Question
We run a lot of engineered flooring using Baltic birch core with solid wood wear layer. We have had some problems with the tooling leaving a small gap due to the glue and plywood fuzzing up compared to our wear layer. We considered diamond tooling but I am not sure their may be an easier answer. From what I can detect, the problem lies in the solid wood shearing off clean, while the end grain of the birch and glues tend to shear off rough and leaves a slight lip, when compounded on the tongue and groove side this leaves a small .030 - .060 gap between the edges. I was wondering if we had a slight back relief of a few degrees right under our solid top layer and plywood if this may allow for the fuzz. I believe my carbide is holding up, it’s just the tough end grain that fuzzes up. I am not sold on a $10,000.00 set of diamond cutters being the answer. Has anyone done this?
Forum Responses
(Solid Wood Machining Forum)
From Dave Rankin, forum technical advisor:
One thing that I have done in the past to help with this problem is to use carbide insert tools with a 5 degree shear built into the head body. This helps to reduce the tearing effect of the tool. Diamond tooling is most likely the best overall solution, but is also very expensive.
For clarification, how much is a lot of flooring? Running flooring full time justifies the diamond easier. Running 15,000 square feet of flooring a month may not justify the diamond as easy.
1) Dull inserts cause problems. Sounds ridiculously simple, but after you change your inserts, there will be a noticeable change in quality and when they are past their life, they show bad results very quickly.
2) Carbide grade is everything. If you are getting run of the mill inserts with a generic carbide grade you will get run of the mill results. Ask your tooling provider about the micro grain carbides (which most inserts are these days, but there are still some less expensive ones out there) and make sure you are getting a good micro grain product. There is a difference in price, but that comes with quality.
3) Pay very close attention to how you are ripping your base plywood. If you do what is essentially a cross cut and then laminate that to a linear top layer, the surface of the plywood is a cross grain cut as opposed the linear grain cut for your wear layer. We had some fellows that tried to precut to the length of the wear layer and did some cross cutting on the plywood. Bad, bad things happened to the quality of the product and several hundred feet were lost.
4) I don’t know how you are gluing, but we are using bladder presses with some additional tricks that ensures even pressure across the width and length of the board. We have had de-lamination problems, which in turn caused edge quality issues, but those were easy to fix.
