Does MDF have a grain or is it isotropic?

There's a lot of articles and chat on the internet about MDF being isotropic - i.e. the same physical properties in all directions. This is incorrect. MDF has a grain similar to paper due to the orientation of the wood fibres. In this video I'm chatting about the grain of MDF and why you need to take this grain in to account when designing projects.
TOOLS & PRODUCTS I USE: gosforthhandyman.com/products...
NEWSLETTER: gosforthhandyman.com/newsletter
PATREON: / gosforthhandyman
SHOP: gosforthhandyman.com/shop/
EXTRA STUFF ON THE WEB: gosforthhandyman.com
INSTA: / gosforthhandyman
TWITTER: / gosforthandy
#MDF #Wood #Woodworking

[@xgothicxgirlx94]

Thank you for the demonstration! I work at a hardware store and I got into a fun discussion, okay argument, with a couple of my coworkers about this (specifically in the context of drilling into mdf). The splitting of the boards was finally what helped it click for the group of us.

[@jakematic]

Fascinating, had no idea. Thanks for the demo !

[@GosforthHandyman]

No worries bud! 👍

[@cherryturbojames]

Glad you addressed this. Anyone who has ever tried to screw into mdf on the edge or end will realise that there is a grain / layer structure great video as always

[@GosforthHandyman]

Cheers bud! 👍👍

[@Teguvas]

Simple answer. It's comppressed in stages till it reaches it's final thickness. This creates different densities between the faces, the least dense is midway. The faces have the highest density so much hardet to split. Try taking a sheet of 25mm thick, take 8mm off each face, then make it 9mm wide, try splitting it then.

[@ventilara]

Hi Andy. going a bit of track but do you think you could edge mdf shelves with a thin strip of mdf rotated 90 deg to replace timber edging

[@GosforthHandyman]

You can do! Sometimes do this on projects - e.g. random alcoves shelves vid on this channel has MDF edge trims. 👍

[@ardemus]

Imagine dumping thousands of pencils on the floor then dropping and anvil on them. You get all manner of fiber orientation when you drop them, and few of the fibers are vertical. When compressed, the fibers won't compress lengthwise, like springs. Press on the tips of a pencil, is it going to get shorter? They'll pivot away from the axis of compression or break and the pieces will fold or rotate, again pivoting away from the axis of compression.

[@GosforthHandyman]

Yup - good analogy! 👍

[@jwheeler91]

Yes the pre-compression will likely align the fibres (along the conveyor).

[@richardhart3847]

Oh and great bids keep them coming.

[@GosforthHandyman]

Cheers bud! 👍

[@peterratcliffe5115]

Absolutely smooshing video

[@cjhification]

Good video, and much as I thought. Layers of fibres are created due to compressive forces. From the axial force of the rollers acting on the board as it passes through and would cause the fibres to orientat them selves perpendicular to that force. Even if it was still damp I don't think there would be enough moisture to cause the fibres to float and I don't think the blowing would cause the orientation you mentioned as it would then fall down on to the belt. Still enjoying your video and glad that the algorithm introduce your channel to me. Not in a position to do patrion at present as my wife's just been retired due to ill health but if I can get a promotion I'll certainly consider it as I like supporting British creators, making UK oriented content. I do make sure to watch the full adds on channels I like, where they are present, as it seems the lead I can do.

[@GosforthHandyman]

Thanks for the kind words Craig! 👍

[@Badgerworkshop]

Very interesting. If you ever want to give up woodwork you can always become an artist. I have heard a lot of very experienced people talking about ply sheets being stronger in one direction. I have always thought the veneers are layered in alternative directions, making it equally strong either away. Just thought this might be another interesting video you could do.

[@GosforthHandyman]

Lol - I should put my illegible scrawls in a gallery! 😂 Ply - I think since there's normally an odd number of layers you'll have more grain running in one direction than another. Although the layers are so thin I can't see how it would make that much difference. 👍

[@k.b.woodworker3250]

Plywood is "better" in one direction than the other because it has an odd number of plies. However, it still works in both directions better than wood.

[@konstantingeorgiev7668]

When using ply the orientation of the top layer has a huge impact on overall strength. So always orient ply as you would orient wood.

