I am a first time poster to “Knots.” I am building a side table and plan to make the top out of a sheet of .020 thick hammered copper with an 2″ x 5/4″ oak edge. I am going to use 3/4″ plywood as the sub-base for the copper. 2 questions:
1. What is the best way to adhere the copper sheet to the underlayment? The company where I purchased the copper said I could use something like PL2000 that is designed to be used with metal but I am concerned that the glue bead will leave gaps between the sheet and the plywood. I thought about using contact cement that is used for laminate countertops since that would provide a flat, uniform surface. Unfortunately, the directions on the can specifically says it cannot be used with copper. Would something like “Sta-Put” spray adhesive work? Any ideas?
2. I want to put a protective coating on the copper sheet to proect it from water stains and discoloration. I would like to use a spray on product if possible. Many thanks to all that reply!!!
Replies
I know a guy who bonded sheet stainless to wood with hotmelt sheet adhesive. It is hotmelt glue in sheet form, intended for wood veneering. You lay it down on the substrate, put the metal on top, and use an iron to melt the glue. I'm pretty sure I've seen it in the Rockler catalog.
For protecting the copper, lacquer is the classical choice. Over the long haul, it may get scratched, and oxidation will appear on the copper. A nice thing about lacquer is that lacquer thinner will dissolve it. You can remove it, polish the copper, and re-lacquer. Spray varnishes are not as easily repairable. Spray lacquer is available in much of the US, but in some regions with bad air quality (for instance San Francisco), it is not legal and not available in the stores.
It may be a bit difficult to find, but the spray foam used in ICF home constructin would do the trick. It's minimal expanding, and when squished between two items, it doesn't expand any further, and it's virtually impossible to remove.
Good luck...
Rip
I've done hammered and patinated copper bar tops. You have no idea how labor intensive that is. I used epoxy to stick it to the substrate and copper nailed it to the edge for a decorative look. I think the PL2000 mighht work if you used a trowel to spread it out evenly. It sounds like you are using the copper in it's pristine form which would show every little lump from the adhesive. .020" is pretty thin. I would do a test with PL2000 and epoxy to see what would work best no matter what advise I was given. I need to see for myself. I used roofing grade copper which was thicker and dould take the hammering. I don't think this is the best forum for your question. It's barely a woodworking question at all. There are metal forums that deal with all kinds of sheet metal work. http://www.allshops.org/ Kind of like if you drop a table saw on your foot do you go to a woodforum or a medical forum???? Most would go to a woodforum it appears.
Mack,
This is fairly easy to do. Take your copper sheet and a palm sander and rough up the back with 100 grit sandpaper. This will give something for the adhesive to grab onto. As for the adhesive, just us West Systems Epoxy. Spread it on the rough side of the copper like you would if you were spreading glue on a substrate for veneer. If you have a veneer press, put it in there overnight. If no veneer press is available, use cauls and clamps to apply pressure. David Marks tought me how to do this. This is the table below that is copper with an aged patina. Hope this helps.
THanks for the advice and the picture. The table you made has the wood edge detail that I am doing. It appears from the responses that the epoxy set up is the way to go.
Use the PL2000 (assuming this is the right product) but spread it out with a notched trowel to get full coverage.
A few glues, apparently PL-2000 being one of them, have a chemical reaction with copper that prevents the adhesive from setting properly. If the packaging says don't use it, don't use it.
Epoxy will work and would be my first choice.
John White, Shop Manager, Fine Woodworking Magazine
A variety of adhesives can be used wwith copper, the common ones mentioned above.
Copper is quite expensive today thanks to political unrest in Chile, but if that's what you want, go for it.
My kitchen base cabs, I built with a copper laminate- much easier to work with(from Chemetal). The idea that copper on interior work needs protection from water is a myth- the water dries too fast for any oxidation to occur- no protection is really needed for this, only for minor scratches.
Expert since 10 am.
Edited 2/6/2007 11:51 am ET by jackplane
http://www.chemetalco.com/documents/Chemetal_2007_Tech_Data.pdf
Most of the laminate companies are offering metal laminates. Chemmetal is on the other side of town from me.
it's a little off point but I just read this article regarding the cost/supply of copper and as it somewhat pertains to this post i thought i would pass it on...
<!----><!----><!---->Chile<!----><!----> low-balls copper price forecast<!----><!----><!---->
Group predicts steep decline in 2007 copper prices
<!----><!---->Chile<!----><!---->, the world's biggest supplier of copper, says the global price of the red metal will tumble in 2007 after record prices last year prompted producers to boost output. <!----><!---->
Prices will average $2.40/lb in 2007, down from $3.05 in 2006, the Chilean Copper Commission projects. Supplies will grow at more than twice the pace in 2007 compared with last year, the state-run group says. <!----><!---->
The average estimate of 61 analysts surveyed by Bloomberg, Reuters and Purchasingdata.com shows the price of copper averaging $2.72 this year. Production in <!---->Chile<!----> will rise 5.1% to 5.63 million metric tons this year, partly as two BHP Billiton mines in <!----><!---->Chile<!----><!----> boost output, Eduardo Titelman, the group's vice president recently told reporters. <!----><!---->
Production in 2006 rose by 40,000 tons to 5.36 million tons, the group said. Output will reach 5.88 million tons next year, according to the group. <!----><!---->
gooooood news!Expert since 10 am.
