Climb Cutting with a Moulder

A shop owner considers the pros and cons of climb-cutting cedar and redwood on a moulder. May 28, 2006

I've got the opportunity to run a pile of 4-8" exterior beds and crown. These are specified to be vertical grain redwood or cedar. In the past we've had a lot of tearout issues with cedar. Depending on the grain orientation, I've had two foot shards ripped off a board. The material is going to be pretty expensive and I can't afford to be wrong on my waste factor. I had a thought about climb cutting on my Woodmaster moulder. The reverse feed switch costs $50. Using a planer/moulder I would think you would have complete control, versus using a shaper. I realize the dangers of climb cutting, which I would not consider on my shaper.

Forum Responses
(Solid Wood Machining Forum)
From contributor C:
As long as you have a reliable power feed, climb cutting is the only way to go. Tearout will be an unpleasant but distant memory. I typically climb cut all but about the final 1/32" depth of the profile, than reverse for a final finish pass. The climb-cutting tends to mash down the grain a bit, so this final light pass cleans it up with little or no tearout.

From contributor F:
Climb cutting on a shaper with a power feed is safe. As far as planer style molders go, I run my RBI at 12 feet per min, and rarely get any tearout. I run single knife heads.
One thing another millman taught me is that you get less tearout on a full depth cut because there is more wood backing up the cut, kind of like a zero clearance saw throat plate. I wish I could give you some insight on reversing a planer style molder but I have not needed to do it on mine. I do have a set of Arkansas files which I think makes a difference in tearout after I hone the profiled knife edge with them.

From contributor R:
With due respect to the other posters, and I know they are some of the best craftsmen in the business, I tend to disagree. Climb cutting on a moulder is not recommended. Can you at least try to get a 12 degree hook angle cutterhead first? Also, try graining the lumber before running. Run the heart side of the lumber down on the bed and mill the bark side this should help you a bunch. If you must climb cut, be very careful and make sure no one is in front of the outfeed side of your moulder.

From contributor A:
Contributor F, I suspect you haven't milled much redwood or cedar. This stuff tends to splinter rather than tear out. The grain can be perfectly straight for many feet. Taking a final 1/32 pass or a full 1/8" are typical solutions to minor tearout on hardwoods.

Contributor R, 12 degrees is industry standard for softwoods such as pine. Those woods are all flatsawn. Vertical grain firs/cedars/redwood probably do not fall into that general category.

I am not comfortable with climb cutting on shapers... they are wide open and when the shards start flying, it can get pretty ugly. I started think about the old Woodmaster because it's quite contained and easily adjustable with an excellent stiff powerfeed. I'm still swaying towards my initial intention. I'll have safety on the forefront of my mind.

From contributor M:
I also have a Woodmaster (along with a Weinig Profimat). I bought a couple of two slot heads for my Woodmaster. One has two 12 degree angles and the other has two 20 degree angles. I find that the different angles do make a difference in quality of cut. I got these heads from, because at the time Woodmaster didn't carry them. Someone has since told me that Woodmaster is now offering a 15 degree head that is an option. This also sounds interesting.

I also have a question for contributor R. Before I bought my heads a little over a year ago, I posted a question about the 12 and 20 degree cutting angle theory. Weren't you the gentleman that told me then that that was a salesman's myth (12 degree and 20 degree theory)? Not trying to find fault, just wanted to pass that on. For what I run, it makes a noticeable difference. Perhaps in some cases it doesn't.

From contributor R:
12/20 is the best situation you can have. I have always recommended 12/20 covers both for whatever you need. I'm glad you have proven it to yourself. Generally speaking, 12* hardwood 20* soft, but I favor the 20* for everything unless I have a tearout problem.