Veneer Lampshade

Finish it

Ellis Walentine

I used to make veneered lampshades and lighting fixture panels and never had any problems with finish odors. I did have some problems with the veneer cracking from the heat of the light bulb(s). I would suggest a couple controlled experiments using the species of wood you intend to use for the finished product. Subject them to heat from a 60 or 75 w lightbulb at 3"-4" distance for a couple hours and see if you have any adverse wood behavior going on. It might pay to secure the perimeter of your panels however you plan to do it, so that they are constrained.

On another note, I found that veneer is pretty delicate stuff, and that it tends to warp, crack and twist, and that some species are much worse than others. I had my best luck with diffuse porous woods such as birdseye maple, and worse luck with brittle exotics and ring porous species such as oak.

I also found that there is an optimum veneer thickness that yields the most attractive glowing effect for a given species. If you are laminating two thicknesses of veneer, you're probably already over the optimal thickness; you b the judge of that. What I did was to laminate a single thickness of veneer to a piece of clear plexiglas and then finish sand it over a light source so I could watch the glow develop as I sanded material away. I considered how it would be done in production, and my best guess was to use a Timesaver-type thicknessing sander that could be tuned to remove just a couple thousandths of material at a time. Suffice it to say that I never was able to follow through with that plan, but you might want to experiment with the plastic approach. As I recall, I had to use a very stinky and probably toxic three-part adhesive to glue the wood to the plexi, but maybe there's a friendlier adhesive around nowadays.

Oh well, hope this helps. I don't think you'll have trouble with finishes outgassing, although I'd be careful about any that are thermoplastic such as shellac. I used Waterlox, which is a simple drying varnish, but spray finishes that catalyze or polymerize would probably be the best, though they will not penetrate the wood. You might want to experiment with penetrating finishes, too. I've seen what immersion in oil finish does to Norfolk Island pine vessels. It's pretty dramatic.

You're into a fun realm here. Let us know how you make out. And post some pix of your experiments.

Ellis Walentine, Host

Re: Veneer Lampshade

Keith Newton

What is the second ply, and what do you want to achieve? If 2nd is clear, and you want the veneer to be translucent, I'd go with a penetrating finish. The wetter the you make it, the better. On the other hand, if 2nd play is white, then a spray top coat would be fine.

Re: Veneer Lampshade

Larry Clinton At Frankfort, (Central) Indiana

I would finish it, I would also equip the lamp with an LED bulb. I prefer the higher temperature type LED bulbs 4K or above for a sunlight type lighting. The big advantage in the LED is that the wattage per lumen is quite low, therefore very little heat is produced VS incandescent bulbs. This means the laminate would likely not even be warmed!

I have a 100 or 150 equivalent LED bulb in my lamp by my chair, even after it has been on for hours the bulb does not produce enough heat that I cannot hold it in my hand (although it is quite warm).

Question for Ellis.....

Barry Irby

You said.....

"What I did was to laminate a single thickness of veneer to a piece of clear plexiglas and then finish sand it over a light source so I could watch the glow develop as I sanded material away."

How did you laminate veneer to plexiglass? What glue did you use?

I have a dodecahedron about the size of a basketball I turned into a light fixture with white plexi. Don't like it. Want to use veneer. How to laminate the veneer to the plexi is perplexing.

Re: Question for Ellis.....

Ellis Walentine

Barry, this was back in the late 70s that I was sticking veneer to plexiglas. The adhesive I used was from a plastics supply house and was a stinky three-part concoction called PS-18. They also sold a two-part (?) chemical called PS-30 that wasn't quite as good. Nowadays, I have no idea what is recommended, but I'll bet the adhesives technologies have come a long way.

Ellis

Re: Question for Ellis.....

Barry Irby

Thanks, I am considering sandwiching the veneer between two thin sheets of plexi. Maybe gluing the edges. The frame I have has very thin "angle iron" frames that are about an 1/8" Not much of a recess.

Re: Veneer Lampshade

jesse cloud

One application where I would avoid hide glue!

Re: Question for Ellis.....

Dick Coers

Doesn't acrylic move a lot more than wood with temperature changes?

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