Take a router and round the corners of the MDF. One of the other problems (besides absorbing water) with the MDF is that it breaks off sharp corners very, very easily.
I applied odeis oil to mine and even decided to seal the holes because if liquid spills on the surface i see it running into the holes. the first time i use a hole it has to be "broken in" but I have no regrets. Odies oil is tung oil based and after it slowly cures it is great.
If making your own top....seal it prior to drilling the holes...might afford some protection...better than none. Wonder if anyone has made a Perspex or plexi-glass top.....waterproof.....but, how much does the heat and cold affect it expansion wise?
Moisture resistant just means the glue is waterproof- the material still absorbs moisture. And that makes it expand- quite a lot (0.017% per percent relative humidity- 1.7mm on a 1m length for 10% change). And it does not return completely when dry. Any moisture on any part and your table is no longer square. And never will be again. Festool know this- it is why the rail and fence are keyed to the frame, not the top. Want dog holes that stay square? Use birch ply- stronger, better, more resistant. I would still seal it.
"Any moisture on any part and your table is no longer square. And never will be again." Why? There is no grain, so change in dimension will be isotropic. So the dimensional change of a side will be proportional to the length of the side. Therefore the "shape" doesn't change, just the dimensions. And thus the relative spacing of the dog holes also won't change. So why do you claim the dog holes won't remain "square"? Please explain...
@@steveh8724 When the moisture level of MDF increases it expands. When it reduces it contracts- but not by the same amount! Any uneven changes in moisture over the table (and it is very difficult to arrange keeping it even) and the result is a non-linear movement. There are research papers documenting this effect. What we really need is someone with very accurate measuring equipment to plot the changes over time, so that we can put some numbers on this effect. Until we have those, it is interesting to note that Medite (a high quality MDF) quote a stability of 0.3% on linear measurements- that is 3mm per metre. Personally, I have started such measurements on my own table, made from 13 layer furniture grade Baltic ply, using equipment to the sub micron accuracy. We need the same for MDF. There are other issues. Dogs are, in engineering terms, dowels. They are, however, a poor shape for this duty- the diameter is larger than the bearing length, in a material that is not rigid, and has holes that have surface irregularity. I have measured errors of >0.2mm still allowing dog insertion. This is not really an issue for woodworking, but flies in the face of claims made on YT, made, perhaps, without understanding the underlying engineering facts. I repeat, Festool do NOT use the dog holes for referencing cuts- they are for clamping purposes. Perhaps they knew what they were doing?
@@workshopdojo High-density fiberboard. Similar to MDF (in german: mitteldichte Faserplatte). But as name says, probably stronger and more resistant than MDF.
Take a router and round the corners of the MDF. One of the other problems (besides absorbing water) with the MDF is that it breaks off sharp corners very, very easily.
That is the cleanest MFT I have ever seen. It gets treated like a coffe table.
Lol, I know right! I even put plastic over it when I’m gluing up 😂
I applied odeis oil to mine and even decided to seal the holes because if liquid spills on the surface i see it running into the holes. the first time i use a hole it has to be "broken in" but I have no regrets. Odies oil is tung oil based and after it slowly cures it is great.
Thanks for this... I live in Florida, and this will be used in my garage (HIGH humidity). I'm going to need to seal it.
Glad it was helpful!
like your videos, maybe show us some of your work? Thanks for posting
I’m making some videos now
If making your own top....seal it prior to drilling the holes...might afford some protection...better than none.
Wonder if anyone has made a Perspex or plexi-glass top.....waterproof.....but, how much does the heat and cold affect it expansion wise?
That’s a great point
Moisture resistant just means the glue is waterproof- the material still absorbs moisture. And that makes it expand- quite a lot (0.017% per percent relative humidity- 1.7mm on a 1m length for 10% change). And it does not return completely when dry. Any moisture on any part and your table is no longer square. And never will be again. Festool know this- it is why the rail and fence are keyed to the frame, not the top. Want dog holes that stay square? Use birch ply- stronger, better, more resistant. I would still seal it.
Ah, very interesting point Mike.
"Any moisture on any part and your table is no longer square. And never will be again." Why? There is no grain, so change in dimension will be isotropic. So the dimensional change of a side will be proportional to the length of the side. Therefore the "shape" doesn't change, just the dimensions. And thus the relative spacing of the dog holes also won't change. So why do you claim the dog holes won't remain "square"? Please explain...
@@steveh8724 When the moisture level of MDF increases it expands. When it reduces it contracts- but not by the same amount! Any uneven changes in moisture over the table (and it is very difficult to arrange keeping it even) and the result is a non-linear movement. There are research papers documenting this effect. What we really need is someone with very accurate measuring equipment to plot the changes over time, so that we can put some numbers on this effect. Until we have those, it is interesting to note that Medite (a high quality MDF) quote a stability of 0.3% on linear measurements- that is 3mm per metre.
Personally, I have started such measurements on my own table, made from 13 layer furniture grade Baltic ply, using equipment to the sub micron accuracy. We need the same for MDF.
There are other issues. Dogs are, in engineering terms, dowels. They are, however, a poor shape for this duty- the diameter is larger than the bearing length, in a material that is not rigid, and has holes that have surface irregularity. I have measured errors of >0.2mm still allowing dog insertion. This is not really an issue for woodworking, but flies in the face of claims made on YT, made, perhaps, without understanding the underlying engineering facts. I repeat, Festool do NOT use the dog holes for referencing cuts- they are for clamping purposes. Perhaps they knew what they were doing?
Informative. I thought you said you "did paint inside the holes". Then worked out you maybe mumbled?
No I didn’t seal inside the holes
Replace it with Valchromat. Done and done .
Did you seal with this?
Use tricoya board 👍
What is that, explain please? I have not heard of this
@@workshopdojo it's like mdf but rated for outdoor use. 40 year warranty i believe, but it's like 270 euros a sheet where i live
The top is hdf
What’s hdf?
@@workshopdojo High-density fiberboard. Similar to MDF (in german: mitteldichte Faserplatte). But as name says, probably stronger and more resistant than MDF.
Should have listened to you, first day I got it out of my shop to site,client got coffee on it ^^ . Sealed now, bench dogs still work.