More questions about veneering

H

HSteier

Well-known member
I'm moving along with my veneering project. I'm veneering the bottom doors of a Charleston bookcase. I've made the doors out of 2" strips of poplar glued up and surrounded by mahogany stripping. The crotch veneer has been flattened as per my prior posting. My next question is "should I cut the veneer oversize for the door and if so by how much?" I've seen instructional videos where they suggest cutting the veneer to the exact size of the ground and tape it to the ground so it doesn't move during glue-up. But this doesn't leave any leeway and it would seem to me that any movement of the veneer during pressing prior to the glue setting would screw the pooch (Dr. Hemingway, that's an America Naval Aviation term for "messing things up").
It would seem best to me to leave an 1/8" veneer overhang all around and then plane off the excess.
That brings up another question. I plan to use urea-formaldehyde glue. I've never used this before. Is there any problem scraping or planing off the excess?

Thanks

Howard Steier
 
Howard,

Do you plan to have an edge treatment on the doors or will the veneer go right to the edge? Also, is it critical if one sheet slides 1/16" or so during glue-up? Depending on the answers to these questions, I may go about veneering the doors a little differently. If it is absolutely crucial, for example, that the figure be indexed to the door, I would allow the veneer to overhang all sides by about 1/2". Wrap the edge of the door with blue masking tape to make glue clean up easier and then at several points on each edge of the sheet of veneer, use hot melt glue to quickly stick a small piece of scrap such that the sheet is indexed to the door. Make sure the scrap is no thicker than the door itself. If using a vacuum bag, the caul should be at least as big as the door, but not by much to avoid flexing the caul over the edge of the door and thus creating an air bubble in the center of the panel (knowledge gained from experience is often bittersweet.)

Urea formaldehyde is great stuff just be sure to follow all the safety precautions. Don't sweat the glueup--UF has a fair open time, depending on humidity and temp. After you place the glued panel in the press, keep an eye on the unused adhesive. Once it begins to setup (firm Jello consistency), take the panel out of the press and clean up all the edges and glue squeeze out. If you wait until the adhesive is fully cured, it is alot more difficult. Place the panel back in the press when you are done, allowing it to cure completely. 

Good luck, have fun, and show us your results.
 
Howard, you have received absolutely the best advice you can get from Mark. This guy really knows his stuff. The only thing I would add is- if you need two, make four and use the best for the final.
Fran
 
I always make my panels a bit oversize.  I'm just too chicken to try and get the slippery sandwich of veneer, glue, and subtrate to all work together.  I've never done a door like you are describing.  I might make the mahogany strips oversized, then trim the door after glueup.  Similar to what Mark described, but just building in the extra material.  I usually get things real close, then use a panel saw to trim it all up and square it to the veneer pattern.

I've never had any issues with Unibond 800.  I use a foam roller to apply it and that helps get just the right amount applied.  I wear a mask when using it (gloves, glasses, etc.). 

Good luck with it.

Tony
 
Tulip poplar isn't noted for it's dimensional stability.  If I were you, I'd hammer veneer this job with hot hide.  It will be easier to repair and if you make a mistake, it will be easy to fix near term. Hammer veneering is fun and fairly low pressure (perhaps because it's reversible).  I've only done this once (on a real project- did many practice pieces).  I liked it.  I had good luck with it.  I had good tools (a good excuse to make new specialty tools- cutting gauge, knife, hammer) and Rob Millard and Pat Edwards email addresses handy.  I was also familair with hide glue, which may have factored in.  But I think more guys should try this.  It doesn't seem to be similar to other archaic stiff I do that seems irrelevant now.  And I think you can do really complicated work fairly easily (by comparison).

Adam
 
Thanks to all.
Mark, indexing the veneer is a great idea. I've never messed with hot melt glue. How do you undo it from the veneer when finished.
The doors I'm making have the veneer mitered into the corners so placement is fairly critical. I believe I could be off by an 1/8" or so but if more, the miters won't come out to the coners of the door.
Adam, I've done a little hide glue veneering and I agree it's fun but I'm using mahogany crotch veneer and I believe that the hammering process might tear up the crotch veneer. I tried to hammer a small burl panel once and it got torn up by the hammer.
By the way, I have a home made press, not a vacuum bag. Do you think this will be OK with unibond? The press works well with "cold press glue". And this brings up another question. "Veneer Systems" sells a cold press glue that they claim is better than that available from Titebond. Any experience or comments?

