Tip sought on end grain cutting board with accent strips

[dmbtjclark]

seeking tips.. end grain cutting board with multiple accent strips. Each time I have built one the accent strips end up with a zig zag, just slightly off at each block. Cannot get a straight line. Is it just my calibration on my saw or am I doing something wrong and do you have any tips to correct?

 

[Henry W]

As with your last post that I recall, I am having trouble 'picturing' the issue. Any chance of a sketch?

 

[dmbtjclark]

 

[Henry W]

Did you use a micrometer to measure the thicknesses of the strips? Best I can figure you have some thickness tolerance issues with the original strips. They show up on the accent pieces because the rest of the pieces the colors is 'uniform.' Does the offset ONLY occur at the accent and to the right (as shown in the pic)? Or is there offset further to the left as well? if only at the accent strips, then those are likely the culprit, if offsets are also occuring further left (as the board is shown in this pic) then any or all pieces are suspect.

If the board as glued up currently is flat - then all pieces are likely cut at 90 degrees (assuming you did not do alternating cuts to offset angles). A look at the end of the board might reveal if this was an issue.

 

[ssmith]

Difficult to know what to suggest without knowing what your process is. It seems the thickness is varying somewhat. How are you making sure it’s consistent? If using a planer, you’d probably need to plane all the wood with a given thickness without touching the planer thickness setting at all. You can use calipers or a mic as Henry noted, but not touching the planer guarantees it.

 

[dmbtjclark]

I used a drum sander to get the pieces uniform.
One thought is to make and glue up the accents separately and as a last step glue them together. So make a big walnut board, a maple and a purple heart, cut to end grain blocks, cut the appropriate accents strips, sand/plane, glue in. That should guarantee uniform stripes.

 

[Henry W]

I used a drum sander to get the pieces uniform.
One thought is to make and glue up the accents separately and as a last step glue them together. So make a big walnut board, a maple and a purple heart, cut to end grain blocks, cut the appropriate accents strips, sand/plane, glue in. That should guarantee uniform stripes.

End grain board seems like so much work to me - but I am easily daunted (if that's the right word). What you suggest should work - assuming consistent thickness. If there is thiickness variation then gluing up separately does not seem like it would change the outcome, unless I misunderstand.

EDIT - trying to look very carefully at the picture, I believe the first (left most) maple strip seems to the culprint. As far as I can see, the left side of that strip seems to line up with the walnut, but the right side varies. Am I right?

 

[Al Olme]

Did you trim the edge of the cutting board on the right hand side of the picture? If you trimmed it, was it because the ends were not even? I'm guessing that because the actual size of the blocks on the right edge varies. I could be way off [and often am] but it looks to me like your strips are slipping during glue up. IF all the strips are the same length when you start, try clamping cauls on the ends of the glue up that are not secured with clamps. I have a set of 4-way clamps to cutting board type glue ups and I had a similar problem. The cauls fixed it for me. Good Luck!

 

[Goobs]

Lots of good ideas and suggestions already posted. I’ll add, as well.

For background, I build and sell end grain cutting boards- this does not make me an expert- but I have made many mistakes and learned a few things I’ll share.

If you want some troubleshooting help, can you do the following:

• Measure the length of the end grain board from the first end grain “slice” to the last edge of the last “slice.” If these numbers are the same, this will tell you if your edge grain glue up was flattened to equal thickness.
• Either take a scrap end grain “slice” or use one at either end of the board and lay a good square at the bottom of the piece and see if the glue lines are perpendicular to the edge (what would have been the face of the edge grain glue up). From the pictures, none of them look perpendicular, but you will be able to best judge this in person.

While there could be a number of things that need to be addressed to get the results you are after- which may be some ideas already presented about stock thickness and glue up issues, I think you need to fundamentally look at your first edge grain glue.

Start with very square and consistent stock for your initial glue up. Make sure this glue up results in a flattened panel equal in thickness and with the glue joints perpendicular to the faces. It is not good enough for each edge to be square to the faces- the glue lines should be square. From here, your end grain board should go together well.

 

[Mrfixit71]

It appears to me that either your purple heart strips or the maple strips are not a uniform dimension over the length of the board, i.e. they are wedge shaped or non-parallel sides. The reason I say this is that offsets between strips are not consistent. I think this is the same thing that Henry is saying.
My experience is that a planer is better than a drum sander for insuring uniform thickness.
When you make the second cut to expose the end grain, keep the pieces in order to minimize any variation over the length of the board.

 

[JohnnyR]

Agree that a planer is better for consistent thickness. Check your drum sand bed. If it's open ended you might have one side much lower than the other creating uneven thicknesses.