Pocket Holes: Allowance for material thickness

[Anony Mouse]

Hi folks.

I'm trying to figure out the positioning of the Drill Guide for various material thicknesses, when the Drill Guide is used by itself (without Spacer Blocks) for repair work.

As I read it, the Drill Guide by itself or with Spacer Blocks is fine if the nominal thickness of the material is 1/2", 3/4", 1" thick or any larger size that is a multiple of 1/4".

But what if you don't have a Spacer Block, or enough Spacer Blocks, or if you're material thickness is not an even multiple of 1/4" ?

If I'm reading the instructions correctly, for material thicker than 1/2" the Drill Guide must be positioned back from the edge of the material by an amount that is determined by the actual thickness of the material. For 3/4" material the Drill Guide is moved back the width of one Spacer Block.

I have measured the Spacer Block as adding 3/8" to the height of the Drill Guide. So, in the absence of a Spacer Block being available...

For 1/2" material = Drill Guide is flush with end of material
For 3/4" material = move Drill Guide back 3/8"

So does it automatically follow then that...

For 1" material = move Drill Guide back 3/4"
For 1 1/4" material = move Drill Guide back 1 1/8"
For 1 1/2" material = move Drill Guide back 1 1/2"
For 1 3/4" material = move Drill Guide back 1 7/8"
For 2" material = move Drill Guide back 2 1/4"

And so on: add 1/4 inch to the previous value in the first column, add 3/8" to the previous value in the second column.

Am I on the right track? If so, I need to expand on that table to cover some intermediate thicknesses as well. For example, I am about to take on repairing several chairs where the nominal thicknesses of the material is 7/8". I think it would be useful to have a table where the first column increments by 1/8" for a range of material thicknesses.

My table would be in millimetres as Australia uses the metric system, but conversion is no problem.

Comments & thoughts?

[Anony Mouse]

3 dozen views and no comments!

With settings being so important to success, surely someone has some useful input on this issue.

Kreg staff ???

[Ryan Zylstra]

Hello,

You are correct in your thoughts about the drill guide block stepping back in those increments, but the Kreg Jig is maxed out at 1-1/2" material thickness. You can use the jig on thicker materials but the longest screw available is 2-1/2". Please keep in mind the settings for the drill bit do not scale so easily and you will want to use one of the jigs to set the drill bit stop collar accordingly.

[Anony Mouse]

Thanks Ryan. I have now printed a table to keep with my Jig. Against material thickness, from 1/2" to 2" in 1/8" increments, it tabulates distance of Drill Guide Block from end of material, along with Screw Length for that thickness. Both millimeters and inches are shown.

I find it a handy quick reference when using the Drill Guide Block by itself. As you say, it is still necessary to set the drill bit stop collar with reference to the Jig markings. Measuring the distance-from-edge worked out fine for the 7/8" material I'm currently working with.

FYI, I started this because I only had one Spacer Block, which wasn't enough for the material thickness I was working with, and my local Kreg reseller is about an hour's drive from me and was out of stock of extra Spacer Blocks anyway. When I get my 3-D printer (within a couple of weeks hopefully) I'll look at creating a range of spacers for the various material thicknesses I encounter.

[Ryan Zylstra]

Maybe the Portable Drill Guide Base would be more value than using material in the 3d printer

https://www.kregtool.com/store/c22/kreg-jigreg-accessories/p108/por...

[Anony Mouse]

Sure, but what about a repair job where you're tightening up a loose joint, and you can't get the lip of the Portable Base over the end of the material to be drilled, because the gap between it and the material it's joined to is too small?

I've got this situation with the wobbly chairs I'm working on at the moment, and the amount of work would be considerably increased if I have to carefully open all the gaps so the lip of the Portable Drill Guide Base fits in.

But I can print very accurately sized spacer blocks to suit a number of material widths. Just grab the appropriate spacer out of the box, sit it on the material, and push the Drill Guide Block up against it. Voilà, exact positioning achieved.

[james wilhelm]

HI  as far as the chair repair goes , I would use  the KREG  MINI  jig , if you have one , great for repair job,s  and not that expensive here ,hope this help,s , JIM !!

[Anony Mouse]

Sure Jim, would be handy if I had one, and next time I make the one-hour drive to the Kreg distributor there's a good chance I'll buy one.

However, even the Mini Jig may need to be spaced back from the edge according to material thickness.

By the way, going by this video https://youtu.be/ca1_aRRF17Q and the comments to it, it would seem that the default material thickness for flush mounting of the Mini Jig is 3/4", not 1/2" as for the normal K4 unit. Is that correct?

By the way, here is my table for the normal K4 jig:

If anyone sees anything wrong with that please advise.