 
Howard,

Go ahead and lay up your face, miters and all, but allow it to hang over the 4 edges of the door as described above. The positioning blocks that are stuck to the bottom of the face will be cut away when you trim the veneer back to the door edge. The masking tape will prevent them from adhering to the sides of your door. Use a fence on the flat of the door aligned to the door edge and use your veneer saw to cut through the face. The waste and positioning blocks should peel right off leaving only the glue squeeze out to contend with. While hide glue is the obvious choice for period work, a taped up face is not the best project to learn hammer veneering on. A mechanical press will work just fine with either UF or PVA which I assume is what Veneer Systems sells. I haven't used their adhesive, but I have used Titebond's cold press and BetterBond sold by veneersupplies.com. They are virtually the same thing although BB has a thicker consistency which I like. BB is also available in three shades for different species. I have used the medium shade on many species from ebony to satinwood and think it yields fine results. Aside from the health concerns and ease of use (UF needs to be mixed by weight--PVA is ready to use), I have found that UF is better at preventing veneer creep, however. I'm not sure how either of these compare to hide glue. And then there is the reversibility factor that Adam mentioned. Any adhesive is a compromise. What exactly you are compromising depends on what your goals and needs are i.e. longer open time, ease of use, intended environment, reversibility, historical accuracy, or survivability.
 
Howard, I own the same press as you, served me over 40 years, and a excellent book by: Irish Cabinet Maker: A.L Keeble, (Cabinet making: Theory & Design, 1930) with a chapter on veneering.  Which I won in a competion. I could send you the complete chapter by e/mail if this would help you out; it has all aspects of veneering, pressing, to inlays, straight to curved work, its no problem if it helps you out. Just say the word.
         
                                              Joseph Hemingway
I post one page as a sample
 
What about veneering in stages. I would do the background (crotch or center section) first then do the borders, cut corners fine line and such. I have found an added aggravation by trying to do it all at once. Why rush things unless of course you are trying to earn a living and then if so work on other areas while your glue sets up. I won't say anything about Elmer's white glue. Veneering in stages works well and then trim to fit. Just an idea
 
Hey Jeff.......you won't say anything "good" or anything "bad" about Elmer's?????

Any time I would have had to make a mitered perimeter like this I'd make the ground and face at least a 1/4" oversize and glue it up. If it shifts a hair oh well since there's an 1/8 or more extra on all four sides. Then make an exact size pattern out of scrap ply or better yet some old plexiglass and use it to position the corners just right and trace around it. No one will ever notice a 16th width variation on a 2" perimeter but if those miters don't come to a point you'll hear about it! Once you get that first long edge to reference from the rest is easy.

Keep in mind I was used to thinking about 2 dozen to 200 of the same piece at a time. It changes the way you approach things.

UF glue is great for not creeping but keep anything less than high speed steel away from it. It will trash a card scraper in a hurry! And wash your hands good, that stuff soaks right in to your pores!

Howard, did you rip the poplar strips out of 8/4 or 10/4 to get vertical grain for your substrate?
 
Jeff L Headley said:
What about veneering in stages. I would do the background (crotch or center section) first then do the borders, cut corners fine line and such. I have found an added aggravation by trying to do it all at once. Why rush things unless of course you are trying to earn a living and then if so work on other areas while your glue sets up. I won't say anything about Elmer's white glue. Veneering in stages works well and then trim to fit. Just an idea
Click to expand...

This is the real test in life, are we in a hurry?  thank yoiu jeff, for posted the correct answers, while I was trying to get him to educate himself.
                       
                                Joseph Hemingway
 
Mark Bortner, I used 8/4 poplar to cut the 2" strips to glue up the panels.
Jeff, the only time I've seen veneer glue up in stages is with hide glue where the newly laid piece is overlaid the prior attached pieces and then they are cut/trimmed together thereby having a perfect seam. How does one glue up a complex pattern in stages using PVA or urea formaldehyde glue. It would seem to me that each individually glued piece would produce a perimeter of glue around the veneer that would cause the veneer seams to meet irregularly even if they were matched perfectly prior to glue up.
Dr. Hemingway, thanks for the advice and help. For better or worse I have more books and videos than I need. What I need is experience and I plan to get some this weekend.
Mark Arnold, thanks for the detailed instructions. This weekend I hope to do a test piece with some cheaper veneer. I'll let you all know how things turn out.

Oh, and now a confession. On one of my posts some-one suggested I post a pictue of my project. Well I don't know how. The truth is even though I own a nice SONY digital camera, I'm intimidated by it. But yesterday I heard that Kodak is withdrawing it's Kodachrome film after half a century so soon I'll have two options; learn to use the SONY or learn to draw.

Howard Steier
 
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