First experience with mdf

[cowboy1296]

I made 3 plaques out of alder laminate mdf. Talk about dust. But it created great cuts and graphics. The alder is paper thin. I almost sanded it off trying to remove a pencil mark. Is there thicker laminates available? The mdf is heavy, which is good, but will a simple drop cause it to break? I am going to attempt to stain the mdf and alder today, any suggestions. Then I am going to coat it with an exterior poly (even though it will remain indoors).

[magic]

Pictures are always welcome

[srwtlc]

Rick, I make hundreds of MDF carved plaques and yes, if you drop it on a corner, it's going to separate the layers of MDF and veneer. I generally try to not have real sharp corners (more than 90º) and let the customer know that if they drop it on a hard surface, it's going to leave a mark.

I use mostly Cherry veneer MDF and the veneer is of good thickness so that I can sand it with a 150 and 220 random orbit sander. After staining, the MDF core will be darker giving nice contrast to the detail. Alder is a soft wood, so it will sand down much quicker too.

Edges need to be sanded smooth so that the finish will build on them instead of soak in. I use a conversion varnish on mine.

Scott

[cowboy1296]

thanks for the reponse. here is what i have made. in an effort to make it thicker i glued two pieces together

[wberminio]

Looks good.Rick

Curious, what they are for?

[cowboy1296]

just to hang on walls. it wont pin on a shirt. they are 16 inches tall

[wberminio]

Rick
I meant -are they for the police force or personal use?

[cowboy1296]

by the cops that wear that badge.

[bleeth]

Although it varies by manufacturer the veneers that are pre-bonded to MDF by the large manufacturers and distributed through outlets have been getting thinner and thinner over time. If you really want to see thin get ahold of some Jacaranda veneers from Japan-you can't hardly touch them with anything less than 220 and even that is dangerous. The only way I know of around it is to lay up your own veneers on raw substrate. For a thicker veneer specify wood on wood which tends to have the thickest face veneers. It also is easier to work with than paperbacks when it comes to gluing and spraying finish.
Nice plaques.

[woodworx]

Industry standard on domestic veneers is 1/32", import is 1/50" after the calibration sand. Most hardwood plywood mills (States, Timber Products, Columbia) buy their faces pre-assembled from an outside vendor. To ask for a thick face veneer in any species would mean the veneer mill would have to halt their production, adjust their gigantic peeler and cut the veneer thicker.

I have seen old cabinets with 1/16" veneer on the face and back of the plywood, but those days are long gone. The trees aren't the same as they were 50 years ago, and the production of plywood certainly isn't the same. To remain competative and to produce a sheet of plywood that won't warp, the mills have all gone to this standard. See the HPVA rules for more information.

[michael_schwartz]

I was sanding some 1/2" Ply from a well known box store and I think the veneer was even thinner than the standard import thickness. So thin that you could see through the veneer in spots, and even a single pass with a RO sander at 220 grit went through in areas.

At least that was better than some 3/4 import ply I had used where about 10% of the veneer would delaminate on each sheet, and the stuff would splinter quite badly regardless of what you did. Completely useless stuff, not even acceptable as a paint grade material.

Why do they even bother selling materials that you can't use to make anything from?

I like to saw my own veneer around 1/8" with a final thickness of 1/16" - 3/32" after sanding

[cowboy1296]

I was cutting two new plaques today and had an issue. One plaque has numerous words and to make the words fit i had to reduce the font to about .65 inches tall. I utilize a new 30 degree vbit to cut the letters in the mdf. my feed rate was 1.5 inches and cut depth was set at .1. so as you can see i was moving slow with it. the letters cut great except in some of the smaller letters, especially e's. a piece of the letter popped out. other then increasing the size of my font is their another way to prevent this from happening again?

[burchbot]

Hi Rick
This was cut with a Centurion 45 degree bit. The letters are .375 high. For letters your size I would use a 60 degree. Not all mdf is created equal. If a 60 won’t cut it, it could be the material.
Dan

[cowboy1296]

Apparently the 30 degree was cutting to deep. I am going to experiment today with some half inch letters. i dont have a 45 degree so i am going to try with a new 60. will let you know how it goes.

[srwtlc]

Quality of the MDF panel can make a difference too. I ran into several sheets where I was having the same problem (loosing the centers of letters), my next order was of better quality and the veneer seemed to be adhered better and the problem went away.

The attached image is of part of a customers plaque (over 1000 made) and it was cut with a 3/8" 90º v-bit from Centurion. The text ranges from 0.25"-0.5" tall. I've found that the Centurion v-bits are best suited to v-carving veneered MDF. These are cut at MS,3.2,1.5 and with a custom ramp profile that makes it run a tad mushy (technical term). ;)

I have at times either made the text just a little larger or at least node edited the islands to be just a little larger. Switching to a 60º can help too.

Scott

[cowboy1296]

test went as follows: the 60 degree did great for .65 but was do big for a .5 inch cut which i tried again to use the 30 and it worked fine.

until a week ago i did not even know how to spell mdf let alone grades. so i am still learning but yalls advise have been great.

[cowboy1296]

Here are some of the finished plaques. Still playing with the hplv sprayer and am going to start working with gel stain for the graphics in mdf

[wberminio]

Rick

I like your work.
Are these gifts ?

[cowboy1296]

somewhat until i run out of money.

[cowboy1296]

I am retired and for a variety of reasons i doubt if i will ever go into business, perhaps contract work. This year i am going to my first arts and crafts show to see if my stuff can attracted attention. I have no formal training with CNC or the cad system. I have self taught myself everything watching as many videos as i can. This is one of the reasons i ask so many dumb questions. The plaques have been a training session for me and even with them i am still learning.

[cowboy1296]

i did a search on this will no findings. but can you do a 3d image in laminated mdf? mdf has done good with v-carve, other then the dust, and i like working with it.

[woodworx]

yes. Use Plum Creek SR2 mdf of Medite 3D. They are ultra-refined particles, so you get less mdf "fuzz"

[srwtlc]

Rick,

I've done a few and it works out pretty good as long as the core of your MDF is what's called a double grind where the particles are finer. I think most veneered MDF is this way, but I have run into a few sheets that wern't as fine and wouldn't finish up as nice. If you stain it, you will however see a ring that will be lighter/darker where the resin is more concentrated at the surface than at the center. Half and half regular stain and gel stain helps.

I don't have a finished picture, but here's one that I did that turned out real nice. Not so much of a horse lover myself, mine would be "Advice from a motorcycle". ;)

Scott

[cowboy1296]

i use gel stain for the first time to color the edges and graphics of the mdf and was real pleased. before it could set i used regular stain for the laminate. all i can tell you about the mdf that i am using is that it was suppose to have been used by a cabinet maker who turned it down on inspection because of some scratches. it takes two men to load it into the bed of the truck. looking at a size view of the mdf it visibly appears to be tight, somewhat of a beige in color.