# edge trim for mdf top + temp hardboard protective layer



## Spikes (Apr 11, 2018)

Hi,

I'm finishing up an outfeed/assembly table and I've chosen to go with a mdf top. I'd like to put a piece of hardboard on top since it's cheaper to replace and in all effect more durable (other posts said they did the same thing and 2yrs later they still had to need to replace it…). In any case, I could not quite figure out a good way to do it, some people said just brad nails (5/8), but my experience pulling out bradnails is not the best one… can somebody describe what the actual process of changing the hardboard top would look like? some other posts mentioned tape, but I don't see how that wouldn't create bumps.

Also what about trim/edging? I'd like to add a trim around the mdf of solid wood, but not sure how to attach it. Some people say glue will work as MDF is "dust and glue", maybe with some brads as well, other say the brads don't hold in mdf and nor will the glue as it will just get sucked in. So confused about what to do. Similar problem with screws, they seem not to hold well in MDF. BTW, I thought about using the trim to hold the hardboard in using the trim, maybe 1/8 higher the mdf.

thoughts?

thanks,


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## MikeDilday (Feb 21, 2017)

Could you use threaded inserts and flat head machine screws?


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## clin (Sep 3, 2015)

I built an assembly table from MDF. Though it is built as a torsion box so the MDF side are the surface and not edge of the MDF. I screwed and glued the edge trimming without issue.

I also used a hardboard top and it has it's own issues. First, it didn't lay as flat as I expected. So I ended up having to put some screws in it to pull it down. I used counter sunk, brass screws so that if I did manage to hit a screw with a tool, the tool would be less likely to get damaged.

If I were to do it again, I'd have used thicker hardboard because I think it would lay flatter under its own weight. I think what I used was somewhere in the range of 3/16".

Another thing I would do different, is my hardboard is trapped inside the edging. The idea was to hold the hardboard in place. But, this proved pointless as I had to screw the top down. But the problem is you never get the hardboard and the edging to match perfectly. So you have a little lip that things can catch on as you slide them over the edge of the table, even if you route the edging flush to the top.

Sure if you glued and screwed the hardboard down then routed it would stay flush. But since the top is meant to be removable, you can't do that. Plus the hardboard probably varies in thickness with humidity and will never be flush no matter what.

So if I had it to do over, I would have the edging flush to the MDF top, and let the hardboard cover the edging as well. You will of course have to hold the top down. It doesn't look as finished this way, but it's more functional. Though certainly this exposed edge of the hardboard will get beat up. But that's why you make it replaceable in the first place.


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## 000 (Dec 9, 2015)

I would glue and nail a hardwood trim to the edges, 
and cover it with a piece of laminate and never worry about it again.


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## BattleRidge (Oct 22, 2017)

My unit has two layers of 3/4" plywood with a hardboard top. Once the hardboard was in place, I used a router with a flush trim bit to bring the hardboard flush with the plywood.

I then installed a border of modified oak baseboard trim around the edges to keep the hardboard in place and to provide protection to the edges. The trim has mitered corners and is fastened to the plywood with brad nails. I eased the sharp edges of the trim with a sanding block for a more pleasant feel.

There is a small gap in the trim at one spot so that a screwdriver can be used to lift the top when the surface becomes worn or damaged and replacement is needed. I also used short sections of double-sided tape in the corners and at various spots to hold the plywood and hardboard firmly together and prevent any lifting or bowing.

The work surface is completely smooth and level and provides a very nice area for assembly, outfeed and general workbench purposes.

If you haven't installed the MDF, it could be worth using plywood instead which would help limit the fastening concerns. I don't generally work with MDF so can't provide any specific recommendations in that area.


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## Lazyman (Aug 8, 2014)

I would use double sided (carpet) tape to help hold the hardboard to the MDF and use brads to fasten it down. It will hold it down pretty well and be easy enough to remove later when it is time to put on a new top. You can use Goo Gone to remove any residue from the tape, especially if you put a coat of WB ply on the MDF before you apply the it.

For the trim I think that brads and glue will work well enough but a coarse threaded screw might give it a little more holding power. If you are worried about holding power of the screws put a few drops of CA/superglue on the screw or in the pilot hole before you drive it in. This will help strengthen the MDF a little.

If you haven't committed to the MDF, I would personally use a nice piece of plywood instead.


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## Tony_S (Dec 16, 2009)

> I would glue and nail a hardwood trim to the edges,
> and cover it with a piece of laminate and never worry about it again.
> 
> - jbay


pffftt….waaay too simple. Smarten up.


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## MPython (Nov 30, 2018)

I built the top for my radial arm saw bench using a three layers: the bottom layer is 3/4" plywood, the middle layer is MDF and the top is 1/4" tempered hardboard. The MDF is permanently fixed to the plywood by several rows of countersunk screws. The hardboard is trapped by 3/4" oak edging that is glued and brad-nailed to the plywood. It lays flat and is secured with a minimal number of screws (3 or 4 at most) across the back edge. I built this in 2012. The hardboard has remained perfectly flat and flush with the oak edging, and I've not had any of the problems Clin discusses. I've been very happy with it.


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## Redoak49 (Dec 15, 2012)

When I have to fasten something to MDF, I drill holes and then squirt some CA glue into the holes and let it dry before putting in the screws.

I put 1/4" headboard on top with counter sunk screws.


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## rwe2156 (May 7, 2014)

Laminate is the best way to go IMO. Glue scrapes right off you never will have to worry about it wearing out.

Hardboard must be attached with screws if you plan on changing it.

GRX trim head screws hold extremely well. I would use them + glue for the edge banding.


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## woodbutcherbynight (Oct 21, 2011)

> I would glue and nail a hardwood trim to the edges,
> and cover it with a piece of laminate and never worry about it again.
> 
> - jbay


EXACTLY. Here is example of glued hardwood edging to MDF with laminate on top.


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## Spikes (Apr 11, 2018)

thanks for all the feedback. Some mentioned using plywood rather than MDF and many have brought up laminate.

The main thing here, as my usual, is that I work with no budget/for cheap and with stuff I find laying around. That's why the MDF (someone else had an extra sheet leftover from a project) and the hardboard vs laminate (it's $10 a sheet instead of >$50 a sheet).

Am I looking at the wrong laminate? is there any such thing that can be had for cheap? most ppl said their hardboard lasted years (2+) so I'd have to replace it 5 times for 10+ years before I'd break even with the laminate.

thanks,


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## Lazyman (Aug 8, 2014)

One way to get cheap laminate is to buy or salvage used or surplus material. Not sure what your dimensions are but I used a laminate desk top that I got for free for my assembly table. I did some epoxy and CA inlay this week and the dried glue drips just pop off. If you have a Habitat for Humanity Re-Store nearby, you might be able to find some laminate or even laminated material cheap.


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## 000 (Dec 9, 2015)

If you were here I would give you enough to use.

Maybe you can check with some countertop shops and see if they have some 
old stock, left over, discontinued sheets for cheap.

I know your trying to save money, but it would be money well spent. Looks better, material slides better, and glue cleans up better. And you won't have to replace it.

If you can't get the laminate, melamine would be my next recommendation.

Edit: Call some woodworking shops, just about any shop usually has left over laminate.


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## mathguy1981 (Aug 30, 2018)

> If you can t get the laminate, melamine would be my next recommendation.
> 
> - jbay


 +1 to this.

You can just buy the sheet of laminate (without the MDF countertop) at Lowes:
https://www.lowes.com/pd/Formica-Brand-Laminate-48-In-x-96-In-Umbra-Oak-Matte-Laminate-Sheet/1000423205
and then just glue it down.


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