Sanding Inside of Bowl

[Paul Rains]

I need help with getting smooth finish in inside of a maple bowl. I am relatively new, and bowl scaper is not working well, I have small lines all the way across bowl, and I have cut into trying to shave them out about as much as I can allow, anymore and I may have nice looking funnel:o

I have the sanding pad to go on end of drill, but lowest grit is 150, doesn't seem to be cutting lines? Bowl still sitting in chuck:(

[Scott Hubl]

You have to start at the proper grit.

If you have tool marks that requier 80 grit that is were you need to begin, trying to start at a higher grit like the 150 will take forever to remove the heavier tool marks, tear out or whatever you have.
Go to a BORG and grab some 5" disk 80 grit hook n loop paper and cut to fit. (works in a pinch if you cant wait to get online or local wood store in correct size)

[Steve Schlumpf]

Paul - without seeing any photos - it sure sounds like you are dealing with some tear-out. Sanding will work but with 150 grit - it is going to take awhile! Problem with tear-out is that the wood fibers have been basically ripped out and their rough surface is a lot lower than that of the rest of the bowl. While sanding will work - I would suggest using a (sharp) scraper some more and doing the best you can to even up the inner surface before spending any more time sanding.

[Scott Hubl]

I found what I was looking to post for you to Watch.

It is a Vid Clip from one of Mike Mahoney's DVD's.

On Power Sanding, Watch it he explains the grit sequence.http://www.youtube.com/watch?v=aY3JHxa7HwA&feature=related

[Kurt Bird]

Paul,
Another thing to try is to hand rub some paste wax into the bowl, particularly in the tear-out areas. Then, cut again with a freshly sharpened bowl gouge or a scraper used in a shear scrape postion. Take very light cuts, and you should be able to remove enough material to improve the finish.
Kurt

[Paul Rains]

thanks, video helps, the 60 grit took out lines, turned out pretty nice, little out of proportion on bottom, but I am learning:)

[Reed Gray]

Paul,
Of course, having sharp tools and good tecnique are the best ways to reduce sanding. Getting the outside of the bowl smooth with the turning tools is easier than doing the inside. You have easy access, and you can see better than on the inside. I do like to use a scraper to clean up the inside. Of course, use a freshly sharpened one with a good burr, then I shear scrape. If you have the scraper flat on the tool rest, no matter how light of a cut you take, you will get some tear out. If you have it up at a 45 degree angle, then you are getting a shear cut which is a lot cleaner, and also puts much less stress/pressure on the wood while cutting. This is not a stock removal cut, it is clean up, and you want only the finest of shavings floating around in the air. When doing this cut, I start lower in the bowl, and pull towards the rim. This is the opposite of how you work the gouge. You can actually start the cut at the top, and push towards the bottom, but it seems easier to me to pull.

You also have to be very light when you are near the bowl rim, especially if it is a larger bowl. When turning the outside, you have all of the inside wood for mass which makes it fairly rigid. Once you remove the inside, it gets wobbly. The wood is fairly thin, and will flex with even light pressure (think of a soap bubble). This can lead to funny marks, that look like chatter work, to even causing so much flexing that you get a big catch and explosion. If the bowl is big, take it down to final thickness in stages, say an inch at a time. Cut, then finish cut, then go down some more, and repeat till you are down to the bottom. You can use a steady rest, but mostly for me, I will use one hand gently on the outside of the bowl (if your hand gets hot, then you are pressing too hard, and you can press hard enough to cause more vibration). This works fairly well, and if you master a shear scrape, you won't have to start sanding at 80 grit or less. I really don't like to sand, and a few minutes extra time in tool work and developing tecnique can save hours of sanding.

robo hippy

[Bernie Weishapl]

Ditto what Reed said. Fresh sharp tools are the key. Myself I have never had any luck at all using a scraper inside a bowl. I use a shear scrape with a freshly sharpened bowl gouge. Get Bill Grumbine's DVD Turned Bowls Made Easy. He shows you 4 cuts that will take the tear out right out of the inside and outside of a bowl. Like Reed I hate sanding so tool work is the key.

[Anna Vinding]

If you have the scraper flat on the tool rest, no matter how light of a cut you take, you will get some tear out. If you have it up at a 45 degree angle, then you are getting a shear cut which is a lot cleaner, and also puts much less stress/pressure on the wood while cutting.

I also just started turning bowls, and the advice about using the scraper at a 45° angle intrigued me since I've been having the same problem with tool marks. How high should the tool rest be relative to the center of the bowl? Are we supposed to keep the tip of the scraper just around the center line, too?

Anna