Caul me a dummy...

[Denette]

I'm making a cutting board.  It's gluing up as I type this very post!  But I'm so frustrated.  How on earth do people get panels to glue up flat?  I just can't seem to get things to stay in line correctly.  I think I missed the lesson everyone else seems to have had on cauls or something, because they aren't doing it for me.

Here are the details.

I'm making an end-grain cutting board.  I want it to come out as close as possible to perfectly flat after the final glue-up because I don't have a drum sander and am pretty spooked about using my planer after reading horror stories about planers exploding with end grain cutting boards in them.  This means that any imperfections in the glue-up will have to be removed using (gag) just my random orbital sander.  So that's why I want a perfect glue-up, if it matters.  And I've got lots of things going for me.  It's exemplary wood.  Clear, straight, dry.  I've got nice big Jorgensen parallel clamps.  I have some shop-made cauls.  Plenty of other clamps.

So I rip some maple and walnut into strips and glue them together, then plane it to about ¾" thick, pretty typical and no problems.  They were a little uneven after that first glue-up, but it doesn't matter if I can plane them.  So I re-rip and get things set up for the cutting board layout I want, and that's where the problems begin.

I have this issue where when things are all covered in glue, nothing will stay in place.  The first clamp I tighten will move everything all out of place if I'm not extremely careful.  Usually the first clamp goes on very slowly as I readjust every board back into position after a couple of cranks.  They move left, right, up, and down.  When I get things straight one way, they're out of line going the other way.  It's enough to drive me nuts!  If I put the cauls on last, the other clamps and glue have enough of a hold on the wood in its position before the cauls arrive that the cauls seem to do nothing.  

This time I decided to try putting the cauls on first, but that didn't do any good other than making things slide even worse than usual and making me have to reapply wet glue halfway through the glue-up because I was taking so long fiddling with it.  I'm leaving it be for now, but it was all kinds of wonky.  

Any sage advice?  

[shaneymack]

Dummy

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[wtnhighlander]

What kind of glue, and how much?

[Coop]

Brendon gave me a pretty good hint. On your second glue up, do it in sections, 2, maybe 3, and you have more control. Also, I've found that parallel clamps first with just a little pressure, then clamp the crap out of the cauls, then tighten the parallel clamps. And if you have enough room, a straight edge on each end, clamped in place will keep the boards lined up.

[Tom Cancelleri]

Check that your edges are 90 degrees. 

[..Kev]

3/4 isn't very thick for a cutting board?

[wtnhighlander]

Here is one way (of many) to flatten the end grain.

[Coop]

37 minutes ago, wtnhighlander said:

Here is one way (of many) to flatten the end grain.

 

Or wait until you're in your mid 80's like I did, and buy a drum sander

[Brendon_t]

I have had this issue before.  Usually when I have too much glue on the faces to be glued.  I don't even use cauls with the final clamp up. 

After getting one face glued, rolled with a breyer and turning up, I bring the clamps closed which will screw everything up.  I use two 2x2 red oak pieces from the edges first to align the edges[ sides of the board]  then  apply a bit of pressure. As in  one clamp at a time add a quarter turn past touching. Using the 2x2 again, I press down on one side over the clamp arm pressing the pieces to align between the clamp rail and my push stick and tighten while holding.  Repeat on other side.  I rarely need more than 5 or 6 light passes on the drum to sand each side.

If you do end up needing major work, just build a router sled. 15 minutes will save you hours. I flattened 6 by hand 3 years ago.  It's a terrible waste of time. 

[Tpt life]

The Russian guy alternates glue ups so that he is always working with longs boards instead of blocks. His pipe clamps provide a gravity hold. After church I'll see if I can find him on YT. I think a flat surface and sheet of waxed paper could help. You could pound down with a mallet if things begin to pop up. I think Brendon might have it though, spread your glue out and give it a few seconds to tack up. (Not skin over, tack up.) Too much glue takes work to squeeze out. It is easier to just start with the "right" amount. That takes experience. 

