I recently tested MDF versus plywood in
10 different ways
but some of you didn't like how I did
the water testing and so today I'm going
to address that I've also got 600 pounds
of cement and a flamethrower you're
gonna see what happens you know there
were a lot of great comments on that
first video but the ones around the
water some of them really stung inside
and I think that can sum them up with
this one here you totally missed the
mark with the wet ability of MDF
plywood will dry out and not be ruined
like swelled up flaking MDF and there
are a bunch of comments that were all
similar to that that after MDF is wet
that it does not go back to the same
shape and is basically ruined whereas
plywood when it dries out is just fine
so we're going to test that today here's
how the first test is gonna go I got my
three samples MDF Maple plywood with a
poplar core and radiata pine I also have
samples that I have finished with two
coats of total boat Halcyon clear now
you'll also notice some measurements on
these and that is the thickness of each
of these pieces of wood when they were
dry and you know we're gonna make this
scientific I've got 12 ounces of water
in each of these mason jars and at the
last minute I thought why not put some
food coloring in there so maybe we can
see the capillary action so here we go
all right I'm just going to put these in
here and hopefully this doesn't overflow
on my bench
I'm going to come back in an hour and
we'll get our first measurements now the
other big issue you guys had with the
water test was that I didn't test the
strength of the MDF after it had gotten
wet and a lot of people said once it
gets wet it just breaks down the glue
bonds of the MDF and when it dries out
it is completely useless so to test this
out I've got the same rig that I used
the last time and it's just basically a
mock-up of a 30 inch cabinet and I've
got a radiata pine shelf and an MDF
shelf and so I just load them in there
and then put 80 pounds of weight on them
and see how much it deflects but this
time it's gonna be a little bit easier
to see because I got a little piece of
acrylic and attached it to a wooden
block because you need very scientific
and accurate measuring devices and then
I Mark the Baseline of where the Shelf
sat with no weight on it and then I
added in the 80 pounds and marked it
again to see how much it deflected and
so if I put the ruler behind here we can
see that the radiata pine in red
deflected just under an eighth of an
inch and the MDF over here in the blue
deflected just over an eighth of an inch
and that's exactly what we found the
first time but now we got to expose
these to water and figure out what
happens for the water exposure on these
not going to totally submerge it in
water because I just don't think that's
real world but what might be real world
is pink towels uh getting this with
water putting it on top and making sure
that I have a constant source of water
on the top of it maybe like in the rain
or if you had a wet towel that you threw
on top of some plywood not really sure
why you do that but maybe you did so I'm
going to soak these in water let them
sit overnight
all right this thing is completely
saturated now all the water is running
off here and I'm just going to set this
to the side I will come back before I go
to bed to make sure it is still wet and
then that way we'll have full exposure
for the 24 hours of course I'll do the
MDF the same way and put it to the side
all right and come back tomorrow
art has been just over an hour since I
dipped these in the Kool-Aid let's see
what they're looking like all right
looking at these dry ones first you can
see the two plywoods have really soaked
up the water whereas the MDF uh it's
coming up a little bit but just barely
over the water line now looking at the
ones with the total Boat House yawn on
it you can see they're faring much
better it's not coming up the side at
all and then the MDF is looking oh wow
look at that it's barely even soaking
into the face at all on this front part
I'm not going to go into the Gory
details right now but here are a few
interesting observations that I've seen
so far and on the MDF it is soaking way
more up at the bottom than it is at the
top and it's just really mushrooming out
and that's because of those open fibers
I'm sure at the bottom and the
unfinished radiata Pine is already
starting to fall apart and Flake this is
kind of weird it just expanded and I
don't think this is going to fare very
well after another 23 hours pretty
interesting stuff I'm gonna put these
back in the jars we'll come back
tomorrow and see how they turned out I
think some of these are going to be a
complete disaster while we're waiting
for the water to destroy some MDF I
wanted to do some extreme weight testing
and for that I got the original rig and
I put some gussets on it and I put them
on there with glue some Me nails and
even some screws for some extra support
and if strength is measured by the
amount of glue squeeze out this thing
should be a hoss so I've got my 600
pounds of concrete and yes I know it's
concrete and not cement so for everybody
who I've already commented
you can go ahead and go change that too
Brad thank you very much for your time
and effort so I started off with
shelf that had the hardwood Edge banding
on the front because that was the
strongest one from the last one and as I
started loading these bags on there
they're 50 pounds apiece and stacked it
up all the way to 300 pounds now 300
pounds there's about 3 16 of an inch
deflection on that and I started hearing
some creaking in The Jig in the setup
but six bags was about as high as I
wanted to go and so I took those off and
then moved over to the radiato but it
was fine at the 200 and the 250 but as I
got to the 300 pounds this happened
oh gosh
