Many remodels require matching an existing trim profile for new doors or windows. When an old profile isn't available, you can make new pieces with a little bit of 'millwork magic'—and a giant pencil
Some new doors I installed recently were just enough wider and taller than the existing ones that I had to get new casing to trim them out. Problem is that the existing ranch casing is no longer in stock at local suppliers but because I only needed 64 lineal feet, it didn't justify the cost of custom molding knives or the setup process to reproduce a matching profile on my W&H molder.
Faced with this common predicament I chose to get creative and apply a bit of 'millwork magic' to get the job done.
Tackling the task
The first thing necessary for this to work is to have matching wood to work with. A trip to a local lumberyard was all that was needed to find some great pieces of pine with similar grain, color and density. I ended up with 1x10's since they were the best match out of the full 1x4 to 1x12 selection. Cutting strips out of these wider boards made it easy to cut around the few knots and defects in the boards for clean, clear casing.
The milling process is pretty typical for this type of work:
- Cut a 'clean' piece out of a piece of existing trim for accurate match-up of profile details.
- Straighten one edge on each board and rip blanks wide enough for the finished trim width plus a bit extra for milling. With a little planning it's pretty easy to leave defects in the scrap or sawdust pile
- Flatten one face of each blank
- Flatten the second face of each blank with a thickness planer
- Straighten one edge of each blank
- Clean up the second edge of each blank with a thickness planer
Each profile is going to need a similar but different sequence to reproduce its shape. I think through steps needed to get each process done with the best possible end result. This ranch style is pretty basic without much chance for sequence issues but I hope it gives an idea of what is possible.
With consistent blanks to work from I made a rough cut of the angled face since getting this part right was key to an accurate reproduction...
- Match bevel angle by eye-balling the tablesaw blade and leave a decent 'fudge factor' so that there's enough thickness left over to get a consistent, smooth finished face
- Make a 'planing sled' for the thickness planer using the existing casing scrap to match up angles and settings
- Use scrap from the planing sled for a wedge on a router base so the round over bit can make a matching radius on the 'high side' of the casing
- Setting up a router table allowed me to remove the guide bearing from the round over bit which was preventing it from making the right cut on the obtuse angle of the casing blank...
- A dado blade setup makes ploughing a 'backout relief' in the back of each piece a simple process.
- OCDC Step: I made a final setup to bevel the edges of the backout dadoes even though no one but me will ever know it... it takes a lot to be good and just a little more to be the best, right? Yeah, probably not...
With some thoughtful planning and attention to detail during the milling process it's possible to get a great finished product with this process. Since I've come to disdain sanding after so many years in the shop it's a welcome relief when a plan comes together well enough that no more than a quick scuff with #150 sandpaper is all that's needed for excellent results, often better than 'factory mouldings' that were made without much attention to detail or quality.
—Matt Jackson is a master carpenter, remodeler, SketchUp Wiz, YouTuber, and contributing editor to ProTradeCraft. He lives and works in Rapid City, South Dakota.