[Mike]

Reds, what happened is moisture. We tend to think of wood as being dry, but it is more like a sponge only denser. As it dries the outside gives off its water first leaving the center still damp. If you have ever seen particle board that has gotten wet you know how wood swells with added water. It just happens faster with particle board. Your laminated pine was straight to start with, and the entire outside surface had slowly given off its moisture. When you cut your dado's you exposed the center of the wood which still had moisture and as it evaporated the wood shrank and bowed up. The way to prevent movement of the wood after cutting is to glue up your assembly right away. This seals the moisture into the "wound" in the wood. Your plan to spring the wood back while doing your glue up is fine. There is one other thing to learn from this moisture concept. When you apply finish to your projects you block the woods ability to let moisture move in or out of it. If you only finish one side you are encouraging the wood to move more on the other side or warp. To prevent this seal both sides. It doesnt need to be fancy, it just needs to be sealed.

 

[Mike]

Shawn, the wood will continue to move with moisture in the air. This is why table tops and panels expand and contract. No finish should be fine for this project. The idea is if you finish one side and not the other you make big trouble for yourself. Take a piece of scrap pine and paint one side with any old paint or finish, let it dry and then put it outside. This will show you what can happen. You might want to use a 2nd piece of scrap and finish both sides for a comparison? There are clear finishes you can use to seal a project that are not noticeable such as sanding sealer. It's not decorative, just seals the wood. I have one suggestion for you, I know that a garage project doesnt need finish, but it offers you the chance to try out your finishing skills on something you wont be upset about if you have trouble. I made an awful mess of the finish on my first project and had to redo it. Think of it as free practice.

 

[Mike]

Bob, you are correct when you say the glue will not stick to any finish. Most projects are easy to finish after the glue up is complete. Some projects have special needs such as raised panel doors. It's ok to apply the finish to the raised panel since it is free floating and doesnt receive any glue. This way when the panel contracts you dont see an unfinished edge, or a blotchy finish.

 

[Mike]

Ed, These glued panels are made from what amounts to 1x2's properly edge joined with alternating grain patterns and decent sanded finish on both sides. As far as pine goes they are pretty stable. I have experienced very little movement on through cuts or when glueing shortly after cutting. These panels are economical and great time savers. The only downside to them is the grain pattern isn't as pleasing as it might be. Carried by both HD and Loews in several sizes. Give them a try this spring.

 

[Mike]

People, thank you for all the tips but we are talking about white wood fresh from HD or Loews. These preglued panels are fairly stable but will move if you make a dado cut and dont glue it or seal it the same day. This is not the solution for fine woodworking projects. This is an easy way for beginers to get started. The ability to work with solid wood in sizes ranging from 12" to 24" widths without a table saw or clamps is what makes these panels a great value.