[@Badgerworkshop]

@@konstantingeorgiev7668 Thank you, very useful

[@richardhart3847]

Hi Andy. I reckon it's to do with the roller compression that create layers, the MDF is compressed from top to bottom and not along the sides. if you cut a couple of MDF squares you can split the MDF along all four edges. But you can't against the faces where the rollers have acted on.

[@GosforthHandyman]

Possibly! 👍

[@mururoa7024]

Yes this is correct. The compression forces a lot of the fibers to lay down as they rearrange themselves to take up less space.

[@johnball4983]

Richard Hart I'm thinking its 'layers' compressed together and not grain- as we know it...?

[@mog-gyveroneill2500]

Absolutely, the compression rollers elongate the fibres forward

[@mog-gyveroneill2500]

Absolutely to do with the compression rollers elongating the fibres forward

[@RJ_Taylor]

Andy Mac's process diagram is the most excellent carpenter's triangle anybody has ever seen!

[@kookyflukes9749]

Do you use a adhesive grab in a hole to stop the wood splitting?

[@GosforthHandyman]

Shouldn't be needed of it's piloted - normally the joint is glued anyway so should be fine. 👍

[@johnthompson3462]

I would go with a mix.I would think they would have to at least damp to compress and stay together. Very interesting vid

[@GosforthHandyman]

Yeah, not sure. You can get compression of dry powders in to a solid - e.g. tablets - no idea if that's what happens here. 😀

[@benchippy8039]

I KZbind mdf smoosher but can’t find anything, where did you learn of this tree smoosher?!

[@GosforthHandyman]

Sure I've seen it somewhere. 😂

[@handyjim]

I seem to remember something about a branding iron you had made am i right, if so can you give me a link to whoever made it thank's

[@GosforthHandyman]

Here you go: gosforthhandyman.com/uk-links/branding-stamp-brass 👍

[@sweenep86]

it’s not a grain, ie visible fissures from growing, mdf delaminates across the direction it was pressed in. The reason it delaminates is because it’s strong in compressed form due to the density of the compacted material, but has no tensile strength because it’s composition is essentially just glue with fibres. A wedge driven into it will exceed the glues strength, hence it splits.

[@GosforthHandyman]

Grain in the same way paper has grain. 👍

[@WoodworkingBrewer]

Just watched Sarawak (how mdf is manufactured) it’s interesting.

[@makermark4]

I call them layers, not grain

[@mururoa7024]

yes, you can find mdf factory footage here on KZbin showing how it's made.

[@GosforthHandyman]

I would describe ply as layers... and possibly OSB. I wouldn't refer to MDF as being made in layers though. 👍

[@makermark4]

Gosforth Handyman didn’t mean made is layers, just splits in layers

[@itwillbenicewhenitsfinished]

Great video, thank you. So how do you make an mdf box? wont two sides be ok and the other 2 split when screwed (assuming a 4 sided box with no top or bottom)?

[@GosforthHandyman]

Pilot hole the screws or use something else like biscuits / domino. 👍

[@itwillbenicewhenitsfinished]

Thanks for replying Andy, I really appreciate it. What ratio of pilot diameter to screw? What can it take before it splits? Best wishes. Keep up the good work

[@wotyacollit]

@@itwillbenicewhenitsfinished use a 3/8th bit and stay at least 2 inches away from the end of the piece whose edge you are screwing into.

[@davegower123]

I vote for #4! They align during compression... But that's just a guess. Cheers!

[@GosforthHandyman]

Could be! I think they're aligned before compression but the compression probably makes them even more aligned. 👍

[@NomenNescio99]

Yeah, it's semantics, but I probably wouldn't call it grain, but you are absolutely correct. You probably will be better off drilling a pilot hole if you want to drive in a screw in the end or side "grain", but you can skip the pilot hole without splitting the board if you do put your screw in the face grain. The pull out force for a screw will also be very different depending on if you go along or perpendicular to the grain. Mdf is practical and useful, but I don't fancy the dust from working with mdf that much.

[@GosforthHandyman]

Folk refer to the grain in the same way paper has a grain to it. 👍

[@NomenNescio99]

@@GosforthHandyman English isn't my native language, with my current vocabulary I only think about wood when I hear "grain". But after some googling and contemplation I can't find another word that would better describe what you talk about. So grain shall be thy name - you miniscule layers of fibers in mdf boards. BTW, You don't have any hints or good advice on how to cut ceiling cornice for a sloping ceiling, I've had a lesson in humility tonight as I just can't seem to find the correct compound angles.

