Pocket hole screws & joint creep

[Bas]

I'm trying to make a simple butt joint between two pieces of plywood. They're about 10" wide. I drilled two pocket holes (at the correct depth for 3/4"), put one piece on the other, and clamped them together with a Kreg right angle clamp. The edges are perfectly flush at this point. The problem is when I drive in the screw. It pulls the board in the direction of the screw, leaving a ridge 1/16" - 1/8" wide. I know, what's 1/16" in the grand scheme of the universe, I guess I'm just uptight about cabinets being square and all.

I'm not sure how I can correct this. I've adjusted the right angle clamp to clamp as tightly as possible, any tighter and I won't be able to close it! The only solution I see is to go buy a second right angle clamp, and use three pocket holes. That way, I can clamp the outer edges, drive the middle screw, release one clamp, drive a screw, then do the final one. But that seems like overkill. Part of the problem I think is that the plywood is prefinished, i.e. very slippery. Then again, the Kreg video shows two pieces of melamine being joined, with only one clamp.

Any ideas?

 

[Trent Mason]

I started cruising with the Kreg jig yesterday and noticed the same thing, but in the opposite direction, away from the screw. Planning on building a jig that I can clamp on and keep it from moving in any direction. :thumbs_up:thumbs_up

 

[Canuck]

Bas

One possible solution would be to place a rabbet (very shallow ie 1/16"-1/8") on the end. The pocket screw should draw the side in until it hits the rabbet shoulder and stop.

I have really only encountered your type of issue when I smear glue on the joint....really slippery. Now I don't even use glue. The pocket screw is so strong.:icon_thum

I also found out (the hard way) that you shouldn't overdrive the pocket screw. I put down the impact driver and reset the clutch on my drill/driver to just snug up the screw until the head bottoms out in the hole.

Good luck.......

Wayne

 

[Skymaster]

Bas: if you have a pc of melamine around or anything with a non stick surface, clamp your pcs to IT,than run the pocket screws, it is a common issue dont ask how I know this:gar-La;. Your best friends with pocket screws are the RAC's :gar-Bi Translation: Right Angle Clamps, one leg is 3/8 pin clamps up like a visegrip, get em on the web Not from Kreg or box stores list prices are nutziod, I got mine a while back for about 18 bucks @. IF I find something b4 u do I will Holler:gar-Bi:gar-Bi

 

[zapdafish]

glue makes the creep alot worse, easier to slide I guess

I use two ways to combat it and it works pretty well.

if the green is being joined to the red, I use a blue board and clamp that board down which does a real good job of preventing creep. I use scrap 3/4 mdf to use as my blue board. Sometimes I will also drill two holes real close together and use the right angle clamp in one and screw in the other. It seems the closer the clamp is to the other hole, the less creep you get.

 

[4yanks]

An old trick I read somewhere suggested putting some grains of sand in a glue joint to keep it from shifting. I have tried it, it works. Another possibility is to use a spline. A slot cutter and router table should allow you to do it while concealing the spline. Biscuits are another possibility (I'm sure that's not what you imagined when you got the Kreg jig). Good luck.

 

[Sully]

I use the backup board like Steve showed. I have found that the right angle clamps don't really do a good job of preventing creep.

J

PS: If you are using glue in the joint and the backup board, be sure to remove the backup board after getting all the screws tightened down. Otherwise your backup board may become a design feature. DAMHIKT

 

[toolferone]

This is a newr clamp from Kreg.

I have not got one yet but want to. It looks like it would stop the creep. I have 2 of the other right angle clamps and they do creep sometimes.

 

[skysharks]

Bas
I have had my Kreg jig and other variations of it for well over 7 years.
Over that time I have driven well over 2000 pocket hole screws. I too used to get the "creep".
Several things have helped me.
1. Increase clamping pressure when using the clamps that are suppose to keep the board faces flush.
2. Prior to joining, drive the screw thru the hole to ensure a clean pathway an remove any material that may hang out of exit hole.
3. A backer board of some type that others here have stated.
4. The use of a long clamp which holds the mating surfacing of the project together as if you were just going to use glue only, and TIGHTEN. I hope that makes sense.

5. Very importaant, If using the newer style Kreg jig with the material hold down clamp located up front as compared to the older style that is on the back side of the jig. Give it to me and I'll make sure that it's OK and you can have my old one. hhehehhe.

