I am proving to myself that I can’t make a perfectly aligned joint with the Kreg pocket screw tool. I can do it with no glue, but as soon as the nice greasy effect that wet glue provides cuts in, then “slip” and I have enough movement at the joint that correcting it with sandpaper just cuts through the veneer. (Oh, that looks nice, Mike.)
I’ve never tired biscuit joinery. Will properly applied biscuits 1) align the faces exactly, and 2) hold them as you glue them?
Or, do I need to alter my design so that some movement just doesn’t matter?
Mike
Replies
Just to be clear here, are you using any form of clamp and if so what?
Doug
I'm using the face clamps that Kreg sells.
What I'm experiencing is about a 1/16" offset as I pull the screw tight when the joint is wet with glue. This doesn't seem to happen if I forego the glue.
Also, unless I put 2 clamps across the joint, I'm getting a little twisting across the joint face as the 1st screw goes home.
At present I'm just making interior frames for a cabinet that I'm building, but I'm always trying to improve my craft, even on stuff that doesn't show, so that I'm better on the stuff that does.
Mike D
Mike,
When I am doing face frames with pocket screws I place the clamp directly over the screw and clamp it as tight as I can. If there are two or more screws in the joint I move the clamp for each screw. Kreg also sells a face clamp that mounts on your bench and clamps the pieces down to the bench. I don't have one but it seems like that would help. Anyone out there use the bench mounted face clamp?
Rob
O.K. I will set the next one up as tight as I can and see if that helps. (grunt! snort!).
I do like the idea of speed, but when I get mis-aligned joints, the speed (and sometimes the piece) goes out the window.
(soon to be) Ham handed in Louisville,
Mike D
(sissy, wimp indeed!) :)
Edited 11/28/2007 11:37 am ET by Mike_D
Put a few granules of sand in the glue joint. This will keep the two pieces from moving as pressure is applied.Another trick is to drive in a small brad and cut it off with side cutting pliers right at the surface. This will leave a little nib of the brad above the surface and this nib will prevent the two pieces from moving.To answer your other question, biscuits will not absolutely ensure a perfect joint.Howie.........
Mike:
I had the same experience with pocket screws, switched to biscuits (Porter Cable 557) and never used pocket screws again. There was a very good article in FWW a few years ago on biscuit jointer use, which should be findable on this site. If you do it right, the joints will line up perfectly. Good luck.
Dennis
I am just the opposite of some of the other posters. Once I tried pocket screws, I reach for them first. With pocket screws, the joint is done in about 2 minutes. With biscuits, you need to wait for the glue to dry, and putting a face frame together often becomes a several hour job using multiple clamping operations. With screws, the whole thing is done in 15 minutes with no clamps save the joint clamps that come off as soon as the screw hits bottom.
I use the vice-grip type joint clamps with the circular pads. Put those puppies on tight and there's no way the joint can move provided the stock is the same thickness on both parts. If it isn't exactly equal, a little judicious shimming on the back side of the thin piece will do the trick.
A thought just occured to me. I use the Kreg screws that are designed for this joint. The threads and head are set up so they pull the joint tight and straight. You aren't trying to save a few cents by using some other type of screws are you? ;-)
Mike Hennessy
Pittsburgh, PA
No, I'm being good! Only the finest, coarse tooth (for plywood) and fine tooth (for hardwood) gEnuine Kreg (tm) brand screws for me.
Mike D :)
Well, I guess you gotta quit bein' such a sissy wimp with them clamps then. Hunker down on 'em! Oh, and make sure your drill stop is deep enough.
;-)
Mike HennessyPittsburgh, PA
Yep. I reckon that you'll need somewheres between 5,000-6,000 psi. Should make a nice article for FWW.Glaucon
If you don't think too good, then don't think too much...
"I reckon that you'll need somewheres between 5,000-6,000 psi."
Yes, I find that is optimum. The only problem is that you have to start out with 1" stock so you end up with 3/4" after you release the clamp pressure. ;-)
Mike HennessyPittsburgh, PA
Hi Mike,
I have used both the Kreg system and Castle type pocket joinery. The Kreg has a somewhat steeper screw angle that causes shift in the mating pieces. Not that the other doesn't,it is just much less prone to it and when it does it's extremely small. In fact you can put a joint together on a flat surface just using your hands if you want.
The key with the Kreg, as mentioned earlier, is to use plenty of clamping force and make sure your stock is the same thickness. Also, when you assemble your joint with glue and clamp, give it 15 or 20 seconds for the glue to tack before driving the screw. It slows the process down but helps the shifting problem.
I've found it very difficult to line up two veneered faces ( ply ) using pocket screws ( it sounded like that was part of your question ). I do use biscuits for registration in this case clamping at one end of the joint and working my way down aligning as I apply more clamps.
Paul
I can see that the Castle system, with it's much flatter angle, should cause less displacement. That dedicated machine sure is nice, but unfortunately, I don't see anywhere that they have a small shop jig like the Kreg. Do you know of a workbench top jig with that flat of an angle?
I'm going to try Other Mike's suggestion to really clamp down on the faces and your suggestion to let the glue set for a few seconds before pulling the screws down tight - maybe that'll do the trick.
Yes, I am trying to line up two veneered faces, and I may well try biscuits next for this type of registration.
