Sacrificial top on workbench? (moved from tool sec)

[Greg Urwiller]

Getting ready to make some shop cabinets. While I'd like to have a laminated wood top (too expensive), I'll probably go with a double MDF layer. I suppose I'll edge it with 3/4" something. While I don't figure on being too rough on the top, would it be advisable to position the edging high and put in a sacrificial layer of hardboard on top? I'm just trying to figure what my total height will be so when I'm done the top will be slightly lower than my TS, so it can also be used for an ext on the left side of the TS blade if ever needed. Not sure of my machine placement yet, but it would be there if I ever needed it.

That said, will an MDF top like this be solid enough for a woodworking vise? Greg

[shane lyall]

Mdf is awful at holding screws/lags. I'd at least add a solid section for the vise. As for the hardboard, it's a good idea to be able to replace the top. I break down 3/4 sheet goods right on a table with a circular saw. Of coarse I set the blade to just come thru by about 1/8-1/4 inch. My sac top is 1/4 luan ply. About $10 a sheet at the borg and I keep a few sheets on hand for cabinet backs and such so I can throw another on when needed. I'm tough on that work table. If I need an odd angle clamped up I screw scraps to it and use wedges. The sac top will last a month or two for me but I'm in the shop 6-7 hours a day 5-6 days a week. Add the top, you won't regret it.

[Aaron Rowland]

I like MDF a lot. I use it for patterns ,prototypes, blast gates and just about every thing that doesn't get a lot of wear or stress. It's stable and doesn't shrink. It's hard to paint as the paint just soaks in like a sponge. I use a mixture of white glue thinned about 75% with water and paint the item. Then hit it with sanding sealer and sand. For worktops NG. It's like paper. Won't hold screws, bolts and if glued will peel the top glue section right off if hit. You can get it to hold screws or bolts if you drill a 1" hole in it and insert a 1" dowel stick with glue.

I love to build work stations. There are an infinite number of ways and very few wrong ones. I'm tall and like high counter tops so I don't have to bend over. Also different apps have different height requirements but that's a personal thing and up to the user so I can't give height requirements. I've made the old style with stretchers and structs but didn't like them. They loosen up and rack. The best I've built use the torsion system. Hollow core doors are almost dead flat and cheap. I stack two of them on top of each other and cover top and bottom with 3/4" plywood. If you want a longer bench offset them. Then I use 3/4" oak on the sides. This top will never warp or give any trouble. I use a vac press to glue them up but clamps with a caul could be used to reach the center. I did the throw a way Masonite cover but quit. I'm very easy on tops and did not fine it necessary. A number of coats of poly give good protection and I sand it down a bit every year and re-coat the Birch top.


The cabinet is made with a solid 3/4" ply sides and back with a face frame for drawers and storage area.

So you can go what every you want and it will still work. Uh, except for MDF.

[Mike Desch]

Howdy:

I made a bench top with two 3/4" sheets of many-ply plywood, one sheet of 3/4 MDF and then used a replaceable top of 1/4 hardboard.
Bench top is rock solid, but in 7 years, I still have not had a need to replace the hardboard top.

However, I do recommend you taking the extra step--just in case.

[Rick Potter]

Two layers of particle board, and 1/8" tempered masonite top, the type made for shower walls with the white finish. Vise is bolted thru the PB, and the top covers the bolts.

Rick Potter

[Norman Hitt]

MDF can make an excellent Workbench Top when properly braced underneath, (and edge banded), that is stable and flat, (much flatter smoother and more stable than plywood), when the economics just won't allow for a laminated bench. For one excellent example of this, click on the link to see the build that Glenn Bradley did, (and he is still using it today). Glenn used 3 layers of MDF IIRC, but no sacrificial top, (it just depends on how rough you are going to be on the top I think.

http://www.sawmillcreek.org/showthread.php?57879-The-quot-Next-quot-Workbench-Part-1

Greg, "IF" you think you will really give it rough treatment for a while and want to use a sacrificial top of hardboard, I would suggest using the smooth both sides 1/4" thick Tempered Hardboard and when one side gets beat up , you can flip it over have a fresh smooth top again. I would place a countersunk short brass screw close to each corner to keep it held down tight and flat. "IF" you should later decide that the sacrificial top was no nolger necessary, you can remove it and take a router with a flushtrim bit and trim the edge wrap so it is again flush with the surface of the MDF Top.

Note: There is more than one part to the workbench build in the link above, so be sure to see it all.

Good Luck, and Happy building:D

[Larry Edgerton]

I disagree with using a 1/4" top for a throwaway. You can not fasten it enough that it stays perfectly flat. It creates a pillow effect after a time especially if you are screwing jigs to the top. I would not use MDF for the top layer either.

