[gma2rjc]

How do you know what length or style of Kreg screws to use with a Kreg Jig.

I am practicing on 3/4" scrap MDF right now and I know it requires the fine threaded screws, but there are different lengths and 2 different styles of heads that came with it.

 

[oh'mike]

I just got one of those and haven't tried it yet---someone here will know---

 

[CaptRandy]

here is their site
http://kregjig.ning.com/forum

 

[joecaption]

Good luck trying to get MDF to hold screws.
It requires a special type of screw and even then they may of may not hold.
What are you trying to build?

 

[gma2rjc]

Thanks everyone.

I'm trying to use up some 1x4 mdf and a 38"x34" piece of beadboard that I have laying around, to build something to hold CD's.

So I'm using the mdf for the 4 sides and the 5 shelves. It was a last-minute idea to build it and I thought it would give me some practice with the Kreg Jig.

Thanks for letting me know that it doesn't work well with mdf. I'll give it a try and see how it goes. At least if it doesn't, I'll know it's the boards and (hopefully) not something I'm doing wrong.

CaptRandy, I did find a chart on that website - thank you. It's in PDF form and I'm trying to figure out how to print it to a piece of paper.

I was wrong in my previous post. The fine threaded screws are meant for hardwoods. They suggest coarse thread screws for mdf.

Barb

 

[Daniel Holzman]

The correct size of Kreg screw is a function of the thickness of the piece it is going into. The Kreg chart, either the hard copy that comes with their jig, or their on line chart, will tell you the proper length of screw. For certain very hard hardwoods, like ipe, you need to predrill. For many hardwoods, and for all softwoods, you just drill it in place.

 

[deverson]

One thing I found out about their screws. If you use ones that are too long, they poke through the front of the face frame. Then you have to start all over again. Not that I've done that, but I'm sure someone has!

 

[chitownken]

Kreg Maxi-Loc Hi-Low screws would probably be the best for MDF or particle board.

 

[woodworkbykirk]

with mdf you have to drill pilot holes in the adjoining piece otherwise it will split and wont have any hold if its within 2" of the edge

 

[REXAMUS]

http://www.kregtool.com/prodimages/ScrewChart.pdf

 

[oh'mike]

I'm watching and learning----I'm always the last guy on the block to try something new---and I have a new toy----any tips and stories about the system are welcome---

 

[ddawg16]

with mdf you have to drill pilot holes in the adjoining piece otherwise it will split and wont have any hold if its within 2" of the edge

I'm assuming the OP is talking about the pocket hole kit....in which case the drill bit should have the pilot hole drill as part of the whole bit.

But yea, without that pilot hole....not going to be pretty.

IIRC....course thread for soft woods like pine and MDF. Fine threads for hardwood.

I typically use 1 1/2" screws for pocket holes in 3/4" stock.

One last thing.....make sure those are real Kreg screws with the flat head surface against the wood. If you use a counter sunk type of screw it WILL split your wood....acts like a wedge.

 

[woodworkbykirk]

of course the jig comes with the bit.. but you have to drill a 1/8 pilot hole in the secondary peice of wood that the pocket hole screw will be grabbing

 

[woodworkbykirk]

the other thing is when you go to drive the screw you have to clamp down both peices together and have them perfectly aligned before you drive the screw. otherwise the 2nd peice will creep up as the screw tightens, when that happens you wont have a flush joint which requires extra sanding


also use

1" screws for 1/2 " stock

1 1/4" for 3/4 thick stock

1 1/2" for 1" stock. 2 1/2" screws for 2x

 

[gma2rjc]

You should get yours out Mike. It's fun to work with. I didn't have a place to fasten down the full-size jig, but the portable one seems to work pretty well.

I'm glad to be working on scrap boards as once I got the shelves put together, there were areas between the shelves where I couldn't get the drill at the proper angle to drive the screws in..... had to rethink things and start over.

I like the clamp that came with the kit, but there are things it can't do, so I'll be buying other kinds of clamps to go with it.... as finances allow :wink:.

The YouTube video's are a lot of help.

 

[chitownken]

They also sell plugs to fill the holes in about 5 or 6 different species of wood.

 

[gma2rjc]

Is there one store that's better than others to buy the plugs and other parts? I got this at Lowe's and they have a good variety, but I don't remember seeing that many of the plugs or some of the things I've seen people using in the YouTube videos.

 

[ddawg16]

Rocker is where I get mine....I have a store within a few miles but their internet shipping is also quick.

woodworkbykirk.....thanks for correcting me on the lengths....not sure why I had 1 1/2" on my mind....I use 2 sizes.....the 1 1/4" and 1 1/2"....90% of which is the 1 1/4".

Regarding the plugs....I have never used them. 90% of what I use pocket screws for is faceframes...the holes are in the back of the faceframe so you don't see them.

One last thing.....let me stress the importance of clamping the material as woodworkbykirk mentioned when driving in the screw. I use a clamp to hold them both pieces flush against the table then I use another clamp to pull them tight against each other. That way the screw does not pull the material up causing a mis-match in the front surface.

When you clamp it right, you end up with a joint with no detectable lip....I'll assemble the whole faceframe without glue....once I'm happy with it.....I take it apart, stain the pieces (except for where the glue goes) then re-assemble using glue.

 

[woodworkbykirk]

with some types of wood, mdf being one of them if you pre assemble then re assemble to glue it you run the major risk of stripping out the hole leaving no holding power.. this is why mdf door jambs dont work. .if you take the screw out once your..... um screwed. you have to switch that screw to a longer one to bite into the framing

 

[gma2rjc]

I see what you mean about clamping the two pieces properly. There were 2 times when I thought I had the clamp on properly and it didn't hold.

I noticed it immediately when I started the drill and one piece of the wood came out of the grip of the clamp. It left a gouge in the mdf. Not a big deal, but had it been a nice piece of wood that was damaged, it would have mattered.

The 2nd time it happened, I reacted to it quicker and the gouge was smaller.

I think what I did wrong on one of them was not centering the clamp over both pieces of wood evenly. And the second time, the two pieces that were clamped together were slightly different in size. One was maybe 1/32" thinner than the other. That's just a guess of the size difference, but the point is the clamp held both of them but when I put pressure on the smaller piece, the clamp couldn't hold it.

I guess it's like anything else where it takes time to learn the little details of what to do and what not to do.

It's fun though. I can't wait to get it out again.

I'll take a look at the rocker website. Thanks!

The mdf does strip out pretty easily. One of the screws I drove in never did catch. It just kept spinning. I might have been pushing it too hard, but I doubt that real wood would have done that.