Working with MDF?

[srjdsmith]

I have not done much with MDF, so I have some questions.

1) Can you run MDF through a thickness planer? (DeWalt 735x) Should I use something like Minwax Hardener before or after planing?

2) If it can be planed (3/4” down to 1/2”) does it need a base under? Like a 1x8 or 2x8?

 

[rancherbill]

I wouldn't do it because it would make a lot of dust.

I don't know if it would produce a nice finish. MDF is smooth, but, I think that's a result of the manufacturing process.

 

[Voi]

Did a bookshelf project several years ago where veneered MDF had to be planed down to the thickness of a hardwood banding instead of vice versa.

We used a thickness sander and not a planer and it worked well. No idea how a planer would work. The sanded side was hidden but finished with conversion varnish. Help up well for years. No hardener was used, before or after.

We did not remove anywhere near as much material as what you're considering. We removed the veneer plus another very small amount of material.

I doubt this helps but thought I would post it anyways.

 

[bonneyman]

Wear a mask! That MDF stuff shoots powder everywhere when you saw it.

Sawdust is one thing, MDF dust is the next level. That stuff is insidious!

 

[srjdsmith]

…but it gives me courage to try it. WITH dust collection. I would think hardener would stabilize afterward like the varnish you used.

 

[mike93lx]

I would do everything in my power to not run mdf through a planer. I bet it trashes your knives, plus it will make a hell of a mess

 

[larry4406]

I’ve used routers on MDF to make eased edges for cabinet doors. Machined nicely.

Agree with the others on the dust!

 

[steel 35]

I’ve used routers on MDF Machined nicely.

Agree with the others on the dust!

“

 

[dnschmidt]

Unless you have carbide blades you will be SORRY. If you ran steel through your thickness planer it probably wouldn't be any worse. The reason you can use router bits is that they are all carbide tipped. No carbide - no good. The Urea glue used to bond MDF together will quickly destroy any steel blades. And, why the hell would you plane 3/4" MDF down to 1/2" when 1/2" MDF is cheap and readily available. Also the beautiful smooth surface of MDF is only skin deep. Once the skin is gone you've got what amounts to a sponge. IN SHORT THIS IS A REALLY BAD IDEA.

 

[Voi]

I’ve used routers on MDF to make eased edges for cabinet doors. Machined nicely.

Agree with the others on the dust!

A router sled might be one way of doing this to avoid damage to planer knives. Then maybe just some thin passes through the planer to make things perfect.

I wouldn't want to do a lot of it, however.

 

[srjdsmith]

I need to have a surfacing setup for router anyway because I have some lumber more than 13” wide that needs to be surfaced- or even thickness adjusted. Any idea who has a good plan for a router sled? Or do I just design one based on my router?

 

[Voi]

I do not have a router sled nor have I built one.

However, from watching a few YouTube videos on them it seems they can be quite simple to achieve good results.

Practicing on MDF which is already flat on one side might be a good place to learn before trying it on lumber.

Outdoors with a powerful fan would be my preference.

 

[K13]

Why wouldn't you just buy 1/2" MDF?

 

[ddawg16]

What are you trying to do with it?
The stuff is messy

 

[billconner]

Why wouldn't you just buy 1/2" MDF?

yeah?

 

[steel 35]

I need to have a surfacing setup for router anyway because I have some lumber more than 13” wide that needs to be surfaced- or even thickness adjusted. Any idea who has a good plan for a router sled? Or do I just design one based on my router?

If you can’t find one think angle iron & skate board bearing, for on the cheap.

 

[Jayman17]

Why wouldn't you just buy 1/2" MDF?

Beat me to it.

 

[srjdsmith]

1) couldn’t find 1/2”
2) had to buy a 4x4 handi panel and only need about about 1/3 of it for the project, so trying to find a use for the rest
3) Stumpy Nubs makes disks for the WorkSharp 3000 out of 1/2” MDF. 3/4” might work, but they’ll be a lot heavier to spin (I don’t have the machine yet, just getting ready by building the work station and getting some accessories)
4) I don’t really care about the knives- I’m about to change them anyway. Only one surface gets any use and I can orient the factory surface toward the good side. I’m not really up for making a total mess with the dust- I just thought I could use what I have.

 

[steel 35]

Thanks for that, I’m digging in the trash today!

 

[srjdsmith]

Are you making disks? How will you do it? Band saw and sand them round? 6” hole saw? If you do it, please let me know how you made it work.

I might forgo using the 3/4” for now and use the factory disks. I’ll make some of my own disks when I can get some 1/2” MDF

 

[steel 35]

CNC Router
Thanks for the Idea.
1/2 or 3/4; Think there really is a difference?

A well known member on here makes dies for a press for thin sheet metal.
And He is Good at it.

 

[mike93lx]

1/2 or 3/4; Think there really is a difference?

About 50%

 

[steel 35]

About 50%

I found the need for 1/2" Don't have that issue yet

 

[RTM]

As others have said, the glue in MDF will trash your planer blades, you WILL get a $hit finish, and you will have nasty dust everywhere.

Find a way to use 3/4 to find different wood for this project.

 

[Dave455]

I’ve done a bit with MDF, but to be honest I couldn’t be bothered again.

It’s generally very easy to work, which is why it’s beloved by some, but I’ve never been satisfied with the end result.

Although it does plane to a degree, I don’t think you’re going to get any sort of reasonable surface from a thicknesser. Maybe try a small piece?

My main objection to MDF is that it never seems to take any sort of decent finish, and if you manage “half decent” it’s then very easily damaged.

