What are cauls you ask? Let me explain in this article what exactly cauls are and how you can use them in your woodworking to create successful projects in your shop.

Comment down below if you have already heard of cauls before this article. If so tell us how you use them in your shop.

What exactly are cauls? 

For me, I never actually knew that cauls had a name but have used them since I have begun woodworking.  A caul is a piece of wood than goes across the work surface to keep it flat and free cupping and bowing. 

For example, I tend to use cauls a lot when working with tabletops and other large panel section glue-ups. Especially when using my Kreg Jig for edge joining. 

The piece of wood is laid across the tabletop and then is clamped down across the surface

So How Do You Make Cauls?

I tend to use whatever piece of scrap wood I can find in the shop. However, making sure that the piece of wood doesn’t bow under clamping pressure itself. 2×4’s seem to work the best in my experience or a 2”x6” ripped down the center is even better. 

Tips For Caul Success 

Here are a few tips for caul success that other woodworkers have taught me and some I have learned on my own. 

  • Wrap you cauls in plastic wrap. Yes, plastic wrap the reason for this is to prevent the glue from sticking to your caul. In the past, I haven’t done this and squeeze out from the tabletop glued the caul to the top of my table.
  • Space your cauls no more than 2ft apart. Getting larger than this span can cause too much force one given end and not provide even clamping pressure. 
  • This is a personal preference but I like to use large c-clamps for clamping my cauls in place just because the force I can apply with c clamps is much larger than traditional woodworking clamps.

Caul Order Of Operations

  1. Measure the panel to be glued up and add 2 or more inches to the measurement.  Longer is always going to be better obviously.
  2. Make sure cauls are wrapped in plastic or packing tape applied to prevent the glue from sticking to the caul.  
  3. Layout of cauls in a 2ft spacing across the panel to be glued. Closer spacing is always better but no greater than 2ft is recommend. 
  4. Clamp the cauls in place with one caul on top of the work surface and one on the bottom. 
  5. Once cauls are in place apply side clamping pressure as you normally would in a panel glue up operation. 
  6. Let the glue dry as we discussed in this article here and then reap the benefits of using cauls.

Final Thoughts

Incorporating the use of the cauls in your woodworking projects especially in large panel glue-ups is to greatly help with warpage and twists. 

Cauls are such a cheap way to help keep you from pulling your hair while building large panels. How do you plan to start using cauls in your woodworking projects? Let us know down in the comments. 

 As always if you got something out of this article be sure to share it with a friend that can use this information in their woodworking adventures.

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