Fxguy

Help bracing large frame.

Recommended Posts

I have a very large picture frame that’s made out of 1/2” mdf. It is made of three pieces that are 27 1/8” tall x 114 1/2” wide. The joints are biscuit jointed along the long edge, but when lifted they have a lot of give. I was thinking of bracing with some 1x3 down the length of the joint but don’t know if the vertical should be solid or the horizontal brace should be solid. Or if I should cross brace with 45’ angles. Any suggestions?

 

 

Sent from my iPad using Tapatalk

Share this post


Link to post
Share on other sites

I am having trouble understanding the problem. Is the frame a triangle? Or a rectangular  frame made with three 1/2” thick pieces laminated together to give 11/2” thick sides?  And when you say it has a lot of give, does that mean the joints are opening?

Share this post


Link to post
Share on other sites

Not a typo. I had to have my local wood shop special order 2 10’ pieces of mdf for it. The picture below shows 2 pieces on top of each other. The finished frame is three pieces, so two very long biscuit joints that run the horizontal length of the frame. This is all for a gigantic jigsaw puzzle, the lower half of which can be seen in the photo.

image.jpg

Share this post


Link to post
Share on other sites

I would go with some vertical material, regularly spaced. If I understand, you are trying to make a 7' x 10' panel. The problem is that it will be prone to breaking somewhere along the length. if you ever set this on a normal table, you will likely have several feet extending out without support, which can cause a lot of stress. You need more strength in that transverse direction. You could run a series of 7' strips, spaced at 12 or 24" on center, along the back. That would greatly increase the strength. It may also start to give you something to use to mount this thing, as the MDF may not be strong enough to hold fasteners for most conventional ways of hanging something very heavy like this. What do you have in mind? A French cleat?  

  • Like 1

Share this post


Link to post
Share on other sites

Ok, so more important to run the bracing perpendicular to the joint. Yeah, we had it laying flat on a table and I had 3  1x2 strips under it to help keep it solid. Hadn’t thought much about the logistics of hanging it other than the thing weighs a ton! I like the idea of a French cleat between the bracing strips. Should distribute the weight nicely and allow for multiple studs to hold it. 

  • Like 1

Share this post


Link to post
Share on other sites

The French cleat would also serve to brace it in the short direction, which isn't a bad thing. 

Share this post


Link to post
Share on other sites

Isaac is on the money. MDF in the dimensions given, has a high risk of breaking under that sort of load. If possible, I might even consider a torsion box of thin (1/4 or less) material as a backer.

Share this post


Link to post
Share on other sites

Thanks for the clarification. Even a backer of 1/8” ply would give a lot of support. It would still flex, but wouldn’t break. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Who's Online   2 Members, 0 Anonymous, 119 Guests (See full list)

  • Forum Statistics

    28956
    Total Topics
    391560
    Total Posts
  • Member Statistics

    21866
    Total Members
    1529
    Most Online
    Naomi
    Newest Member
    Naomi
    Joined