The dust is carcinogenic, so another reason not to use it!

 

[Jeff C]

MDF is terrible stuff. I knew a trim carpenter that had to get his sinus cavities cleaned out because they filled up with dust from working with MDF. It also dulls blades and bits much quicker than wood. The cut/routed/machined edges never paint well. About the only decent use for the stuff is flat panels in stile and rail doors.

 

[steel 35]

Sure it’s nasty, but nothing like surfacing the hole table.
I pulled enough out the trash for 3.

Did you get the plans for the rest?

 

[propmaker]

At work everyone always says not to plane MDF. I needed 1/2" one day and only had 3/4 and I didn't want to wait for a delivery. It planed up fine. I wouldn't make a steady habit of it, but I also would hesitate to do it again if needed.

 

[The Cobbler]

I've planed ( with a power hand planer) cheap doors with MDF styles & rails, . you loose the finish, you'll lose the blades if they're not carbide, and it is very dusty .
all has been said previously, just adding my $0.02

 

[srjdsmith]

Sure it’s nasty, but nothing like surfacing the hole table.
I pulled enough out the trash for 3.

Did you get the plans for the rest?

I got Stumpy Nubs’ plans but I’m modifying them a bit. I just picked up the machine today. Didn’t have time to do much other than dry fit some pieces and set the machine on it. I’m making the actual slab the machine sits on a double layer with adjustable feet on the top one so that I can level the machine with the working surface and use different thicknesses of disks.

I noticed that they now have 1/2” MDF in, so I won’t have to plane the 3/4” down. I might make some 3/4” disks to see if they’ll spin correctly.

 

[Dave455]

MDF is terrible stuff. I knew a trim carpenter that had to get his sinus cavities cleaned out because they filled up with dust from working with MDF. It also dulls blades and bits much quicker than wood. The cut/routed/machined edges never paint well. About the only decent use for the stuff is flat panels in stile and rail doors.

There is nothing about having “sinus cavities cleaned out” that sounds the least bit appealing….!

 

[steel 35]

Why wouldn't you just buy 1/2" MDF?

My Answer would be!

I have never seen it.
I had scrap's
I Spent sooo much on my Router
I Thrashed my MDF Top sooo many times
I Have Two 2 Inch Fly cutter's, A Syclone, Filter's, exhaust, Eye protection Some times;
Ear protection.
My 3M Mask Filters are not Dirty
But Dam the crashes I have seen
Fuggen
Textein Driver

And No I can't sharpen a dam Kife

 

[dnschmidt]

You don't live next to a Home Depot? The ones here in Phoenix carry MDF in 3/4, 5/8 and 1/2". It's as common as dirt.

Why wouldn't you just buy 1/2" MDF?

My Answer would be!

I have never seen it.
I had scrap's
I Spent sooo much on my Router
I Thrashed my MDF Top sooo many times
I Have Two 2 Inch Fly cutter's, A Syclone, Filter's, exhaust, Eye protection Some times;
Ear protection.
My 3M Mask Filters are not Dirty
But Dam the crashes I have seen
Fuggen
Textein Driver

And No I can't sharpen a dam Kife

 

[srjdsmith]

Dubuque, Iowa. If Menard’s doesn’t have it, I can’t get it. There’s a Lowe’s and a couple farm stores, but they typically have less selection than Menard’s

It’s ok. I finally got a sheet of 1/2” I’ve cut the squares and marked the centers, but I haven’t cut the circles yet. I’m reorganizing my whole lathe area and until I have the space arranged, I won’t be sharpening anything anyway.

 

[bdbecker]

Never mind... I misread your post. I see you were able to find it at Menards.

 

[aka Larry]

You don't live next to a Home Depot? The ones here in Phoenix carry MDF in 3/4, 5/8 and 1/2". It's as common as dirt.

I'm doing an MDF project soon and it's been hard to find here. At my local Lowes they have the stacks labeled "MDF/Particle Board". The sales people have no idea that those are two different things. I'll likely have to drive an hour an a half to find some in a neighboring county.

 

[crerus75]

I sort of did what you're planning to do. I made an MDF sharpening wheel that I mounted on an old 1750 RPM induction motor. I marked a center and then used a circle cutting jig on the table saw to get it progressively rounder. I then mounted it up on the motor and trued it with a chisel. I load it with polishing rouge and can get a moderately well-honed knife or chisel to shave arm hairs in a few seconds.

 

[WWheeler]

MDF is terrible stuff. I knew a trim carpenter that had to get his sinus cavities cleaned out because they filled up with dust from working with MDF. It also dulls blades and bits much quicker than wood. The cut/routed/machined edges never paint well. About the only decent use for the stuff is flat panels in stile and rail doors.

Here's a post of mine from 2018 showing a custom tool box I made out of MDF in the mid 1990s, the box itself and the drawers, covered with a scratch-resistant laminate, that I'm still using today. Just finally had to change out the drawer slides for some new ones a few months ago.

 

[mike93lx]

Here's a post of mine from 2018 showing a custom tool box I made out of MDF in the mid 1990s, the box itself and the drawers, covered with a scratch-resistant laminate, that I'm still using today. Just finally had to change out the drawer slides for some new ones a few months ago.

The laminate is the reason that has held up.

 

[WWheeler]

The laminate is the reason that has held up.

Of course. Just showing that MDF has a LOT more uses than flat panels in cabinet doors. It's super strong, and extremely heavy. Table tops (router tables, etc) cabinets and speaker boxes and such are great uses for MDF. It'll last longer than steel if you make sure it's sealed up properly, which can be tricky.