Warning about milling prefinished flooring

[John Blazy]

Just a little tip - don't run any of the new melamine coated flooring through your jointer, unless you have carbide knives - totally destroys edges.

I just finished laying new bamboo flooring, and I hardly believe it was the bamboo veneer, but when I was jointing a simple chamfer for a threshold edge, I saw sparks as I was running the pc over the jointer, and then it would not cut. Looked for metal, and ran it again, saw sparks again, looked at the knives and saw whats in the pic below.

Most finishes are pretty soft, but the new prefinished flooring nowdays has hard-as-steel clearcoats, and is likely a melamine resin or some UV cured hardcoat.

I always new to never run a melamine edge through the jointer, but didnt realize that these new floor coatings are also in the same class. On the positive side - the finish is so silky smooth, and tough.

DullKnivesfromBamboo.jpg

[Adam Herman]

bamboo has a high amount of silica in it as well. It is suggested to use only carbide cutting tools and to surface it by sanding and not planning. I believe it is the wood itself and not the coating. I have had no trouble with pre-finish hickory or oak for example.

[Andrew Hughes]

I heard from a friend that does floors that the best commercial flooring has a oxide finish.Like sandpaper with the heavy grit.
So John it looks like you were jointing Sandpaper.

[John Blazy]

Ok, so now I need to sand off the finish, then joint the bamboo itself to see if the bamboo is really the culprit. Not sure what an "oxide" finish is, but that is not good for blades. Thank God I have diamond sharpeners for my T-saw blades and jointer knives.

Ok, paused in the middle of this post to grind off the finish, then joint the raw bamboo. No sparks, milled a 1/8" chamfer no problem, multiple passes, no dull knives - nice flat arris.
Then grabbed a new piece with the topcoat intact, and sparks again on the jointer, with another section of roached knives.

So verdict it that its the finish, not the wood.

[Van Huskey]

Aluminum oxide is used to finish practically all prefinished flooring and is brutally hard on knives. It has a hardness essentially equal to tungsten carbide. This is one of the main reasons sanded/finished in place floors are almost dead.

[Ken Combs]

Aluminum oxide is used to finish practically all prefinished flooring and is brutally hard on knives. It has a hardness essentially equal to tungsten carbide. This is one of the main reasons sanded/finished in place floors are almost dead.

Yep, I installed 500+ft of bamboo in our home and was surprised to see the aluminum oxide finish info on the package. And, I could tell a definite difference in the keenness of my miter saw blade when I finished.

[John TenEyck]

Aluminum oxide is what's used to make most sandpaper. So, yes, you were jointing sandpaper. I wouldn't try carbide knives either.

John

[John Blazy]

Wow, I just read a ton about these new aluminum oxide finishes. When I was a UV coatings chemist, we added powdered Teflon slip additives to the coatings, and it migrated to the surface during cure, adding a silky smooth slickness. Never used ALOX though. Things have come a long way. Turns out that its powdered aluminum oxide that is added to UV cured urethane roll coatings on prefinished flooring. Very impressive - doubles the wear life.

My cat can't run on this floor - its hilarious to see her try to run from me on what used to be carpet.

Here's a pic of the bubinga end trim that I rabbeted onto the ends. Been saving that pc of block mottle bubinga for about 20 years, finally used it.

BubingaTrim-topvu.jpgBubingaTrim-frontvu.jpg

[John Vernier]

I'm sure the finish is causing you problems, but unfinished bamboo is also very hard on tooling. When I was teaching at a college wood shop we had a student who found a source for bamboo flooring offcuts and he wanted to make furniture out of it. He got a tentative OK from the shop manager to mill the material, and trashed the blades on several jointers and planers before somebody told him to stop for good. As I recall it also did a number on carbide saw blades, it's a nasty combination of abrasive wood and tough adhesive.

[Andrew Joiner]

Ok, paused in the middle of this post to grind off the finish, then joint the raw bamboo. No sparks, milled a 1/8" chamfer no problem, multiple passes, no dull knives - nice flat arris.
Then grabbed a new piece with the topcoat intact, and sparks again on the jointer, with another section of roached knives.

So verdict it that its the finish, not the wood.

John,

You are a lot like me. You test things to learn and find out why materials act the way they do.

I really appreciate you going back and testing your jointer knives again just to be sure!

I always pay close attention to your posts and have a ton of respect for you and your work.

Thanks for reporting in.

[Rich Engelhardt]

Wow, I just read a ton about these new aluminum oxide finishes. When I was a UV coatings chemist, we added powdered Teflon slip additives to the coatings, and it migrated to the surface during cure, adding a silky smooth slickness. Never used ALOX though.

Teeny tiny itty bitty correction.....

Aluminum Oxide is - adalox. Alox is a bullet lube.

[John TenEyck]

Teeny tiny itty bitty correction.....

Aluminum Oxide is - adalox. Alox is a bullet lube.

ALOX is also short for Aluminum Oxide. Has been for decades in the abrasives industry.

John

[John Blazy]

Alox is a bullet lube.

Oooh, now I really like my new word ALOX. I just made it up cuz i was too lazy to type it all. Too busy testing sh**. For real. I'm doing mold release tests in 2K acrylic reactive cement right now, and love this forum when I need a break.

Thanks for your kind words, Andrew. Too much scientist in me to just trust limited data. Down side is that it keeps me from shipping my deadline jobs on time.

[Rick Fisher]

I always balk at that stuff, try it myself and then say .. wow ..

I recently decided to make bench tops out of LVL beams. Beautiful and strong as heck .. destroyed the knives in my jointer and planer milling all that glue. I did the prefinished flooring thing too. Ruined the edge on the blades in about 40 feet .. Glue is a bit more forgiving .. but It actually left chunks of Tersa knife missing..

[Rich Engelhardt]

ALOX is also short for Aluminum Oxide. Has been for decades in the abrasives industry.

Nope - ALOx - (notice the small x) is what you're thinking of.