Strong, thick, light veneer panel


bradpotts
 Share

Recommended Posts

I have been building a lot of projects lately where the clients want thick looking pieces. Because I usually use mdf for veneering, weight starts to become an issue. So this is how I tackle that problem. I build a torsion box with 1/4 veneer on the top. 

Using 1/4" mdf for the cross pieces and 3/4 mdf for the outside box part. 

IMG_6935.thumb.jpeg.89e4d7bef8715b5f72808f5e364cf494.jpeg

Then glue the 1/4" mdf veneer panel on top. I make the veneer panel oversized and trim down the excess with a flush trim bit. 

IMG_6953.thumb.jpeg.f20f2f29f78adcb78338c846a2b4e52c.jpegIMG_6954.thumb.jpeg.f105e3e2ebacf39a4363a82b535a16df.jpeg

Hopefully this helps anyone with a similar problem. 

 

  • Like 2
Link to comment
Share on other sites

I've been making quite a few lighter weight panels like that. my advise is to ditch MDF and go to solid wood for the front and back length pieces and if possible any pieces parallel. MDF is ok but it's heavy and has extremely poor resistance to bending. Making it into a box beam helps but having a long grain solid piece of wood will allow you to reduce structure and maintain strength, thus reducing the weight further.

0821211151-01.thumb.jpeg.b3a810f33e799e6724aa5be5c3358cdd.jpeg

This picture is using plywood but i remembered sagulator and ran some comparisons using ply and solid wood for the internals. Solid wood has almost twice the rigidity compared to plywood thus allowing you to use half the amount of wood for the same strength. With top and bottom skins there is little need to do cross bracing as tightly as you did. I just recently finished a shelf that is 8 feet long 24" wide and 1.5" thick. I can jump on the center while the ends are on saw horses. Total weight is maybe 15 lbs. I'm not veneering so i used 0.185" thick plywood (Luann ply) 1/4" MDF would be better for surface finish. It's a great method and it's how IKEA makes their furniture light weight but still somewhat strong.

Link to comment
Share on other sites

On 11/16/2021 at 9:45 AM, Coop said:

Brad, with that many cross pieces, do you have a system for cutting out the notches where they overlap? How are these attached to the 3/4” outside pieces? 

The way that I cut them is to cut them all to length and then tape them all togeher. Then I use a miter gauge to push them through a 1/4" dado blade. I do add a very small spacer in the dado blade so they all fit together nicely. IMG_6959.thumb.jpeg.938931b883f08856bf00e65137defbde.jpeg

  • Like 2
Link to comment
Share on other sites

On 11/16/2021 at 9:53 AM, wtnhighlander said:

Nice tip, Brad. I'd like to see more of your veneer projects, especially how you do joinery with those MDF panels.

For these panels, They are going to be glued into dado's. IMG_6957.thumb.jpeg.8c19a4405ad37150ecd4a73d51b4ad57.jpegIMG_6958.thumb.jpeg.215727a65c5aba2cb6cb544340bc317a.jpeg

 

  • Thanks 1
Link to comment
Share on other sites

On 11/16/2021 at 1:49 PM, Chestnut said:

I've been making quite a few lighter weight panels like that. my advise is to ditch MDF and go to solid wood for the front and back length pieces and if possible any pieces parallel. MDF is ok but it's heavy and has extremely poor resistance to bending. Making it into a box beam helps but having a long grain solid piece of wood will allow you to reduce structure and maintain strength, thus reducing the weight further.

0821211151-01.thumb.jpeg.b3a810f33e799e6724aa5be5c3358cdd.jpeg

This picture is using plywood but i remembered sagulator and ran some comparisons using ply and solid wood for the internals. Solid wood has almost twice the rigidity compared to plywood thus allowing you to use half the amount of wood for the same strength. With top and bottom skins there is little need to do cross bracing as tightly as you did. I just recently finished a shelf that is 8 feet long 24" wide and 1.5" thick. I can jump on the center while the ends are on saw horses. Total weight is maybe 15 lbs. I'm not veneering so i used 0.185" thick plywood (Luann ply) 1/4" MDF would be better for surface finish. It's a great method and it's how IKEA makes their furniture light weight but still somewhat strong.

Thanks for advice Drew. There are a few reasons for the way that this process is done in this particular way. The First is the cross pieces makes sure that when you adhere the top and bottom panels in the vacuum bag, the top and bottom to not become wavy when the air is sucked out of the bag. The second is that it adds more glue surface. Finally, in my opinion it feels more solid. You can knock on the piece and it doesn't sound hollow. The problem with using solid wood as apposed to MDF it has a tendency to bow. If you glue a bowed board for the long perimeter, you will then need to re-square the whole panel. With MDF you can make the perimeter to final length and width and flush trim the top and bottom pieces. I would use a different material for the perimeter if for the joinery you plan on is putting dominos or screws in it. I think you are seeing this process only through the eyes of strength. 

Link to comment
Share on other sites

1 hour ago, bradpotts said:

I think you are seeing this process only through the eyes of strength. 

Weight actually but in a round about way strength yes. Making a 32" wide 96" long panel gets close to 125 lbs quick with mdf. Same panel from pine and pine plywood is around 25 lbs. I'm just expanding on the procedure offering up advice for any one that is interested. It's a really good technique that I've used quite a few times over the years. Depending on the use case it can be expanded and changed considerable.

Another option if you flat with no waving is to use extruded foam for the core (the pink stuff). You could probably drop down to 1/8" MDF because it's continually supported. 1/4" will likely sound better if that is critical. This kind of construction is common for making very strong light weight panels. It'd save you a lot of time constructing the internal webs as well.

I've not had any experience with bowing i guess, proper milling and material prep is critical to keep anything strait. I'm also doing this with clamps and weights not a vacuum bag.

Link to comment
Share on other sites

 Share

  • Who's Online   1 Member, 0 Anonymous, 84 Guests (See full list)

  • Forum Statistics

    29.9k
    Total Topics
    406k
    Total Posts
  • Member Statistics

    22523
    Total Members
    3644
    Most Online
    JamieYYC
    Newest Member
    JamieYYC
    Joined