Avoiding wood splits

accuab
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I was in the shop doing some testing to get the right drill bit for pilot holes. I was drilling into the length of one piece of and testing. I noticed that the wood still split unless the pilot was so big that the screw barely gripped. So I tested with the brad nailer. Even after turning the pressure way way down, I still saw small wood splits. So I tried next with a trim nail and hammer. That caused small splits as well. Is there anything really that doesn't split at all. For the screws I was using 1 5/8 course drywall. Keep in mind that I'm not talking about going into the face of the wood. I was going into the side where a cut is. I'll bet many of you that put screws in your box have tiny splits in your wood that you don't know about.

 
I had this problem with my MDF the problem was my drill bit it wasn't long enough at least the cutting edges weren't it would get to the solid part and then the wood shavings had no where to go and the pressure split the wood. If you get a longer drill bit with longer cutting edges it might help.

 
Drill bit is plenty long enough. The drill bit isn't what is causing the split. Anything going into the wood besides a drill bit is splitting it.

 
I've never had MDF split when pre-drilling. I stay at least 2" from the corner, and use 1.625"(1 5/8") long coarse thread drywall screws. Either you're doing something wrong, or the MDF you're using is bad.

 
Have you ever pulled a joint apart after putting the screw in? And keep in mind I'm not saying it split on the face. The face of the board was no problem. I'm talking about a screw, brad, or nail directly into the end of a board.

Some of my splitting came from sinking the head of the screw in without using a countersink bit first. But the brad did split some even when set to not sink the head and turning the pressure down.

 
Have you ever pulled a joint apart after putting the screw in? And keep in mind I'm not saying it split on the face. The face of the board was no problem. I'm talking about a screw, brad, or nail directly into the end of a board.
Some of my splitting came from sinking the head of the screw in without using a countersink bit first. But the brad did split some even when set to not sink the head and turning the pressure down.
Why in the world would you need to screw into the side of a piece of MDF?

 
MDF *****. That's why. Try different screws. I use Spax. No predrilling, very minimal (if any) splitting, but when dealing with MDF, it's the nature of the beast. If you use a good plywood with excellent lamination, that won't happen.

 
Why in the world would you need to screw into the side of a piece of MDF?
it's not that I would screw directly into the side. It's putting a screw through the face of one and into the end of another. I really was doing my test all wrong cause I was putting the screw a little too far in for my test and it was getting to where the screw expands near the top. I've got most of my box built now with no splitting that I know of. I still don't know why the brad nailer was splitting it though. I thought maybe that without the face to shoot the nail into first, the end of the board was taking the blunt force of the air pressure. With shooting it through a face before going into a end of a board, the velocity of the nail is slowed down before it hits the second piece.

I'm much more accustomed to using a real sheet of wood than mdf so I had to get used to using it again. I wasn't used to having to deal with wood splits. I don't think I have built anything with mdf in like 8 years. I did see online mentioning those screws that TaylorFade mentioned and they do seem to be good just not worth the price.

 
Are you using #6 or #8 screws? I typically use an 1/8" bit with #6 screws and get no splits. But the screws are only to clamp the pieces until the glue dries, so they don't have to be real tight.

 
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accuab

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