fixing split in mdf (1 Viewer)

[Bob Bartlett]

Glued up my kit 81 speaker cabinets and I had a very small gap on the back panel. I used glue and clamps and pulled it tight. After a few days I noticed a very small split on the back panel on the end of the board on the same side with the gap. The crack is actually in the mdf and not in the glued joint. It is not very wide and the box is still sealed, but should I just put some glue in the crack to help seal it? I never built a sealed speaker and was curious if there is alot of pressure pushing on the back panel when the speaker is in use? I am worried it could possibly crack some more.

 

[James Mudler]

Is it from the screw? Having a hard time visualizing.
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Luke, I'm your father

 

[Bob Bartlett]

No, I didn't use screw. If you looked at the cabinet from the side and looked at the back panel's cut edge that is where there is a split, almost like the mdf is splitting in half. I threw some gorilla glue in it and sealed it up, I think it will be okay I was just worried about later if it could get worse.

 

[James Mudler]

Man that is kinda odd. MDY will chip easy but I doubt it will spread. I had many corner chips with MDF from Home Depot. I prefer Lowes.
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Luke, I'm your father

 

[Pete Mazz]

Sounds like you've got quite a bit of stress in the panel, probably caused by a less than perfect cut. I would keep an eye on it for a day or two, then force some wood glue into the split and clamp.
Pete
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[Kerry Hackney]

Sounds like your MDF split after you clamped it to pull it tight. The glue joint is stronger than the fibers in the MDF so it pulled the panel apart when it tried to return to the original position. You can certainly inject glue into the crack with a hypo glue injector. The polyurethane is very very strong. Sand it smooth once it dries and it should be fine. As long as a hunk didn't tear off the corner it should be easy to fix. The split probably doesn't go very deep and shouldn't grow after the initial movement. It is possible to pull the laminations in plywood apart for the same reasons. It's tricky to force a joint closed that doesn't naturally want to meet correctly.
Your cabinet is most likely plenty strong, you just don't want any buzzy noises from where that panel pulled apart.
Good luck....

 

[Bob Bartlett]

Thanks everyone for the reassurance it seems the glue will hold it fine. I am new to wordworking and I am learning the hard way.