Pocket Holes and MDF

[Bill Splaine]

I'm building a shop table for my new shop. I've never used pocket hole fasteners so forgive this newbie question.
The frame will be 3/4" plywood and I wanted to have a 3/4" MDF top that will be sealed and waxed. The PH jig/drill will put the fastener holes in the plywood.. but, the question is.. do / should I pre drill the MDF or will the PH screws drive properly into the MDF?

Thanks.

[Dan Rude]

It will not be an issue, The screws will drill into the MDF just fine. You just have to decide about using glue or not. I didn't and used the table for years. If I do not get a buyer for it soon I will take it apart and use it for other projects. Dan

[Rich Engelhardt]

Use coarse screws.

I usually use coarse screws & glue, then remove the screws after the glue has dried. Kreg pocket screws aren't all that cheap.....

[Justin Ludwig]

Use coarse screws.

I usually use coarse screws & glue, then remove the screws after the glue has dried. Kreg pocket screws aren't all that cheap.....
There's plenty of sources for pocket screws that aren't branded and expensive.

[Osvaldo Cristo]

Use coarse screws.

I usually use coarse screws & glue, then remove the screws after the glue has dried. Kreg pocket screws aren't all that cheap.....

Very good idea. Usually I go to pocket screws for temporary and not valuable projects like some play structures for the wife's cats last week... they barely are worth the price of the screws.

[Osvaldo Cristo]

I'm building a shop table for my new shop. I've never used pocket hole fasteners so forgive this newbie question.
The frame will be 3/4" plywood and I wanted to have a 3/4" MDF top that will be sealed and waxed. The PH jig/drill will put the fastener holes in the plywood.. but, the question is.. do / should I pre drill the MDF or will the PH screws drive properly into the MDF?

Thanks.

1. Pocket screws are self drilling so no need for pre drilling if you are using appropriate screws. As stated previously you need coarse thread screws. Probably 30 mm or 1 1/4" long

2. MDF is a fragile material and you can have problems if using a impact driver. Prefer a driller set at low torque or hand screwing if feasible

[Art Mann]

I have a 28" X 72" work table built out of 3 layers of 3/4" MDF and covered with 1/4" replaceable Masonite. The base is made of 2 X 6 cherry lumber. I secured the top to the base with pocket hole screws like you are planning to do and have experienced zero problems in 20 years. I would recommend you consider 2 or 3 layers of MDF glued and screwed together rather than just 1 due to the increased mass and stability. Also, I would not leave the MDF exposed on top as it is fairly weak and will get damaged easily. I agree with Osvaldo that you need to take it easy on the screws to avoid spin out in the soft material.