# Mixing MDF with other wood?



## JohnnyB60 (Jun 15, 2009)

I had some extra time last night and decided to make a holder for my No4 Smoothing plane. I didn’t want it to turn into a huge project and only want to hang the plane on my pegboard without worrying about it falling off. So I grabbed some scrap pieces and only took of the rough edges to make the glue stronger. 

I had a small piece of MDF that was already the perfect size and all I had to do was cut out the shape of the plane and glue it to a soft piece of pine for my base. I had a small piece of oak that was too short for anything else so I ripped it into thin pieces to hold the plane in place which I thought would be better than the pine to hold the weight without splitting. 

Then after it was done I thought about sealing with it some boiled linseed oil when I remembered having some MDF peal apart after sealing it with linseed oil and thought maybe I made a mistake in using the MDF.










There wasn’t much left of the MDF after cutting out for the plane and it’s pretty much just a spacer, but it does support the oak that actually holds the plane. Now that I think about it, I don’t think the MDF is going to hold up over time and probably fall apart. I guess I could just glue something over the sides to tie the oak to the pine base.

So now this simple thing is turning into a project and I really don’t like repeating projects. Do you think the MDF is going to hold up or should I make another one?


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## Stick486 (Jan 4, 2013)

MDF does not belong in the shop or part of any project...


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## JohnnyB60 (Jun 15, 2009)

Stick486 said:


> MDF does not belong in the shop or part of any project...


I agree and I don’t even know where it came from since I don’t use MDF except for one time to make my table saw sled. I was in a hurry and didn't want to plane down a piece of wood and if I didn't have it sitting there, I would never have used it. I think I kept it to use as a block.


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## Stick486 (Jan 4, 2013)

JohnnyB60 said:


> I agree and I don’t even know where it came from since I don’t use MDF except for one time to make my table saw sled. I was in a hurry and didn't want to plane down a piece of wood and if I didn't have it sitting there, I would never have used it. I think I kept it to use as a block.


Baltic Birch for sleds and jigs...
hard to beat...

how did the plane repair go???


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## JohnnyB60 (Jun 15, 2009)

Stick486 said:


> Baltic Birch for sleds and jigs...
> hard to beat...
> 
> how did the plane repair go???


it worked great! Thanks Stick. The sole was perfectly flat and I don't think the iron has ever been sharper. I did run a file across the chipper edge a little making it nice and tight against the iron.I still need to go through the rest of my planes, but I want to make a new drawer for them and try my hand at dovetailing.


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## PhilBa (Sep 25, 2014)

MDF has it's places. Seal it with a filming finish like polyurethane - BLO seems like a particularly bad choice because it doesn't film. The advantage of MDF is that it is dimensionally stable and mills pretty easily. On the other hand, MDF doesn't wear well, isn't very structural and produces the worse saw-dust of all. I hate, hate, hate the dust from it. I use it for templates that don't need to live long and sacrificial fences. For jigs and such, I prefer BB or maybe a hardwood.


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## cocobolo1 (Dec 31, 2015)

I would think the MDF failed because you shouldn't get the open edge wet at all, otherwise the aforementioned effect is what happens.

Reminds me of that laminate flooring that they sell so cheaply. MDF inside with that diamond hard finish on the top. Get it wet and the joints right away expand and it looks like hell.

BTW, when that happens, don't expect your warranty claim to be honoured. Less than 3% of all laminate flooring failure claims are honoured. If you use it make sure it never gets wet.


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## JohnnyB60 (Jun 15, 2009)

PhilBa said:


> MDF has it's places. Seal it with a filming finish like polyurethane - BLO seems like a particularly bad choice because it doesn't film. The advantage of MDF is that it is dimensionally stable and mills pretty easily. On the other hand, MDF doesn't wear well, isn't very structural and produces the worse saw-dust of all. I hate, hate, hate the dust from it. I use it for templates that don't need to live long and sacrificial fences. For jigs and such, I prefer BB or maybe a hardwood.


Thanks Phil,
I was just looking to see if I can cut out the MDF on my table saw, but I’d have to use a taper jig which it’s too much work and probably unsafe. I did something similar with my dad’s band saw when I was 8 or 9 and cut the tip of my thumb off.

I guess I’m going to attach side panels to tie it together. And use some polyurethane to seal it.


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## JFPNCM (Dec 13, 2009)

Stick486 said:


> MDF does not belong in the shop or part of any project...


Not bad for a cheap shelf.


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## Stick486 (Jan 4, 2013)

JFPNCM said:


> Not bad for a cheap shelf.


if you don't mind it sagging under it's own weight or all the ''stuff'' you have to do to it so it doesn't sag...


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## JohnnyB60 (Jun 15, 2009)

I ended up gluing plywood to each side to tie it all together so the MDF will not split apart.

I'm waiting for the glue to dry now and then I'll sand the edges smooth before sealing it. I learned my lesson and not going to do this again. I may make a better one later when I get all my other projects done.


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## wags999 (Nov 6, 2013)

MDF is an excellent choice for many project, they even make a exterior MDF that is used in outdoor signage. I agree BLO is not the right product to finish MDF, like was said something that has a film will last well and looks good. I have seen many architects offices done completely in MDF for desks, etc, all coated with Poly or Varnished and looked great and held up well. Around the shop I typically will use BB but many plywoods are classic core which is plywood with a thin layer of MDF under the veneer, it will stop telegraphing to the veneer. As with most items there are different qualities of MDF and PB. Nice project !


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## JFPNCM (Dec 13, 2009)

Stick486 said:


> if you don't mind it sagging under it's own weight or all the ''stuff'' you have to do to it so it doesn't sag...


I keep the runs very short as fillers.


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