I have a piece of Doug Fir that's 4x4x96". I want to wrap it in, say,
walnut, so that as you look at the end you see a square of end grain
Fir with 3/8" of end grain Walnut around the outside, and the Walnut
meets at the corners in a miter joint - not a butt joint. Any ideas
on the best way to apply and cut the walnut skins so that the miters
(bevels?) meet nicely along the entire length? I was sort of thinking
some sort of router set-up where I glue on a skin oversize then rout
the miter/bevel into it. Sort of like a reverse or upside down
chamfer bit set-up.
JP

*Sort of like a reverse or upside down
chamfer bit set-up.
JP

I am not sure you can bevel\miter it in place. I would first make a
small piece mitered at one edge to use for setup. Do one of the sides
with miters but slightly oversized. Use the sample piece to line up
one edge and check the other edge to see how much needs to be taken
off. Use other sample pieces to setup the TS fence to try the new
reduced size, then do the final cut on the first side once you have it
dialed in. Attach the first side.

Then just work your way around the faces. Fit the new miter edge to
the existing edge and check the next side with a sample. Use a sample
to set the fence and try the next miter, etc.

You only really need a tight fit at the ends so you can do a bit of
fudging by sanding down the fir a bit to help close a miter at the
endand pullin the walnut with clamps.

Not sure of the exact design but it would be much easier if you just
had to fit up short pieces at each end and then run rough fits down
the rest of the beam between to two ends. If you undercut one side
that is a lot of 96" walnut to thrhow out and start over.

Cut the miters at 44.75° - 44.90°...., if you can, so that only the
outer edges touch. If there is any space showing on the endgrain,
fill it in with some small slivers. If you're more accurate with the
miter cuts, maybe the glue will fill in any endgrain spacing. A
slight glue line, on the endgrain, might be hidden with some fine
sawdust mashed into it, also.

Sonny

On 1/26/2012 4:53 PM, JayPique wrote:
I have a piece of Doug Fir that's 4x4x96". I want to wrap it in, say,
walnut, so that as you look at the end you see a square of end grain
Fir with 3/8" of end grain Walnut around the outside, and the Walnut
meets at the corners in a miter joint - not a butt joint. Any ideas
on the best way to apply and cut the walnut skins so that the miters
(bevels?) meet nicely along the entire length? I was sort of thinking
some sort of router set-up where I glue on a skin oversize then rout
the miter/bevel into it. Sort of like a reverse or upside down
chamfer bit set-up.
JP

Lets say you get to where you want, do you think the fir will be stable
enough through temperature/humidity changes to not open the walnut joints?

I did a similar glue up with oak wrapped around hollow "plywood posts"
to form bed posts. And did in fact use butt joints. Over two years
they have remained stable. BTY the oak was 3/16" thick.

Expansion and contraction issue: Another option would be to cut the
corners off the 4X4 fir and either use the central portion of the fir,
allowing the walnut edges to expand and contract, or use the short
face triangle cutoff corners of the fir (attached in the corners of
the walnut skin), allowing the center portion of the walnut to expand
and contract. Still, though, cutting your walnut bevels just shy of
45°, so that the outer edges attach tightly.

Sonny

On Jan 27, 9:06*am, Sonny wrote:
Expansion and contraction issue: *Another option would be to cut the
corners off the 4X4 fir and either use the central portion of the fir,
allowing the walnut edges to expand and contract, or use the short
face triangle cutoff corners of the fir (attached in the corners of
the walnut skin), allowing the center portion of the walnut to expand
and contract. *Still, though, cutting your walnut bevels just shy of
45°, so that the outer edges attach tightly.

Sonny

There is a slight differential in movement between walnut and fir
given a humidity change, but remember that as you look at the end of
the blank all you see is end-grain of both the fir and the walnut.
Does this change anything?

On Jan 27, 8:56*pm, JayPique wrote:
On Jan 27, 9:06*am, Sonny wrote:

Expansion and contraction issue: *Another option would be to cut the
corners off the 4X4 fir and either use the central portion of the fir,
allowing the walnut edges to expand and contract, or use the short
face triangle cutoff corners of the fir (attached in the corners of
the walnut skin), allowing the center portion of the walnut to expand
and contract. *Still, though, cutting your walnut bevels just shy of
45°, so that the outer edges attach tightly.

Sonny

There is a slight differential in movement between walnut and fir
given a humidity change, but remember that as you look at the end of
the blank all you see is end-grain of both the fir and the walnut.
Does this change anything?

By attaching the two woods, either way, you would be reducing the
amount of contact between the two woods, hence reducing the expansion/
contraction effect one will have on the other. If you have the spare
lumber, make 2, foot long, test pieces, one each design, and subject
them to a range of conditions.

Sonny

"JayPique" wrote:

I have a piece of Doug Fir that's 4x4x96". I want to wrap it in,
say,
walnut, so that as you look at the end you see a square of end grain
Fir with 3/8" of end grain Walnut around the outside, and the Walnut
meets at the corners in a miter joint - not a butt joint. Any ideas
on the best way to apply and cut the walnut skins so that the miters
(bevels?) meet nicely along the entire length?
--------------------------------
Something to keep in mind, it will be nearly impossible to maintain a
sharp wooden corner in the real world over time, so take advantage of
it.

