Techniques
Building cabinets, not necessarily 32mm specific.
Subcategories: Boring Doors Shelves
On this page: Custom Crown MDF Edge Preperation Router Templates
Custom Crown
Two piece, 2 - 1/4", top mounted crown that can have whatever reveal you want, e.g. 1/4" reveal to cabinet (the mock-up in the foreground) or doors. Its made with a Grizzly bit in a table router. The white fence was originally built for routing lock miters but I use it for everything. The clamped on MDF provides a tunnel that is the same size as my stock (5/8 x ~2 - 5/8", wide enough for a full miter on the bottom). Once the stock is routered, it needs two passes (top edge first, leave a hair of flat) on the tablesaw (38deg is standard, I needed 40, the saw scale or router bit are off).
The base piece also gets a 38deg. miter and I use a jig (image) to glue it to the crown. The key part of the jig is a round-over profile to match the cove in the crown. You could set it up anyway you want. For me the aluminum stop and loose round-over worked fine. If you tilt the spring clamps they can provide both down and forward pressure. With MDF I had almost perfect alignment on the bottom edge, a hard block sander evened things up quite nicely. There's also an image showing the full glue-up.
The next thing to try is lipped crown that will work with half-overlay upper cabinets. This will require at least 3/4" material which should be able to provide a slight reveal. I ran a 3/4" piece with the above, but cut the base to 21mm, i.e. flush to door face (19 door + 2 bumper, no reveal), without thinking it through. The jig would have to be setup with an 8mm strip underneath the base piece.
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MDF Edge Preperation
MDF provides an excellent surface for paint. MDF's one weakness is the porous cut edges. I've tried a lot of things in the past. Lacquer undercoater and tight grained wood edgebanding work reasonably well. Lacquer undercoater, while much better than quick dry oil based primer, leaves a rough edge that needs to be sanded. The process needs to be done twice to get an edge free of pores. Sanding and keeping the narrow surface flat and square isn't easy. Edgebanding is less labor intensive but also needs careful prep. I worry about the seam showing up from the ongoing expansion and contraction of dissimilar materials. I also do a lot of 1 - 1/2" thick edges which would require custom banding material.
I've found that lightweight glass micro-balloon based spackle is faster and better. While you can apply it with a spackle knife, its messy and slow. Custom applicators/scrapers are the only way this method will be faster. Applicators/scrapers are best made with thin stainless steel bent on a sheetmetal break. My preferred brand is Red Devils OneTime, Dap's Fast 'N Final is a bit thicker/drier and not as easy to use. The trick is to spread it on and scrape it off as fast as you can. You want the surface to remain as clear as possible, i.e. no visible spackle. When it dries, a light sanding (220) is all that's needed. When you sand the edge you'll notice that the dust is white. While it doesn't look like it, the spackle fills the pores and seals the material. The spackled edge will take the primer just like the face.
Woodweb discussions on MDF prep:
Prepping MDF for Paint
Priming MDF Edges for Finishing
Sealing the Edges of MDF
The later has a comment that says "Don't make the mistake of building up a 1-1/2" MDF edge with two layers of 3/4" material and then lacquering it. The glue line will witness.". The only time I've had a glue line show is when the glue line was too thick. The only time that happened was when I used a wide (4-6"?) buildup strip. My standard buildup strip is less than 2" wide. Using a toothed glue spreader and plenty of spring clamps will make witnessing a non issue.
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Router Templates
I use router templates a lot. I'm trying to clean out an image directory so this isn't the greatest example. This one was used to route the coutertop to allow an applied end to pass down to a counter at a lower level (image), at the end of the lower counter where it dies into a mantle and to provide a vent to the top of the cabinet from a component cabinet. The holes and pins align the template to the construction holes used to mount the bookshelf end-panels to the counter.
I used this one to scribe wainscot to a cabinet. There's also a closeup of the resulting fit (before caulk/paint). I took the necessary measurements, enlarged them by 3/16" to work with a 1/4" bit and 5/8" guide, marked a scrap of 1/4" MDF and cut it on the table saw. Due to the sloping floor, I had to tweak the template from 90 degrees and take a second pass.
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