workbench MDF top using bench holdfasts

If you were dead set on using mdf for its low price and flatness (as I can’t think of any other reasons) then you’d definitely sacrifice durability…

however, if you were to sandwich your mdf between a top and bottom layer of 1/4 ply then you’d have the durability of ply and the other benefits of mdf.

the hold fasts will certainly dig into the sharp edges of the top and bottom of the bench holes and if you were using only mdf then I can’t imagine the holdfasts being very effective for very long at all. Cladding them with ply would add a longer life to them.

I’d also consider adding an inch or two to the strip of holes as I understand the more vertical the hold-fast – the more usable it is.

-- Ben, England.

My bench top is 3 1/2 inches thick. 4 layers of 3/4” plywood, a layer of 1/2” MDF and a replaceable 3/16” hardboard top. I know that all sounds like it would be more than 3 1/2” inches, but thanks to cheap a$$ undersized plywood its just a tiny bit less.

The cast holdfasts from Woodcraft won’t work on it, but the steel ones from Gramercy Tools work fine. They can be purchased from Tools for Working Wood. I haven’t had an issue with the holes wallowing out like I suspected I would. I did read in a recent tool evaluation in Fine Woodworking magazine that holdfasts have a problem when bench tops get thicker than 4”. The tool has to be able to tilt a certain amount to work.

-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.

Here’s my plywood bench top.
It may work well for you.
No problems with holdfasts on it.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fiberglass trees. http://prmdesigns.com/

shipwright – wow your bench is awesome !...thanks for sharing your link and I will read the blog

-- Measure "at least" twice and cut once

dpjean, I have my bench top made with 1” MDF for the top and bottom layer with 4 layers of 1/2” OSB glued and sandwiched between. I have been using it for two years now without any problems. I have not used any holdfasts, but have been using dogs and the vise to hold material in place without any movement in the dog holes. Its held up real well and is nice and flat.. I have not tried using it as the center layer so can’t comment on that. I am including a couple shots of my bench so you can see what I have done.. I wrapped it in Cherry and its been a work horse for me..

You can tell from all the shavings underneath it, that its seen a fair share of planing on it.. I would use the same top again if I were to make another.. Papa

-- Papa@papaswoodworking.com

I used particle board and plywood for my bench top. I had it laying around and did not have to worry about getting the top flat. The bench top is 2” thick and I use hold fasts from Rockler. They hold great. One thing to keep in mind is that the hold fasts should not be very smooth. If they are they will not hold properly. If your hold fasts are smooth, just rough them up with sand paper.

-- Julian