Gazette Archive 9/11/97
Clean Melamine Edges: By Jim Mattson
I like to use melamine for the interiors of built-ins, behind doors and drawers, and the insides of kitchen cabinets. It's cleanability makes it ideal for kids rooms and a variety of working surfaces. Most of my shop's storage cabinets were quickly made of this plastic-coated particleboard and I always keep some pieces around for jigs and fixtures.
Aside from it's heaviness, melamine's greatest drawback is the difficulty encountered when trying to get a clean cut off the tablesaw. The top side, where the blade enters the panel, is easy to keep smooth while the bottom side, where the blade exits, comes out chipped and ragged. Large manufacturers tackle this problem with a variety of machines like CNC routers and scoring panel saws. Sadly, these are usually beyond the reach of those who operate their trade or hobby from a one-person shop. There are also special sawblades available which advertise clean cutting ability, but my experience leads me to believe the durability of their edges doesn't justify their high price tags.
Luckily, most cuts we'd make building melamine cabinets don't require squeaky clean edges. Backs, some sides, tops and bottoms might be out of sight from the glaring light of scrutiny. Ends which are buried in dados and rabbets, and edges tucked behind a faceframe are also exempt. The problems arise when cutting shelves, dividers and doors. Often these pieces are equally visible from both sides, and the perfectionist in each of us requires a clean cut.
So, what's a cabinetmaker to do???
The following are two techniques I use when working melamine which anyone can employ with only the most rudimentary shop equipment. The first needs a router table (or jointer with carbide knives) and results in the best edges you can get. The second is called half-ripping and uses a tablesaw to produce highly acceptable edges.
The Router Table Method
This method also works well to straighten any edge irregularities left over from tablesawing. If your melamine crooks slightly after sawing, you can rout the concave edge and re-run the opposite edge through the saw to achieve true parallelness.
If you have problems getting true uniformity of sizes, (some pieces smaller than others), you can use one piece as a template for flush-trimming the rest with a hand-held router and top bearing bit. With large jobs, it might be worthwhile to install a vacuum clamping system on your template, but I like the following technique better for it's speed.
Half-ripping on the Tablesaw
The best sawblades for half-ripping are fine-toothed, carbide ATBs or triple-chips. ATBs (Alternate Top Bevel) will give a better cut but triple-chip cutting edges are more durable when used against this abrasive material. Naturally, as in all tablesaw cuts, the quality you get is dependent on the trueness of your arbor, the blades alignment with the fence and a steady feed rate. Any weakness with your hardware or tablesaw technique will show up in misaligned or burned half-rips.
I've also found it advantageous to bust out full sheets into smaller parts about half inch oversized before dropping the blade into the half-rip mode. And, best of all, this method works nicely to eliminate any chipouts when cross-cutting plywood.
If you have any questions or comments about what you've just read, feel free to email me direct at The WWA.