Clamping question

[Tim Hadaway]

So today I got my first opportunity to put my awesome Kreg jig to work. I am building the most basic and simple table top that will be removeable for a kitchen island. My friend just wanted one piece of 3/4 birch with a maple band around it. Easy enough. I don't have a 'per se' clamping table, so I have to do the best with what I have got for now. My question is this.

When installing a hardwood band to plywood is it normal for the plywood to "ride high"? This is how I did it, and I don't understand why I have about 1/32-1/64 difference in the ply and the band.

I used my table saw as a clamping table. I rigged up a normal C clamp with a scrap piece of hardwood to hold down the ply. I clamped the band to the saw butted up against the ply....everything was firm and it all looked on plane....I moved the clamping rig for each screw. The bottom should have been flush since both items were clamped to the same piece of metal on the saw. I ran my screws in and somehow the ply was raised by 1/64-1/32....not a big deal, I know, it will sand out, but am I missing something on clamping plywood....?????? Is this normal?  It's got me scratching my head....I thought I had figured out the perfect system for temporary use. After Christmas I will be building my assembly table/outfeed table, but I have a few projects to do between now and then. Any insight will be appreciated. Hope everybody had a Happy Thanksgiving!

Tim H

 

[David Dean]

well that plastic clamp isnt strong and your 1/4" is to far over your top you need about a 1/16 or a 1/32 hang over and use a good steal clamp.

[Jay Boutwell]

Tim, I build alot of cabinets and my method of applying a hardwood band seldom requires the use of a clamp.  I use a flat surface to lay both pieces on.  Since the pocket holes are bored on the underside of the ply wood and I apply a light coat of glue to both surfaces. Lay the plywood upside down (pocket holes are now up) place about 4 layers of news paper or other suitable material of about 1/32 " thick under the plywood so that it is just behind the plywood edge.  Move the edged band in position and aline it  Starting in about the middle of the length of item you are working and insert the pocket screw into pocket hole.  Grasp hold of the hardwood band apply pressure down onto the support surface (table, bench, level concrete floor ect) and drive the screw in.  The pressure down on the hardwood band with prevent it from moving while the screw pulls the plywood tight against the band.  Work from the center outwardstowards the ends.  The paper you added under the plywood will give you about a 1/32" of hardwood above the plywood.  Now sand the hardwood flat with the ply surface.

Note:  it is better to sand the hardwood down instead of the ply as now days the veneer on plywood is very thin and you will usually cut through the veneers.

Another trick I have used often when doing this is to use the edge of the  flat shank of a woodchisel  (midway between the cutting edge and the handle) and use this as a scraper.   I take my wood chisels and hone the flat surface until it is flat.   This gives you a very nice 90 degree surface on the flat part of the blade to the edge and that make a very nice scraper.  Since grasping the blade and the handle and using the chisel in this manner you can apply enough pressure that you can rapidly cut down the edge of wood.  Becareful of the sharp edge of the woodchisel and move in the direction of the woodgrain and against it to prevent tearout.

[Ryan McAllister]

I agree with David and Jay. The plastic Irwin clamps just aren't strong enough and the jaws will flex under too much pressure. I try to always leave the band a little high as well and I like to use a flush trim bit on the router and bring the two surfaces flush, a little touch sanding and your done!

[Tim Hadaway]

Thanks guys.....I need to get more clamps....those plastic things are junk for serious clamping.

[Ken Darga]

Tim,

The clamps mentioned, are not junk, they're designed for light to medium duty clamping pressures---

they're very useful for many clamping tasks.

For HD clamping pressures, other types are more effective.

For satisfactory results, the proper tools need to be used.

Tim Hadaway said:

>>>....those plastic things are junk for serious clamping./p>

[Tim Hadaway]

Oh, I agree Ken, hence the statement "those things are junk for "serious clamping". They do have their use....I use them almost every day for something. I was just trying to "overuse" them. On another note...do you, or anyonbe else reading this, have, or have you used the Kreg corner clamps?....Just looking for advice on the use of these.....maybe I just need some practice, but to get everything lined up, flushed up, and clamped takes about 4 1/2 hands....lol.....even then, with them clamped what I would think is pretty tight, it is possible to move the wood in the clamp which worries me when driving the screws.

[Jay Boutwell]

Tim, the Kreg corner clamps are very nice tools of which I appreciate when I am clamping together a face frame to a cabinet case.  They work very well without problems and are actually pretty fast to use especially if you have more that one set.  I have 4 of which I use two on each side of a cabinet case and pull the face frame into alinement and holding it there while I apply some screws.  I also use them when I am building a cabinet case such as a lazy susan and I am using 3/4" plywood and attaching a corner to a second piece of 3/4" ply. like the sides to a back. ( I build all my lazy susans using 3/4" ply for the sides and the backs) 

 I used to use bar clamps and or pipe clamps to do this but since the kreg clamps came out they have taken the place of bar clamps.  You are right about one thing, it takes practice as everything had its degree of frustration until you get the hang of it.  Would I reccomend them????  yes I would.

[Tim Hadaway]

Thanks Jay....I am sure I will get better with them....I know there are some adjustments that can be made, and I play with different thickness materials, so that will be a trial and error thing. I am using them to build basic square frames. I just got them this morning, and played with them at the kitchen table while we were having our morning coffee.....you should have seen the wife's expression when I showed up with a couple of short 1x4's to play with....that was priceless.

Jay Boutwell said:

Tim, the Kreg corner clamps are very nice tools of which I appreciate when I am clamping together a face frame to a cabinet case.  They work very well without problems and are actually pretty fast to use especially if you have more that one set.  I have 4 of which I use two on each side of a cabinet case and pull the face frame into alinement and holding it there while I apply some screws.  I also use them when I am building a cabinet case such as a lazy susan and I am using 3/4" plywood and attaching a corner to a second piece of 3/4" ply. like the sides to a back. ( I build all my lazy susans using 3/4" ply for the sides and the backs) 

 I used to use bar clamps and or pipe clamps to do this but since the kreg clamps came out they have taken the place of bar clamps.  You are right about one thing, it takes practice as everything had its degree of frustration until you get the hang of it.  Would I reccomend them????  yes I would.