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Posts posted by bradpotts

  1. 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.


    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. 

  2. 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

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  3. 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. 


    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. 


    Hopefully this helps anyone with a similar problem. 


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  4. On 10/18/2021 at 8:27 AM, legenddc said:


    Had a thought in the shower this morning to use a track saw for the miters instead of the table saw. Keeping at 9' long board square with a table saw blade could be challenging. Will have to test it.

    I agree, I would also use a track saw to make this miter cut. 

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  5. On 8/23/2021 at 7:29 PM, wtnhighlander said:

    @bradpotts, how long does it take to set that up?

    I don't remember how long it took the first time. I leave it set up all year round. I would guess maybe an hour. I did replace the tarp part last year. It lasted about 2 and a half years. 

    On 8/24/2021 at 7:05 AM, Mark J said:

    Any kind of fan or air filter?

    I had a fan in there for a little while but it didn't really do anything. I just leave the door part open and haven't had any problems. 

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  6. On 8/8/2021 at 8:51 PM, larryjhill704 said:

    How did you construct the stave?  How thick are the hardwood?

    Im going to attempt constructing a exterior door and have been looking at different construction techniques.

    I want to say that the top and bottom veneer was 3/16 each. That would make the poplar core 1 3/8. I made the veneer oversized though to make sure that I could run it through the jointer and planer and not get down to the "core" Here is a picture of what it looks like. 


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