and so if you're thinking about using
300 pounds on shelf pins maybe don't so
take the jig out of the bench and I
reinforced it with some solid wood
cleats and that should hold at least
enough for the shelves to break before
they do now there's one other thing that
I also had to fix other than the jig and
by the way ah the label now is right
side up that was really bothering me
before when I started loading it up and
it took the 300 pounds just fine even
though it was sagging quite a bit now I
went back to the MDF with the hardwood
front and I took it all the way up to
600 pounds and it was deflecting 5 16 of
an inch but it was really pretty strong
I removed everything put the radiata
pine in and amazingly that one made it
to 600 pounds as well although it did
have a full three-quarter inch
deflection on it then it was time for
the MDF and I put it in there and I was
really uncertain as I started stacking
it up and getting to 400 and 500 pounds
it was sagging like crazy so I added
those the last few bags on there
and to my amazement it did not snap it
held to 600 pounds even though it
deflected 7 8 of an inch at that point I
wanted to add some more weight and I
started having some pretty bad ideas I
kind of want to just make it fail I've
got those two dumbbells but I also kind
of don't want to destroy all my cameras
where'd those things go they're over
here
this is a bad idea I should not do this
yeah we're not doing that I was pretty
disappointed that I wasn't able to make
it snap and I'm sure you are too so I'm
gonna go back to the store pick up
another 400 pounds of concrete and then
we're gonna come back and either this
thing's gonna hold a thousand pounds or
it's gonna snap but I gotta go get it so
we'll do that later in the video and for
all you data lovers and nerds like me
here is a chart of the weight and the
deflections per shelf so you can see how
it progressed across there and the
biggest takeaway for me was just how
strong that MDF with the hardwood Edge
banding was it performed three times
better than the MDF at the 600 pound
weight and usually over twice as good as
the radiata Pine so if you're gonna be
making a shelf using MDF with hardwood
Edge banding is a great way to go all
right we're back to the Kool-Aid test
and it's actually been maybe 26 or 27
hours and uh
I can already tell the MDF has not fared
well right off the bat after drying them
off and measuring them you can tell a
huge difference between the unfinished
and the finished you can see how much
more of that red dye that it really
soaked in especially on the MDF that
face of it of the one with the Halcyon
is still Brown versus the Deep Red over
here of the MDF same on the radiata much
less on the finished and then a lot here
and then the maple actually held up
really well with just the finish on it
you can also see on the finished one it
really held back the water running up
the sides as well now I only put two
coats of finish on these and I know I
didn't hit every little nook and cranny
so if that film finish is not perfect
water is much like life and Jeff
Goldblum has told us that life
finds a way the other big takeaway was
just how much the MDF sucked up you can
see this is just a mushroomed up it is
just huge so lots and lots of water in
there we're just gonna have to see what
happens when it dries if it reduces down
or not all right now I've got the
shelves also and these things stayed
nice and wet
oh yeah so taking a quick look at these
kind of interesting you can see exactly
where the water is on the MDF but on the
radiata is definitely spread out and
that's consistent with what we saw on
the other test the MDF is definitely a
raised up and I can tell it has gained a
little bit of water but not that much
and it did not go all the way through so
that total penetration has not been
there and I think part of that is just
because the face of MDF is more
resistant to water absorption than the
edges but the radio out of pine man look
at the bow on that it really has warped
which is what happens a lot with plywood
whereas MDF swells and it's also soaked
in a lot more on the edges on this one
than the MDF but those are just general
observations what we really want to know
is the strength so I'm going to let
these dry out and then we will put some
weight on them and see if they deflect
more than when they started all right so
we've tested these against water and
weight but what about heat I mean this
is a torture test right so I've got an
iron here I'm going to crank this thing
up and then we're going to start putting
it on these samples and see what happens
I did some testing on these and I put
the iron down for one minute on one side
and then five minutes on the other side
on each of these to see what it would
look like and here's what I found now
after one minute the two plywoods had
barely any discoloration at all you can
just kind of tell where it was now the
MDF on the other hand definitely had
discoloration where you can see exactly
where that iron was the five minute Mark
things got a little interesting on the
maple plywood you can obviously see
exactly where the iron was but what's
happened is the veneer is kind of
bubbled up all around that heat so that
heat got into that thin veneer glue and
has definitely messed with it now the
radiata pine is nice and smooth because
it has that thick veneer but you can
definitely obviously see the
discoloration and some of the charring
and burning now on the MDF it is also
nice and smooth but obviously it is just
a very much more pronounced and when I
pulled it up I did get a little bit of
smoking oh
oh gosh I love the smell of burnt MDF in
the morning now I wouldn't advise
exposing any of these to heat but you're
going to get some pretty immediate
discoloration on the MDF and on the
plywoods that can hold up for some short
