Plank glue

[dvlp47]

Typical first timers question I'm sure, What is the best blue for planking, I'm using white glue and something just doesn't seem right....

[Griphos]

Most people use PVA glue, I believe. You’ll find useful info on this in the articles section. Remember, though, that PVA glues are not simply mechanical, and don’t just stick any surface to any other surface. They only work fully when they can penetrate the grain of both pieces. So end grain joins will not hold much, and cross-grain joins are not as strong as parallel grain joins. The strongest join on planking, then, will always be the join between two consecutive plank edges. The join between the plank and the bulkhead or frame will depend on the kind of grain of the bulkhead or frame at the point of contact.

[druxey]

If you are relying on any glue holding wood in place without pre-bending it to shape first (except, perhaps CA), you will be disappointed. See the planking tutorials at the top of this section for more information.

[grsjax]

Which kind of glue sort of depends on if you can clamp the plank in place.  If you have room to clamp than a good white glue like Elmer's Glue All will work fine although druxey's comments about pre-bending the plank is also a good idea.

If you can't clamp the work than you will need mechanical fastenings like nails to hold everything together until the glue can dry.  Another way is to use CA on a few areas to hold the plank tight and use PVA or white glue for the other areas. 

In addition if possible always glue the planks edge to edge.  That is the strongest bond you can get in gluing planks.

[mtaylor]

To me, pre-bending is not an option.  I've had planks pop off and straighten out when they do.  Since I've been pre-bending, I have yet to have that happen.

[Jaager]

To present the map - you choose your own route:

PVA bonds thru a polymerization reaction.  The chains have to penetrate the substance of the wood to produce a strong bond. The closer the two wood surfaces - the stronger the bond.  A force that crushes the wood fibers is something to avoid, but below that force, the stronger the clamping pressure the stronger the bond.  Total coverage of both meeting surfaces is a good goal.  Preparation of the meeting surfaces is a detail to consider. Sanding the surface with a grit finer than 220 runs the danger of leaving the surface with no substance for the polymer chains to penetrate. Sandpaper can leave the pores filled with wood flour if too fine a grit is used. Scraping leaves clean and open pores.

[wefalck]

Good points by Jaager. One needs to understand the mechanism of bonding of glues/cements and different types of surfaces.

 

There are two fundamental types of fitting:

 

- the parts are held together by interlocking; an example are screws, where the male and female thread interlock; this is usually the strongest joint.

- the parts are held together by a force exerted on them: an example are nails, where the friction from the compressed wood fibres keeps the nail in.

 

If the surfaces are sufficiently rough for the PVA to key-in, the glue will form an interlocking joint.

 

Cementing metal to metal or other surfaces with CA, mean to largely rely on physico-chemical interactions with certain parts of the CA molecules and the atmospheric pressure that pushes the CA onto the surface. Particularly with shear-forces, it is easy to peal off the cement.

 

For this reason it is always a good idea to provide for some interlocking. Wooden dowels combine all the different actions. Glued carpenters' joints are another example of combining the different types of actions.