cutting board feeling glue line

[Joseph Chang]

Hi,

I made some end-grain cutting boards as gifts. I use a home-made drum sander, followed by a random orbit sander to 220 grit. The wood feels smooth but I can definitely feel the glue lines between the blocks.

On one of the boards I first hand planed (totally exhuasted :D ) and finished with a ROS. Unfortunately, I got some chemicals on the board :( so I went to wash the board thoroughly using soapy warm water. Once it completely dried, I don't feel the glue lines. This gets me wonder how to get rid of the glue lines.

Does anybody notice the same thing? How do you get rid of the glue lines?

Thanks,
Joseph

[Jon Grider]

I can only speculate,but I wonder if it's the kind, type, or age of glue you used? Perhaps it never fully cured before you sanded it and was still soft enough to migrate? I use TBIII on my boards and leave them clamped for at least 24 hours with no problems. The TB III is still a little soft after 24 hours but it makes using a cabinet scraper a good choice to remove much of the squeeze out.

[Phil Mueller]

Not sure either. I haven't experienced that. I use hardwood (maple, walnut, Purple Heart, etc) and titebond II. I let the glue dry for about 1/2 hour and scrape off the squeeze out and leave it clamped at least 4 hours. I flatten it with a belt sander and smooth with a ROS. A ridge at the glue line can only be dried glue or the blocks aren't flat where they meet.
Did you feel glue lines after planning, before washing?

[keith micinski]

The only other thing I can think of is if your using two different types of wood in an alternating pattern. The end grain shouldn't be moving that much but everything moves a little and they could be expanding or contracting at two different rates. I just th out if something else. Maybe your not feeling a ridge but a valley which makes more sense since you said you used a drum sander. Glue shrunk a little and you had a not quite tight joint?

[Robert Engel]

Common causes of glue line gaps:

Mis-jointed surfaces
Indequate clamping
Taking out of clamps too soon

Combination of any of the above.

[Prashun Patel]

Visible glue joints are usually for me caused by inadequate jointing and clamping as Robert says. It's tricky to clamp a large lamination like that effectively if the pieces are not jointed perfectly.

Sanding too quickly after glue up can also leave depressions on the joint so I have read. I have not experienced this myself tho.

[glenn bradley]

I need a little clarity before I weigh in. What are the types of wood you notice the "ridge" between? What type of glue did you use? Are you sure this is the glue or is it the elevation of the adjoining block? If you slide a chisel across the "ridge" does a curl of glue peel away? I will say that I have not found a ROS to be a good tool for making anything flat, especially across two different materials. Smooth yes, flat no. I use the hardest pad I can get and only use the ROS for final sanding, briefly as possible with a high grit.

[William C Rogers]

I just made some cutting boards and noticed the ever so slight condition you described. I didn't notice it until after soaking them in mineral oil for 3 days each side. It is only a thousand or two difference, but can be felt. I am making some more, however I intend to wipe them down with water, let dry, then sand with the ROS at 220. I will see if that makes a difference.

[Ellery Becnel]

I just finished six end grain boards yesterday. I had an issue when I first made some with the glue line. My milling/jointing was not perfect. It resulted in a distinct visible glue line. I did not realize it until after the final glue up.
You can certainly feel the different textures from one species to the next. Now I hold the two pieces together to the light. If I see any light, no go. I use a precision straight edge to check flatness of each piece. I use Titebond II.
I clamp for 24 hours. I use cauls to clamp the multiple strips, to keep them from swimming away. Now I can go straight from the clamps to the V-drum sander, on the final glue up. It took a while to figure this one out. I hope this
helps. I do not feel the glue line any more.

Ellery Becnel

[Wade Lippman]

Never had a problem like that, but after using a drum sander I start my ROS at 100. I wouldn't be surprised if that made a difference.

[Joseph Chang]

Thanks for everyone's suggestions. Sorry I wasn't clear about what I've done.

The boards that I can feel the glue lines are only maple. I always uses TBIII for my cutting boards and I usually left it clamped around 24 hours (I uses Jet parallel clamps).

The board that I can't feel the glue lines are maple and cherry. There are maple/maple and maple/cherry glue lines and I can't feel either of them, which makes me think it's not due to the wood species. I don't remember if I felt the glue lines after planing before washing.

I want to say the glue lines are ridge not valley just by how I feel across them, but I can't be certain. There are no visible gaps that I can tell. I would like to say it's a couple thousands as William said. Maybe it's after the mineral oil + mineral oil/beeswax finish.

My drum sander leaves very bad sanding lines (that was why I experimented with hand plane) so I usually start at either 80 or 120 on my ROS.

Next time I will check individual pieces more carefully before glue-up as Ellery suggested.

Again, thanks everyone and happy holiday.

Joseph

[glenn bradley]

My drum sander leaves very bad sanding lines (that was why I experimented with hand plane) so I usually start at either 80 or 120 on my ROS

Just food for thought. I have abrasives for the drum sander from 60 to 400 grit. I usually stop at 320 for boards. This leaves very little work to be done and I just do a quick touch-up with 320 - 400 with a hard pad on the ROS to eliminate the lines. To each his own.

[Andrew Hughes]

I also agree with what everyone's recommends.Not sure if someone mentions that you can thin the glue a bit so it's not so hard to squeeze out the excess.Maple doesn't take much glue to hold.

[Bob Varney]

I have had this problem also, think it is after mineral oil different woods soak it up at different rates and swell slightly( thousand ) was smooth to feel before oil. I sand again after oil smooths right out.