term but on the long term especially on
the thin veneer plywood you're going to
have an issue because those veneers are
going to start separating and I would
say that the radiatopine held up the
best out of all of them but this is a
torture test and uh I think we need
something stronger
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foreign
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I was having a lot of fun out there with
that flamethrower I feel like Colin
Furr's out there or something I was
actually a little surprised that these
things just didn't burst into flames and
uh when I stopped hitting them with the
fire they pretty much went out but they
are just all charred up and uh
especially the maple that thin veneer
it's all just peeling up and crispy and
we've kind of got the crocodile skin on
the radio out of pine going on and then
the MDF looks like the Great Salt Flats
this is kind of like modern art over
here but that was all just for fun do
not mix flame in Wood all right we are
back to the water test and I let these
dry under a heavy fan fan wasn't heavy
but the wind was heavy for 24 hours and
there's some really interesting results
so let's start with the MDF and exactly
what you guys said would happen did
happen uh it expanded and then when it
dried it really didn't go back to that
shape and there's nice and Flaky you can
see some voids that have actually formed
in there so I would absolutely say that
this is completely unusable now the
other hand the plywood didn't really
deform a whole lot and really the maple
plywood held up really well it didn't
separate at all the radiata pine did
have that part that started coming off
and it's got a huge warp to it now a
great way to think about it is MDF is
like a sponge it's going to soak up a
ton of water but it's not going to
really travel very far along the
material whereas plywood is more like a
straw because the water will go through
the fibers and it will really run down
and it can ruin a lot more of your
product than it would with the MDF and
to recap everything I have my TPS
reports available let's check out a
chart from them did you see the memo
about this so I've got all the samples
listed out here and how much they grew
in percent so that it's nice and Level
Playing Field and you can see that the
plywoods they took up only about four to
six percent after that one hour and 24
hours in the water and after they dried
it actually came back down to just under
where it was at an hour in the water so
it's definitely still going to be a
little bit deformed but not nearly as
much as the MDF now the MDF soaked up
that red water just like the Kool-Aid
man it just got swole oh yeah yeah you
can see the finished ones didn't reduce
quite as much as the unfinished and
that's basically because they have a
film finish holding that water in the
same way it holds it out and that
finished MDF just kept growing and got
all the way up to 30 percent so you guys
were absolutely right that MDF is going
to expand and then it's going to kind of
stay that same size whereas plywood is
pretty close to what it was before it
got wet that's when they've been fully
submerged so let's take a look at the
shelves and see what happens when the
water's on the surface all right the
shells are dry and the MDF you can see
the water exposure here and it's rough
and it's a little bit raised but not
anything like it was when you had it
fully submerged and I think again that's
because of the face of the MDF resists
water pretty well and so this did not
really swell up and there's no
separation in the sides now on the radio
out of pine you can't really tell much
difference although there is some
staining here and there the biggest
thing with this one it is just really
warped and we'll probably see that when
we put it in the test jig now sure
enough that radiator board was bowed
higher than before and when I put it in
the rig and marked it on the acrylic it
was actually about a sixteenth of an
inch of a bow higher but oddly enough
that apparently made it stronger and it
resisted the weight more and only
deflected around a sixteenth of an inch
versus closer to an eighth of an inch
before it got wet on the other hand the
MDF actually sagged down a little bit
about a sixteenth of an inch but
surprisingly it deflected right about
the same they were both about 3 16 of an
inch before being wet and then after
being wet so you're probably okay if you
just have some surface water on MDF as
long as it doesn't get in there and you
can really see that it's expanded and
kind of broken down those bonds inside
all right guys this is the last chance
to break some MDF so I've got a much
longer board this one is 48 inches and I
also ripped up the old test rig and made
it into some little makeshift stands so
I've got a thousand pounds of concrete
let's put it on here and see if we can
get it to snap I guess before I start
throwing the concrete on here I should
stand on this and
see if it breaks hopefully it doesn't
that would be anti-climactic wouldn't it
I think this test rig should be fine I'm
gonna Mark the center of this
look at that I nailed it
well I'm loading this up a big thank you
to all of the folks joining the ftbp
builders Club
all right here's 200 pounds wow this is
sagging horribly more if we're not going
to get anywhere close to a thousand
pounds all right so this is
250
all right 300 pounds 350.
my gosh
here we go 400 pounds
I do not know if this is going to snap
all right 450.
[Laughter]
oh my gosh that scared the crap out of
me all right guys we did it and uh I'll
show you that here in slow motion in
just a second but if you want to check
out some other MDF versus pilot videos
you can check them out right there and
uh I'm gonna go change my shorts
foreign
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