Plan on breaking the corners with a 1/8" round over router bit or
suitable hand plane.

With the corners broken, it will be much easier to hide the joints.

Have fun.

Lew

On 1/26/2012 4:53 PM, JayPique wrote:
I have a piece of Doug Fir that's 4x4x96". I want to wrap it in, say,
walnut, so that as you look at the end you see a square of end grain
Fir with 3/8" of end grain Walnut around the outside, and the Walnut
meets at the corners in a miter joint - not a butt joint. Any ideas
on the best way to apply and cut the walnut skins so that the miters
(bevels?) meet nicely along the entire length? I was sort of thinking
some sort of router set-up where I glue on a skin oversize then rout
the miter/bevel into it. Sort of like a reverse or upside down
chamfer bit set-up.
JP


I can't imagine any dimension lumber being consistent enough to even
think about attempting this. If the core were MDF or plywood you would
have a better chance. It will be fairly difficult to cut the walnut
strips with a true 45 degree full length on each side. I own some
decent equipment and I wouldn't attempt it on anything that long. They
don't make enough hold downs, edge guides, leading and following tables.
Is the 4x4 structural?
what is the reason for the mitered edges?

--


___________________________________

Keep the whole world singing . . .
Dan G
remove the seven

On Jan 29, 9:43*am, DanG wrote:

* * * * I can't imagine any dimension lumber being consistent enough to even
think about attempting this. *If the core were MDF or plywood you would
have a better chance. *It will be fairly difficult to cut the walnut
strips with a true 45 degree full length on each side. *I own some
decent equipment and I wouldn't attempt it on anything that long. *They
don't make enough hold downs, edge guides, leading and following tables.
Is the 4x4 structural?
what is the reason for the mitered edges?

This is more of an exercise in planning than an actual project. I
have since found reverse-bevel bits that are used in countertop
fabrication, which, if I removed the bearing, could be mounted in a
router table with an offset fence such that it would cut and trim the
miter appropriately. I wasn't thinking of using wet dimensional
lumber as the core, I was going to use kiln-dried, straight-grain,
rift-sawn Douglas Fir. (that's a mouthful, huh?!) The mitered edges
are needed because I was planning to slice the blank into a couple
hundred end-grain coasters!

On Sun, 29 Jan 2012 08:43:20 -0600, DanG wrote:

On 1/26/2012 4:53 PM, JayPique wrote:
I have a piece of Doug Fir that's 4x4x96". I want to wrap it in, say,
walnut, so that as you look at the end you see a square of end grain
Fir with 3/8" of end grain Walnut around the outside, and the Walnut

What does "3/8" of end grain Walnut around the outside" mean?
Are you talkin' quartersawn? I've never seen a 96" wide stick of
walnut from which you could cut end grain.


meets at the corners in a miter joint - not a butt joint. Any ideas
on the best way to apply and cut the walnut skins so that the miters
(bevels?) meet nicely along the entire length? I was sort of thinking
some sort of router set-up where I glue on a skin oversize then rout
the miter/bevel into it. Sort of like a reverse or upside down
chamfer bit set-up.

I'd guess you wanted to dress the 4x4 down to remove the radii, then
start fresh with the thick veneer. You could probably do the miters on
a table saw with holddowns and featherboard. Do you have a micrometer
feed on the fence or a jig for that? It would be highly recommended.
Ditto on a router table, but it would be dicier without long infeed
and outfeed tables connected, featherboards on both sides, and a
holddown on either side.

I can't imagine any dimension lumber being consistent enough to even
think about attempting this. If the core were MDF or plywood you would
have a better chance. It will be fairly difficult to cut the walnut
strips with a true 45 degree full length on each side. I own some
decent equipment and I wouldn't attempt it on anything that long. They
don't make enough hold downs, edge guides, leading and following tables.
Is the 4x4 structural?

Good question.


what is the reason for the mitered edges?

For clean, seamless edges. I'll bet.

--
The most decisive actions of our life - I mean those that are most
likely to decide the whole course of our future - are, more often
than not, unconsidered.
-- Andre Gide

On Sun, 29 Jan 2012 07:39:03 -0800 (PST), JayPique
wrote:

On Jan 29, 9:43*am, DanG wrote:

* * * * I can't imagine any dimension lumber being consistent enough to even
think about attempting this. *If the core were MDF or plywood you would
have a better chance. *It will be fairly difficult to cut the walnut
strips with a true 45 degree full length on each side. *I own some
decent equipment and I wouldn't attempt it on anything that long. *They
don't make enough hold downs, edge guides, leading and following tables.
Is the 4x4 structural?
what is the reason for the mitered edges?

This is more of an exercise in planning than an actual project. I
have since found reverse-bevel bits that are used in countertop
fabrication, which, if I removed the bearing, could be mounted in a
router table with an offset fence such that it would cut and trim the
miter appropriately. I wasn't thinking of using wet dimensional
lumber as the core, I was going to use kiln-dried, straight-grain,
rift-sawn Douglas Fir. (that's a mouthful, huh?!) The mitered edges
are needed because I was planning to slice the blank into a couple
hundred end-grain coasters!

Ever considered _sobering_up_ and rethinking that one, Mark? bseg

--
The most decisive actions of our life - I mean those that are most
likely to decide the whole course of our future - are, more often
than not, unconsidered.
-- Andre Gide