I have one I build doors on that has been good for many years. It has a Novaply 3/4"base, and a sheet of 3/4" oak ply on the top. The Novaply[particleboard] is screwed to the bench structure. The oak ply is screwed to the Novaply. The edging [ash] is screwed to the oak ply. This way the top sheet could be replaced.

Its been about fifteen years in a commercial shop, and although it is not pretty, it is still in good shape. I screw fixtures to the top all of the time so it gets holes, so when I have extra epoxy left after a glue up I will dump it on the top and squigy it around, filling the holes and any nicks or, opps, router marks. Next day I get out a scraper and flatten it back out. I kind of like the character it has developed over the years, so unless I do something really stupid, I'll just keep patching her up.

Larry

[Norman Hitt]

I disagree with using a 1/4" top for a throwaway. You can not fasten it enough that it stays perfectly flat. It creates a pillow effect after a time especially if you are screwing jigs to the top. I would not use MDF for the top layer either.
Larry

I have to disagree that 1/4" TEMPERED hardboard will not stay flat if screwed down at the corners, "if" used the same as a laminated bench, BUT yes, IF you are going to screw things to it, nothing that is not glued down solid will stay perfectly flat, Including plywood, because the screw will raise the grain of the top surface of the underlayment of MDF or plywood or even a laminated hardwood, which will lift the sacrificial top. If I were going to screw jigs to a bench though, it wouldn't be on my "main" workbench whether it was made of MDF, plywood OR laminated Maple, Beech or SLP. I would make and use a junk bench for that, but that's just me I guess. :D

[Prashun Patel]

My bench is MDF on top of a hollow core door, then topped with 1/4 hardboard. The edge banding holds the hardboard in place. No screws. It stays flat. My complaint with the MDF is that over time, it doesn't hold dogs as well.
Also, any vises have to be bolted through the top with the nuts countersunk; you can't use lag screws. I mean, it works and is stable and was cheap, but it's not perfect.

[Chris Kennedy]

I have a workbench with a double layer of MDF and banded with 3/4 pine. I coated it with BLO, thinking it might make it less prone to shed dust. I don't know if it has made a difference, but I like it. I routed slots and put in t-tracks with hold down clamps. I really like it. I opted not to put a sacrificial top. MDF is cheap enough that if I wreck the top layer, I will just pull it off and put another one on.

Cheers,

Chris

[Larry Edgerton]

. If I were going to screw jigs to a bench though, it wouldn't be on my "main" workbench whether it was made of MDF, plywood OR laminated Maple, Beech or SLP. I would make and use a junk bench for that, but that's just me I guess. :D

Well good for you.

My bench has served me very well. Hundreds of thousands of dollars worth of commisions have gone across my bench. A bench is a tool, period. Why would I make an inferior bench to hold projects that cost 50 times the benches worth? That would just be sill don't you think? Your kind of woodworking snobs crack me up. If you are such a wood worker, why would you have a bench with masonite on it in the first place? Shouldn't it be solid Beech?

[Norman Hitt]

Well good for you.

My bench has served me very well. Hundreds of thousands of dollars worth of commisions have gone across my bench. A bench is a tool, period. Why would I make an inferior bench to hold projects that cost 50 times the benches worth? That would just be sill don't you think? Your kind of woodworking snobs crack me up. If you are such a wood worker, why would you have a bench with masonite on it in the first place? Shouldn't it be solid Beech?

I don't believe my post deserved that, so I'll just leave it alone and politely bow out of this thread.
Have a nice day.

[Andrew Joiner]

My bench has served me very well. Hundreds of thousands of dollars worth of commisions have gone across my bench. A bench is a tool, period.

A workbench choice is such a personal thing. I have designed mine over the years based on how I do my work.

My first real woodworking bench was at a custom millwork shop. It was a 4x8 sheet of fir plywood on a solid base. I hated it because it was all slivers layered over slivers. After decades of pounding and sliding huge doors and store fixtures on it the fir fibers were spent. I had to share it with my boss and he said some day we'll replace this top when we have time. It never happened while I was there.

Next I started my own wood business and used what I learned to design my personal bench. I had little money and time. I came up with 2- heavy benches made from recycled crates. They had 3'x7' tops and on heavy nylon glides to slide apart for building big things. Mainly they were 5' apart so I was an arms reach away from both benches as I worked in between them. The tops were 1/2" particle board so no slivers! I flipped them over once every few years because they'd get full of holes and router cuts.

