Question bout Bowls

[Ben Werner]

Ok so I'm turning this bowl (not end grain, other way) and I just have a couple of questions accompanied by pics.

1. When it is spinning the part of the grain where its being cut back?. is all rough... I can get it fairly smooth but not smooth enough. So I start with 180 grit sand paper, but it gets all nasty and up there and white and streaky, See images below, It happens on both "sides" where i'm cutting into the grain. even though it looks rouph it pretty much feels the same, nice and smooth.
http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8763_IMG_2.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8763_IMG_2.jpg)http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8760_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8760_IMG.jpg)http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8759_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8759_IMG.jpg)http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8758_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8758_IMG.jpg)
I find that 180 just makes it worse, but using like 320 sands it smooth without all the streaks, the prob with doing that is it takes forever because I need to take off a fair layer of wood. This has happened to me for all bowls turned out of wood like this. Any suggestions to what I can do to elliviate this problem?



2. What to do to fill these cracks:
http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8769_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8769_IMG.jpg)http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8768_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8768_IMG.jpg)http://i60.photobucket.com/albums/h34/benknobi89/Maple/th_187-8767_IMG.jpg (http://i60.photobucket.com/albums/h34/benknobi89/Maple/187-8767_IMG.jpg)

same bowl as above just sat overnight without being hollowed.... any suggestions? I was thinking along the lines of making it look funky like charcoal and epoxy... how would that look?

Ben

BTW: once the outside is done I plan on using my new scraper to do the inside :D

[Jim King]

Ben: When I turn peices that have not sufficiently dried I get the same tendancy to be a bit rough and discolor on each side just as you do, this is really end grain on each side. That is why I rough turn everything, boil them for a few hours and dry them well. This will also help the laquer down the road in a few months from getting a cloudy look to it from moisture in the wood trying to get out. I dont final turn and finish until the wood gets down to 6-8%.

[Bernie Weishapl]

Ben I agree with Jim. If you wood is wet and you are just roughing it out I would do no sanding. I would dry it first after roughing your blank out. If your wood is dry and you have it turned to the wall thickness you want I start sanding at 80 grit, 100, 150, 180, 220, and 320 for bowls that are going to be used. If it is a display or artsy piece I use 400, 600 and 800 grit.

On the cracks Ben it depends how big the cracks are. I have used epoxy mixed with Denatured alcohol to the consistancy of milk. Filled the crack with sawdust from sanding or coffee grounds and then soaked the crack with the epoxy mix. If it is a hairline or small crack I just use Super Glue.

[Jonathon Spafford]

It just looks like tearout to me... try putting some paste wax or mineral oil (any oil would probably work) on the streaks and then taking a fine cut with your gouge. After, put some more wax on and than either take a square scaper and hold it at an angle against the wood and shear scrape it... or take a cabinet scraper and hold it almost at a 90 degree angle and use that to shear scrape (if you use a cabinet scraper you don't need a tool rest to use it) If you use a square cabinet scraper please don't stick the corner in the wood as it won't be good. After shear scraping most tearout should be gone... now you can start sanding. You can put more oil or wax on if you like. Once you are done with 150 grit... your tear out should be pretty much gone. If there are a couple spots left stop the lathe and sand them out by hand. THen you can just sand through 320.
If your bowl is still wet you will have to wait till it is dry to finish it.

[Reed Gray]

I agree with Jonathon, that what you have is tearout. The best ways to get rid of tearout are sharp tools, light cuts, and/or the 80 grit gouge. You can get the fibers wet with water, oil, or what ever you have handy, lit it soak in for a minute or three, then take very light cuts to remove the wet wood. This works best on dry wood. Good cutting techique, sharp tools, and 10,000 more times. If that doesn't work, get it wet, and repeat the above. You can sand wet wood, but it is a pain.
robo hippy

[Curt Fuller]

Ben, you're still young enough that someone may discover a cure for that tearout in your lifetime (maybe even you). It happens to some extent in almost every bowl, in that part of the bowl where it transitions from the bottom to the sides. Some woods are worse, some not so bad. Some bowl shapes worse than others. The best cure I've found for it is power sanding. It's another one of those wallet draining features of woodturning. But get yourself a nice right angle, close quarter type drill, a set of soft flexible sanding discs and various grits of paper and the sanding will go much faster than trying to do it by hand. Also if the wood is wet use a heat gun or hair dryer to dry the surface to make it sand a little better without gooing up your sandpaper.
As for those cracks, if you're trying to turn green bowls over a two day period, like tonight for the ouside and tomorrow for the inside, you're gonna have trouble with cracks. You can bag it, shrink wrap it, throw shavings in with it, or any of the other tricks but you're still going to run the risk of cracks. For green bowls it's best to try to turn from start to finish in one setting, keep the walls thin and uniform, and remember to keep your fingers crossed. Or, rough turn to slightly larger than the finished size you want and then go through one of the drying processes like DNA, boiling, microwave, or months in a paper bag.

[Dennis Peacock]

Yup, that's tearout and tooling marks. Even very light variations in tool control will yield that look. I get those all the time Ben. :o
Patience and sanding with a good sanding schedule will take care of that in no time....but this is where the patience comes in to play. The worst wood that I've worked with that shows this behaviour the most is Elm. Pretty stuff when finished well, but boy.!!!! Just getting all the marks out of the wood is very time consuming (for me at least).

[Ben Werner]

hmmm sounds interesting... It just doesnt seem like the tear out i've come to know and hate... :p:eek: No suggestions as to what to do with those cracks?? The reason I left the bowl was cause the log has been sitting up in our baking attic all summer so I thought it wouldnt crack... ah well. I know how to "prevent" it but what should I do now that I have it?? those cracks are getting bigger by the minute... I actually just hollowed it out (with my new scraper!!!!) trying to stop them from getting bigger and then stuck it in dna... not that itll do much good now.

So any radical ideas to make it look good even with all those cracks? some sort of special filler concotion?

[Jonathon Spafford]

The best cure I've found for it is power sanding. It's another one of those wallet draining features of woodturning. But get yourself a nice right angle, close quarter type drill, a set of soft flexible sanding discs and various grits of paper and the sanding will go much faster than trying to do it by hand.

I haven't had trouble finishing a bowl off without power sanding and it doesn't take to long... I have found that three or so passes with a shear scraping cut after oiling the wood is enough to take out most of the tearout. Now if you start sanding right away without taking the scraping cut that is a different story: that will take you a lot of time and a lot of 80 grit gouge.

Those scrapers you got for your b-day should do the trick, Ben... btw, happy birthday :D

[Ben Werner]

Ok so I just pulled it out of the DNA and all the cracks are gone! I asume that thats just because the wood absorbed some DNA so it swelled... is my thinking correct? If thats so will they just appear again as bad as they were before, or will they come back but not so bad? any ideas?

[Ted Calver]

Ben,
I hate to say it, but you probably should chalk this one up as a learning bowl and set it aside in the kindling box. I think the cracks will return after the DNA evaporates and even though you could fill them with CA, or CA and a filler, or epoxy and a filler, there is a better than usual chance the bowl will fly apart during finish turning due to the nature and position of the cracks. In the end, you might have a plain wood bowl that some folks might think had a little more character from obviously repaired cracks, but wouldn't your time be better spent doing another bowl and trying all the good advise others have offered? I like to reserve extraordinary measures for extraordinary pieces of wood. Just a thought....can't blame you if you want to work through the process just for the experience.;) :D