Minimum board thickness on 15" planer

[Jim Ammon]

Recently, I purchased a Jet JWP-15CS 15" Planer. I chose this model
over the Delta DC-380, because it included an enclosed base with
rollers, a dust chute, top rollers and rollers on the infeed and outfeed
extention tables. However, when I uncrated it, and looked at the spec
sheet, I noticed something that I hadn't noticed before. The minimum
thickness board that the Jet can plane is 1/2", whereas the Delta can
plane a 1/4" thick board (I thought I had checked on this, but I guess
not). Anyway, I was wondering what other people's experiences have
been. Have they really had much of a need to plane 1/4" boards? (I
realize this depends on the type of work one does). A Fine Woodworking
article on the machines didn't even mention minimum thickness and gave
the Jet a high rating, leading me to believe that most people get by
with the 1/2 min. Also, are there workarounds, when one wants to plane
a board thinner than the min thickness, such as temporarily bonding it
to a shim board, to increase thickness? One friend said he prefers to
use a thickness sander for thin boards, but I'm not inclined to buy yet
another expensive machine.

Please respond to the newsgroup or my address below. I'm currently on a
friend's machine.

Thanks,

Jim Ammon
jima...@hotmail.com

[John Newman]

Jim,
I also have a JET 15" planer which I "modified" to solve three problems: 1.
minimum thickness, 2. support for long boards and 3. snipe.
I have added a long piece of 12mm (or 1/2") MDF covering all of the
rollers. It has a chunk of wood screwed to the underside of the infeed to
stop it moving, and two hardwood guides each side on the infeed top, exactly
15" apart. The top surface of the MDF under the feed rollers and cutter is
kept polished with a liquid wax. The total size is 15" x 60" long. (Could be
shorter if space is a problem.)

So, the end result is virtually no snipe and I can thickness down to about
3mm. (ie under 1/4")
If I ever need to thickness boards at the other end of the range (5-1/2" to
6"), I temporarily remove the MDF.
The only problem is the scale is out by 12mm (or 1/2" in the US). Must get
round to changing it sometime.
--
John D Newman
Hillcrest Woodcraft, Darlington, Western Australia.
Restorer/collector scientific instruments.

Jim Ammon wrote in message <36CE6CF5...@hotmail.com>...
>Recently, I purchased a Jet JWP-15CS 15" Planer. However, when I uncrated

it, and looked at the spec
>sheet, I noticed something that I hadn't noticed before. The minimum
>thickness board that the Jet can plane is 1/2",

[the Riddles]

Jim, I have had a jet 15" planer for about 14 years and have run literally
thousands of bf of hardwood lumber through it without a hitch, only routine
knife changes. only complaint is the imprint left by the serrated outfeed
roller which is a nusiance but is easily sanded out.
Have never had trouble planing thin boards; however, I keep a piece of
plywood cut cover the bed of the planer. this covers the bed rollers,
keeping them from raising the work from the bed into the knives. the top of
the board is covered with plastic laminate and the bottom has a hardwood
strip to keep it from being pulled into the planer. I use this whenever
planing thin work, or planing a board on its edge.

[Jim Ammon]

Thanks for the feedback. I fiddled with the crank on the Jet a bit and found
that I could actually crank the table up to an indicated 1/8" thickness. What
was going on? Could it really plane a board this thin? I talked to Jet today,
and they told me that the planer could in fact plane a board thinner than 1/2",
but they recommended going no thinner than that for safety reasons. Perhaps the
thinner board is in danger of flexing when it goes through the rollers? I
suppose one could take lighter cuts and adjust the roller pressure. Any reason
you can think of that would may planing a thin board dangerous? Perhaps that's
exactly what you were addressing with your custom add-on?

Thanks,

Jim Ammon

[Gator]

I have one of the notorious Delta 12" planers and to do anything under
1/4 inch, I have a board with a one inch lip on it that I slip into the
planer. The lip make it stable and the board allows me to drop the
cutter head down without worrying about getting too low. If the blades
are sharp, I can plane below 1/8", if necessary... "Course, the blades
haven't been "Scary Sharp" since I don't know when".. <grin>

[the Riddles]

Jim, the only thing I can think of making planing the thin boards dangerous
is that they do break up in the machine easier. 1/4" isn't a lot of wood so
plan on some of it breaking apart in the machine and possibly kicking back.
try to make a little extra just in case and pick pieces with the straightest
grain possible since the boards will break apart around any curly grain or
knots. Rick

[bfeng]

The danger with planing thin stock is that it can blow apart
and produce some pretty impressive kickback and debris.
Stock that is too thin will also be flexed by the rollers
and you will see more uneveness on the ends.
Using a 3/4" piece of MDF as a backup board solves the latter
problem, but check the grain on your stock before
planing to much stuff down to 1/8" or 1/16".

I regularly plane my own veneer (typically down to 1/16")
on our planer without problems (other than the occassional
blow up).

--

John Feng

MÜLLER-BBM VibroAkustik Systeme, Inc.
325 E. Eisenhower Parkway, suite 300
Ann Arbor, MI 48108

voice: 734-327-4147
fax: 734-327-4143
email: bf...@mbbm.de

[Preston Andreas]

When I got my 15" Jet planer, I decided to see how thin I could plane a
board. I put a 2" wide 3/8" thick piece of oak over a wider piece of 3/4"
oak. I got the board to slightly less than 3/64". The next pass ate up the
board and sent it to the dust collector. I think that with a very tight,
straight grain piece of wood and very sharp cutters, I might have even
gotten it thinner. And by the way, I made sure not to stand behind the
planer while doing this.

--
pand...@texas.net
Gator wrote in message <36D65DEA...@gator.net>...

[bfeng]

Preston,

Straight grain would've helped. Slightly descending grain
( relative to the direction of feed) would be even better.

--

[Gerry Glauser]

I've got one of those Delta 12 also. I replaced the bottom with a long piece
of melamine (about six feet), with levelers on the ends that are adjusted to
just touch the bench, letting the base of the planer set the angle. A cross
piece holds it aligned in the planer. With this, I regularly plane 1/4 inch
material from a variety of woods. I've gone down to 3/32 with very light
cuts, but the wood doesn't always hold together.

(BTW, ditto on the blades.)

--Gerry Glauser

On Fri, 26 Feb 1999 01:40:10 -0700, Gator <ga...@gator.net> wrote:

>I have one of the notorious Delta 12" planers and to do anything under