On those crude ugly benches I built furniture for my states Governor and a stairway for the state historical society building.

Today in my hobby shop I have what works for me . 2- benches 5' apart. But now they aren't as crude. Instead of crates I used new 2x4's for bases and mdf for 1 top, baltic birch for the other. Both tops can be flipped when they get all scared up.

[Eric Nordby]

I have a diefenbach bench that I covered with a new piece of flat 3/4" marine ply. For my purposes I first installed two outer legs of red cedar rips set perfectly square by using pyth 3-4-5 measurements. I piloted, glued & screwed the long leg making certain to stay straight as an arrow then installed the shorter leg square without glue in case of seasonal changes in the wood. Next I installed borders and some blocks underneath to make certain the table top doesn't move when it's on top of the bench. I finished all with a couple coats of poly. When I set up the TS and bench I made certain to accommodate the new top height so I can slide sheet goods from TS to bench without snags. It's easy to slide off and stays upright off the back side of the bench when i don't need it but for the most part stays on the bench 85% of the time. Works for me and has lasted 10 years. I've sanded and repoly'ed a couple times when it's gnarly and filled forstner holes and such as needed. The poly prevents glues from really adhering so a chisel/ scrape now is super easy.

[Joe Angrisani]

I don't believe my post deserved that, so I'll just leave it alone and politely bow out of this thread. Have a nice day.

Well done, Norm......

[Callan Campbell]

Interesting, my own experience mirrors both Prashun p. and Larry E. . My own crude affair of a workbenck is 2 sheets of 3/4 oak plywood and a 1/4" hardboard top. I have poplar banding all the way around the layered top. I've seen the 1/4" temp. hardboard lift up at the corners in my basement shop whenever the humidity gets to its worst level. It hasn't affected my woodworking since once I clamp something to the workbench, it lays flat and my work seems to come out square as I would want it to. Once the humidity drops just a bit, the corners lay flat again. I have coated both sides of the 1/4 hardboard with a mix of Turpentine/BLO . The glue drops and squeeze-outs are easily scraped off or wiped off from the surface of the hardboard. I hate working with MDF, so it wasn't a consideration when I was building my workbench. Like Larry or others, my top now has "character" all over it.....

[John Coloccia]

I figure that one day, my bench may get beat up to the point that it's no longer usable. When that happens, I'll take it to my local mill, toss it on the wide belt and flatten it again. If it's so bad that I can't do that, I'll stick a 1/2" top of something on it, take it to the local mill, toss it on the wide belt and flatten it.

To me it's like the first ding on a new car. The first one is the toughest. After that, it just doesn't matter any more.

As far as jigs and things like that are concerned, I've made some of them so that I can just bolt them on through the dog holes. The ones that I can I toss in the vice, usually just clamped between the dogs. I haven't had to drill any additional holes to hold jigs yet.

Anyhow, that's just how I work. My bench IS the sacrificial top to my floor :D

[Jim Becker]

My bench is MDF on top of a hollow core door, then topped with 1/4 hardboard. The edge banding holds the hardboard in place. No screws. It stays flat. My complaint with the MDF is that over time, it doesn't hold dogs as well.
Also, any vises have to be bolted through the top with the nuts countersunk; you can't use lag screws. I mean, it works and is stable and was cheap, but it's not perfect.

I possible solution for both the dog issue and the vice attachement issue is to build some hardwood into the "sandwich" to specifically address these issues.

[Larry Edgerton]

My bench is MDF on top of a hollow core door, then topped with 1/4 hardboard. The edge banding holds the hardboard in place. No screws. It stays flat. My complaint with the MDF is that over time, it doesn't hold dogs as well.
Also, any vises have to be bolted through the top with the nuts countersunk; you can't use lag screws. I mean, it works and is stable and was cheap, but it's not perfect.

Prashan

I use hollow core doors on site, and to toughen them up I drilled holes in one side and injected foam. Helped some, and is still light. On the MDF. When you drill the hole, treat it with a thin epoxy. Keep applying it until it quits soaking in, and it takes a lot. That is how I treat the edges of my patterns so the router bit does not sink in, works awesome.

[Rick Potter]

Larry,

Great tip on using epoxy on pattern edges.

Thanks
RP

[Kirk Poore]

My primary bench is a piece of 1/4" masonite screwed to the top of a layer of 2x6, applied after the 2x6's were lagged to a pair of cross members (2x6's set on edge). After 7 years the masonite's chewed up in a few spots, but it's plenty flat after having thousands of dollars of furniture built on it. Of course, I spared no expense on the paint for the bench--a couple layers of leftover white latex look great and keep the warpage down.

Kirk