[@gbww]

Could it be that the rollers will compress the fibres top and bottom more (through being in contact), so the interior fibres are just layered up and not compressed quite so much?

[@GosforthHandyman]

Don't think so - seems to be similar fibre orientation throughout. 👍

[@gbww]

@@GosforthHandyman true, perhaps a combination of the fibres being blown onto a laterally moving conveyor (I forget which option that was!), with the rollers then compressing the outer surfaces into a more 'solid' composition? I'm not letting go of this rollers theory 😂 but do feel like the outer edges must end up 'different' due to that being where the pressure is applied - doesn't explain the orientation mind you... I think I'm having a debate with myself here... 🤣

[@stephenshipley1066]

I don't know how MDF is made but what you draw (ignoring the resin) is a pretty good picture of a paper mill. Off to the right would be a long series of over and under heated rollers to complete the drying process A few things to point out: 1: that belt is moving at a VERY high speed 2: we are talking about wood fibres (not amorphous dust) so they are like tiny pine needles 3: they go on to the belt in a very dilute mush and the water falls through the mesh of the belt Hence the high speed of the belt orients the (long, not shapeless) wood fibres in what is known as the "machine direction" as they begin a long drying process. You can see this for yourself by taking a decent paper and just tearing it freehand. One way it will tear neatly because you are tearing along the "grain" i.e. between the fibres: the other way it will be jagged as you tear across the "grain". Don't try this with newspaper which is the paper equivalent of the lowest quality of OSB. A sheet of A4 from your printer should do. I think that MDF is made up of many thin layers made something like paper. These layers are then pressed together to achieve the desired thickness. I don't know when the resin is incorporated. What you call a grain is what I would call laminations i.e. layers. MDF is behaving more like plywood (which effectively has no grain because the grain in each layer is laid at a 90 degree offset) but plywood does have layers and your screwdriver experiment would probably go much the same if you did it with plywood. So I would say that: a) wood and paper have a grain b) MDF and plywood have laminations But whatever you call it MDF is not like a block of plastic and it behaves differently between the layers as opposed to across the layers. And we need to be aware of this. Sorry, but you did ask ;-) PS in case you are wondering, in the early 70s, I spent a week at a paper mill (Alders of Tamworth) as part of an industrial training program. PPS that was the first time I saw a cyclone - with the paper mush going through it to remove any grot (technical term, obviously).

[@GosforthHandyman]

Close - very similar to what you're saying but MDF isn't made of thin layers pressed together. The fibres are rolled together in one continuous process - so very similar to paper production to be honest. 👍

[@stephenshipley1066]

I think the pencil-anvil comment below is the best.

[@Method_MOK]

I can hardly believe you spent this much time 12+ minutes talking about this ... and further that I sat here and watched it. Thanks for the close look - have fun!

[@GosforthHandyman]

Welcome to the channel! 👍

[@altronixvideo]

So what about chip board? That doesn't have the same layering, but seems like it would be made in the same way, but just have larger bits.

[@GosforthHandyman]

Not sure to be honest! Will try to find out for a future vid. 👍

[@SteveHit1]

Another excellent video, thanks. Maybe you could visit the Egger factory at Hexham and show us the real MDF fabrication process?

[@GosforthHandyman]

Tried but they don't want to be filmed! 😂😂

[@cjhification]

Before watching the video I'd say it has layers due to the construction technique of compression, which causes the layering but I personally wouldn't call it a grain as it's not differing density rings like you would find with a wood grain. However as short hand for, if you drive in to the edge it will split apart then yes I agree it has a "grain". Now to watch the video and see what you've got to say.

[@GosforthHandyman]

Pretty much what you said! 👍😀

[@k.b.woodworker3250]

What I'd like to know is what is the better grade of mdf that is often talked about when making benchtops with dogholes, like the MFT? I've never seen any other than standard grade here in the U.S. Perhaps in Europe it is more available in grades.

