Pocket holes and Ipe

[ken wells]

I am a Kreg newbie. Is it possible or advisable to try to drill pocket holes in Ipe? In one case it will be a cedar 1 x 4 with pocket hole into 2 x 2 Ipe. Will the Ipe need to be predrilled and how would you do that to line up with pocket hole? What screw would you suggest? Thanks

[Jay Boutwell]

Hi Ken

Ipe  wood is a very tough wood that can be hard to drill.  Kreg does make a upgrade bit that can be used to drill the wood. The make a cobalt drill bit that is around the 25 dollar range that fits in their auto drill pocket machines but is also an upgrade bit for the Kreg jigs.  It might be slow going but well worth the time as Ipe is a great hard wood for decking.

In reading your post you are drilling the holes into ipe that is used as the decking structure so you

should still drill the pilot hole since most screws will not stand up to the twisting that it will take to insert them.  You might be able to make yourself a plug that will fit the jig drill guide with a small hole in the center to guide the bit. Then use a small drill bit like one of the aircraft type bits.  Drill this after you drill the initial pocket hole and then drill a small  dia hole something like a 1/8 bit.   For screws I would definitely use an out door screw.  I wouldn't want to have to redo this project because the screws let go or rusted out.

[Jay Boutwell]

Ken, I got to thinking about your project and think it would be easier to just drill the pocket hole and then lay the planking into position and just use a small dia air craft type bit and line it up with the pocket hole center and drill the small pocket hole.  That way you would not need to make a drill guide.  I normally would not recommend drilling a pilot hole however this is some very tough wood.  
 
Jay Boutwell said:

Hi Ken

Ipe  wood is a very tough wood that can be hard to drill.  Kreg does make a upgrade bit that can be used to drill the wood. The make a cobalt drill bit that is around the 25 dollar range that fits in their auto drill pocket machines but is also an upgrade bit for the Kreg jigs.  It might be slow going but well worth the time as Ipe is a great hard wood for decking.

In reading your post you are drilling the holes into ipe that is used as the decking structure so you

should still drill the pilot hole since most screws will not stand up to the twisting that it will take to insert them.  You might be able to make yourself a plug that will fit the jig drill guide with a small hole in the center to guide the bit. Then use a small drill bit like one of the aircraft type bits.  Drill this after you drill the initial pocket hole and then drill a small  dia hole something like a 1/8 bit.   For screws I would definitely use an out door screw.  I wouldn't want to have to redo this project because the screws let go or rusted out.

[Ken Darga]

Ken,

When installing screws into ''hard'' hardwoods, I always drill pilot holes into the base material,

and use a clearance hole in the material that is intended to be fastened. 

A clearance hole will permit the top member to be fastened firmly to the base material.

The clearance hole, in the top member, can be 1/32" larger that the screw shank.

A pilot hole dia, of .003-.005" dia larger than the root dia of the threaded screw.

I want the screw threads to grip into the wood---

I don't want interference between the screw shank and the material.

(When binding occurs, the screws will break (snap-off); hence the reason for a pilot hole).

For accurate measurements, I use dial calipers.

Applying a ''lube" to the threads reduces the driving forces, which will reduce the risk of screw breakage.

When installing a screw, without a pilot hole, the screw will be displacing the material,

interference will occur, and the result will be screw breakage.

There are wood screws on the market, that have a "self tapping/thread cutting" feature---

the leading end of the screw cuts threads for the screw threads that follow. 

Make sample test pieces, to insure satisfactory results, before proceeding to the final result.

Corrosion resisting stainless steel screws would be my #1 choice.

(There are screws on the market that are advertized for exterior use applications.  

Not all are as advertized).

A screw length of 1-1/2" is adequate for fastening 1x4 cedar boards, to the 2x2's.

Select a screw head where the recess in the screw head doesn't easily strip-out.

This is an effective style screw head.

Avoid cross-point head types.

