Why am i getting raised glue lines on cutting boards?

[Nick2cd]

Every time i make an end grain cutting board i sand it down until it's butter smooth. i religiously start at 50 grit and then work up through 80, 120, 220. at the completion of sanding, i can't feel any of the glue lines and it's smooth as silk. once i wipe on my General Finishes salad bowl finish (diluted to 50% w/ mineral spirits) with a cotton rag, i notice i often get raised glue lines that i can slightly feel once it is dry. i then have to lightly sand it down with 220 until the raised lines are flat then apply another coat of finish. i repeat the process until an adequate finish is built and it remains smooth. is this common or am i making an error somewhere? btw, the wood is dry and acclimated to my shop.

[tdale51@yahoo.com]

Nick,

How long are you letting the cutting boards set after glue up? The wood fibers soak up moisture for a considerable time from the glue. This causes the wood fibers to swell until they release that moisture,thus causing raised joints. I'm not certain this applies to end grain so much as long grain but I would let the project set for a few days between glue up and sanding, maybe that'll help.

Dale

[Nick2cd]

the problem doesn't present itself until i apply finish. i have sanded on a monday and then finished a week later with the same result.....smooth until finish is applied

[Craig]

What type of glue are you using?

[Nick2cd]

I use titebond III.

[Craig]

Any chance the finish dilited with mineral spirits is softening the glue? Typically if the glue wasn't completely cured before finishing you would get die-back(a recess), not raised glue lines. Since the wood fibers are absorbing the finish, I don't suspect any wood shrinkage.

I'd test the finish on some dried glue & see if it softens it any.

.

[Nick2cd]

i'll give it a try and see if it softens the glue. this is the same finishing technique and dilution Marc recommended for these boards. maybe he'll chime in and confirm or deny similar results.

[blkdiamond]

That is odd. I have used the same process and finish (GF Salad Bowl and Mineral Spirits) as you on the cutting boards I have made and I haven't experienced the same problem. The only difference is that I am using Titebond II.

[Nick2cd]

hmmmm, wonder if it has anything to do with the titebond III specifically?

[dcustoms]

I had the same problem with titebond II no idea why it does it I just sanded them down and applied finish until they went away. My guess however is that the glue was raising up because the glue joints were wider than normal, ie. there was a slight gap that filled by glue. But as I said i am not really sure.

[thewoodwhisperer]

I can indeed confirm that this happens quite often. Bottom line is we have to remember that an end grain board is nothing more than a series of glue joints. And like any glue joint, it rarely stays perfectly smooth. Whether it is wood movement, swelling from absorbed finish, glue line creep.....doesn't really matter. Its just something that happens. This will also happen after the board gets used in the kitchen. If this board is for your own use, you can actually do something that will help the board to stay smoother over its lifetime. Finish the board as recommended in the video and sand between coats to knock down the joint lines. You should end up with a fairly smooth board by the last coat. Once fully cured, take it into the kitchen and start using it. Let it do what its going to do and don't stress about the joint lines.

After a few months and many uses, you will probably notice the top is not only a little scratched up, but the joint lines are always noticeable when you run your fingers over the surface. At this point, let the board dry completely and then take it back in the shop. Sand the top thoroughly with 320 grit paper. Apply a very light diluted coat of your varnish and wipe off all the excess. Let dry and bring it back into the kitchen. From my experience, I have found that this second treatment after a "break-in" period results in a surface that stays smoother and looks better than one that is fresh out of the shop.

Keep in mind that every time I use my board, the surface gets rough and I can feel all the joints. But after it dries again, everything flattens out and the board is pretty darn smooth. Some joints can still be felt but its not bad at all. Considering what it is and how it is used, I would never expect this surface to be perfect anyway.

[Nick2cd]

(sweet sigh of relief) Thanks for clearing that up, Marc. I'm not concerned with the glue lines themselves....as you said, it's going to get used and abused. my biggest concern was whether or not i had a flaw in my technique that was causing them to become proud. now that i know that it isn't just happening to me, i can rest easy. I just finished one up for a charity event. it will be auctioned off this week. The coordinator of the event loved it and valued it at $300......he gave me a tax write off receipt in that amount!!! i told him it was not worth that much but he insisted so i obliged. Thanks again, Marc! you're even helping me chip away at my taxes this year.

[JohnM]

I’m dealing with this issue too, I have a theory that is somewhat tested out. I thought that the sanding might have sheared away the wood better than the glue, and simply burnished the glue down and then it later kind of stood up. In order to test this, I used a block plane on the board that had glue lines popping up, and after cleaning it, water popping it, and lightly sanding with 220 it’s a lot better. That being said, this board was used for about a month in the kitchen, so simply redoing it after use might be what has helped it. Planning just one side was a nightmare and took over two hours so that can’t be the answer (I just wanted to test shearing vs sanding.) I have a board that I’m working on now where I used a card scraper thinking that shearing off the glue joints and wood is better than sanding. So far the new board feels good, but I can still feel some lines. 

my card scraper sharping skills suck, so maybe you might have even better luck than me. 

[Tpt life]

It helps to have time to monitor. Glue is removed much more easily after it tacks, but before it is hard. We’ve all missed that window, no judgement…but I’d try to find that time. 

[gee-dub]

On 4/9/2026 at 2:47 AM, Tpt life said:

It helps to have time to monitor. Glue is removed much more easily after it tacks, but before it is hard. We’ve all missed that window, no judgement…but I’d try to find that time. 

So true.  That window varies with our environment.  In summer where I live it is about 20 minutes and I just set a timer on my phone to remind me to go back and slice the leathery stuff off.  In winter it is more like 30 minutes for me.  It is certainly easy enough to draw a few lines of glue on a board and come back every 10 minutes or so to check the consistency of the lines to find your window.  You want it to come off clean and not pop with a liquid center.  I use a few things for this operation.  This one is pretty cheap.  I have it in a 1" and it has performed well for this task.