07-21-2010 09:39 AM
For most of us, we work with flat stock and create workpieces that are square and level. We'll accent that square and level work with decorative edges and perhaps incorporate a really cool flair or two.
But what happens when you want a really BIG piece of flair on the workpiece. Say... an ogee shape which is sized a bit like Gulliver compared to the Liliputian shapes that you can make with your router bits?
I encountered that challenge a while back when designing some Art Deco pieces for my living room. In the Deco period they often played whimsically with feet, legs and bases. This furniture was factory made, and with factories came the ability to use large presses and advanced techniques to get wood to do stunt bends.
But what if all you have is a garage shop and still want to do the work? Well, you need to turn to other techniques.
I wanted to make an ogee bracket foot for a pair of cabinets. I have a vacuum press, and I was easily able to lay hands on 1/8" bendy ply (plywood that's only got three laminations - two in one orientation, a thin core at 90° to that and which takes bends very easily, but yet is still very strong). With that material in hand, it became necessary to make a jig, and to make a whole lot of little ogee shapes.
Actually... that's HALF the number of ogee shapes that I ended up needing, all made from 3/4" plywood.
All of these shapes needed to be put onto a strip of plywood, which acted as a base. This ribwork would later be used to support the bendy ply as I conformed it in the vacuum press.
But what about the corners? They'd need to be solid, as the two ends and the front face meet at a 45° miter.
Then came the bendy ply. It was cut into strips and I rough cut the mitered ends. They'd be conformed to the exact miter later... and I'll show why in a moment.
Once put together, the pieces looked like this without, then with the bendy ply skin:
In the center of the U-shaped bracket feet is a simple riser and the cabinets were to sit on the riser.
When veneered and put back into the vacuum bag, the feet turned out like this.
All this work, just so that the cabinet could finally turn out looking like this:
Doing bendy curvy work isn't rocket science. In fact, it's really a series of very straightforward techniques. If you happen to have a vacuum press your life can open up into some seriously new territory. Bendy, curvy, sexy shapes are definitely possible with some simple techniques and a bit of patience.
07-21-2010 10:04 AM
Hello Matt, Thank you also for taking the time to be a teacher,
Two Questions comes to mind,
1. I see where you would have had your height & length for the foot print of your base. In my case I would have sketched out the OG. What was you system for the gragule flow of you cutout & its design ?
2. In following you past post I see where you use Hide Glues. What consistency, how spread, both sides, why, pit falls ?????
07-21-2010 10:20 AM - edited 07-21-2010 10:21 AM
What I started with was an X-ray -type drawing of what the core and the outer surfaces would look like, done in full scale. I drew out a pleasing final shape that was almost six inches in length (back to front) and about three and a half inches high. With the X-ray technique I could fill in the various layers, essentially making concentrically smaller shapes with each layer, until I arrived at the final size for what would be the core. Then I traced that out and it became my master tracing template for the shapes that I had to cut out.
The ogee shape was laid out like this. I take the length and the height and bisect them. The convex and concave sides meet in the middle and should be symmetrical to eachother. Here's a quick example of what I mean:
Then I added thickness for the base, and that's where this shape came from. Here are a bunch of uncut blanks. I cut down the middle of the S-curve at the band saw and then each side was faired using the router table jig shown above.
As for adhesives, I actually don't use hide glue. I use a two-part urea formaldehyde glue called Unibond 800. Follow the clickable link and you'll see where I get it. It's a liquid resin and a powdered catalizer. The catalizer comes in three different colors. 'Light" matches birch and maple, 'Medium" matches oak and 'Dark" matches walnut, bubinga, etc. This way you can customize the color of the glue line to hide it.
I always use this glue when doing bent work because the glue dries to a glass-hard consistency. Because of this it completely eliminates cold creep and seriously diminishes springback (mostly a consideration when doing bent laminations). Yellow glues dry to a rubber consistency. They allow the work to come and go MUCH more freely than Unibond does. There's a time and place for using glues like Tightbond, but this kind of work isn't it.
But hide glue.... aaahhh, there's something I'm eager to get into. I want to get into hammer veneering. It's old-school technology, but it works seriously well. That involves a hot pot, hide glue granules, water, a brush and a veneering hammer. Think of the veneer hammer about like a squeegee. It's not used to strike, but rather to spread and smooth out the surface.
MMmmmmm.... Maybe next year or the year after. Too much to do before then!
07-21-2010 12:41 PM
Well, in all again,,, thank you Matt,
So much to learn. I have aprox. 30 sheets 16" x 96" of black walnut, & about 1/2 that amount of red oak veneer. Was kind'a a guift I know kind of hard to believe, could take pictures though for proof. I can only do so much in the square. It occupies a high segregated space, flat supported, tied tight to floor joists out of harms way. So in this next comes vacuum bagging. All of this beautiful slinder pieces sits there calling to me, whats next !!! Ironic or fate if you will, here come a series on my favorite wood web-site, answering that pestering question.
07-21-2010 04:49 PM
That was a very interesting project and I am impressed with your methods.
Did you use bendable plywood for this project or 1/8" plywood? I have tried the vacuum bag trick but I haven't had much luck with it, however I have used contact cement with good results. I use the barrel style of bendable plywood for it is easier to bend in tight places and then I fill it with a Timbermate slur.
When sanded and stained it looks great. Then I first use a wash and allow it to dry over night and then rub in full strength stain. I will have to try your method when I have enough capital to use your method. I think the pot is rather high though.
07-21-2010 08:21 PM
Ralph, did you suggest Matt was high on pot? Kidding, this is so awesome, I love reading about different techniques. I would like to know what the method is for making different shaped decorative mouldings, not the profile but the lay out, I can do mitered ends, squares, rectangles, etc, but a rectangle with a unique corner? Still haven't figured that out yet.
07-22-2010 08:55 AM
No thanks.... cigars only, thankyewvurrymush...
And RALPH: All your questions are actually answered in the text. You need to read beyond just the pretty pictures.
The really cool thing about this technique is that there are NO 'standard sizes' that you need to concern yourself with. Do you want to make a smaller ogee shape? EASY: just make smaller cores and have at it from there.
OR, would you like to make half-barrel or other arching shapes? That's easy, too. The main mantle and the pillars on this mantle job were done just like the feet on the cabinet, shown above. For the main mantle the shape was more gradual and didn't require any time in a vacuum bag. Glue and brads conformed it to the rib work with no fuss. The pillars sport arch shaped cores and they were put in the vac bag just like the ogees, above.
It's kind of the case that if you draw it you should be able to build it. Going beyond flat/straight/square is simpler than you might have thought.