In this turning issue of the
Woodworker's Journal eZine, we're bringing you a couple of
discussions about facets of turning. The first deals with different
approaches you can take to turning a burl with a crack in it. (The
suggestions apply to burls of different woods -- we know that photo
isn't oak.) - Editor
Burl Help from WoodCentral
"I
am turning an oak burl bowl about 12" in diameter by 7"
tall. It has several voids and a large crack on one side running from
top to bottom. I have put medium [cyanoacrylate] into the crack and
so far, it has held together. I have been turning about 500 rpm and
have pretty much finished the outside. Now to the inside. I would
appreciate any suggestions on what I can put around the outside of
the bowl so that I can turn the inside without it coming apart. The
outside does not have any finish on it yet. Thanks in advance for any
and all suggestions. "- Bob M.
Bob
received a couple of different suggestions for how to deal with this
problem. - Editor
"Fiberglass
reinforced packing tape. Metal band clamps." - Jim
"Bob,
clear stretch wrap is perfect for the application you describe
depending on the shape of the bowl. Just wrap several layers around
the piece and top with some tape to keep it secure. Another option is
to create a wooden ring or two sized to fit the outside of the bowl
in one or two places and hot-melt glue them in place to secure the
bowl. When you are all done, take a heat gun and remove the ring and
glue." - Mike S.
"I
love to turn pieces with voids and cracks. I use cheap vinyl
electrical tape to wrap the outside. Shrinkwrap plastic also works
well. The plastic shipping wrap as mentioned by others also works.
Too much wrap is not a problem. Enjoy." - John V.
He
also received a warning. It's good to keep woodturning safety in
mind. - Editor
"Bob,
it is good to be wary. This is the exact scenario that has unintended
consequences. Even with the bands and tape, please stay to the side.
If it comes apart, the immediate impulse is to turn the lathe off.
Usually to do this you get into the line of fire: not good. I
witnessed this at a club meeting in west Texas a couple of years ago
that resulted in a trip to the hospital and many stitches. Several
guys had diligently poured CA glue into the crack and pronounced it
good. This also just happened to a friend of mine a couple of months
ago in Houston. He is just now healing up enough to start turning
again. Either remote the switch or rehearse where the plug is.
Voids
are not usually a problem, but cracks top to bottom are an invitation
to the front seat of a thriller. Turn at the slowest speed possible.
The best option is get another piece of wood." - Jerry
Power Sanding from
Woodworking.com
"Can
we start a discussion on power sanding? I’m starting to figure out
I’m spending way too much time sanding by hand. I tend to sand for
days as I can’t stand to see even one sanding line no matter how
fine. Can you take a wild stab on how much time power sanding saves
you? Do you finish sand using a power sander? What exactly are you
guys are using: pneumatic, electric, or self-powered deals like the
Sorby? If you had to do it over again, would you go with the same
equipment or try something else? What are you using to sand with;
i.e., what’s holding the sandpaper? Are you using 2” or 3” pads
or both? Where do you get your sanding pads and how long do they
last? What grits do you use the most? Anything I didn’t ask?"
- Al R.
It's
unlikely that there's anything Al didn't ask, and he received
responses to many of those questions. - Editor
"On
a typical bowl, I spend less than five minutes running from 120-grit
up through the polishing buffs (up to white diamond). For finishing
the interior of bowls, I use the 3" new wave disks mounted in
one of two pneumatic die grinders. You can buy the disks online in
packs of 50 for under $15.00. One nice side [benefit] of using the
pneumatic is it automatically helps clear some of the dust for the
[dust collector] to pick up. One warning, though, don't run the die
grinder at full speed -- 20-30,000 rpm will blow apart the innerface
holder if you're not careful, so keep the air pressure down to around
40-50 psi.
