Originally Posted by
Mark Bolton
This is something I am sure many here are especially tuned to. We spray nearly 100% waterborne finishes in the shop so its a daily issue. Nearly 100% is like 99.999985%. And using waterborne this sort of stuff rears its ugly head constantly and water grain raise is critical.
Shops that plane a lot of material and no onboard sharpening, and you run your knives down a ways you will #1 develop a knick or knicks in your knives that will pound down the wood fibers at that knick as opposed to cutting. You will never see the issue. You can run the material through a widebelt or drum, sand with RO til your blue in the face. Take every pain in the world. Stain, and into the booth, and on the first coat of finish... poof. Up comes a perfectly straight planer mark. On any stained material that mark will appear as a light streak because the wood fibers when re-hydrated swell up and expose the raw wood below. Raw material its so obvious you can feel it with your hands and see it in low angle raking light.
We will raise grain with water usually twice and sometimes more way before any material ever makes it to final sanding.
Of course there could be an argument that water grain raise is contributing to what we think of as creep however agan there is no issue (or far less than perceptible) with TB original and Super. So my guess has always been that the practice of grain raising with water is a good one. Surface water on KD material is a zero issue for us. I also make it a practice to water-wipe most everything anyway in the event there is a rogue waterspot or something that will pop out on finishing. Thats an old trick from the construction days. You have a bunch of pine doors that may have been unloaded in a light sprinkle of rain or a passing shower. Sand them, hit them with stain, and the waterspots are out like a sore thumb and there is no way to get rid of them. Get in the habit of a water wipe on everything by default and you simply turn the entire door into a giant water spot and go on with your day.
Im sure many here have read about issues with biscuits telegraphing through finish when using PVA and people leaving the biscuit slots unglued and only gluing the face of the boards as opposed to the NYW practice of brushing the biscuit slots and biscuits full of glue. The same issue would be true for Domino's. If the slot/biscuit/domino is close enough to the surface you could have a swelling/shrinkage issue there due to moisture in the glue an so on.
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