double bookmatch help.

[drumpriest]

Anyone here have advice on milling the edges of commercial veneer for a double bookmatch? (4 pieces of veneer bookmatched in the X and Y axis)

thanks,

[kwgeorge]

Well I have gotten pretty heavy into veneering especially with burls and book matching so I am probably going to give you a lot more information than you request but I like to talk about the subject!

When book matching veneers you have potentially 4 possibilities. So then it comes down to what looks best to you. What I like to do is to take a sheet of the veneer and take a digital picture of it. It is important that the picture be taken parallel to the veneer. After I have my picture I can then take it into Photoshop and manipulate it. I will make 4 copies of the original and manipulate them by rotating and flip and then stitch them together to test different patterns. As you can seen in this picture I have quite the knot in my Madrone Burl veneer so this leaves me with only 3 possible book matches.



After I have my picture I can then take it into Photoshop and manipulate it. I will make 4 copies of the original and manipulate them by rotating and flipping and then stitch them together to test different patterns. This is the results of my first efforts on stitching. I think since the veneer is going to be a focal point of the piece it should draw the eye to it. I like the flow of this one and it focuses on the center.



Although this one makes a very interesting pattern I am afraid I will lose a lot of it due to the design of the table I am making. So this pattern is out.



Now this one is my choice as it focuses to the center and creates a very interesting quilted pattern. Very 3-D and combines all the elements that I am looking for.



One does not have to have Photoshop to do this kind of Digital preparation and there are many free digital photo editing software available for download that will accomplish this task rather nicely. The one that comes to mind right off is “Gimp”.

Now on to the question itself! I have tried about every way there is to trim 90 degree sections on veneer and have learned what works and what does not. For one thing you should not cut veneer with a knife that you intend of book matching. The knife blade has a tendency to leave an angled edge instead of a flat edge thus increasing the possibility of a visible glue line in the end product. So now let’s talk about what works;

Method 1) you take two pieces of MDF that you have created nice 90 degree edges on. You attach a wider strip of MDF to one edge. Then you lay the veneer on the MDF and align it to the attached edges, place another sheet of MDF on top of that leaving 1/16” of veneer exposed. Then using a veneer saw against the flat edge of the second MDF piece draw it towards you will light constant pressure. Repeat until you have cut through the veneer. Rotate the veneer using the fresh cut edge as a reference and make the second cut.

Method 2) Using the same MDF boards as described above with the exception of making the edges parallel and allowing the veneer to overhang you then use a router with a nice sharp flush trim bit installed and “Climb cut” to trim the veneer. You do need to clamp the MDF together to do this.

Method 3) this is probably the best way to go, you use a crosscut sled. To do this you attach a reference board about 1/16” to the right side of your cut line. Screw it down and then use that to reference the veneer against. Now raise the saw blade until it is just above the veneer you wish to cut. Make sure you are using a plywood or fine crosscut blade. Place a waste board on top of the veneer you have reference against the fence you installed, place the waste board on top of that and apply downward pressure on it. Then make your perfect cut. The saw blade should only score the waste board and defiantly not cut through it.

Anyhow there is a really long answer to your short question and I guess it is totally obvious to everyone that I have nothing to do this morning!

[Ken Massingale]

Kenneth,
Thanks for that information. I have saved it for the future, real good stuff.
ken

[Wood_workur]

This is called "Quarter Matched" veneer. What you need is four sequentially cut piece of veneer, with as much of the grain matching as possible.

Now figure out how you will have the piece oriented in the finshed piece.

Take two jointed boards that are perfectly straight, and screw them together with the veneer placed between them, and the veneer is linedup with the cut lines for one of the axis.

Using a flush trim bit, cut the veneer.

Unscrew the boards, and then tape the pieces together along the axis you cut.

Now repeat the flush trimmin stuff for the other axis, keeping the cuts square.

Tape the last joint.

Glue the veneer to the substrate.


I will try to find a webpage on this later.

[kwgeorge]

If you would like to see the method Alex is talking about I wrote it up here quite some time ago.

http://www.theturnersshop.com/woodwo...r/veneer1.html

[Wood_workur]

yes, kwgeorge posted a link to EXACTLY what I was talking about.

[drumpriest]

Yes Quarter matched is indeed the proper name for it, I just havn't used the proper name for it often enough for it to stick in my vocab as of yet.

