Bowl Interior End Grain

[Howard Hale]

I continue to practice turning as a new turner and enjoy bowls. Have turned a variety of wood in both wet and kiln dried. I have pretty well been able to clean up the end grain rough places on the exterior with power sanding. However, I struggle to get a nice smooth finish at those same spots on the interior. I have tried to turn the walls more but the very open grain seems to continue to no end. Sanding helps but still leaves clear evidence of the rough places.

Any suggestions for how to improve these places in my bowls?

Thanks.

 

[hockenbery]

I use a gouge. With a gouge the secret for a smooth surface is lighter cuts
1/2” shavings for roughing. Then 1/4”, 1/8”, 1/16, 1/32, 1/64 then 1/128.....
Turn the rim smooth before hollowing the interior.

To get a smooth surface -> sharp tool, light cuts, bevel riding.
I use a 1/4 gouge on the first inch of side wall If you don’t have one the large bowl gouge does a nice surface the small gouge improves it.

Stick with the bevel riding push cut

Don’t try the shear cut. Unless you have someone teach you will likely get a massive catch

Fast forward to 21.06
Mounting and turning a dried bowl

View: https://www.youtube.com/watch?v=sCZWsHB4vlM

 

[Howard Hale]

Thanks for the suggestion and video. I have tried to continue to take light cuts and it does reduce the rough area. However, it seems that this open grain goes deep. Perhaps I just need to keep taking light cuts until it is gone.

 

[Howard Hale]

Here are a couple photos of the problem areas.

 

[Richard Coers]

Your form design is not doing you any favors either. That tight radius at the intersection is going to be brutal to sand. What tools are you using for turning? Your final turning pass should be done with a fresh edge on the gouge, and an extremely fine cut. I see a couple circular scratches so you are trying to power sand and hand sand with the blank turning? You can use a drill and pad, and sand the trouble area with the arbor lock engaged. It lets you concentrate on the tear out. They remove the arbor lock and feather out the area with the blank spinning.

 

[hockenbery]

Thanks for the suggestion and video. I have tried to continue to take light cuts and it does reduce the rough area. However, it seems that this open grain goes deep. Perhaps I just need to keep taking light cuts until it is gone.

most beginners find a 1/4 depth of cut easy to control. They need to practice a lot to get comfortable with 1/2 deep cuts and with 1/8 “ deep cuts. Shallower cuts take more practice. When you are learning a sharp tool and a 1/4” cut may give you an acceptable surface.

Use bevel riding finish cuts to remove the last 1/4” of wood.
Also start your entry on the wall cut slowly. Let the gouge sit at the top of the wall until it cuts a little space for the bevel to ride.

If you can keep cutting as long as you have torn grain you can run out of wood.

If you are signed up for the AAW virtual symposium, be sure to watch Glenn Lucas on Friday.

 

[Robert D Evans]

I've found that coating the problem area with sanding sealer can help stiffen up the wood grain so you can get a good finish cut. Also a negative rake scraper can clean up tearout if it's not too deep. Every piece of wood is different and sometimes you just have to try different things to see what works.

 

[Brandon Sloan]

I struggled with this same issue not that long ago. Al’s video helped, another thing that helped me was setting turning goals. Work on one thing until you are satisfied with your results.

First thing is bowl design. I noticed that the good bowl turners don’t turn flat walled bowls. Work on creating continuous curves and smooth inside transitions. Ultimately this will help with sanding.

Once I got comfortable with the design of my bowls, I started focusing on my current goal. I call it “Quitting Grits” I’ve been able to quit 80 grit by zeroing in on finishing cuts. 120 doesn’t get as much action either. This forum is a great place to learn. It’s helped me tremendously. Good luck!

 

[Emiliano Achaval]

Al is spot on with his advice. I would like to add that since I hosted Stuart Batty for a week in my shop, I do not like to say ride the bevel. Riding the bevel implies putting pressure on the wall. I prefer the expression "float" the bevel. I can turn super thin if I wanted to by floating the bevel, if you put any pressure on the wall you will get chatter. It does take some practice to make a super thin cut. A continuous gradual curve on the inside makes it easier to cut it and sand it. Bill Jones was asked how he got so good at turning, he said "why, you just stand in front of the lathe"

 

[john lucas]

Follow all of Al's advice. One final thing. When all else fails I turn off the lathe and either power sand just that area or I use a round hand held cabinet scraper to clean up the area. I also find a tool with a smaller radius cuts those area cleaner. I use a Hunter #5 cupped carbide cutter. If it's near the lip where I can "glide the bevel" I will use my 3/8" spindle gouge that has a 35 degree cutting edge. I don't understand why this works but a cutter with a smaller radius seems to cut problem wood cleaner even if the actual cutting angle is the same. I've done this experiment numerous times on woods like curly maple and birds eye maple along with other woods.

 

[Donovan Bailey]

Follow all of Al's advice. One final thing. When all else fails I turn off the lathe and either power sand just that area or I use a round hand held cabinet scraper to clean up the area. I also find a tool with a smaller radius cuts those area cleaner. I use a Hunter #5 cupped carbide cutter. If it's near the lip where I can "glide the bevel" I will use my 3/8" spindle gouge that has a 35 degree cutting edge. I don't understand why this works but a cutter with a smaller radius seems to cut problem wood cleaner even if the actual cutting angle is the same. I've done this experiment numerous times on woods like curly maple and birds eye maple along with other woods.

In regard to your statement on a tool cut with a smaller radius, Jimmy Clews teaches and demos using this technique. In fact, he uses a little 1/4" gouge to make the point. Interesting.

 

[robo hippy]

I am guessing that the piece you showed is a soft maple, maybe Ambrosia? That is more prone to tear out than other woods. Some times getting the wood damp, as in spritzing it with a spray bottle, and then very gently cutting off the wet wood will help. Some times sharpening on a 600 grit wheel and/or honing will help. I prefer, when cutting in that area, to have my flutes rolled over on their sides, and cutting with the more vertical part of the nose for a higher shear/slicing cut angle. A NRS (negative rake scraper) can help clean it up a bit, but it works better in harder woods and across the bottom of a bowl than it does in softer woods and on the walls. Some times a shear scrape (I have a video dedicated to that on You Tube) can help. Some times you just have to go to the 80 grit gouge. Sand at slow drill speeds and lathe speeds. Higher speeds when sanding don't let the abrasives dig in and cut. Looks like you are hand sanding. Some times you have to stop and sand those spots by hand. The card scrapers can help also.

robo hippy