[pkinneb]

C shaffer did you mean mtmwood? He has some awesome you tubes on making end grain cutting boards

[Tpt life]

I was catching some Russian or Baltic guy before I found MTM. I forgot my wife committed us to the beach. I will have to dig later. 

[h3nry]

I tried the salt trick recently, now I'm a fan. A few grains of salt sprinkled onto the glue really does helps the joint stop slipping as you crank up the clamp pressure. It takes a lot less salt than you might think.

[Tpt life]

Doesn't matter, MTM does the same.  

[Barron]

Even with good caul use you are unlikely to get it perfectly flat.  You can build a sled, or hunt up a drum sander.  However you can flatten it with a random orbit sander, despite what some will tell you.  

I've done close to a dozen, all with the ROS and no one has ever complained about the final product. In fact, the hard part is to get people to cut stuff on them instead of treating the, like rectangular sculptures.  And no one has ever put a straight edge on one of them.

The most important thing I lerned was to start with really coarse grits, like 40 for the first sanding.  Put some music on your ear buds and go to town. 

[Denette]

23 hours ago, shaneymack said:

Dummy

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Thanks!

23 hours ago, wtnhighlander said:

What kind of glue, and how much?

Titebond 2, hard to say how much.  I was trying to be conservative so I didn't have loads of cleanup, and also only glued one side  of each joint before gluing up the cutting board.

23 hours ago, K Cooper said:

Brendon gave me a pretty good hint. On your second glue up, do it in sections, 2, maybe 3, and you have more control. Also, I've found that parallel clamps first with just a little pressure, then clamp the crap out of the cauls, then tighten the parallel clamps. And if you have enough room, a straight edge on each end, clamped in place will keep the boards lined up.

That's pretty sound advice!  I'll start on another cutting board tomorrow and see how that goes.

23 hours ago, Tom Cancelleri said:

Check that your edges are 90 degrees. 

They are!  I spent a whole day this past week tuning up my jointer.

23 hours ago, TIODS said:

3/4 isn't very thick for a cutting board?

That's the thickness of the boards along the grain - it was 4/4 lumber to start with.  I'm trying to make it 1 ¼" thick, though once I get it flat it might be closer to 1" with how it's looking.

23 hours ago, wtnhighlander said:

Here is one way (of many) to flatten the end grain.

 

That is brilliant!  I did this earlier and it got a side dead flat.  Sweet!  I'll go back tomorrow and get the other side flat as well.  I would have today but had church and other things going on that kept me out of the shop.  One thing I didn't do quite right was take it in increments.  There were some spots where the router was hogging out nearly ¼" of wood (it clamped so crooked, y'all) and it tore out in a few spots so that I'll either have to take another 1/16" off with the router or sand it for ages.  Leaning toward the router again.

22 hours ago, K Cooper said:

Or wait until you're in your mid 80's like I did, and buy a drum sander

I don't want to wait that long! Lol.  I might look around and see if there's a cabinet shop in my area that will let me borrow a drum sander for an hour and then run a crap ton of cutting boards through it.

22 hours ago, Brendon_t said:

I have had this issue before.  Usually when I have too much glue on the faces to be glued.  I don't even use cauls with the final clamp up. 

After getting one face glued, rolled with a breyer and turning up, I bring the clamps closed which will screw everything up.  I use two 2x2 red oak pieces from the edges first to align the edges[ sides of the board]  then  apply a bit of pressure. As in  one clamp at a time add a quarter turn past touching. Using the 2x2 again, I press down on one side over the clamp arm pressing the pieces to align between the clamp rail and my push stick and tighten while holding.  Repeat on other side.  I rarely need more than 5 or 6 light passes on the drum to sand each side.

If you do end up needing major work, just build a router sled. 15 minutes will save you hours. I flattened 6 by hand 3 years ago.  It's a terrible waste of time. 

Yeah, I don't have a brayer.  I ought to get one!  They seem to make spreading glue so much easier.  It's one of those tiny things I keep forgetting to get.  I did something like what you're saying to keep things in line when I glued it up this time, and the axis that I did that on was the least-screwed-up on the cutting board, so I'll definitely keep doing it!

