I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net

Instead of making dados to fit the full thickness of the plywood, consider
making narrower dados and then rabbet the ends of the plywood to fit them. A
1/8 rabbet off each side will leave a 1/2" for strength and should eliminate
the surface thickness variations that are affecting your dado joint ( a good
fitting 1/2" dado is better than a 3/4" poorly fitting dado). Better
quality plywood like birch cabinet ply may cost a little more, but the
thickness tolerances are much tighter, and therefore are easier to cut good
fitting dados for.

--
Charley


"Art Greenberg" wrote in message
...
I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net

On Tue, 27 Mar 2007 12:07:43 -0500, Charley wrote:

Instead of making dados to fit the full thickness of the plywood,
consider making narrower dados and then rabbet the ends of the
plywood to fit them. A 1/8 rabbet off each side will leave a 1/2" for
strength and should eliminate the surface thickness variations that
are affecting your dado joint ( a good fitting 1/2" dado is better
than a 3/4" poorly fitting dado).

I am having trouble seeing how this would get around variations in
thickness. I think any method of making the rabbet that references the
surface of the plywood would just transfer that variation to the
remaining tongue.

Better quality plywood like birch cabinet ply may cost a little more,
but the thickness tolerances are much tighter, and therefore are
easier to cut good fitting dados for.

I did say I used BB (baltic birch). Are there grades of that material,
or sources, that have better thickness tolerance?

--
Art Greenberg
artg at eclipse dot net

Art Greenberg wrote:

I am having trouble seeing how this would get around variations in
thickness. I think any method of making the rabbet that references the
surface of the plywood would just transfer that variation to the
remaining tongue.

You reference from the uncut face, such that the tongue thickness is
constant while the rabbet shoulder varies.

Chris

On Mar 27, 8:09 am, Art Greenberg wrote:
I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net

Art- if usnig a saw to cut your dadoes, an adjustable dado cutter head
should do the trick. Get it honed in on a piece of scrap them hit
plywood.

If you are using a router, they make bits purposely undersized to
route the dado to be the same thickness as the plywood.

You shouldn't have to scratch off the edges of a dado no matter what
you are using to cut.

Robert

Basically, he's saying trim the board instead of the dado to fit. Its not
all that easy to reliably trim a little strip (3/16" wide strip) next to the
edge of a board. A straight board guide clamped to the shelf and a rabbet
plane work pretty well.

For trimming a dado after the fact, the side rabbet plane set by Nielson
seems pretty nifty, though not much use for anything else.

I like the approach of cutting the dados the right width in the first place.
This means precutting the shelves to know what thickness is required. Then
you have to play games with dado blade setup on the tablesaw or use of a
router with an adjustable dado jig.

I am very surprised you got inconsistent width boards in BB plywood. I've
found it to be very, very consistent in thickness and quality.

"Art Greenberg" wrote in message
...
On Tue, 27 Mar 2007 12:07:43 -0500, Charley wrote:

I am having trouble seeing how this would get around variations in
thickness. I think any method of making the rabbet that references the
surface of the plywood would just transfer that variation to the
remaining tongue.

On Tue, 27 Mar 2007 11:41:44 -0600, Chris Friesen wrote:
Art Greenberg wrote:

I am having trouble seeing how this would get around variations in
thickness. I think any method of making the rabbet that references the
surface of the plywood would just transfer that variation to the
remaining tongue.

You reference from the uncut face, such that the tongue thickness is
constant while the rabbet shoulder varies.

OK. That would mean using a router "on edge", or (equivalently), stand
the board up on a router table, or a table saw. Not easy with a 3-4 foot
long 12 inch deep shelf.

--
Art Greenberg
artg at eclipse dot net

On Tue, 27 Mar 2007 13:21:17 -0500, Bob wrote:

Basically, he's saying trim the board instead of the dado to fit. Its
not all that easy to reliably trim a little strip (3/16" wide strip)
next to the edge of a board. A straight board guide clamped to the
shelf and a rabbet plane work pretty well.

