rough spots after turning a bowl
jtpryan
Ecnerwal
<21725383.2009.1318214754114.JavaMail.geo-discussion-forums@yqai1>,
jtpryan <jtp...@gmail.com> wrote:
It's problem every bowl has to a greater or lesser extent (except
perhaps segmented ones that don't have any end-grain showing.)
Sharp tools help (less there to begin with.) Sanding sealer can help
(locks the fuzz in position so it can be sanded away, rather than combed
with the sandpaper.)
--
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Bill
> I just finished turning a small bowl from a piece of bloodwood I picked up at Woodcraft. It all came out fine (one of my first projects), but I notice that there are 2 diametrically opposed "rough" spots on the outside. Sort of like a fine grit sandpaper as you run your hands over them, and you can see them in the right light. I assume they are some kind of end grain, but how can I avoid this? No amount of sanding seems to change it and I went to 600. The original block was a piece 6x6x3.
you went to fine sandpaper too soon - if you really want to get rid of
the fuzzy area, go back to 120 grit and resand until you absolutely
cannot detect the fuzzy area - if in doubt, put some finish on and look
at it - you should see scratches from the sandpaper but no fuzzy area.
When the fuzzy area is completely gone at 120 paper, then work your way
back up through the grades, probably no need to go above 400. to be
sure it's gone, apply water or a finish before going to 400 - just
enough to see if your "area of worry" is gone.
On some really stubborn pieces, I've covered the whole piece in CA glue
and then sanded it back to make the tear out disappear (it was very
rotten, but interesting wood)
jtpryan
Gerald Ross
> I see. Man, I spent some time sanding that too. Went from 60 to 180 to 220 to 600. So, it would be a lot easier to sand if it was mounted, how do you usually do that? I don't have a tenon anymore.
bowl jaws with the buttons to hold the rim of the bowl. They only
work for sanding or finishing of the Outside or bottom of the bowl.
If you notice the roughness before dismounting it sometimes helps to
sand in the opposite direction--provided your lathe is reversible.
--
Gerald Ross
I'm sure it's in the manual somewhere...
Dr. Deb
If you are haveing extreme problems, and some woods do fuzz up more than
others, black gum for instance. I was complaining about this at my
woodturner's club and one of the guys put me on to MinWax Wood Hardener. It
does not change the color of the wood but does harden the fibers to where
you can sand them smooth. It does not give you the hard glossy effect that
thin CA gives, but does provide enough firmness to enable you to sand
smoothly.
Deb
Kevin Miller
End grain tearout is the bane of all turners, especially those just
starting out. But here's a few tips:
1: Sharp tools. Sharpen frequently, and sharpen just before a final
finish cut.
2: The bowl should be turning as fast as safely possible within your
comfort zone, and you should take very slow cuts.
3: On the parts that have tearout, smear on some paste wax, then use a
2" sanding disk in your drill like one of these:
http://www.packardwoodworks.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=packard&Category_Code=snding-bholdext
(watch the line wrap)
Start w/80 grit or so, and sand under power. The paste wax will soften
the wood slightly and allow it to sand easier, cutting through the
tearout. After the 80 grit has done its job there won't be much of any
wax left. Just step through the grits after that. Each grit should
just take out the sanding marks left by the previous grit. If you still
have tearout when you do 120, reapply the paste wax and go back to 80 grit.
I saw in a later post you've already cut off the tenon. Bummer. But
not a showstopper. Make a jam fit chuck, put the bowl on it, then bring
up the tailstock to hold it in place. You can use a small piece of
scrap between the bottom of the bowl and the tailstock so you don't poke
a hole in it. That'll allow you to sand under power.
4: Lastly I'd recommend that you get some scrap/fire wood and practice
on it. Save the expensive wood for when you have the basics down pat.
Hope this helps...
...Kevin
--
Kevin Miller - http://www.alaska.net/~atftb
Juneau, Alaska
In a recent survey, 7 out of 10 hard drives preferred Linux
Registered Linux User No: 307357, http://linuxcounter.net
Bill
> I see. Man, I spent some time sanding that too. Went from 60 to 180 to 220 to 600. So, it would be a lot easier to sand if it was mounted, how do you usually do that? I don't have a tenon anymore.
of wood on a faceplate and turn a 1/4 inch (aprox) deep groove into it
that exactly holds the rim of your bowl. You don't have to make a jam
chuck, just get a close fit. put a scrap of leather (from an old shoe)
on the bottom (just hold it there with your hand) and bring up the
tailstock to press on teh leather. If you are worried about the point
pushing through, put a piece of wood against the leather first (a small
piece) and let the tail stock push on that. Don't over tighten, just
snug it up nicely and turn on the lathe and sand away. That will let
you do the outside at least.