I have a small commission to work on that presents a small challenge. The piece is a shadowbox, the type of display case with lots of little nooks for nick nacks. The nooks are about 2″ square in a 36×20″ grid–so there’s lots of them. The nooks walls are 3/16″ thick curly maple, 2″ deep.
The client loves curly maple (who doesn’t), and I want to pop the figure as much as I can. However, I am hesitant to use oil on the piece. If I use it before assembly, there’s no way I’ll get all those pieces glued up without the oil interfering. If I oil after assembly, I’m looking at a tedious and messy job of cleaning out a bizillion little nooks, and it would take too much time to buff them all out.
Shellac is also out of the question, because the frames are paduak.
Final obstacle–my client is hesitant about using any dyes. She likes the blond look of the wood.
So–anyone have any ideas? I’ll do a test to see what lacquer will do for grain enhancement, but I don’t expect it to do too much.
Thanks
Paul
Replies
What about using oil before cutting the joinery? That way you'd expose raw wood for the glue while still getting the grain pop from the oil.
Waddaya mean it wont fit through the door?
Douglass2cats wrote: "What about using oil before cutting the joinery?"
I haven't read all of the other replies yet, but I just wanted to say- WHAT A GREAT IDEA!!! (I kind of hope that my response doesn't paint me out to be a total idiot/dupa (sp?)) I have never thought of doing that ... awesome!!!
Boy- been doing this for a lot of years, and had never thought of doing that ... nor have I ever heard of it being done ... does this mean that I have to continue to read all of the books, mags, etc., etc., that I can get my hands on? Where do I find the time to do the actual woodworking? 8^D lol
-Peter T.
I can't take credit for the idea. I'm sure it's been around since humans have been working wood. I don't recall where I picked up on it though. The other nice benefit is that if you do get a little glue squeeze out it's easier to clean off and the finish will stop the glue from soaking into the wood. It didn't help with Paul's problem though as he's really not using joinery to put the grid together.
I've known about the technique for years. Unfortunately I wasn't smart enough to use it until recently. Here's links to earlier posts that have a couple of tables with gridwork shelving that I did. I did one of the halfmoon tables and two of the square ones (at separate times). The gridwork here is infinitely simpler that the 200 that Paul is dealing with, but for me these were the biggest finishing PITA I've ever dealt with. Not only did I have the finishing to worry about, but the sanding between coats, tacking off, etc. By the time I got to doing the last table (the 2nd square one), I was highly motivated to try the finish-first/cut-joinery-second approach and it was a lot easier. To level things off after assembly, I still had to take a ROS to the top of the grid shelf and refinish it again, but ONLY on the top edge of the gridding where it was easier to do. Anyway, enough rambling...
HalfMoon Grid Shelf http://forums.taunton.com/tp-knots/messages?msg=20211.4
Square Grid Shelf (see 2nd pic) http://forums.taunton.com/tp-knots/messages?msg=22295.5
Added: Forgot to mention - the first pic of the square one shows the Paduak/Shellac color bleed problem mentioned here as well. Live and Learn.
Waddaya mean it wont fit through the door?
Edited 4/8/2005 7:51 am ET by douglas2cats
Edited 4/8/2005 7:52 am ET by douglas2cats
Edited 4/8/2005 7:54 am ET by douglas2cats
What about using tung oil for the finish. It may not "pop" the grain as well as some other methods but it will enhance it quite a bit. It's also an easy wipe on application and you can build and polish it easily.
Beat it to fit / Paint it to match
Thanks for the replies so far.
As far as joinery, I was planning on glueing the vertical (up/down) pieces to the horizontal pieces without any joinery--just a butt joint of end grain to face grain, with some partial gluing of the nook walls to a backing. I think this will work because the pieces are small and the entire assembly creates a torsion box. Normally I would do this, but I don't see routing 200 3/16" wide dados into other 3/16" stock. I think the entire assmbly, supported by the thicker frame and backing, will be structurally sound for holding little nick nacks. [For assembling, I'll have a jig that is a piece of 3/4" ply with shallow grooves cut in it to hold all the pieces at the proper place. The jig will have a finish on it to prevent the glued pieces from sticking to the jig itself].
Tung oil, BLO, any oil will be the same--before glueing it will be impractical to keep the glue away from glue "joints", and after assembly it will be impractical to wipe out all the nooks cleanly. It's about 400 inside corner joints to clean out per shadowbox. Too much hassle to wipe it cleanly (I think).
