Gary Beasley

When I'm turning bowls theres always a couple of spots where the end grain raises up it's nap and refuses to clean up smooth and is very difficult to even sand down. Why is this happening and how can I make it go away?

john lucas

It is usually happening because on a side grain bowl you are cutting into the grain on 2 sections of the bowl. I'll say 10 oclock and 5 oclock but that assumes that the grain is running parallel to the floor when the wood is stopped. For the rest of the bowl you are generally cutting down hill or with the grain.
I find that a reallly sharp tool is necessary, followed by a light cut. On really bad woods I put some Johnson's paste wax on the areas and it usually takes care of it. You have to remember to not push the tool. Let the tool cut as fast as it needs so lighten up your grip and let the tool glide through the cut.
On reallly bad areas I soak them in thinned lacquer This stiffens the fibers so they will cut better. This also works on punky wood.

Gary Beasley

Thanks. I'll try some laquer next time and see what happens.

john lucas

Gary sometimes it's just a matter of how the edge of the tool approaches the work. If the wood is hitting the edge at 90 degrees the cut is rougher. If you can rotate the tool so that the edge is slicing through the wood at a steeper angle you get a cleaner cut. Sometimes this takes only a small rotation of the gouge. Turn the lathe off and push the tool through the wood. observe how the wood is crossing the cutting edge and see if you can improve the angle.
Sometimes having a bowl gouge or spindle gouge with a sharper angle on the cutting edge is all it takes. I have a bowl gouge and spindle gouge ground to 40 degrees. If the bowl is shallow enough I an use these. They cut much cleaner than a bowl gouge with the standard 55 to 65 degree grind.

phinds

Yep, John has it right. It's mainly the cutting angle. Also, when you're at the end, you need nice light passes at a fairly sharp angle so that you're shaving the wood, not in any way crushing (which is easy to do with end grain).

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phinds
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timberly

Hi Gary I agree with every thing John said but I would also try altering the speed .I find a finishing cut with a sharp chisel at a rate of knots helps

Gary Beasley

I wish I could alter the speed some more, I'm using the slowst spped the pulleys make. I'm wondering if a motor speed controller would work on that kind of motor.

john lucas

You don't really need to change speed, just change the speed you are pushing the tool through the cut. It accomplishes the same thing. Raising the speed of the lathe simply lets you move the tool at a faster rate. What you are trying to do is take a small controlled bite. You can do that by either speeding up the lathe and moving the tool at the same rate, or by slowing down the lathe and moving the tool slower.
Cutting angle, feed rate and softening the wood or lubricating it with wax all seem to help in this instance.