[@Smithb83]

We have MRMDF - moisture resistant MDF which is better quality, it's about £10 more per sheet I believe. Not personally used it yet. I understand that when cut it doesn't go so "fluffy" at the edges. Someone with more experience with it may be able to expand 👍

[@davidfarnall3211]

As Barrie Smith says, here in the UK we have MRMDF, which is a denser, heavier product with different resin binders. It's a much better material to work with than standard stuff, but tougher on tools and you really, really want to have good dust control to avoid getting it into your lungs. We also have a number of different manufacturers and this gives us different qualities of "regular" MDF, most obviously seen between DIY sheds (cheap and often horrible) and good timber (or for you in the States, lumber 😀) merchants who care for their customers and supply quality materials.

[@barrieheard9426]

Axminster tools have hdf mft tops.

[@k.b.woodworker3250]

Thanks, Barrie and David. At least I'll know what to look for if I ever see it. I guess I can use a coating like wax or shellac to improve the stuff that is standard here.

[@neilstevens1206]

We have MRMDF (moisture resistant) which is green in colour, FRMDF (fire retardant) which is red. There is also ECO friendly or ZFMDF (zero formaldehyde). All of these are a little harsher on your tooling than standard MDF

[@CementRoots]

I believe the panels are layered and built up like how an old powder/ resin 3D printer works.... so its a fine layer after layer until the final thickness achieved and compressed.... its not like laying concrete where the material is dumped in all at once....

[@GosforthHandyman]

Pretty sure it's dumped in all at once then compressed several times. 👍

[@grampacross7386]

I'm thinking that it's vibrated during the process for compaction.

[@GosforthHandyman]

Very possibly! 👍

[@steveng5503]

I agree. MDF offcuts also makes excellent kindling. When split along the grain, it burns like hell. Very easily lit with a naked 🔥, preferably and old one who’s lost your phone number 😆. As always Andy, a BIG 👍 from me. Looking forward to the next video, KZbin politics permitting?

[@GosforthHandyman]

Ha ha - cheers Steven! I don't think it's very safe burning MDF so take care! 👍😀

[@konstantingeorgiev7668]

MDF is made from wood fibers. The fibers get separated from each other and mixed with thermosetting resin (usually based on formaldehyde). The whole mass looks like paste. Then it gets spread out on conveyor belts and pre-cut with water jet. The actual compression happens on a press and not on a roller. During this process the resin sets and any excess water evaporates. Because of that you end up with a material that has layers - MDF will be less dense in the middle and the density will increase in the direction of the faces. This gradient will increase with thickness. The same applies to particle board as well. HDF on the other hand doesn't require resin to bond the fibers - it is manufactured at a much higher pressure, which causes the fibers to bond.

[@alanmullock381]

Tis the work of the devil Andy!🤣🤣🤣🤣🤣🤣🤣👍👍👍👍👍👍👍👍

[@GosforthHandyman]

Ha ha - the dust is a nightmare. 👍

[@mururoa7024]

MDF doesn't use "saw dust". The wood fibers are chemically separated from each other to remove all the wood resins. They're not cut from each other, which is why they're long.

[@GosforthHandyman]

Er... did I say it uses saw dust?? Don't think I did. 😂👍

[@mururoa7024]

Well, 7:21 was probably just a slip of the tongue. ;)

[@gnic76]

This is a video link on how MDF (courser office grade stuff) is made. kzbin.info/www/bejne/qpK4Y42IrMmcfrc When people talk about "grain" direction I think most are referring to grain direction like plywood has. It is stronger along the length of the sheet as opposed to the width. MDF doesn't have that, so cutting parts out is more about what gives you the least amount of waste. I think the edge grain is due to how the raw material and fillers are compressed. Interesting vid showing how easy it splits apart on the edge. Thanks.

[@StamosTee]

Interesting.I would call it layers, not grains although.

[@GosforthHandyman]

Does paper have a grain?

[@ProfessorDIY]

MDF DOES NOT have grain. The argument is silly, grain is caused by growth which clearly does not apply to MDF. It has layers because it is compressed. Thanks for the video.

[@GosforthHandyman]

Does paper have a grain?

