Replies

1. 
   hammer1 | Feb 16, 2010 10:40am | #1

   Grain direction is a major factor with many cutting machines. A lot of folks think grain is the annual growth rings but grain is different. Some species and figured lumber has grain going in all different directions. The rule of thumb is slow down and take less of a cut. That doesn't mean skimming 1/64" since that can beat up your blades but 1/32" might be appropriate for some difficult lumber. If you blades are sharp, you aren't feeding to fast, you shouldn't have tear out except on rare occasions.

   If determining grain direction has you baffled, you can learn about grain by slicing down an edge with a utility or other sharp knife. Going with the grain, the knife should cut off a nice sliver. Going against the grain and the knife will dig in. You can also see the grain in some species. Red oak for example, has small brown slashes that indicate grain direction. It may run opposite from the annual growth rings. I might have a picture.

   
1. 
   SARGEgrinder47 | Feb 16, 2010 11:09am | #2

   You didn't mention what
   You didn't mention what species. That is also important as some have grain running in several directions on a given piece. Maple is one of those. And as mentioned you have to read the grain correctly on standard species. You can't expect a good cut going against the grain.

   Shallow passes. On my jointer and 20" planer I use only two depths. 1/32" and 1/16". And if I am working with maple I skew the fence on my jointer and skew the feed on my planer after lightly wiping the cutting surface with distilled water.

   Good luck...

1. 
   alexrkramer | Feb 16, 2010 11:32am | #3

   2 new questions; how does taking 1/64 off material damage blades? by scewing the jointer fence, do you mean so that your piece is heading slightly off-perpendicular to the cutter head? is the distilled water to create a clean, smooth surface? thanks for all of your help and advice.

2. 
   SARGEgrinder47 | Feb 16, 2010 03:48pm | #4

   I will answer the two questions that relate to my post Alex. Yes on the fence diagonal to the cutter head. Most fences on jointers will skew but.. very few people actually realize that. The problem with that lies in the fact the way most are designed.. it is a pain in the hinny to set up the skew then return it to the normal position. On my 8" the manufacturer took that into account and set up the adjustment so it can be done in a couple of minutes. You probably realize what I mean by skewing through the planer if your table is wide enough so...

   As far as how does the wetting affect the cut.. I cannot truly say. It will slightly raise grain just as it does when you do this before the last coat of sand-paper in finish which I have been doing for years. I read on a forum about the wetting trick before planing several years ago and simply tried it. It worked so I have continued to do so from that day forward. I won't attempt to guess the scientific reason as again.. I simply don't know why but do know it works for me. Maybe one of the more scientific thinkers can explain why?

   Won't comment on the 1/64" as I have never heard that statement. I have skimmed that amount on occasion but if it damaged the blade any degree I could not truly say. I can tell you I put a lot of miles on planer blades and as far as I know skimming had no real adverse effect to my knowledge.

1. 
   Westchester | Feb 16, 2010 03:58pm | #5

   Alex -

   Are the problems at the beginning and / or end of a cut ?

   SA

1. 
   alexrkramer | Feb 16, 2010 05:05pm | #6

   all throughout. mainly workin w/ cherry lately. biggest problems are with the jointer, particularly with curly pieces, which makes sense because the grain is all over the place. i tried moving my fence to a sharper part of the jointer cutter head and that made a significant difference. i guess soon i'll need to sharpen those knives. the issues with the planer arise when i occaionally send pieces through on edge to get them to a uniform width. thanks for all of the comments and help to everyone.

1. 
   DonStephan | Feb 16, 2010 08:20pm | #7

   A new set of knives helps me, but I haven't been able to eliminate chipping and tearout. A widebelt sander would be one followup approach. The other would be a toothed low angle jack plane, the direction I took.

2. 
   ring | Feb 17, 2010 12:56am | #8

   Sarge, just a footnote to your post -

   The oldtimers used kerosene instead of water, sometimes in profuse amounts.   Some years ago I mentioned this fact online and almost got crucified by the self-righteous safety patrol, so I'm not recommending it (!) just stating a fact.  Unlike water, the kerosene inhibits rust in the planer, and keeps everything sliding along smoothly.  Just thought you'd like to know...

   regards,

3. 
   flairwoodworks | Feb 17, 2010 02:21am | #10

   Sarge,

   One idea behind why water works is that it swells the fibers so that they better support each other.  I don't recall hearing about kerosene as David mentioned, but I have heard of denatured alcohol.

   And I'm pretty sure that my DJ-20's fence doesn't skew and can't think of how a fence would skew...

   Sidenote: I like the new improvements with the replies!  Good work, crew!

3. 
   jointerman | Feb 17, 2010 02:17am | #9

   I feel your pain! About a month or so ago I posted about tear-out on my planer (and to a lesser extent the jointer) while planing cherry. My blades were sharp, and dust collection was more than adequate. I had decided it was my older two-blade portable planer, so I upgraded to a 3-blade DeWalt 735 planer with two speeds.

   Lo and behold, still some tear-out! I decided that when the grain goes wavy and funky, there's just no real recovery from some tear-out. For me this really shows up on cherry more than any other species.

   Wiping down the board as Sarge mentioned probably helped the most. I had read that it softens the fibers and lets the blade shear the wood instead of tearing it out. I've heard that a helical cutter head will shear the boards and eliminate tear-out but I can't confirm that.

4. 
   SARGEgrinder47 | Feb 17, 2010 11:30am | #11

   Thanks for the tip on kerosene David.. as that makes sense about the rust issue. Frankly I never over-worried about the rust as I wipe the blades after each use when using the water. For that matter every couple of days as I live in the humid south USA. After each project I also spend an entire day cleaning shop which includes re-sharpening any chisels I use.. dust in cracks and crevices.. emptying dust bins on cyclone and vacuum.. cleaning cutter-heads and machine parts along with a new cost of wax on cast iron so I have had no major issue. About every two months with that routine. And no real issue may partly due to the fact the only time I wetten is with maple and cherry and I use very little with my menu of local white oak.

   But the wettening works to a degree so I may try kerosene but only in the summer as those terrible fumes permeate up into my house when the outer shop doors aren't open. My lovely is very sensitive to chemical vapors.

   Chris.. my guess it the fact that is does raise grain which means the fibers swell with contact with moisture so.. as far as the DJ 20 not having any mechanism to skew.. I wouldn't be so sure. I was made aware of this by Scott Box who was the former president of Steel City and now heads the General International Distribution Center in the US just recently opened. Scott repped for Power-matic and Delta for many years and his father worked for Delta his entire life.

   But with that said.. I will check with him on that particular model the next time I speak to either him or his brother JIm at the GI Dist. Center. If I find out it will I will call and tell you what to look for as the two other machines he showed me were not openly apparent as to how.

   I personally use straight HSS knives but.. I have seen the effect of spirals on cherry and maple.. a definite improvement but not the holy grail IMO with those woods as you still have to clean up from what I saw. The main reason I have no personal interest in spirals is the only true advantage I have seen is with the squirrelly woods which I personally use few of. I simply can't personally justify the extra cost for what I would gain personally.

1. 
   KeithNewton | Feb 17, 2010 08:57pm | #12

   http://www.woodweb.com/knowledge_base/Knife_Grinding_and_Woodworking_Manual_5.html   http://www.woodweb.com/knowledge_base/Knife_Grinding_and_Woodworking_Manual_5.html   

   It really sucks that I typed out a post about as long as Sarge's above, then went to pick up a link to post, but when I returned, all my comments were gone. No wonder some of the others are moving on. 

   Here is the link which gives ideal sharpens angles, cutting angles, and knife cuts per inch.