# I keep tearing the end grain



## Carlswoodturning (Mar 6, 2013)

I searched to see if this has been covered, maybe I'm not good at searching, so I apologize if I'm asking a q already answered many times.

I've been making narrow trays (4.5" wide 21" long) cut and rough sanded to final size. I then round over the edges on the router table. Near the ends it curves in making a cove, then reverses to make the outside of a circle.

I know that I'm going in the right direction, (not climb) but due to the shape of the tray, the grain is cut on part (creating a cove) in what turners call compressing the grain. Then the direction changes, and makes a circular end, so the cutters are pulling the grain apart as they cut. I get a very rough torn grain on those parts. I know many people are successful routing outer curves, but I haven't been able to get results that can be sanded smooth, as some fibers are pulled out and torn off.

I saw another post where someone cutting a circle had torn grain, and it was suggested that he climb cut on part, conventional on other part. The problem I see, is that the feed direction doesn't raise the grain, the direction the bit spins does. On one quarter of the circle, the cutter is pushing into the grain, cutting fibers that are supported by uncut fibers. Next quarter of the circle, the fibers are being pulled up away from the fibers under it, making rough, torn edge. We talk about this a lot in turning, seems to me to be a problem also with routing.

How can I get better results? It seems to me that the only way would be to have another bit spinning opposite, and change part way through the curve. Obviously, that can't be done.

Long way to ask a question, but other discussions I've seen didn't address this. Thanks for reading.

One more thing, the wood is 3/4", I'm putting a 3/8" radius top and bottom, and raising the bit slightly, making 3-4 cuts. I don't think I can be more gentle with it. I'll try to upload a picture, if so you'll see I also use a bowl bit inside, have the same problem with the inside curves.

Nope, can't attach the picture(?)


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## Stick486 (Jan 4, 2013)

see if any thing in these PDF's help...

.


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## Carlswoodturning (Mar 6, 2013)

Thanks Stick, those articles are very good to explain climb cuts, and one shows the part of the circle where the rotation of the cutter pulls the fibers before cutting, causing some to tear. The solution given to climb cut that part doesn't change the direction of the cutter. Maybe I'm looking for a solution that doesn't exist. The species of wood I'm using (gum) may be more prone to tear than others

I not very experienced at routing, but am at turning, where we have the same problem.

I tried to upload a picture, to make the problem clearer, read the directions, but at THIS post, the paper clip is not present in the top bar, so I can't 
Add the pic.


So, without a pic, I'll just say that climb cut or not, the rotation of the bit is the same, and on part of the curve the cutter still pulls the fibers away from the already cut fibers, tearing some out.



So, hope this clarifies my question without the picture.


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## Cherryville Chuck (Sep 28, 2010)

Carl when you use the advanced post option it shows which file formats are accepted. Make sure yours is one of the ones in the list. If it is and you still can't attach then pm me and we'll try to work through it. 

While it's true that bit rotation does contribute, climb cutting can still help because the fiber in front of what is being cut has already been trimmed off so it can't get ripped out as easily. What may happen is that it might be the fiber in front of what is being cut or a bundle of fiber that is being affected. It's worth a try to see if that helps.


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## Stick486 (Jan 4, 2013)

for the picture..
just drag and drop it from from the file/folder it's stored in...

CCW rotating router.. Bosh makes one...


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## Carlswoodturning (Mar 6, 2013)

Ok, the advanced option brings up that paper clip, will add the pic that way.

As for the drag and drop, I'm using an iPad, can't do it as far as I know, Apple won't let me open 2 windows at once. Copy and paste adds the pic extremely large, and usually I can't get the paste option on this screen. 

Back to woodworking! 

I can see that climb cut can help, but due to the change from inside to outside curves, I can't use the fence. (I've been using a top bearing bit) Since I take very small amounts off each pass, maybe I can keep it from flying off, I'll practice with some scrap.

I suppose a new bit might help also.


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## MEBCWD (Jan 14, 2012)

Here is a video that explains what is happening and the bit to use to solve the problem. This is not the only bit with top and bottom bearings, check around and you will find several and some spiral and even compression bits.


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## tomp913 (Mar 7, 2014)

The parts for the turtles I've been making have the same problem in that the grain direction "changes" as you go around the part. I compensate by varying the direction of feed based on the grain direction, sometimes routing in the "normal" direction and then switching to climb cutting. I get better results by cutting the areas where I use climb cutting first and then filling in between them cutting in the normal direction. I'm only cutting a 1/4" roundover, for a larger radius I would probably cut in two passes but following the same procedure.


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## Barry747 (Jun 16, 2011)

Carl, I have several of the bits that Mike mentioned, 2 Katana and one Whiteside. Different lengths and diameters. I use them with templates as shown in the video and I rarely get tearout. When I do it's because I went too far against the grain before stopping. However, if you're only routing one edge then tom's suggestion is the way to go. When climb cutting be careful that you don't lose control of the work piece.


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## scottgrove (Sep 4, 2016)

you could try and epoxy consolidating the entire piece with a very low viscosity epoxy like Smiths Epoxy. This won't leave a layer of finish on the surface but will strengthen the fibers. I've also had luck with CA glue. I like Parson brand which is designed for this purpose. Used for punky wood before carving and or turning.
hope this helps.


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## Carlswoodturning (Mar 6, 2013)

Thanks Mike, Tom, Barry and Scott.

The double bearing looks like the perfect way, except that I'm rounding the edges, top and bottom, so would need an upside down bit, using the center of the piece to guide the bearing. I think I will get one (or3) of those to make the general shape though, to eliminate tear out there.

Tom, your technique seems like the best way to reduce tear out, (short of a reverse spinning bit) but since my piece is 3/4" thick, I might still need to use the table. I could clamp it down similar to what you do, using side clamps, to use a handheld, but then turning it over, I'd be clamping with the rounded side down. Plus the clamps might be thick enough that the bearing would hit them. I'll try clamping to the table, leaving part overhanging, routing only where it overhangs. Still faster than sanding out the tears!

Scott, I have experimented with hardening the grain with CA glue, I've actually been doing that after the tear out, to allow me to sand most of it out. I also use de waxed shellac to seal before a top coat of poly, and that helps with sanding. I should have thought (been smart enough) to use CA or epoxy BEFORE rounding the edges, hey, that's why we have a forum, right?

Thanks again all!


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## tomp913 (Mar 7, 2014)

@Carlswoodturning

My parts are 3" thick (2 layers of 2x material) so thick enough to clamp with the handscrew and have access to all sides off the one set-up. With your part, it looks as if you have a longish part with straight edges and just the shape on the ends so it should be easy enough to clamp it in the middle to give you access to both ends and then just finish the straight sections at the end.

I use the little MLCS trimmer because of it's size and dust collection, although I need to make a larger base to give me a little more support and control.


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