For trimming a dado after the fact, the side rabbet plane set by
Nielson seems pretty nifty, though not much use for anything else.

Right. I wonder how well those planes will work in plywood, where its
cutting with the grain in some of the veneers, across the grain in the
others.

I like the approach of cutting the dados the right width in the first
place. This means precutting the shelves to know what thickness is
required. Then you have to play games with dado blade setup on the
tablesaw or use of a router with an adjustable dado jig.

I am very surprised you got inconsistent width boards in BB plywood.
I've found it to be very, very consistent in thickness and quality.

I thought that should have been the case, and that is exactly why I
bought a number of sheets of the stuff to keep for projects like this
one.

I dealt with my local lumber yard, which had to special order it.
They're much more accustomed to dealing with construction lumber, and I
was dismayed to see that they treated the BB just like construction
lumber - just thrown into the truck as if it were underlayment or
sheathing. An experiment that seems to have failed. It may be necessary
for me to rent a truck and drive a bit to get decent product.

--
Art Greenberg
artg at eclipse dot net

Art Greenberg wrote:


I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in
thickness, so
the dados needed some tuning.
snip

Take your choice, stacked dado on a T/S or a router.

Make dado in two (2) passes with an undersize cutter.

PITA, but it solves the problem, just keep your dial caliper and
marking chalk handy.

Lew

On 27 Mar 2007 11:09:09 -0700, wrote:
Art- if usnig a saw to cut your dadoes, an adjustable dado cutter
head should do the trick. Get it honed in on a piece of scrap them
hit plywood.

I used both a router with a jig, and a tablesaw with dado set and shims.
I fussed with both using a sample piece. The problem is, the sample
turned out to not be wholly representative of the batch of plywood I
had to work with.

If you are using a router, they make bits purposely undersized to
route the dado to be the same thickness as the plywood.

You shouldn't have to scratch off the edges of a dado no matter what
you are using to cut.

If only that were true. I bought a bunch of Baltic Birch thinking it
would be consistent enough in thickness to make it so. I guess, even
with BB, I'll have to hand pick each piece using a dial caliper.

Sigh.

--
Art Greenberg
artg at eclipse dot net

"Art Greenberg" wrote in message
...
I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net


Sand the surfaces of the plywood where it will fit into the dado with a ROS
until they fit.
Or use a top bearing pattern bit and a straight edge as a guide to widen the
dado.

"Art Greenberg" wrote in message
...
On Tue, 27 Mar 2007 13:21:17 -0500, Bob wrote:

I am very surprised you got inconsistent width boards in BB plywood.
I've found it to be very, very consistent in thickness and quality.

I thought that should have been the case, and that is exactly why I
bought a number of sheets of the stuff to keep for projects like this
one.

Just to confirm you were getting what you thought you were, did it come in
5'x5' sheets? That's the only form I've ever seen BB come in.

Bob

On Tue, 27 Mar 2007 14:48:36 -0500, Bob wrote:
Just to confirm you were getting what you thought you were, did it
come in 5'x5' sheets? That's the only form I've ever seen BB come
in.

Yep.

--
Art Greenberg
artg at eclipse dot net

On Tue, 27 Mar 2007 19:01:48 GMT, Lew Hodgett wrote:
Take your choice, stacked dado on a T/S or a router.

Make dado in two (2) passes with an undersize cutter.

PITA, but it solves the problem, just keep your dial caliper and
marking chalk handy.

PITA is an understatement.

I don't see how to control the TS with the accuracy needed to do it this
way, without one of the really cool positioner-based fences from
Jointech or Incra.

Certainly doable with a simple router jig that is adjusted using the
shelf as a gauge. I have a gadget from Woodline that works that way
(DadoWiz), and that's what I used for most of the dados. But I did _not_
anticipate the need to reset it for each end of each shelf.

