i started to pour on a slathering, that MDF sucked it up like a Texas desert sucks up rainwater. Half a can was gone and i had done 1/4 the bench top. I switched to brushing it on, and used the remaining can to get a layer on the rest of the bench. Then i looked at the price of the can... $31... Yeah, i can feel the words *Sucker* burned into my forehead.

So my questions now are:

- Should i stick with the finish I started with? Mainly just a sealer... not looking for any particular effect.
- can i switch to something cheaper like...?
- how much more can this top hold? Did the first layer seal it and will the next layer take much less? or will the mdf swell and fill up my garage???
- for a 2' x 8' top, how much more will i need? the first can was the size of what you'd get mineral spirits in (is that a Qt? didn't look)

In the end, if i can get away with another can, i'd be ok with sticjking to what i started using. (sub $200 for a nice bench is fine in my book) but if i need a gallon or two... ???

Thanks for your opinions...
Author:  ernie [ Fri Dec 02, 2016 9:50 am ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Hi I/ve used miniwax waterbased polyurethane or the regular poly to seal MDF templates moulds , forms, tops etc, at lowes or HD thicker is your friend , you might thin the first 1 or 2 coats with paint thinner 10% till it gets soaked in then straight out of the can. I.ve used tung oil for furniture and tool handles where you apply a vy thin coat.But I would not use it on mdf
Author:  Robert Lak [ Fri Dec 02, 2016 10:32 am ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Can I use the poly over the tung oil/linseed oil mix that I already applied?
Author:  A.Hix [ Fri Dec 02, 2016 11:08 am ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Robert, get a gallon can of Boiled linseed oil. It is fairly cheap, and it works great for workbench tops. You can thin it out a bit with mineral spirits, like 3 to 1 ratio of oil to thinner. Be sure to get BOILED linseed, not raw.
Author:  douglas ingram [ Fri Dec 02, 2016 11:15 am ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Robert Lak wrote:
The woes of a woodworking newbie. 6th grade shop did not prepare me adequately. Another example of a public education...


While you're at it, you could also blame your parents!

All joking aside, you could just leave the MDF top bare. My main work bench has a multi-layer MDF top and the top layer is considered replaceable for when it eventually wears out, and its untreated.

But now that you've already applied an oil finish that option is closed. The first coat of oil will be the most absorbed so subsequent coats will build on top of that. However, this is a work surface not display furniture, so just leave it alone and call it a day. You will spill stuff and bang it up and the less fussy you are about it now the easier it will be to accept all of the battle scars that your bench top will eventually accrue.

A one liter can of oil finish really isn't very much for a bench of this size. I'm surprised that you were charged $31 for this size of can. My local Home Depot, for example, charges $21 for a liter of Tung Oil and only $11 for a liter of Linseed Oil.

If you need more, for a workbench, straight boiled Linseed Oil is just fine.
Author:  Robert Lak [ Fri Dec 02, 2016 11:53 am ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Thanks!

Unless there's some additional thoughts here before I head home from work... I see HD has a gallon of boiled linseed oil for $25... sounds like a deal.
Author:  Terence Kennedy [ Fri Dec 02, 2016 12:23 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Melamine is a good replaceable top too. That's what all mine are. Flat and glue does not stick to it-kind of. Melamine over two 3/4" pieces of HD particle board. Very solid.

I really beat my tops up.
Author:  ernie [ Fri Dec 02, 2016 12:35 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Robert yes , you can put the polyurethane over linseed oil or tung oil . but I would wait a few days until it is thoroughly dry, and scuff sand with 320 or 400 grit before applying the poly.Or leave the top as is. with tung oil. I personally like a hard finish that can be cleaned off. your choice .
Author:  Clay S. [ Fri Dec 02, 2016 12:57 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
MDF will soak up most finishes like a sponge (and can swell). It usually is painted first with a primer before any top coats are applied. As Doug mentioned, leaving the top unfinished, or as Terrence mentioned, using melamine coated particle board as the top layer, might be a better choice.
A third possibility would be to laminate the top with a piece of Formica (HPL). It is a bit tougher than MCP and cleans up better than bare MDF. If you have a local cabinet shop, they might give or sell you a piece pretty cheap. Big box stores also sometimes carry HPL.
Author:  George L [ Fri Dec 02, 2016 1:37 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
I built my workbenches so that replacing the top layer is relatively simple. If that is true of yours, I'm with Douglas; call it good and get to making guitars. [:Y:]
Author:  truckjohn [ Fri Dec 02, 2016 2:52 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
If you soak more oil into the MDF - it's likely to swell and become lumpy/uneven....

on the Woodcraft product.... They generally sell product that is several levels of quality better than your local BORG. (Big orange retail giant). Don't fret the price.. You likely got a product that will work as intended rather than the cheapest schlock they could get into the can....

I would rather leave the top of a workbench dry anyway... Less chance of oil rubbing off into your guitar project and making finishing a challenge...

Just let the stuff dry a few weeks, then lightly sand with 320 and call it good. Time to build a Guitar!
Author:  Bryan Bear [ Fri Dec 02, 2016 2:56 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Since this thread is drifting away from what finish to put on, I'll add that my bench is actually the formica counter tops that I took out of my kitchen during a remodel. I built the bench under it. I now have a huge U-shaped workstation with peninsula all formica. I love being able to easily scrape glue blobs off and it takes a beating. It is white so sometimes I draw plans out full scale and do calculations on it then just wash it off when the project is done. I have plywood inserts in the sink and cooktop cutouts where I do any chopping so I don't drive a chisel into the hard counter-top. If I ever have to do it again, I will go with white formica for sure.
Author:  Alex Kleon [ Fri Dec 02, 2016 3:31 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
My main 4' x 6' work bench top is just particle board with white HPL on top. I figured that if it got too dinged up, I would flip it over, and put on a fresh piece of HPL. That was about 8 years ago, and it is still holding up.

Alex
Author:  RustySP [ Fri Dec 02, 2016 3:57 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
I covered my plywood topped bench with 1/4" hardboard/Masonite. It's got a smooth shiny side, takes a lot of abuse and is easily replaced when it wears out.


Sent from my iPhone using Tapatalk
Author:  SteveSmith [ Fri Dec 02, 2016 4:08 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
RustySP wrote:
I covered my plywood topped bench with 1/4" hardboard/Masonite. It's got a smooth shiny side, takes a lot of abuse and is easily replaced when it wears out.


Sent from my iPhone using Tapatalk


Same thing except I put wipe-on poly on the masonite. After 8 years or so I still haven't needed to replace it.
Author:  Cal Maier [ Fri Dec 02, 2016 5:03 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
+1 on the Masonite. It's inexpensive and provides a reasonably durable finish that can be replaced when it needs to be.
Cal
Author:  Link Van Cleave [ Fri Dec 02, 2016 8:34 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
Seems like with the advent of MDF everyone has forgotten particle board. I use it on my assembly bench top. there are different grades but you can get some nice stuff at cabinet supply type places.
Won't suck up too much finish like MDF and is way tougher.
L.
Author:  wbergman [ Sun Dec 04, 2016 5:18 pm ]
Post subject:  Re: Newbie in the process of learning a lesson - MDF workben
I do not use water based varnish on raw particle board, mdf, etc. anymore. I once made some work tables out of very nice chip board that was milled smooth at the factory. The water based poly caused the fibers to swell, leaving innumerable valleys to collect dirt. Oil based poly for me now. Regarding swelling, I do not know if it is safe to use water based over poly over an oiled surface. Also, my recollection is that the water based cost twice as much as the oil based.
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