[@toddstrope157]

I also have difficulty with using the term “grain” with MDF. Using the term “grain” as a loose explanation of the properties of MDF being demonstrated in the video seems a bit of a stretch, but not necessarily improper. I suspect the process of rolling to thickness causes a tempering of the face surfaces of the MDF, with the interior being left untempered or softer. With splittable woods such as oak or hickory, you can split three quarter material multiple times along the grain to get sub-quarter thick planks without much waste. Three quarter, or 18mm MDF on the other hand, was demonstrated to split once. So I would propose that wood has a very fine multiple grains if “grain” is to be defined as alternating layers of hard and soft layers of fibers, and MDF has essentially two grains with 2 outer hard and one soft inner layers of fibers. Is that a reasonable way to reconcile opinions?

[@williba24]

Nip off to Hexham and see how it is made.

[@GosforthHandyman]

Tried - they don't want to be filmed - too secret obviously! 😂

[@elsmorian]

Did you leave your laser level on @1:30 😉

[@GosforthHandyman]

The green thing in the background? It's a flashy USB cable. 👍😀

[@elsmorian]

Ahhh!

[@andrewholdaway813]

Maybe this:- fennerschool-associated.anu.edu.au/fpt/mdf/manufacture.html Could explain the apparent grain in mdf, it seems to be saying that the boards are compressed in such a way as to ensure that the faces are denser than the core. Maybe what we are seeing is the different density layers separating.

[@GosforthHandyman]

Very possibly! 👍

[@apex007]

I didn't see the guy with the hair dryer: kzbin.info/www/bejne/kIOoYn9tltOiqdU

[@GosforthHandyman]

Hiding 'round the back. 👍

[@meangreen7389]

MDF is the glorified name of simple particle board. PB/MDF has bonding agents; one is formaldehyde. Not a of fan of PB ladened with formaldehyde for long term exposure in workshop settings.

[@GosforthHandyman]

Isn't particleboard the same as chipboard (in the UK)? If so, much bigger chips than MDF... but yes, both often use formaldehyde in the production process. Same with plywood, OSB and most composite materials. 👍

[@meangreen7389]

Gosforth Handyman - Your are correct. But now a days, formaldehyde emissions are so low in plywood products that plywood products are exempt from formaldehyde emission regulations in Europe and in the United States.

[@rimmersbryggeri]

Naah it's a general fibre orientation but since it's not a continuous fibre its not an actual grain.

[@GosforthHandyman]

Wood grain isn't a continuous fibre though, is it?

[@rimmersbryggeri]

@@GosforthHandyman The long grains are quite alot longer fibres than you would see in mdf or even osb. Butif you think abot it voow is fibres held together by lignin so I think its pretty much a continuous fibre so that it can carry water all the way up by capilary action. Have you ever made a withy?

[@GosforthHandyman]

No never made one! 👍

[@rimmersbryggeri]

@@GosforthHandyman But being from the north you would certainly have eaten rhubarb. It has quite long fibres in the same way as wood.

[@TheStrongwomans]

Next video osb

[@GosforthHandyman]

Ha - very rarely use it but think there some vid on YT about it! 👍

[@markrowland5393]

Apparently, OSB is relatively waterproof certainly compared to MDF. I had thought that OSB was a sketchy, cheap material but I have been put straight on that recently.

[@jsfaulds]

It's not a grain it's a layer

[@JimAckroyd]

You're right, layers of grain.. lol

[@GosforthHandyman]

Grain as in how paper has a grain. It's not made in layers.

[@jsfaulds]

OK If the fibers don't settle in layers try and split a piece of 18mm diagonally. Good luck

[@GosforthHandyman]

Yes it splits in layers but it's not *made* in layers. Plywood is made in layers. 👍

[@mickfaragher7897]

I thought pixies made MDF🤔

[@GosforthHandyman]

Made of pixie dust. 👍

[@animationcreations42]

Next video: Is MDF actually wood?

[@GosforthHandyman]

My god - can you imagine the comments on that? 😂

[@animationcreations42]

@@GosforthHandyman imagine all the engagement though!

[@dandive4719]

It's layers of fibres not grain.

[@GosforthHandyman]

Does paper have a grain?

[@handyjim]

you'll have to watch how it's made

[@GosforthHandyman]

There's a couple of good how it's made episodes on MDF but doesn't go much in to the detail. Still interesting though! 👍

[@SirBenJamin_]

Don't listen to this nonsense. It's not a man stood there with a hairdryer. That's ridiculous. It's probably at least TWO men. Else it would take all day. 👍

[@GosforthHandyman]

Powerful hairdryer. Much more powerful than the one I use. 👍