"For
the exterior, I slap on some ps sandpaper in my DeWALT random orbit,
or hand sand as needed. The exterior doesn't typically need too much
work. I start with 120, then 180, 220 and hand sand with 320 or 400,
0000/00000 steel wool, then the red rouge buff, and finally the white
diamond buff. The buffs get mounted in a cordless drill. As an aside,
I keep all my sanding disks in small (6" x3") plastic bins
mounted on pegboard adjacent to the lathe. Once done with the finish
sanding, I've got a polished wood surface that only needs one
wet-sanded coat of tung oil followed with one or two additional coats
for a low-gloss sheen. In many cases, I've skipped the finish
altogether, as the polished wood is magnificent. I have 2"
velcro pad wheels that are permanently mounted in each unit and small
storage bins on the pegboard behind the lathe with different grit
sets. Note that each of the grinders have safety releases on the
actuator handle. I threw away an inexpensive grinder without one
after I placed it down and it started dancing across the bench."
- Dave D.
The
next responder thought he must be doing something right, regardless
of how he accomplished it. - Editor
"I
use the cordless drill with a 2-inch pad for starters. starting with
80- or, if I'm lucky, 120-grit, working up to 180. Then I switch off
to the 2-inch DA starting in at 180 and working up to 400. I must be
doing something right. My one and only mentor that I get to see in
person, a veteran turner of 25 years, tells me my finish and sanding
is flawless." - Quartlow
"I
also power sand with battery-powered drill motor as the
counter-rotation of the paper against lathe rotation nearly insures
that you have no grit lines. I don't like the Sorby Sander as you
must have it positioned just right with the pressure just right to
get it to rotate. You can hand sand and nearly keep from getting the
grit lines, but you must keep the paper moving at all times." -
Dick
"Won't
a Dremel tool work? Nice and compact. You can buy small sanding pad
attachments. I saw an article somewhere that someone made his own
power sanding pads. Get the small sanding pad attachments, attach
some 1" foam pad (like on swimming floatation toys) and then
attach your hook and loop to it. Then sand away." - Kirby
This
guy is pretty sure he has saved time by power sanding -- although
it's possible his estimate is off, by a year (or decade) or two. -
Editor
"To
date, I have saved 237 years ... at least, that is what it seems
like, anyhoo. It takes me about 10-15 minutes to sand a bowl, and
that is a very leisurely pace. I ain't in a hurry.
I
sand from 80 or 120 (depending on how cooperative the wood was, if my
technique with the gouge was 'on' that day, the alignment of Mars to
Uranus, etc.) through 320, 400, 600, or 1,200 grit, depending on the
bowl. If I think it's a cool looking bowl, it gets sanded through
1,200 grit. The Sorby is pretty much a waste of money [in my humble
opinion], although I still use it once in a while on bowls I can't
reach into too well. I use the Sioux 3/8" angle drill, and it's
a very nice tool, although the price tag made me gag a little. But
it's worth every penny since I don't use air tools. Velcro® 2"
sanding pad., and I have the 3" extension from Packards for
getting into the deeper bowls. I'm still kinda looking into making my
own discs, punching them out of stock Velcro-backed sandpaper. If
it's a HUGE savings, I will try it." - WoodMangler
And
this response addressed the questions individually; we've handily
identified them for you in our italics so that the responses make
more sense. - Editor
"There's always going to be some
lines. Think not? Get an electron microscope and go nuts. Pneumatics.
Folks don't ask to borrow pneumatics. But unless you are willing to
get a big compressor, don't go there. I run a 7 HP, 80 gallon tank
that is hard lined throughout the shop. [What's holding the
sandpaper?] Power-Lock disks.
And, on my random orbit sander, Velcro.
Mostly 2" disks on a 1" mandrel. But have 1", 2"
,3" available. The ROS is a 6" unit with a 5" pad on
it. So the air motor has more 'oomph' to run the pad. How
long do they last? They last until I snap then off and throw them
away. [What grits do you use the most?]
100, 180, 220, 320. Then I go to micro-mesh from 1,500-3,600 by hand
control. I have up to 12,000. But haven't had a need for it as yet. I
also have the Beall bowl buffs, and rouge, white, and pure carnauba
wax. Final finishing.
There's a myriad of different things out there. My best results are
with up to 3,600 grit and the pure carnauba applied and buffed 2-3
times. I'm getting very highly polished results and it is lasting
very well. (That's over a CA finish, then the wax applied.)" -
Sonny E.