13 hours ago, C Shaffer said:

The Russian guy alternates glue ups so that he is always working with longs boards instead of blocks. His pipe clamps provide a gravity hold. After church I'll see if I can find him on YT. I think a flat surface and sheet of waxed paper could help. You could pound down with a mallet if things begin to pop up. I think Brendon might have it though, spread your glue out and give it a few seconds to tack up. (Not skin over, tack up.) Too much glue takes work to squeeze out. It is easier to just start with the "right" amount. That takes experience. 

A flat surface and waxed paper frighten me.  Wouldn't the excess glue squeeze-out get into the wood and fill in the pores, resulting in loads of sanding to get down past it?  Or am I being paranoid?  (Of course, I guess glue in the grain is better than a warped board!)

9 hours ago, h3nry said:

I tried the salt trick recently, now I'm a fan. A few grains of salt sprinkled onto the glue really does helps the joint stop slipping as you crank up the clamp pressure. It takes a lot less salt than you might think.

Definitely trying this!

2 hours ago, Barron said:

Even with good caul use you are unlikely to get it perfectly flat.  You can build a sled, or hunt up a drum sander.  However you can flatten it with a random orbit sander, despite what some will tell you.  

I've done close to a dozen, all with the ROS and no one has ever complained about the final product. In fact, the hard part is to get people to cut stuff on them instead of treating the, like rectangular sculptures.  And no one has ever put a straight edge on one of them.

The most important thing I lerned was to start with really coarse grits, like 40 for the first sanding.  Put some music on your ear buds and go to town. 

I need to pick up some 40 grit it sounds like!  Lowest I've got is 80.  

 

-----------------------------------------------------------------------------

So to sum up what I'll be doing differently on the next cutting board:

1. Glue faster & use just a touch more glue than I did this time. (Soon I'll buy a brayer.  I've been using a rubber spatula - time to upgrade!)

2. Put a little salt on the glue to help it grip.

3. Put down wax paper on my table saw and use its dead-flat surface as a guide; apply clamps to the top side of the cutting board to use gravity to my advantage.

4. Put on the parallel clamps gently, then clamp on the cauls, then parallel clamp the crap out of it.

5. Get some 40-grit sandpaper for cleanup

 

Thanks guys!  I'll let you all know how it goes tomorrow...

[Brendon_t]

Ib used 60. 40 was just too  gnarly 

[Denette]

Did some shopping this morning and picked up a few odds and ends. Before I use it and potentially go down in forum history as the idiot who soaked his cutting board in laxatives, I have to ask - is this the same mineral oil as you use on a cutting board?

[midtnwoodworker]

Yes that will be fine on a cutting board.

[Denette]

Yes that will be fine on a cutting board.

Thanks! Good to know!

[wdwerker]

You might see little piles of sawdust under your board in the morning ....<grin>

[Denette]

You might see little piles of sawdust under your board in the morning ....

Lol!

[Rapid Roger]

1 hour ago, Arrdenet said:

Did some shopping this morning and picked up a few odds and ends. Before I use it and potentially go down in forum history as the idiot who soaked his cutting board in laxatives, I have to ask - is this the same mineral oil as you use on a cutting board?

I asked the same question several years ago. I didn't want to give all my relatives the "Green Apple Dirty's".

Let it soak in and dry before another coat is added. A person suggested that I put the board in a pan and cover with mineral oil for a few days and then let it dry for two weeks. Didn't sound like a good idea to me.

[Denette]

Well, it's finally turning out alright!  I used same router trick for the opposite side of the board, and it worked just wonderfully.  After maybe an hour and a half of sanding, I got it super smooth (the router gouged pretty deep in some places and I had to sand the whole surface down to the level of the gouges) and then routed in a couple of inset spots on the bottom to lift it by and added a no-drip edge groove.  Now I've applied the first bit of mineral oil to it and it looks so stinking good.  Starting another cutting board right now!  Hopefully the second one will be far less eventful...

[shaneymack]

Looks great ! I like the design

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