Avoiding Tearout, Lamp base question.

Re: Avoiding Tearout, Lamp base question.

jake niedling

Which direction are you cutting - from outside in to the center or from the center out to the edge. When the boards are stack, the best cut should be from the center out to the edge. This way your cutting down hill on the end grain. If you go from the outside towards the center, then your cutting into the end grain and it would be difficult not to get some tearout with this cut.

Re: Avoiding Tearout, Lamp base question.

Roger

Try putting on some of the finish you intend to use on the finished work, and turn while still wet. Works for me.

Re: Avoiding Tearout, Lamp base question.

john lucas

I agree with Jake. Turn from the center out. If your still getting tearout try using a tool that has a more acute edge. Bowl gouges typically aren't that sharp unless your using Stewart Batty's 40/40 grind. YOu could also try shear scraping but even then try to go downhill with the grain which would be from the center out if the boards are stacked.

Re: Avoiding Tearout, Lamp base question.

Barry Irby

I have been cutting from the center out. The wing on that gouge is pretty sharp and I have been using it to shear scrap. I got better as I went along. By the time I got to the fourth one I did fairly well. Wish I had thought ot the finish trick, Thanks.

Re: Avoiding Tearout, Lamp base question.

Hugh

What kind of wood are you dealing with?

Get some hard wood.

Hugh

Re: Avoiding Tearout, Lamp base question.

Don Stephan

Try a spindle gouge, drop the handle more, and point the gouge perhaps 30 degrees left of vertical, so the cut is an exaggerated slice, riding the bevel. Sharpen often, and take thin cuts. You may have to practice some when you are still 1/4" fat on the diameter, and experiment with the three gouge positions (rotation, angle to the lathe bed, and angle to vertical.

Re: Avoiding Tearout, Lamp base question.

John C Lucas

You could.also use a Hunter Osprey. Usually when i have tearout problems i can make a pass or two and that tool.will.clean it up.

Re: Avoiding Tearout, Lamp base question.

Mike Stafford

I am always hesitant to make this recommendation because people sometimes aren't capable of doing what I suggest because of their turning skills. No one should ever turn at a speed at which they feel unsure of themselves.

Increasing the speed of the piece sometimes improves the quality of the cut.

Recently I have been turning a lot of layered bowls which are similar to what your lamp base sounds like. There are multiple woods involved in my blanks so not only is the grain changing but so is the density/nature of each layer. I find I am constantly changing the speed to improve the cut but I also find it necessary to change the angle of attack with whatever tool I am using. Sometimes a smaller tool will yield a better cut. Rather than using a bowl gouge I have been using a detail gouge with a shorter grind.

I also find that on occasion an application of some finish can improve the quality of cut.

In other words, all of the above. I don't know of one single answer that works for the situation you describe.

Re: Avoiding Tearout, Lamp base question.

mikeee12345

You could also laminate segmented wood rings which allows orientation of the grain in each segment which can reduce the amount of tear-out when turning. Turning at higher speeds with a sharp tool can help provide for a cleaner cut depending on the wood type. Some wood types require more sanding during the finishing process when this problem is encountered. A sanding sealer can also be applied to the piece when turning which can help reduce the amount of tear-out.

what I do

John K Jordan

>>>

I am always hesitant to make this recommendation because people sometimes aren't capable of doing what I suggest because of their turning skills. No one should ever turn at a speed at which they feel unsure of themselves.

Increasing the speed of the piece sometimes improves the quality of the cut.

I'm not the least hesitant - I like to crank the speed up as I as I judge safe. If a turner is not able to judge a safe speed, I strongly recommend as I do with anyone - stay out of the line of fire every time you turn the lathe on! (Every time.) I don't crank up the speed with junk wood with voids and cracks.

For the best quality cut you can't have the tool tool sharp, you can't have the speed too high, you can't move the tool to slowly, and you can't make too light of cuts. So use a hair-spltting honed-to-a-polish well shaped edge, crank the speed up, make extremely delicate "whisper" cuts, and move the tool slowly.

If one doesn't have the tool control to make extremely light cuts, stop everything and start over again with spindle turning. That will teach the fine tool control.

I also do other things on problem areas:

- Try turning in reverse (turn the inside on the other side of the piece, or stand on the other side of the lathe for outside cuts.

- Soak the wood in sander sealer and let dry completely. I even thin the sealer even more so it might soak deeper. Several coats might be needed.

- Mist the surface with water and let it sit for a bit to soften the fibers then cut while wet.

- Douse the tearing-out section with fine CA glue. This sometimes works but can stain the wood in some species. Adding a few drops then immediately wiping with the grain can help.

- Try a different tool or several different tools. As mentioned, try a very sharp Hunter tool, the smaller the diameter the betters. Same as mentioned, a smaller diameter gouge might work better (a large diameter edge can take more of a "bite" and may tear out more. A spindle gouge ground with a fairly "pointed" tip will remove much less material at once. On spindles I've had some species tearout and chip badly with a skew but not a 3/8" spindle gouge.)

- Try cutting the other direction, uphill instead of downhill with the grain as we are supposed to. Occasionally I've found this worked better, perhaps in just small areas.

- Try removing some wood and the tearout with a sharp negative rake scraper with a delicate burr. With a light touch this can take delicate shavings so fine they float around in the air.

BTW, this is the NRS shape I find the best, about a 60-deg included angle. I ground these from Thompson scrapers and a skew chisel.

JKJ