That doesn't mean that I'm necessarily going to give up on pocket screws, entirely, but perhaps just not for this type of application. We'll see what happens. I'm sure that there's a learning curve with the biscuit joiner as well.
Mike D
you can get perfect joints with pocket screws. You need use better clamping techniques. I found biscuits to be finiky. They are as likely to make a missaligned joint as anything else. Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Mike ,
You can make one if you want a good pocket hole jig .
This one has been in service for over 20 years .
As the last poster said if your pilot is not drilled through all the way there is a pretty good chance that's the problem .
regards dusty
Edited 11/28/2007 9:43 pm ET by oldusty
Hi, Old Dusty,
Yep, I'm drilling all the way through.
It's likely that I have stuff to learn before I get the result that I want. Fortunately, I'm practicing on stuff that won't show.
Nice jig, by the way - thanks.
Mike D
Biscuits have a little bit of play in them. It's not much, but it's enough that you can get a ridge that you can feel between the two pieces. Worst case is probably less than 1/64".
-Steve
Kreg is notorious for slippage. Part of the problem, especially if you're using the jig, is that if you follow the settings they give, then the drill bit doesn't quite penetrate the first part of the joint, and doesn't contact the second part at all. I guess they do this to avoid damaging the jig with the tip of the bit. So when you drive the screw it blows out a small sliver of the first part, which doesn't help with alignment. You can clamp the pieces together dry, and then drill a short pilot hole through the remnant of the first part, and into the second part, to provide a passage for the screw. This of course is a pita, and does away with one of the supposed benefits of Kreg, speedy operation. Unless you want to keep changing bits, you have to have a second driver handy for the pilot hole. I've pretty well given it up for precise fits.
Jim
Any chance that you're overtightening the screws? I've been using pocket screws for about a year now and can't wait until biscuits, glue, clamps, and long waits fade to a really distant memory. - lol
One of the problems I had when I first started using pocket screws was overtightening the screws. Once I figured out that a "12" setting on my 14.4 cordless would ratchet the chuck at just the right moment, that problem became history.
I also wonder why you're using glue at all. Pocket screws give you a very strong mechanical joint and that small amount of additional strength you get from gluing end grain-to-long grain probably isn't worth the aggravaton of a slipping joint. I quit using glue after the first couple of face frames I made and have never had a failure.
I use the Kreg pad-style vise grip clamp and clamp it across the joint. That holds everything in place quite nicely while I run in the screws.
What can I say. I'm a retired engineer.... we're sorta compulsive. ("anal" was the old term, but that was SOOO rude!) A little glue is good .... a little more is better. Screws ... Glue... Clamps!.
Heck, if I wasn't married-with-children and had women-folk that take them from me, I'd wear both belt and suspenders. You gonna clamp that or what? Need another clamp? I read that you can't have enough clamps.
Mike D :)
P.S. The screws are not stripping out (barely), so they can't be overtight, right??
Edited 11/28/2007 8:58 pm ET by Mike_D
Mike -
Don't give me any of that "engineer" baloney - I are one, too. - lol
Engineers come in two flavors. The first does things like everyone else and cruises safely through their career never rocking the boat. The second kind is always questioning the status quo and looking for new ways to do things - sometimes just because the old way is boring.
I'm definitely in the second group. Very early in my engineering career, I was "adopted" by a group of rebels, malcontents, and neer-do-wells in my company and it ruined me for life. I made a career out of finding new ways to do things and challenging the establishment. It's been a helluva ride and I don't regret any of it. - lol
Now that I'm semi-retired and making a semi-living designing and building cabinets and furniture, I follow the same pattern - figure out how everyone else does something and then look for new ways to get it done.
What's wrong with a belt and suspenders?!! You have probably heard the old question about why old men wear suspenders? To hold their pants up!! Ha! Ha!
Im 62 so I resemble my old comment.
http://www.sawmillcreek.org/showthread.php?t=8119
I hope this helps.
That's cool. Sounds like he's solved the problem.
How do you see the pictures refered to in the thread?
Mike D
Sorry Mike, I don't know. I couldn't see the pics either.
No problem! It's a great post without the pictures.
Thanks,
Mike D
I use Kreg and plywood "all the time." If using the Kreg vise grip clamp, I adjust it to be just tight when closed, then I open it and give it 1/2-3/4 more of a turn to tighten it further.
For clamping longer sides (at 90 degrees), I use a pair of bar clamps. Sometimes I live dangerously and adjust the piece I'm screwing in a slight 16th off, and let the slippage pull it into place.
Last, for edge to edge plywood joins, understand that it isn't the strongest joint and be sure the ply pieces are the same thickness. It's amazing the variation you can get...
I used the Kreg system but use two clamps:
first the face clamp that came with the mega-kit. This helps a lot.
Second, I bought two of the monster clamps that fit one side to the edge of piece of wood being glued and a pin that fits in the hole you aren't putting a screw in (I always use pairs at least. Kreg calls it a "right angle clamp"
Here's a link to the clamp:
http://www.rockler.com/product.cfm?page=10470
and I also followed the other poster's advice and drill deeper so that pushout of wood doesn't happen, either.
The little-bit-o'-sand trick sounds cool ... I'll try that next time.
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