wood size limitations using pocket hole jig

[skronk]

Hi all,

I am struggling a wee bit with the spec. of some pocket hole jigs. They state maximum width of stock as around 38mm.
Now the really daft question.......

Does this mean I could not pocket hole joint a 50mm to another 50mm ? or is there another way to do this using the jig ?

I like making planters.....hence the question. Pointless spending £60 or so on a Trend jig if it won't do the job ?

Thanks for your time.

 

[JakeS]

Does this mean I could not pocket hole joint a 50mm to another 50mm ? or is there another way to do this using the jig ?

For the typical design of pocket hole jig, what you're attaching to doesn't matter, because you only put one half of the joint in the jig; the other half you just have to hold in clamps as you screw it together, and if you can do that you're fine.

If the jig you're looking at doesn't fit the width of stock you want to use, you can also get a simpler design of jig which is literally just a drill bushing held at the correct angle in a block... so you clamp it onto whatever stock you want to use directly and drill away with the special pocket-hole drill bit. This is the Kreg version, but I'm sure there are others: http://www.ebay.co.uk/itm/Kreg-MKJKIT-M ... 51aee90d9c

 

[skronk]

Does this mean I could not pocket hole joint a 50mm to another 50mm ? or is there another way to do this using the jig ?

For the typical design of pocket hole jig, what you're attaching to doesn't matter, because you only put one half of the joint in the jig; the other half you just have to hold in clamps as you screw it together, and if you can do that you're fine.

If the jig you're looking at doesn't fit the width of stock you want to use, you can also get a simpler design of jig which is literally just a drill bushing held at the correct angle in a block... so you clamp it onto whatever stock you want to use directly and drill away with the special pocket-hole drill bit. This is the Kreg version, but I'm sure there are others: http://www.ebay.co.uk/itm/Kreg-MKJKIT-M ... 51aee90d9c

Thanks Jake,

What you say is quite true, but I wanted one with a baseplate I could screw to a bench that might take 45-50mm stock. Looks like a non starter.

 

[jdeacon]

It doesn't sound as though it will help you, but in the common K4 Kreg jig, the block with the bushing can be removed from the jig for large stock and for repairs. The block even comes with little slide on feet (well, there's one in the kit at least) to help clamp it at the correct offset; but that's not much help for very thick stock.

I did a load of 4" x 2" (45mm finished) in my K4. I've just measured it and it would go to 47mm with the pressure foot fitted. But I don't see why you couldn't remove the pressure foot, put a thinner bit of scrap in and get up to 50mm.

 

[skronk]

It doesn't sound as though it will help you, but in the common K4 Kreg jig, the block with the bushing can be removed from the jig for large stock and for repairs. The block even comes with little slide on feet (well, there's one in the kit at least) to help clamp it at the correct offset; but that's not much help for very thick stock.

I did a load of 4" x 2" (45mm finished) in my K4. I've just measured it and it would go to 47mm with the pressure foot fitted. But I don't see why you couldn't remove the pressure foot, put a thinner bit of scrap in and get up to 50mm.

Thanks for that....will look into it !

 

[JakeS]

Looking again at the UJK pockethole jig that Axminster sells, the drill-bushing block is attached to the base with what looks like machine screws:

http://www.axminster.co.uk/ujk-technolo ... t-hole-jig

The photos show the block removed from the base and the comments suggest that the clamp is removable, so it should be fairly trivial to attach both to a bit of scrap plywood with whatever gap you like between them. Obviously the larger the stock the less central the screws will come out without further messing around with height adjustment, mind.

 

[nanscombe]

Kreg - Selecting the correct screw

You would also need longer screws as well.

The longest Kreg screw (for pocket holes) is 2 1/2 inches (63mm) which they use for joining 38mm stock together.

When all is said and done pocket holes are a hole drilled at an angle which, when the jig is used, seems to come out from the centre of the timber (as seen in the Kreg chart above).

Maybe you could build your own jig?

Or use a different jointing method, when I built my planters I just used half lap joints for the frames. I made a couple of simple jigs, one to make the length of the joints consistent and the other, used with an "old woman's tooth", to get consistant depths.

 

[JakeS]

You would also need longer screws as well.

Not necessarily. The height of the jig controls how far up the hole starts, and thus how far away from the jig (on the bottom surface) the screw will eventually come out, but the length of screws required is controlled by the position of the stop cuff on the drill bit itself. If you raise the jig so that the hole comes out closer to the centre of your large stock but then also raise the cuff correspondingly (cf. Pythagoras and trial and error, or trigonometry) so that the drill goes further down than before and the step in the drill ends just as far from the bottom of the stock as before, then you don't necessarily need screws which are any longer... any concerns you have about their fixing power aside, that is.

 

[nanscombe]

I was simply going by the prescribed usage of the jig as opposed to doing one's own thing.

Besides, I would have thought that "fixing power" might well figure in the idea of a joint although you could supplement them with dowels or the like.

Or, you could treat the 50mm timber as if it was 2 x 25mm glued back to back and affix screws from both sides, although the pocket holes might not be hidden unless you infill them.

 

[skronk]

Thanks to all who replied.

 

[JakeS]

I was simply going by the prescribed usage of the jig as opposed to doing one's own thing.

Besides, I would have thought that "fixing power" might well figure in the idea of a joint although you could supplement them with dowels or the like.

Sorry - I wasn't trying to have a go at you, just pointing out that the screw length used is by no means proportional to the width of the stock; Kreg's suggesting some reasonable lengths for different configurations, but the only thing that makes a difference is where you set the collar on the drill bit.

I wouldn't use 5mm of protruding screw to fix a joint that had to be reasonably solid, but I wouldn't expect that you'd realistically need a different screw for 50mm stock as compared to 37mm (or whatever the stated max was) stock.

 

[TRITON]

I use the wee Kreg one. Its handy but ive never considered pocket screws to be anything other thn a holding joint with biscuits or the like with glue being the real strength.
That is obviously just my very humble opinion but i agree will you all that theyre handy.
Are you looking to pocket alone or with reinforcement ?

The further back it sits the closer to the center the breakthrough goes. so its just down to using non kreg or jig screws for whatever length you would require :?

 

[Noel]

Just freehand it using the stepped drill bit. A bit of practice on scrap may be needed.

 

[Random Orbital Bob]

to be honest, if you're joining 2" stock why not just glue screw and then plug the holes with grain matched plugs from a plug cutter. Hell of a lot quicker, less fuss and if you use cascamite, plenty strong enough.

 

[woodworkingMK]

Kreg has another version of the jig which is for thicker materials,

https://www.kregtool.com/store/c13/kreg ... jigreg-hd/

The drill bit is also bigger.