My MFT has a big zit

[kdzito]

Raw MDF is prone to absorb any moisture due to a humid environment or liquids contact, which will swell the area(s) where it's exposed.     Unfortunately this is one big con of raw MDF.

Besides raw MDF, there are other types and the most appropriate is a Moisture Resistant MDF that resists swelling and repels moisture and then we don't have to worry about trying to seal the top.  Manufacturers of this are Sierra Pine (Medex) and Norbord.  Maybe Festool should consider this as well.    

Seems like a good idea but wouldn't you have to seal the four edges and all the inside walls of every hole where the core would be exposed?

Neill

No, the components of glue and sawdust that make up the MDF panel have different concentration levels since the glue (adhesive) which acts as the binder to hold the sawdust (wood fibers) together has a higher concentrate in Moisture Resistant MDF than used in Regular Grade MDF.  It doesn't matter where the MDF panel is exposed as the glue permeates at the same concentration level throughout it.  Basically the glue acts as the sealer and with a higher concentration of it creates a more resistance to moisture.  To clarify, there isn't a raw MDF, I should of said Regular Grade MDF and there is also Flame Resistant MDF as well.

 

[ForumMFG]

Seems like a good idea but wouldn't you have to seal the four edges and all the inside walls of every hole where the core would be exposed?

Neill

Not really. I didn't on mine. Guess you could but sure seems like it would be overkill.

I'm with Neill. The whole point to sealing it is to keep out mositure and glue.  Mositure can still enter the holes and cause warping.

 

[clev1066]

I put several good coats of Johnson's paste wax on my MFT when it was new, and probably a coat once a month since. Visitors have made the mistake of sitting drinks down on the table since, and never a problem. It also makes it super easy to clean adhesive from the table. I did get a little down each hole, but probably only 1/4" or so. I think it is the cheapest insurance you can get for the surface of your MFT, and can't think of a single reason to not wax it often.

 

[ForumMFG]

The only reason I could think not to put wax on your MFT top would be fear of getting the wax on your work piece some how or just personal preference not to put it on.  You can get wax on your work piece and then not realize it.  When you go to stain it, the stain will not penetrate because the wax is on it.  This is possible.  Has anyone had a problem with that?

-Dave