Thanks all for the feedback. The sandwiched router trim was my first though, though I'd read about how to do it with a veneer saw as well. Can you guys give an opinion on the performance difference between a spiral flush trim and a sheer or straight for this purpose?? I am thinking with the swirling grain typical of burl veneer it might be time to spring for a spiral.

I'm sure to butcher my first attempt or 2, so I'll be playing with some lesser veneers, but I"m looking forward to it. I've done vac press veneering, just not with bookmatching.

Thanks again,

[atgcpaul]

Use mirrors

Although the photoshop method works, it not really convenient to use in the
shop or if you're not too tech savvy. If you're getting into veneer, a quick
and easy way to visualize these sequence matches is to use a pair of mirrors
that are hinged together with duct tape. You can keep the mirrors open to 90
degrees and rotate them around your veneer sheet at different points. When
you look into the mirrors, you can see the resulting 4 piece match--like a
fun house or kaleidescope. If you don't like it, just move the mirrors to a
different spot and see what you get.

If you've prepared your square edge template as already described, you can
slide your template into the area between the mirrors, remove the mirrors,
and then use your veneer saw against the MDF square template to cut your
veneer.

Mirrors also work great for more complicated veneering like a sunburst. If you
want a 12 piece sunburst, for example, you close the mirrors to 30 degrees
and you can see what you'll get. I put a 30-60-90 plastic drafting triangle
between the mirrors to get the right angle. Once I get it in the right spot,
I slide in a 1/4" hardboard triangle template, remove the mirrors, and then
I can cut the veneer.

Paul

[drumpriest]

Being tech savvy isn't a problem, as I'm a computer graphics programmer by trade. The reason that I posted was really to see what opinions people had about flush trimming vs veneer saws.

Also if taping the veneer using veneer tape vs blue tape is a big deal. I've seen the mirror method, and I think you are right that it's more convenient for in the shop, as I don't take my computers into that dusty environment.

[kwgeorge]

Although I fail to see why one would take the computer to the shop to preview veneer matches that is beside the point. I spend a massive amount of time planning a project before I make the first cut and to me the computer is nothing more than a good planning tool and as useful as any other tool I own. Using the computer also lets me apply the veneer virtually to its end position including any complex shapes that it may end up in.

Using a veneer saw with a strait edge will give you good results but on complicated grain veneers such as burls better results can come from climb cutting with a router and the proper setup.

You really do not want to use blue tape while pressing very thin commercial veneer. The tape is too thick and could potentially compress the wood fibers of the veneer or the substrate during the pressing operation. Also it really does not hold that well and the joint could separate under the stress of pressing. I use the blue tape as a temporary solution to bind the veneer together while I apply veneer tape. Since veneer tape is applied wet it will shrink some as it dries thus pulling the joints even tighter. It is also very thin and easily removed without damaging the veneer.

The reason that I posted was really to see what opinions people had about flush trimming vs veneer saws.

Sorry, in future replies I will keep more to the question at hand.

[drumpriest]

Thanks again George. I am very glad for all of the additional information, so please don't misinterpret the above statement. I just wanted some additional clarification on those points.

I myself typically model and texture a version of what I'm going to build, if it's anything complicated. I don't think there's a better way to see if your proportions are going to be nice, for instance.

[atgcpaul]

Veneer tape is a must have

I'll use blue tape to hold things temporarily, but
use only veneer tape when I do the pressing. The
non-holey tape was suggested to me because it's
stronger. I have both but use the non-holey now.

Before I learned, I tried using a scraper to remove
the tape after pressing. It's much easier to lightly
wet the tape with a sponge, the vegetable glue loses
hold and the tape comes off really easy.

I learned veneering with a veneer saw and how to sharpen
it. Once you have a trusted straight edge, it's pretty easy
to use--and quiet--and relatively quick. However, you may
have to get creative as George suggested when you work with
tricky grained veneer. My teacher learned with an Exacto
knife and straight edge but he's primarily a saw guy now.
We'll use Exactos in class for finer inlay work, though.
You need a thicker blade that fights deflection.

I haven't tried the flush trim method so I can't comment,
but it seems people here like it and it was one of the
first suggestions I read on-line when I started getting into
veneering.

Paul