OK. I just assumed you were doing half-lapped joints for the gridding. I'm no torsion box expert, but I thought the half-laps were largely responsible for the strength and rigidity of a torsion box. If you were going to box in your gridding on both front and back, the butt jointing would probably be OK, but IMHO you're asking a lot from the glue joints. The end-grain is already going to give you a weaker glue joint plus the very small area of the mating surfaces (3/16 x 2) doesn't help you any either. If I were building this, I'd be concerned that over time some of the gridding spacers could work free and fall out. As far as gluing the grid walls to the backing, I still think finishing (whether oil or something else) then cutting could be a viable method. Just cut your stock slightly wide, then finish and trim to final width - giving you a raw wood edge for gluing on the back. Of course, that doesn't really work for the interior grid joints if you're set on going with the butt joint approach.
I wouldn't want to route 200 half-laps either, but what about gang cutting? Clamp all the identical pieces together and cut simultaneously. Admittedly this could probably done quicker with a dado blade on the TS, but you're stock would have to be 1/4" instead. Or what about making the grid pieces thicker in one direction and cut shallow dados to hold the 3/16 spacers running in the other direction? That would also provide some mechanical holding instead of just relying on the end-grain glue joints.
I totally agree with you that wiping out oil from inside corner joints after assembly is impractical. But aren't you going to have similar (but maybe slightly less) problems with ANY finish you use if done after assembly? Whether it's oil, shellac, varnish, lacquer, etc. - sprayed, brushed, wiped? I can't imagine wanting to use anything on the inside of that many holes after assembly.
Just MHO.Waddaya mean it wont fit through the door?
Thanks for the input--I guess you see this isn't a straightforward project!
I don't believe torsion box strength comes from the internal joinery--it's more from the topology of having all the parts constrined together. I made my router table top using this approach (with 1/4" poplar strips) over 15 years ago, and it is still going strong, despite doing everything but jumping on it.
As far as the butt joints, I do plan to size the end grain, which will provide a stronger joint (since much of the weakness comes fromt he end grain soaking up the glue, weaking the glue bond). I was planning on using PVA glue, but maybe an epoxy would be better? I don't know--I'll have to check into it.
My finishing approach (or at least, what i expect to do before this board convinces me not to) is to spray lacquer before the back is applied. I think with care and light coats, shooting it from four angles and two sides will do the trick. I'll need to mask the backs of the nook walls to ensure they'll stick to the backing.
Thanks for suggesting using thicker pieces, but the client is fixed on thin. I've actually got her up from 1/8" dividers; I believe the extra 1/16" will provide enough additional strength that this will work. The idea about finishing oversized pieces and then trimming them down is good, but it only helps me half way. Gang cutting doesn't work too well either, because the nook design involves many larger nooks made by eliminating spacers between adjacent nooks (1x2, 2x2, and up to 4x4).
At this point my thought is that its a display case hanging on a wall, and if I keep the horizontal pieces solid (and perhaps dado them into the frame slightly), gravity won't pull any walls down. Side walls might pop out over time if the glue joint is starved and the wall is hit, but this is also unlikely. In any case, the repair will be easy, and that's half the battle, n'est-ce pas?
Sounds like you've already weighed all the tradeoffs and know where the potential problems lie. That's the important thing. It's hard to know here whether posts are coming from newbies or folks with more sawdust under their belt. The glue-sizing is a good idea. You are going to post some pics of the finished project and let us all know how it turned out aren't you?
Waddaya mean it wont fit through the door?
Just my thoughts, but a horizontal application with glued butt joints may work OK, but I wouldn't trust them in a vertical situation. It won't take much wood movement to break the glue line and send a precious nick knack falling. I'd use saddle joints for intersecting and continuous pieces and stop dadoes for the perimeter and places where the shelves don't continue. If you can't get a finger and a rag in the compartments, what makes you think you can spray with any control? I think I'd use a wiping finish after assembly and before the back was applied. A number of pieces could be finished before assembly, with a wiping finish you could easily avoid the dadoes. Epoxy would be a choice if the dadoes were contaminated, your going to need some open time with a complex assembly anyway. You could end up with a heck of a mess of glue clean up with just butt joints, there will be squeeze out. Glue won't be necessary with saddle joints. With the stopped dadoes, you can glue just the front half and allow for some future movement. I don't figure on having to repair my work at a later date unless there is glass involved, but I wouldn't use a glued butt joint either.Beat it to fit / Paint it to match
Paul,
I would pre-finish the stock for the squares and then cut them to size thus providing a clean butt joint. Call these the "verticals". I would pre-finish the other pieces, the "horizontals" and then dado a thin - 3/16" x 1/32" seat for the verticals. The whole thing should take very little time since there is only one set-up for the verticals and maybe 16 indexed setups for the the dadoed horizontal pieces. The pieces are now finished, all of the joints are self-aligning and the joints are clean. The biggest obstacle I see to this project , other than the finishing aspect, is keeping everything aligned using simple butt joints without the dado. I think you may be overly minimizing the problems of maintaining equal spacing during the entire assembly process. The shallow dadoes will eliminate most if not all of these problems.