JP, you made kitchen cabinets with copper? That sounds awesome - do you have pics you can share?
not the cabs, just the countertops. sorry if that was unclear.Expert since 10 am.
I've done this before using 16 oz. copper (typically used for roofing and flashing applications). It ain't cheap these days, but I had a sheet left over from a gutter job I did years ago. (Also, even though it is a bit pricey now, it's still probably cheaper than nice hardwood.) I used contact cement -- mine didn't say "No Copper", so maybe you just need to look at a different type/brand. There are water and solvent-based types -- don't recall which I used.
I cemented the copper down to a plywood substrate and then installed wood edging around the top that were formed with a channel along the back so it wrapped around the edge of the top a bit to hold the copper down -- like a shallow channel. I then "distressed" the top with a ball peen hammer. As another poster said -- "labor intensive". Tap-tap-tapped that sucker for HOURS! The plywood had enough "give" to allow the copper to dent fairly easily -- I'm not sure it would work if you used a harder substrate such as MDF.
The project (a portable bar) turned out fine and has lasted about three years now. As for coating the copper to keep it shiny, I wouldn't. Instead, I would treat it with a chemical to "age" the copper (available at stained glass suppliers), giving it a nice "old penny" look. If you try to keep it shiny, it'll be a never-ending task. If you go with the natural patina of copper, it will be pretty much maintenance free. But that's just me -- I like to build 'em, but I don't wanna take care of 'em!
If you plan to distress the copper first and then glue it down, you should probably use a thicker glue, like PL, and spread it with a finely notched trowel, or you may not get enough contact with the copper to adhere it properly.
Mike Hennessy
Pittsburgh, PA
Thanks for your response. I see that you hammered the copper yourself. I bought a sheet of hammered copper from a copper supplier with a "Connecticut Liberty" hammered finish. I haven't received it yet so I can't say for sure how it will look., although the web site makes it looks nice.
I see that you did the same thing with the edge that I am going to do. I am using 2"x 5/4 thick oak and I will rabbit out 1- 1 1/2" material from it so that the substrate and the copper will fit under the edge and flush with the bottom, leaving a 1/4" reveal on the top, if that makes sense.
I have a can of DAP contact cement that says it can't be used with copper. To be honest, I was surprised to see that warning on the can so it probably has a nasty chemical reaction. I will need to look a other maufactuers to see if this is a problem. I would rather use a product that coats the entire substrate and/or copper sheet with a thin, smooth layer of adhesive rather than trowel on a tube adhesive and risk having the copper not lay down perfectly flat. This is pretty thuin material so I will only get one chance.....
Someone previously mentioned this in his post. David Marks does a lot of work with adhering metal to wood. I know that you can contact him on his website and see what adhesive he would recommend.
David is travelling right now, so you probably wouldn't get a response. BUT, he uses West Sytems Epoxy for adhering copper to a substrate.
Jeff
I've done quite a few copper tops, I'll give my two cents here. Use a heavier gauge Or if you can try and get an import already pingged up, up from mexico, they use a harder copper than the regular roofing stuff you get up here. Next up is cementing it down. Like Mr. White said some adhesives will cause an electrolysis which could cause the adhesive to fail. And last, do not seal. If you want a bright look then just keep polishing. If you want a patina then use a dilute mixture of liver of sulfur til you get it how you like it, then use a little wax over that to keep that color. IMHO My two cents.
I've never heard of liver of sulphur and have a project in mind where your suggestion would be useful. Can you tell me what it is?
It's a chemical used for patina on copper. You can sometimes find it at hobby shops or jewlery makers supply shops. I can try a google for you, but you may have that capability yourself.
Thanks, I was just looking for a starting point.Found a link to some info: http://www.finishing.com/128/71.shtml
Just read the link. I will not be using liver or lime of anything to treat my copper top. The chances of it maiming and/or killing me vs. actually working is high.
That was about my reaction as well.I understand that a patina can be put on copper by fuming with ammonia. Sounds a bit safer to me.
I purchased the copper sheet already hammered out with a "Connecticut Liberty" finish on it from the supplier. Is is .020" thick. It seems that the epoxy seems to be the most recommended way to attach it to a substrate.
You mention you would not put a finish on the copper to keep it new looking. What about several coats of paste wax? Would that would for at least several months? I wouldn't mind waxing periodically.
I'm pretty sure that you do not need to put any thing on it to keep it nice, just an occasional copper bright. One of my clients has a large copper counter top on her island 30"x 72", we darkened it and also her copper sink. The house cleaner didn't like the darkened sink so little by little over the past 4 years she has managed to bring it back to brightness and keep it there with simple cleaning. I think she uses Ajax or something like it without the abrasives. There was no coating that I know of that would have held up to the demands of a kitchen sink, and once a coating would have started to fail, I didn't even want to think about that kind of mess. Actually I like the bright look now. I only used wax to keep the patina from coming off of the copper top. Either way It's going to look good and you won't need much wax to keep it nice. I always use briwax clear on metals with good results.
Oh yeah I almost forgot, I never used plywood cause it moves around too much and does'nt lay as flat as MDF with a 3/4" web under it.
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