I suppose I could go back and re-cut each dado this way, that would take
care of the problem. But it seems so much easier to neander it with the
scraper ...

Live and learn.

--
Art Greenberg
artg at eclipse dot net

"Bob" wrote in message
...

"Art Greenberg" wrote in message
...
On Tue, 27 Mar 2007 13:21:17 -0500, Bob wrote:

I am very surprised you got inconsistent width boards in BB plywood.
I've found it to be very, very consistent in thickness and quality.

I thought that should have been the case, and that is exactly why I
bought a number of sheets of the stuff to keep for projects like this
one.

Just to confirm you were getting what you thought you were, did it come in
5'x5' sheets? That's the only form I've ever seen BB come in.


Just to confirm, Baltic Birch is not the only plywood that comes in 5x5
sheets. There are plenty of imitators and I think he got one of the ones
sold as BB.

Art Greenberg wrote:

PITA is an understatement.

I don't see how to control the TS with the accuracy needed to do it
this
way, without one of the really cool positioner-based fences from
Jointech or Incra.

A UniFence will do the job; however, there is a way using both T/S and
router.

First pass use T/S with undersize dado, then clean up to size with
router and a straight edge.

Just make sure you use a common reference for all cuts, either top or
bottom of T/S dado cut.

Have fun.

Lew

On Tue, 27 Mar 2007 20:27:03 GMT, Leon wrote:
Just to confirm you were getting what you thought you were, did it come in
5'x5' sheets? That's the only form I've ever seen BB come in.

Just to confirm, Baltic Birch is not the only plywood that comes in
5x5 sheets. There are plenty of imitators and I think he got one of
the ones sold as BB.

Ot-oh ... could be. Is there a way I can avoid making the same mistake
again? What should I look out for?

--
Art Greenberg
artg at eclipse dot net

On Tue, 27 Mar 2007 20:49:12 GMT, Lew Hodgett wrote:
A UniFence will do the job; however, there is a way using both T/S
and router.

First pass use T/S with undersize dado, then clean up to size with
router and a straight edge.

I only need to take of a little - I had success with a few passes with a
scaper. So setting the straightedge could be a bit fiddly, but it is
certainly worth a try.

Just make sure you use a common reference for all cuts, either top or
bottom of T/S dado cut.

Of course.

Have fun.

Always!

Thanks for the suggestions.

--
Art Greenberg
artg at eclipse dot net

"Art Greenberg" wrote in message
...
On Tue, 27 Mar 2007 20:27:03 GMT, Leon wrote:
Just to confirm you were getting what you thought you were, did it come
in
5'x5' sheets? That's the only form I've ever seen BB come in.

Just to confirm, Baltic Birch is not the only plywood that comes in
5x5 sheets. There are plenty of imitators and I think he got one of
the ones sold as BB.

Ot-oh ... could be. Is there a way I can avoid making the same mistake
again? What should I look out for?


The 5x5 5 ply can be Russian stuff, too. Not as good as the Finnish.
Usually has a violet stamp on it with Cyrillic FKA (factory) and a number.

George wrote:

The 5x5 5 ply can be Russian stuff, too. Not as good as the Finnish.
Usually has a violet stamp on it with Cyrillic FKA (factory) and a
number.

SFWIW, my landlord uses Birch ply to fabricate tooling to stamp gaskets.

Absolutely refuses to use Russian material.

Lew

You can do it with any tablesaw fence that stays in one spot. Alternatives
to your dado set up include loose mortise and tennon, biscuits or splines.
"Art Greenberg" wrote in message
...
On Tue, 27 Mar 2007 19:01:48 GMT, Lew Hodgett wrote:
Take your choice, stacked dado on a T/S or a router.

Make dado in two (2) passes with an undersize cutter.

PITA, but it solves the problem, just keep your dial caliper and
marking chalk handy.

PITA is an understatement.

