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Forum topic by Mark56 posted 540 days ago 1411 views 0 times favorited 9 replies Add to Favorites Watch
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Mark56

6 posts in 540 days


540 days ago

Hello,

I’m writing a little post here to share my experience with simple butt joints. I’m making cutting boards in various types of woods. I constantly have to butt joint pieces of maple 0.70 thick and about 15 inches long. I tried all three Titebond glues. I always look for new things to improve it and here are two techniques I use:

First I use a calibrated jointer set to remove one millimeter of material each passes. I run the pieces at least 5 times each.

- One, Before applying the glue I take a nail and I score the joint. This allow more glue to stay in the joint. (It was a technique I saw from a guitar maker who used to do that before gluing the fingerboards to the neck).

- Two, I talked to a guy at Titebond who recommended me to take the glue I use and create a mixture of one part glue and one part water. This make the glue finer and allow to penetrate the wood. You wait a minute or two and you apply a coat of regular glue.

When you clamp you pieces it’s important not to clamp it very hard. You want squeeze out but you don’t want everything out.

Now, I made cutting boards for my house with Titebond I and I’m very happy with. I clean my cutting board with water and leave it on the kitchen rack. I never had any split or weak joint. The board is like new except for the knife marks. I put some oil on it regularly. For more security I used titebond II for my clients (it says for Cutting Boards on the back of the label). Well I got some returns after few weeks!!!! So now I’m using titebond III with the two techniques mention about.

I don’t want to use any fancy joints on my boards or biscuits. I’m wondering if other woodworkers have better ideas out there.

Thanks,


9 replies so far

View nwbusa's profile

nwbusa

1016 posts in 883 days


#1 posted 540 days ago

I pretty much do the same thing with TB3, except I don’t joint the edges or score the joint with a nail. I just rip the strips on my table saw and glue them up. I think if you have a reasonably clean joint and use enough glue and clamps, it will be a strong cutting board.

-- John, BC, Canada

View MonteCristo's profile

MonteCristo

2094 posts in 785 days


#2 posted 540 days ago

The glue joint by itself is stronger than the wood, assuming it’s long grain to long grain contact. My guess is that there is no real benefit in doing more than making sure the surfaces mate well. The conventional wisdom (as I have always heard it) it that it’s hard to apply too much clamping pressure, i.e.. inadequate pressure only weakens the joint.

Titebond I is a poor choice for cutting boards, which are washed frequently and may well be dumped in a sink full of water. Titebond III is the best of the Titebond line because it’s the most waterproof, but even then it’s a poor idea to soak a cutting board unless you’ve glued it with epoxy.

-- Dwight - "Free legal advice available - contact Dewey, Cheetam & Howe""

View Mark56's profile

Mark56

6 posts in 540 days


#3 posted 536 days ago

Hello,

I continue my post with this photo. I made a cutting board with only butt joints.

Butt joint #1 – Two pieces glued together no dovetail or biscuits.
Butt joint #2 – Maple and walnut glued together no dove tail or biscuits.
Butt joint #3 – Two pieces of walnut glued together. No dovetail or biscuits.

I’m ok with the joints 1 & 2 but do you think the walnut and maple together should have biscuits?

I use Titebond 3

 photo ScreenShot2013-02-02at55242PM_zpsc2a59fe9.png

View Mark Kornell's profile

Mark Kornell

471 posts in 1128 days


#4 posted 536 days ago

Mark,

What your refer to as butt joints #1 and #3 in your picture are not butt joints, but are edge joints. Butt joints are what you show as joint #2 – when the end grain of a board is joined to another (regardless of wood species mix)

For edge joints, you do not need to score with a nail or use glue sizing. All you need is two edges that are a match for each other. Some people will glue an edge directly from a good tablesaw cut, others will make sure the edges are jointed first. The match doesn’t need to be perfect, but the closer you can realistically get, the better. Once you have to edges that mate well, simply apply glue evenly one one or both edges and clamp the boards. Clamp pretty hard, too. The result is a very strong joint, and does not need any joinery to enhance it. If you do it well, you won’t see much, if any, glue line.

When you are gluing end grain, the problem is that the glue wants to wick away from the end surface via the open ends of the wood pores. Proper clamping pressure merely assists this process and weakens the joint. The use of a glue size (the 1:1 glue:water solution) to prep the end grain surface is meant to plug the wood pores, so that the full strength glue stays at the surface and can do what it is supposed to do. Even so, the joint is fragile compared to an edge joint.

Typically, you’d look for ways to strengthen this joint. Commonly, the use of scarf or finger joint would be employed. Or even look to redesign your project so you avoid this type of grain orientation.

A biscuit does not really offer enough reinforcement, but it is thinking along the right lines. I’d recommend using a tight-fitting spline along the length of the joint, probably to a depth of at least 1/2”. Maybe a bit deeper.

-- Mark Kornell, Kornell Wood Design

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Mark56

6 posts in 540 days


#5 posted 535 days ago

Hi,

These are all great information here. Thank you so much for your time!
What type of wood do you recommend for the spline?

Thanks,

View 404 - Not Found's profile

404 - Not Found

2544 posts in 1566 days


#6 posted 535 days ago

Read Mathias Wandel’s Glue Joint Strength Test for some surprising results re cramping pressure.

http://woodgears.ca/joint_strength/glue_methods.html

View Mark Kornell's profile

Mark Kornell

471 posts in 1128 days


#7 posted 535 days ago

The spline would be made from either of the two woods you are joining. I’d pick the harder of the two – maple, in this case – but for this application, it wouldn’t really matter.

Three points on using a spline:

1) The grain orientation of the spline should be in the same direction as the grain orientation of the boards you are joining. Don’t make a spline where the grain goes cross-grain, as the joint will fail in short order.

2) In general, if you are going to butt join two different wood species, you’ll want to ensure that they have similar expansion coefficients. If you have one wood that expands at twice the rate of the other species, your joint will need to be designed differently in order not to fail. I think you’re OK with maple and walnut, but look it up to be sure.

3) Make the thickness of the spline groves about 1/3 the thickness of the board. I.e., if your boards are 3/4”, make the spline 1/4” thick. Doesn’t have to be exactly 1/3, that’s just a guideline.

Also, if you don’t want to see the spline on the edge of the cutting board, then don’t cut the grooves all the way through. Stop them about 1/2” from each edge (and make the spline to match the length). Strength-wise, there’s no practical difference between that and a spline that goes all the way through.

-- Mark Kornell, Kornell Wood Design

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Mark56

6 posts in 540 days


#8 posted 535 days ago

Hi,

One last question.
what about if my walnut grain goes horizontally? Does it make any difference when I joint it?

Thanks,

View Dallas's profile

Dallas

2854 posts in 1084 days


#9 posted 535 days ago

I’m not sure what you mean by horizontally, but consider learning to make half lap joints.

I made a number of edge grain cutting boards for Christmas gifts. I used a lot of different woods butted together, or so it seemed. What I actually did was made half lap joints to give myself something other than end grain to glue to.
On a few of them I used draw bore pins to pull them tight and give a cool look to the board. The boards were walnut, maple and cherry but the pins were Youpon Holly.
Youpon, like it’s cousin American Holly is almost pure white and adds a great accent color.

-- Improvise.... Adapt...... Overcome!

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