MAC


MAC

 

[Joe Scharle]

Bas, my workaround is 2 small blue clamps in front of the part that's gonna move for most parts.
If it's really important, I'll make a very shallow (1/16") rabbet to prevent movement.

 

[Bas]

Folks, thanks for all the suggestions. I'll get a second right angle clamp and use a backer board/ clamps to ensure the piece being joined can't move, and take it from there. Failing that, I can always take out the brad nailer and do some therapeutic joinery

 

[Travis Porter]

From what I have read, the Kreg jigs are notorious for this behavior. Supposedly the Castle/Porter cable automatic units are much less susceptible to this. Something about the angle of the screws making it creep.

FWIW, if you have already tried it with your existing screws, the screws will try to go back in the same places again.... Frustrating.... But, I do like my Kreg jigs and Foreman.

 

[Bas]

From what I have read, the Kreg jigs are notorious for this behavior. Supposedly the Castle/Porter cable automatic units are much less susceptible to this. Something about the angle of the screws making it creep.

FWIW, if you have already tried it with your existing screws, the screws will try to go back in the same places again.... Frustrating.... But, I do like my Kreg jigs and Foreman.

I might get the HF version. It is solid aluminum, and looks extremely well made. But as for the screws going into the same spot - I was smart enough to try a few test pieces before committing to drilling holes into my carefully cut cabinet sides with shelf holes... I have to be 100% sure I can do this right at least some of the time. I am sure I'm going to have enough errors to fix because of something stupid...

 

[Phil S]

I happen to have a Porter-Cable Model 550 Pocket Cutter. This machine uses a pivoting router to make the pocket and then a pilot hole is drilled thru a bushing. The hole is exactly parallel to the board face, this keeps the faces of the two boards being joined in alignment without having to add a bunch of clamps to keep the boards from misaligning. Anyhow it works much better than the angled Kreg process. Not sure why PC stopped selling this - Yes I am - the kreg jig came out a lot cheaper.

If you would like to test drive the 550 let me know and I think you can find a used one on ebay

 

[Gofor]

The latest edition of Wood mag (issue 198 July 2010) has and article on "Five-Minute Face Frames" that may give you some tips on the Kreg joinery. See page 43. I don't have a pocket screw set up so cannot offer advice.

Go

 

[BobcatBob]

A lot of people don't use glue when using pocket screws, but I usually glue and screw. However, I first glue and clamp, let it sit for about 10 minutes and then screw in the pocket screws. The glue has set up enough by then to keep the boards from creeping.

Bob

 

[zapdafish]

I rarely use glue as well. Primarily used glue when I first got the jig and was playing around with it. If its a cabinet and its going to be hanging on the wall I dont use glue. If its something where the joints might be stressed due to it being moved like a table or rolling piece of shop equipment, I started to add glue. Having the backer board has really eliminated my creep problems. Seems like the screw lifts up the first board and tries to crawl forward as it enters the 2nd board, with the backer board clamped down by 4 bessies, it aint creeping :icon_thum

I made several spacers out of mdf that are the same height as the bessie clamp so I just place the work on the spacers, position the backer board, use a quick clamp to hold it in place, then screw down the bessies.

 

[reprosser]

...The only solution I see is to go buy a second right angle clamp, and use three pocket holes. That way, I can clamp the outer edges, drive the middle screw, release one clamp, drive a screw, then do the final one. But that seems like overkill.
Any ideas?

I use two clamps sometimes and it helps. BTW - you don't HAVE to put screws in the extra holes used for clamping.

 

[junquecol]

My theory ( remember that theories are just like opinions, everybody has one) is that you are most likely using course thread screws. The pitch of the screw is advancing it faster than the point is drilling into the second panel. I usually drill a pair of holes at each location, put the clamp in one, and FINE thread screw in the other. I also put a second clamp at other end of panel. Letting the screw feed itself, I screw panels together. Use very little pressure on your driver. If panel does shift, I then remove screw and use other hole. After I have panel "tacked" with fine thread screws, I sometimes come back and replace with course thread screws. You could just do fine thread screw, and if panel didn't shift, remove it and replace with course thread screw. Hole would already be predrilled.

 

[MarkRei]

Woodcraft Magazine (April / May 2010) wrote an article recommending the Route-a-Pocket tool to solve joint creep issues. Here's a link to their website that includes video of the tool.
http://www.whiteoaktools.com/cart/index.php

The tool has a shallow 10 degree screw angle so it has less joint creep.