I don't see how to control the TS with the accuracy needed to do it this
way, without one of the really cool positioner-based fences from
Jointech or Incra.

Certainly doable with a simple router jig that is adjusted using the
shelf as a gauge. I have a gadget from Woodline that works that way
(DadoWiz), and that's what I used for most of the dados. But I did _not_
anticipate the need to reset it for each end of each shelf.

I suppose I could go back and re-cut each dado this way, that would take
care of the problem. But it seems so much easier to neander it with the
scraper ...

Live and learn.

--
Art Greenberg
artg at eclipse dot net

Router table with a tongue cutter would do it. References on side.

"Lew Hodgett" wrote in message
ink.net...
Art Greenberg wrote:

PITA is an understatement.

I don't see how to control the TS with the accuracy needed to do it
this
way, without one of the really cool positioner-based fences from
Jointech or Incra.

A UniFence will do the job; however, there is a way using both T/S and
router.

First pass use T/S with undersize dado, then clean up to size with
router and a straight edge.

Just make sure you use a common reference for all cuts, either top or
bottom of T/S dado cut.

Have fun.

Lew

On Mar 27, 9:09 am, Art Greenberg wrote:
I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net

Side rabbet plane will work fine in plywood.

Or, as someone else suggested, rabbet the plywood shelf to fit a
narrower dado. You will still have to adjust it by hand, but it's
easier to trim the thickness of the tongue with a rabbet plane than it
is to trim the dado with a side rabbet.

John Martin

On Wed, 28 Mar 2007 01:39:10 GMT, CW wrote:
You can do it with any tablesaw fence that stays in one spot.
Alternatives to your dado set up include loose mortise and tennon,
biscuits or splines.

I used splines to construct the core when I built a large (4' x 8')
torsion box table. I used inexpensive plywood I bought at the home
center, and expected a fair variation in thickness, using splines
avoided having to deal with that. But in that case, the load is
distributed across many such joints, and the skins. These shelves will
hold books, and I thought a dado would be a better choice. I didn't
consider biscuits or mortise and tennon for the same reason. Am I wrong
about that?

--
Art Greenberg
artg at eclipse dot net

From other posts it sounds like your router bit fits ok for the thinnest
part of the sheet. If this is the case when you set up your fence for the
router run a layer (or possibly 2 or 3 layers) of tape along the fence. If
dado is too tight, remove 1 layer of tape, run dado again and it will widen
by the thickness of tape. Repeat until you get a nice fit.
Not much more fiddly than a single pass dado and a very cheap micro
adjustable fence at that.


--
Up here for thinking,
Down there for dancing.

"Art Greenberg" wrote in message
...
I'm making a closet organizer for SWMBO. Ya know, to score points, so I
can buy more tools. 8-)

I picked up some BB plywood for this project. Assembly involves a few
dados. I found that the BB does have a little variation in thickness, so
the dados needed some tuning. I used a card scraper for this, and after
I figured out how to attack the side wall of the dado properly, it
worked OK, but to took a long time. I found that I needed to refresh the
edge on the scraper pretty often.

What alternatives are there? Would a side rabbet plane work OK in
plywood?

--
Art Greenberg
artg at eclipse dot net

FWW had an article several years ago about making slip joints using a
jig holding a slab vertically that slid on the rip fence, WORKS
GREAT!

On Tue, 27 Mar 2007 18:51:58 -0000, Art Greenberg
wrote:

On Tue, 27 Mar 2007 11:41:44 -0600, Chris Friesen wrote:
Art Greenberg wrote:

I am having trouble seeing how this would get around variations in
thickness. I think any method of making the rabbet that references the
surface of the plywood would just transfer that variation to the
remaining tongue.

You reference from the uncut face, such that the tongue thickness is
constant while the rabbet shoulder varies.

OK. That would mean using a router "on edge", or (equivalently), stand
the board up on a router table, or a table saw. Not easy with a 3-4 foot
long 12 inch deep shelf.