Doug
Doug -
great ideas (one reason I love this board). I hadn't thought of making a jig to run several dadoes to seat the verticals. That's something that I can see being relatively easy to do (just taking care for each horizontal member to know when not to run a dado where a larger nook is located).
The combination of the jig and trimming to size after finishing solves the problems of glue up.
Still, I originally posted this as a finishing question, only to get construction & design answers. Is that because most of us hate (or I should say, are intimidated by) finishing, or is there no one out there who knows how to make the grain in CM pop without using an oil step?
Paul,
Your original question regarding using oil was based on the notion that if you pre-finish with oil you would taint the glue joints. I think that is an unfounded concern if you doing your cuts and dadoes after you finish the pieces. I just finished 2 prairie-style lamps that had a total of 80 pieces and each piece had to be fumed, sealed, grain filed, 3 coats of oil/poly, rubbed-out between coats and then waxed before assemble. The mortises were stuffed with a non-absorbent material and the tenons were taped-off with painters tape. I use this approach on large case work as well and I have not experienced any joint failures to date.
If you are still adverse to using oil then use shellac. There is no rule that states the curly can not be finished in shellac and the frame in another material. It helps me when I step back and view each component in its own right and unique characteristics rather than trying to view the entire piece from a single perspective.
Doug
Good points Doug, but I am still curious about ways to enhance grain figure without using oil. Shellac for the CM part and lacquer for the paduak is a good idea. Are there any others?
I'm still interested in part because I haven't yet tried routing 100 dados that are only 1/32" deep. It should be straighforward with the right jig, but still...
I'm also still interested because I'm a curious type, trying to soak up as much info as possible!
Personally, I've only used boiled linseed oil ("BLO"), wiping oil (oil and poly/varnish ala Maloof's) shellac, lacquer and wax over maple. Al of these top coats can be used over BLO or oil/poly wipe ons.
The one point that you may be overlooking is that the oil and/or the top coat can only enhance the base that you provide through your preparation. Highly figured woods show best when they are planed, scraped, or sanded in this order. Generally, if you are using rubbing oils then the wood should be have a highly burnished appearance before application. If you are using build coats as with lacquers or shellac over natural or stained surfaces, then the final prep can be less so to provide adhesion. I forget the term on the light reflection but highly figured woods, such as curly, need to have the fibers sheared to maximize the figuring. The reason for this is that the fibers are not parallel to the surface and sanding alone produces fuzzy ends that defuse the reflected light.
Hope I'm not lecturing you on something you already know.
Doug
Doug -
yes, I was familiar with those points about figured woods, but that was also a very good summary for others who may be interested in working with these beautiful woods. Thanks for the interest and input!
Paul
I don't understand one thing: Why is shellac out of the question for padauk? I thought you could put shellac on anything.
"Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
I don't understand one thing: Why is shellac out of the question for padauk?
Paduak will bleed out its red color when using shellac, even if the wood was oiled first. The alcohol solvent in the shellac leaches out the natural color in the wood, leading to staining of neighboring wood. If the shellac puddles any, or you get a thick brush mark, the dye that leaches in will leave a streak or mark. This is my experience working with shellac and paduak!
Ah, I get it. Thanks for the warning, although it's unlikely I will ever use padauk."Everything should be made as simple as possible, but no simpler." A. Einstein
http://www.albionworks.net
Paduak will bleed out its red color when using shellac, even if the wood was oiled first. The alcohol solvent in the shellac leaches out the natural color in the wood, leading to staining of neighboring wood. If the shellac puddles any, or you get a thick brush mark, the dye that leaches in will leave a streak or mark. This is my experience working with shellac and paduak!
**************Thanks, Paul, I was unaware of this.Leon Jester
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