Some square-head screws are not all that desireable---

I've found some types, strip easily---it's easy for the bit to not firmly seat on all sides in the screw head.

I presume you intend to make this product last for 50+ years, since you want to use Ipe hardwood.

[Jay Boutwell]

 Something in addition, when selecting the screw for a Kreg bored pocket hole you should always select a screw with the correct type head.  Since the Kreg bit bores a flat bottom hole, you should use a pan head screw.  If you use a bugle head the cone shape will enter the pocket hole and as it bottoms out in the pocket hole it will act like a wedge and most likely will split the pocket hole as it tightens up.
 
Ken Darga said:

Ken,

When installing screws into ''hard'' hardwoods, I always drill pilot holes into the base material,

and use a clearance hole in the material that is intended to be fastened. 

A clearance hole will permit the top member to be fastened firmly to the base material.

The clearance hole, in the top member, can be 1/32" larger that the screw shank.

A pilot hole dia, of .003-.005" dia larger than the root dia of the threaded screw.

I want the screw threads to grip into the wood---

I don't want interference between the screw shank and the material.

(When binding occurs, the screws will break (snap-off); hence the reason for a pilot hole).

For accurate measurements, I use dial calipers.

Applying a ''lube" to the threads reduces the driving forces, which will reduce the risk of screw breakage.

When installing a screw, without a pilot hole, the screw will be displacing the material,

interference will occur, and the result will be screw breakage.

There are wood screws on the market, that have a "self tapping/thread cutting" feature---

the leading end of the screw cuts threads for the screw threads that follow. 

Make sample test pieces, to insure satisfactory results, before proceeding to the final result.

Corrosion resisting stainless steel screws would be my #1 choice.

(There are screws on the market that are advertized for exterior use applications.  

Not all are as advertized).

A screw length of 1-1/2" is adequate for fastening 1x4 cedar boards, to the 2x2's.

Select a screw head where the recess in the screw head doesn't easily strip-out.

This is an effective style screw head.

Avoid cross-point head types.

Some square-head screws are not all that desireable---

I've found some types, strip easily---it's easy for the bit to not firmly seat on all sides in the screw head.

I presume you intend to make this product last for 50+ years, since you want to use Ipe hardwood.

[ken wells]

Thanks for the reply's!

I am making the deck box on the Lowes website. Using Ipe tongue and groove for the exterior cladding and cedar for the frame and interior.  I built my deck last summer out of Ipe so I am well versed with it.  I will face screw and plug the Ipe cladding to the cedar so no problem there.  The plan has the cedar frame 1 X 4 with a pocket hole going into a 2 X 2 Ipe leg.  This is the joint I am most worried about.  I plan to use stainless steel screws but I am having a problem finding them with fine thread pan head. Any suggestions? What length for this joint?

I am also worried about the weight of the deck box when finished.  It maybe a couple of hundred pounds.

[Rick]

Ken,

You can use 1-1/4' or 1-1/2" long screws since you are going into 2x2 ipe.

If you can't find fine threads in SS, try starting the screws, back them out, remove the cedar, and then pilot drill the ipe.  Then reassemble.

I've machined a lot of ipe, it's not bad to work with except for that yellow dust.

ken wells said:

Thanks for the reply's!

I am making the deck box on the Lowes website. Using Ipe tongue and groove for the exterior cladding and cedar for the frame and interior.  I built my deck last summer out of Ipe so I am well versed with it.  I will face screw and plug the Ipe cladding to the cedar so no problem there.  The plan has the cedar frame 1 X 4 with a pocket hole going into a 2 X 2 Ipe leg.  This is the joint I am most worried about.  I plan to use stainless steel screws but I am having a problem finding them with fine thread pan head. Any suggestions? What length for this joint?

I am also worried about the weight of the deck box when finished.  It maybe a couple of hundred pounds.

[ken wells]

Thanks Rick and everyone,

Lots of test holes are in my future. I will let everyone know how it turns out.

Ken