MDF Splits!! Pics*

[PV Audio 5,000+ posts]

did you not SEE what just happened with screws??? screws FTL.

You're right, but you're also dead wrong. Screws are unnecessary, but they make box building oh so efficient. If you have clamps, lay down your wood glue, clamp the wood, then screw. The screws hold the clamped force together so that you have a solid bond. While completely unnecessary, most box builders don't have the time to wait for a panel to dry completely over an hour or so.

 

[Wrabe001 10+ year member]

I didn't know screws were unnecessary till NOW!!! I will start fixing this tomorrow morning. I will post pics up around 11am. I wish i could wait around for the glue to dry and not use screws, but i have work all weekend and i need to finish this. I have been in the making for about a week now(takes forever between school/work). So let me get this right, drill, countersink, screw. How often should i put screws now that im using glue? I bought titebond 2 wood glue. Also how much wood glue do i apply? Are 2" fine drywall screws okay?

Thanks for everyones help

 

[thatkidbob 10+ year member]

I used #7 1 1/2" coarse thread deck screws in my most recent box and it turned out very nicely....

I only used screws every 9 or 10 inches (but i used at least 2 screws per panel, no matter how short). It took a lil while to build because i still don't have clamps big enough for the boxes i build. I predrilled holes and screwed the box together for a test fit (i predrill with a drill bit thats almost too large), then unscrewed the box, glued the edges, and screwed it back together.

When the whole thing was together i used a strap clamp around it horizontally and put about 300 lbs of weight on top of it... 12 hours later when everything was dry, i removed the screws and the box is still strong as hell. It went home with the happy customer the night before last.

 

[Wrabe001 10+ year member]

Sounds like glue is the way 2 go. Im going to pre-drill all my holes with the right drill bit this time. I think ill glue everything once i get it right. I just don't want any weak panels with splits.

I keep hearing #7 and #6 screws, i cant find these at HD, where shouldi find them. Im using regular 2" fine drywall screws.

Should i use coarse or fine?

 

[thatkidbob 10+ year member]

COARSE!

they go in quicker.

just use a big drill bit and test various sized holes on a scrap piece of wood before you start on the box.

Dry wall and Deck screws are the best (in my experience). I got my #7's at wally world...

 

[Wrabe001 10+ year member]

okay, length wise 2" or 1 1/2"?

 

[Wrabe001 10+ year member]

oh also i got a air compressor, can i use something else besides drywall screws that are better?

 

[Big Dee 10+ year member]

okay, length wise 2" or 1 1/2"?

1.5 is ok for most/all of it, but say you are attaching a double thick baffle that is 1.5 inches thick, you would need some longer screws, so I always have both sizes on hand.

 

[thatkidbob 10+ year member]

oh also i got a air compressor, can i use something else besides drywall screws that are better?

well hell... if you've got a brad nailer too you could shoot finishing nails instead... MUCH quicker... almost no splitting... no drilling, no countersinking, no nothing.

1.5 is ok for most/all of it, but say you are attaching a double thick baffle that is 1.5 inches thick, you would need some longer screws, so I always have both sizes on hand.

this guy is right on point... with double baffles you'll either need to use longer screws or think ahead and attach one baffle to the box, then attach one baffle to the other.

 

[PV Audio 5,000+ posts]

okay, length wise 2" or 1 1/2"?

Since you haven't been doing much of this, I would even tell you to go smaller to 1.25", as there's less chance of splitting.

 

[iamamp3pimp 5,000+ posts]

1 5/8 is what i use, on everything

 

[djman37 5,000+ posts]

i got screws and wood glue on mine, then all the corners & edges are sealed with Big Black C0ck

then you are good.//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[djman37 5,000+ posts]

You're right, but you're also dead wrong. Screws are unnecessary, but they make box building oh so efficient. If you have clamps, lay down your wood glue, clamp the wood, then screw. The screws hold the clamped force together so that you have a solid bond. While completely unnecessary, most box builders don't have the time to wait for a panel to dry completely over an hour or so.

not DEAD wrong. Knowing what screws in MDF can do, even pre-drilled, I choose to wait. Mind you, the boxes I build are taking extreme pressure, MT's and DD9515's attached to 20.1's strapped and 40.1's.

In oder to save time, you make a sacrifice. You can't argue the BEST way is to glue and clamp. I'll agree a FASTER way is to screw|brad and glue. I built a box that didn't use ANY woodscrews, T-nuts and bolts for speaker mounting:naughty: +1 for no wood splitting.

 

[Flipx99 5,000+ posts]

I use wonderboard screws so predrilling isn't as necessary. They also self countersink but you have to be very careful with the drilling. You don't just full blast power it in there, more like nice and easy....

Once I buy some crown staples, I am going to try that method.

 

[ramos 5,000+ posts]

I use duct tape and tree sap //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif