glue up for cutting boards

[Robert McGowen]

Hi,

I have a "newbie" question. I go through a 1000 sheets of plywood a year, but am just getting into real "woodworking" if you know what I mean!

I made 3 cutting boards (first time) during the past week. I used Titebond III glue. Two were made with the grain long ways and the third was made with the end grain up. They were made with various hardwoods, mostly hard maple, and sanded down to 400 grit. They were smooth as glass. :) On each one though, from several hours to overnight, I could once again feel the joint where the pieces of wood meet. A quick once over with 400 grit and they were smooth, but the next day I could feel the joints again. I used a simple "salad bowl" finish from Woodcraft. After doing this two or three times, they stayed smooth. What is causing this? Am I doing something wrong? I have a guess, but I already feel foolish asking!

Thank in advance! :D
Robert

[Gilbert Vega]

Not an expert on this, but my guess would be that the different woods were absorbing the finish at different rates and expanding at different rates. After several coats , they were saturated and held their lenghts.

[Joseph O'Leary]

It sounds like glue creep. I have never used Titebond III but I have experienced this with Titebond II. This past spring I made around 15 cutting boards for Christmas presents. Several were made like the one in the cutting board tutorial on this site, lots of strips. The others had many strips with a circle glued in each end. I used 3 different brands of polyurethane glue, and finished them all with General Finishes Salad Bowl Finish. The woods included, maple, jatoba, beech, walnut, sapale, cherry, anigre, purple heart and mahogany. I did not have any of the problems you described in the 6 months that the boards sat around.

[Jim Becker]

PVA glues do tend to have what Joseph called "Glue Creep". It's one of the few down-sides to these wonderful adhesives. About the only way to totally eliminate it is to use a different kind of glue...the polyurethane glue that Joeseph mentions is an appropriate choice but is used differently. One, be sure to wear gloves unless you enjoy black stains on your hands for many days after the work. Two, these glues cure in the presence of moisture, so applying it to one side of the joint and wiping the other side with a damp sponge is one method for working with it. Don't use an excessive amount of this glue, either...it's not necessary and will just cause a lot of foamy mess that you need to clean off after curing. (Although it's far easier to remove than dried PVA) Poly glues are also non-gap filling, so be sure your edges to be joined are straight and true.

[Ian Abraham]

I use polyurethane glue for things like that - it works well. We have a very humid climate so I dont have any problems with it curing without adding water, but I guess that could be an issue in other areas.

Go with Jim's advice - there is no solvent for it and the only way to get it off your hands is to wait for the skin to wear down :o (speaking from experience)

Cheers

Ian

[Howard Acheson]

PVA adhesives take anywhere from 5-7 days to fully cure and develope full strength. As long as they are curing you may be able to feel a raised glue line.

Also, any waterbased adhesive will cause the wood to swell in the glue line. If you sand or otherwise smooth the glueline before the water has fully evaporated, you will find a depression when the glueline is fully dry.

[Russ Filtz]

Would plastic resin or epoxy be a good choice then for cutting boards?

[Ralph Steffey]

Resin or epoxy will work but polyureathane is the right choice for cutting boards.

[Robert McGowen]

polyureathane = Gorilla glue?

[Dave Avery]

polyureathane = Gorilla glue?


Yes, though there are other brands.....

[Alan Turner]

On Titebond II, I have had glue creep, and have also had it with other PVA's, but never with Titebond Original (red label). Hence, Titebond Original is all I use when using a PVA.

[Michael Adelong]

Does glue creep mean that the parts have physicaly moved in relation to each other after the initial curing of the glue?

When I read Robert's post, my initial thoughts were that the moisture in the glue was raising the grain in the wood along the joint.

Michael

[Mike Kelly]

Robert it could be glue creep as some have referred to, but you mentioned you were using "various" hardwoods, so I suspect it has more to do with the different shrinkage rates of the different woods you are using. I have made benches with different woods and had the same problem. If you built a cutting board out of all the same material, did it have the same problem? If you glue up same species in some sections run your finger over the two same boards and see if it moved. I think your problem is coming from the radial and tangential shrinkage rates of different woods and different cuts of woods rather than the glue used. This link will show you what I am talking about.

http://www.woodweb.com/knowledge_base/Warp_in_Drying.html

This link will give you the different rates for different species of wood.

http://www.woodbin.com/calcs/shrinkulator.htm

[Joseph O'Leary]

Robert, when I made my boards I tried Gorilla Glue, Elmer's and a product by Liquid Nails. I was just trying them to see the difference. I found Elmer's to be the thinnest, more solvent, less poly?? I found the Liquid Nails to be the thickest. I found that I used much less with the thicker product. All three performed very well. They are a pain to clean up when wet, I do wear gloves. The foam is very easy to clean right out of the clamps. I also like the fact that poly's like clamping pressure. I know that PVA's can be over clamped, squeezing out, and leaving the bonding layer too thin.