finishing an mft top

Bertotti

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Oct 18, 2020
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I have seen threads on how people finished their MFT tops. My question is did it really make any difference in the operation or the longevity of the top? Was it just for aesthetics? Did you find any one product worked better than another? What are the pitfalls if any of a finished top? A lot of fo questions sorry for that but thanks to all who have any insight and reply, in advance!
 
I did a 4x8 top, over a Paulk style bench.  After drilling the ~ 300 holes, I thought I should try to protect the top a little bit.  I put on a couple coats of Varathane poly.  Looks fine and feels ok but.... Now everything I put on the table kind of slides around more than I would like.  I have a piece of 1" foam insulation I use when breaking down a lot of plywood and its slides even worse.  I guess it depends on how you use your table but in my case, I kinda wish I had not done it.
 
I use Howard's Feed and Wax for all my tops.  You can find it online or probably at your local ACE Hardware store.  This was a good find .. goes on easy and protects the MDF tops.  I found a new coat every now and then will easily remove pencil marks (like an eraser) I make from different layouts.  It's cheap and worth trying.
 
I have birch ply bench tops that are 'MFT' styled. These I finished with a couple of coats of matt hard wax oil (Fiddes). Looks nice and havent had any 'sliding' issues. I'm often dragging bench top machines into position and the HWO really helps keep the surface good. I did have to ream out the holes after applying the HWO.

I also have a conventional worktable (birch ply again) that gets used more like an MFT. I consider the top to be sacrificial (although I dont cut through to it) and havent treated that one. It marks easily although also looks 'work like'.

The coated tops do withstand spillages of stain, paint, varnish and glue with mostly just wiping off without a mark left behind. Not so for the untreated one!
 
Slipping is my big concern. I can live with some staining on the mdf. Thanks, everyone!
 
I've used Osmo PolyX on mine.  As with other products, it's important to coat the entire top (top, bottom, sides, and the 20mm holes).  This keeps things like humidity from warping the top.  One caveat with PolyX is to wipe the product down into the holes, but know that this will diminish the hole dimensions somewhat, making dogs really tight going in and coming out.  I used a 20mm drill bit to ream out the holes in one of my tops, but found that this over-enlarged the roles.  Next time, I'll use a 20mm hand-held reamer to do the job.  I suspect that it will reduce the over-cut.  I've not experienced any new slipperiness.
 
Rick Herrick said:
  After drilling the ~ 300 holes, I thought I should try to protect the top a little bit.  ....  I guess it depends on how you use your table but in my case, I kinda wish I had not done it.

Can't you sand it?
 
I just got the systainer with the three different Festool oils in it. I wonder if any of these would be good for an mdf top?
 
Bertotti said:
I just got the systainer with the three different Festool oils in it. I wonder if any of these would be good for an mdf top?
. Any of the three would work. Just go light on wiping the oil, avoid getting a hole really saturated so there is no chance of the diameter swelling on you.
With a light touch, you’ll only get the very tops of the holes with any oil, no harm.
If you haven’t worked with oil finishes before... important safety tip...
Leave the oil soaked rag or paper towel outside to dry instead of in your shop.
Avoids combustion issues from the oil.
The Surfix kit has you store the sponge applicator in the metal box, this generally works well at limiting air exposure to the curing oil on the sponge if you go this route versus a rag or paper towel.
I think I used the Outdoor Oil from the kit on my MFT top. Will have to look up the threads on this topic.
 
I do not treat my MFT tops. They do get a few stains but no material issues. They do tend to sag so I just flip them over. If my tops were exposed to moisture, I would protect them with a finish.
 
I would be reluctant to put wax on the top as transfer might affect my ability to apply the finish.  If I did use it, I would be careful to wipe all of the excess off (difficult because of all the holes though).
 
I would definitely recommend finishing the top but be careful on what you use. If top already made or purchased with the holes only use oil like products (Linseed Oil and the like). If you use a film finish and it gets inside the 20 mm holes the dogs wont fit nicely or at all without force. However, if you make your own top then pre-finish with your preference before drilling the holes then you don't have to worry about film finish getting inside the holes.

Finishing the top definitely helps with longevity such as: protects from glue/finish sticking to it and/or easily comes off, putting finish also gives the MDF a bit of strength (if using like poly).

If you don't want to put a finish at the very least put on some paste wax.
 
I wouldn't bother, but I cut, drill, grind, finish, paint, eat lunch, on, and generally use my benches. Some friends of mine say that people like a well-used bench...maybe it looks good to customers too.
 
I have not been here in a short while but so far I have not finished my top. I still intend to but I noticed something. The top I made was very snug on the dogs. I worked them until they fit snuggly but after a week they were overly tight and I had to make a lever to get the dogs out of some holes. I have never had this issue on my mft3. What is the difference between it and the top I made? The material is MDF looks and feels identical but something isn't the same. Are the CNC machined mft3 tops somehow sealing the sides of the holes? I wonder if rubbing some oil in the holes and burnishing it out and redrilling would eliminate the issue.
 
Bertotti said:
I have not been here in a short while but so far I have not finished my top. I still intend to but I noticed something. The top I made was very snug on the dogs. I worked them until they fit snuggly but after a week they were overly tight and I had to make a lever to get the dogs out of some holes. I have never had this issue on my mft3. What is the difference between it and the top I made? The material is MDF looks and feels identical but something isn't the same. Are the CNC machined mft3 tops somehow sealing the sides of the holes? I wonder if rubbing some oil in the holes and burnishing it out and redrilling would eliminate the issue.
.  The factory holes might be a tiny fraction larger than 20mm to facilitate easier removal of 20 mm dogs, jigs and pegs.
Several people who have made dogs and jigs to fit the stock and homemade tops have posted their issues with getting a decent fit but not being so tight that it’s a struggle to remove what ever you put in a top hole.
 
I used clear penetrating epoxy sealer on my MFT and on the bamboo surfaces of my Walko. I was in the process of applying it to an oak threshold for an exterior door, had extra and figured why not use it for those work surfaces. I didn’t worry about it getting into the dog holes either. For the most part you wouldn’t even know it was there but it does a nice job protecting the surfaces. It toughens them up but doesn’t make them slippery at all. Easy to apply and just soaks in without pooling. You would need to really work at it to screw it up.
 
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